Ply thickness RANT

Having experienced your exact problem, and not possessing the "plywood" sized
router bits, I've been very happy with the router jig
http://www.rockler.com/ecom7/product_details.cfm?offerings_id=10482 -
manufactured by Accurate Woodworking Tools http://www.accuratewoodtools.com/. It
automatically sizes the dados to the exact thickness of the plywood (or other
stock) that you have, using a standard 1/4" or 1/2" router bit.

No connection to either company, just a satisfied woodworker.
--
JeffB
remove no.spam. to email

Ed & Sue Beresnikow wrote:
> >>Okay, WTF? I have 1/2" plywood. One sheet is 1/2" right on the
money.
> >>Okay.. odd, but okay.. The other partial sheet is 23/32... That's
what I
> >>was expecting. The third partial is just *under* 7/16, and the
last sheet
> >>is something that is none of the above, although it *IS* exactly
9mm.

That's plenty bad enough. But if you want a real PITA try a little
remodeling where you cut out some of the plywood underlaying a tile
floor and then try to build it back up to the match the surrounding
field. Maybe the plywood manufacturers make floor leveling com-
pound on the side.

>
> While I agree with the frustration over plywood thickness variations
I
> think we need to keep some perspective here.
>
> Isn't a 23/32 thk sheet a thin 3/4 inch or fat 11/16? Not really in
the
> 1/2 inch range?

OK.

>
> Plywood these days is manufactured to metric thickness specifications

> and unfortunately also allow the variations that we trip across.

That's no excuse.

There is no reason they can't make metric sized plywood 12.54 mm
thick just like they make metric socket sets that use a 12.54 mm
drive.

If they made socket sets that took a 12 mm or 13 mm drive they
would't seel very many , expecially not to repeat customers.

They same should be true for plywood. Measure it befor you buy.
If it is some bastard dimension, (your choice as to what is
kosher or not) buy it elsewhere if you can.

> Much
> is dependant on the type and then the finish quality including sanded

> and unsanded.

I don't agree, the manufacturer knows how much they will sand off
the surface befor they lay up the neneers.

That's like saying that 2 x 4 s are 1 1/2 by 3 1/2
because a rough cut 2 x 4 was surfaced down to those final dimensions.
Fact is, back in the early 1960s the lumber folks were able to
surface a rought cut 2 x 4 down to 1 5/8 by 3 5/8 for s4s. I doubt
very much that the technology for surfacing lumber has become
more wasteful since then.

The fact is these undersized whatever are products from companies
that make their product a little cheaper to gain a cost advantage
over the companies who do it right.

It's your choice whom you buy from.

--

FF

I also ran into this problem with metal 1"x1" square tubing. Even
though all the pieces were 1/16" wall, some had corners that were more
rounded than others. When the pieces were welded, the guy had to
fiddle around with the beads on some of them to get the edge flat and
square.

[email protected] wrote:
> ...
>
> There is no reason they can't make metric sized plywood 12.54 mm
> thick just like they make metric socket sets that use a 12.54 mm
> drive.
>

That should be 12.7 mm. Twice.

--

FF

Hax Planx wrote:
> I'm wondering if you get more consistency with Appleply or real Baltic
> birch. You know, the expensive stuff. I'm not surprised it would be a
> problem with home center quality materials. But in their defense, these
> materials are intended for construction, not precision woodworking.

It's been my experience with BB that the tolerances are very good.

I just experienced this problem a couple of weekends ago with a birch
veneer core plywood from Menards. I bought 4 sheets of 3/4" plywood
(from a stack that I had them open) and two of the four sheets were
24/32 and two were 23/32. I've never had this issue with BB (5x5 sheets).

Jeff

>>Okay, WTF? I have 1/2" plywood. One sheet is 1/2" right on the money.
>>Okay.. odd, but okay.. The other partial sheet is 23/32... That's what I
>>was expecting. The third partial is just *under* 7/16, and the last sheet
>>is something that is none of the above, although it *IS* exactly 9mm.

While I agree with the frustration over plywood thickness variations I
think we need to keep some perspective here.

Isn't a 23/32 thk sheet a thin 3/4 inch or fat 11/16? Not really in the
1/2 inch range?

Plywood these days is manufactured to metric thickness specifications
and unfortunately also allow the variations that we trip across. Much
is dependant on the type and then the finish quality including sanded
and unsanded.

In the case of 1/2" ply it will be sold from 11 thru 12.5 mm (~7/16"
thru ~1/2") and at 3/4" the range is broader with 23/32" being smack
center at 18.5mm. Check any ply manufacturer site for details.

Sadly none of this is of help when trying to complete a project using
left overs and often even with separately purchased panels. I have seen
a few tips to use tapered shims to tighten panel to dado fit but this
doesn't fit my mind as a 'quality' solution.

... or as is always said double or more measure panel thickness before
cutting the dado one by one ... groan :-(

Ed

dadiOH wrote:
>
> John Moorhead wrote:
>
> > Am I now to expect that 1/2 ply, er, 23/32 can't be relied upon, and I
> > should expect something between 3/8" and a full 1/2"? This is NUTS.
> > Especially at close to 50 bucks a sheet.
>
> Welcome to the wonderful world of imports.
...

Nothing restricted to imports, either...

"J. Clarke" wrote:
...
> ...If it flexes 3/8 inch while cutting a dado then you need to _fix_ it
> because it's _busted_.
..

It's probably using that dado set after trying to cut aircraft Al w/
it... :) :(

I agree...unless the RAS in question is a real POS, it should be quite
possible to do as accurate work as necessary...

"Swingman" <[email protected]> wrote in message
news:[email protected]...
> "Upscale" wrote in message
>> "Swingman"wrote in message
>> > A necessary PITA these days if you work to any kind of tolerances where
>> > multiple units must have the same measurement, and things like drawer
>> slides
>> > must fit drawers made long before a cabinet is put together.
>>
>> This is your business right? Isn't there any way you can negotiate
> slightly
>> purchases of plywood that all conform to the same thickness? What a royal
>> pain in the butt.
>
> No one in the building industry, at least in this area, will guarantee
> anything regarding material dimensions these days, and if they did, it has
> been my experience that you would do well to verify it yourself in any
> event.
>
> Since I am one of those who does FF's first on cabinets, it saves time,
> not
> to mention peace of mind, in the long run to insure that I don't have to
> re-cut dadoes in FF's.
>
> I do a good deal of pre-planning, and since I order on a purchase order
> before delivery, I generally make two trips in any event. The first to
> check
> color, grade, grain, price, etc, the second to take delivery.
>
> In between is when I take the extra step to cut a dado as a "thickness
> guide" for individual sheets when I pick up the order.
>

Your dado thickness guide is a keeper. I like that. Thank you sir.

I do some metal work. Mostly fabrications out of squate tubing. Although
there is far less size discrepancies in metal than wood, it is an increasing
problem there too. Particularly in the corner shape. Which changes the time
and skill required to do the fabrication.

Like you, I bring samples to the yard to check them against what they give
me. And I submit samples each time I order. Even then, they screw up the
order now and then.

So I have already been doing this. I just did not think to apply it to wood.
<smacks forehead>

Ed:

Thanks for the Plywood industry info.

I had always assumed the plywood thickness problem was caused by that North
American Treaty thing (NAFTA ??) and the high volume of Plywood being
imported from Canada. (Canada being on metric standard, and exporting to
Asian countries also.) Being a low volume plywood buyer, I just noticed the
problem back in the 90's when NAFTA was passed and put two and two together
and I guess I got 6.

I was wrong. Sorry Canadians, I guess it is not your fault after all.

Phil

If you ask nicely, I would bet Leon will send you plans for his jig. Fast,
easy setup, and accommodates various sizes easily.
Pat Warner does the same thing with two pieces of wood and a couple of
clamps.

"JeffB" <[email protected]> wrote in message
news:[email protected]...
> Having experienced your exact problem, and not possessing the "plywood"
sized
> router bits, I've been very happy with the router jig
> http://www.rockler.com/ecom7/product_details.cfm?offerings_id=10482 -
> manufactured by Accurate Woodworking Tools
http://www.accuratewoodtools.com/. It
> automatically sizes the dados to the exact thickness of the plywood (or
other
> stock) that you have, using a standard 1/4" or 1/2" router bit.
>
> No connection to either company, just a satisfied woodworker.
> --
> JeffB
> remove no.spam. to email
>

Another Phil wrote:
> Ed:
>
> Thanks for the Plywood industry info.
>
> I had always assumed the plywood thickness problem was caused by that
> North American Treaty thing (NAFTA ??) and the high volume of Plywood
> being imported from Canada. (Canada being on metric standard, and
> exporting to Asian countries also.) Being a low volume plywood buyer, I
> just noticed the problem back in the 90's when NAFTA was passed and put
> two and two together and I guess I got 6.
>
> I was wrong. Sorry Canadians, I guess it is not your fault after all.
>
> Phil
>

Phil:

I will file your note along with the recent letter from Newt Gingrich.

:-)


--
Will
Occasional Techno-geek

"Hax Planx" <[email protected]> wrote in message
news:[email protected]...
> dadiOH says...
>
> > John Moorhead wrote:
> >
> > > Am I now to expect that 1/2 ply, er, 23/32 can't be relied upon, and I
> > > should expect something between 3/8" and a full 1/2"? This is NUTS.
> > > Especially at close to 50 bucks a sheet.
> >
> > Welcome to the wonderful world of imports.
>
> I'm wondering if you get more consistency with Appleply or real Baltic
> birch. You know, the expensive stuff. I'm not surprised it would be a
> problem with home center quality materials. But in their defense, these
> materials are intended for construction, not precision woodworking.

First, it's my supposition that the BB has a tighter tolerance. As for the
rest of your comment, I believe most of us are talking about hardwood ply
from our local hardwood supplier. At least I was in my case.

todd

D'oh! Yes, 23/32 is "3/4"... I just had it on the brain... I guess I mean
15/32, or perhaps 29/64 or 59/128ths, ad nauseum...

I guess I'm getting the same disease the lumber mfrs have... you heard what
I said, but you weren't listening to what I *meant*... rrrr...

My rant still stands, tho'...

John
"Ed & Sue Beresnikow" <[email protected]> wrote in message
news:[email protected]...
>>>Okay, WTF? I have 1/2" plywood. One sheet is 1/2" right on the money.
>>>Okay.. odd, but okay.. The other partial sheet is 23/32... That's what I
>>>was expecting. The third partial is just *under* 7/16, and the last
>>>sheet is something that is none of the above, although it *IS* exactly
>>>9mm.
>
> While I agree with the frustration over plywood thickness variations I
> think we need to keep some perspective here.
>
> Isn't a 23/32 thk sheet a thin 3/4 inch or fat 11/16? Not really in the
> 1/2 inch range?
>
> Plywood these days is manufactured to metric thickness specifications and
> unfortunately also allow the variations that we trip across. Much is
> dependant on the type and then the finish quality including sanded and
> unsanded.
>
> In the case of 1/2" ply it will be sold from 11 thru 12.5 mm (~7/16" thru
> ~1/2") and at 3/4" the range is broader with 23/32" being smack center at
> 18.5mm. Check any ply manufacturer site for details.
>
> Sadly none of this is of help when trying to complete a project using left
> overs and often even with separately purchased panels. I have seen a few
> tips to use tapered shims to tighten panel to dado fit but this doesn't
> fit my mind as a 'quality' solution.
>
> ... or as is always said double or more measure panel thickness before
> cutting the dado one by one ... groan :-(
>
> Ed

"Swingman" <[email protected]> wrote in message
> A necessary PITA these days if you work to any kind of tolerances where
> multiple units must have the same measurement, and things like drawer
slides
> must fit drawers made long before a cabinet is put together.

This is your business right? Isn't there any way you can negotiate slightly
purchases of plywood that all conform to the same thickness? What a royal
pain in the butt.

"Upscale" wrote in message
> "Swingman"wrote in message
> > A necessary PITA these days if you work to any kind of tolerances where
> > multiple units must have the same measurement, and things like drawer
> slides
> > must fit drawers made long before a cabinet is put together.
>
> This is your business right? Isn't there any way you can negotiate
slightly
> purchases of plywood that all conform to the same thickness? What a royal
> pain in the butt.

No one in the building industry, at least in this area, will guarantee
anything regarding material dimensions these days, and if they did, it has
been my experience that you would do well to verify it yourself in any
event.

Since I am one of those who does FF's first on cabinets, it saves time, not
to mention peace of mind, in the long run to insure that I don't have to
re-cut dadoes in FF's.

I do a good deal of pre-planning, and since I order on a purchase order
before delivery, I generally make two trips in any event. The first to check
color, grade, grain, price, etc, the second to take delivery.

In between is when I take the extra step to cut a dado as a "thickness
guide" for individual sheets when I pick up the order.

--
www.e-woodshop.net
Last update: 4/17/05

I also feel your pain. I bought a set of "plywood" bits. Tried the "1/4""
on a scrap. Worked great. On my latest project--I was furious. I assumed
the plywood would fit nice and tight. But no, no, no, loose as hell.

Just make a fricken standard. How hard is that.

David


"John Moorhead" <[email protected]> wrote in message
news:[email protected]...
> Folks -
>
> Okay, Sunday afternoon.... Just finished a glue up, and don't really want
> to start a finishing project... So, how about a "shop job"? Sure, he
> thinks - How about building that set of drawers for the bench? Maybe get
> the crap off of the bench and into some drawers? Maybe? Got enough
> poplar and pine on hand? Yep, good! Got 1/2" plywood for the gallery?
> Yep, good! Not so fast, bubba....
>
> Okay, I have several sheets of 1/2" ply... I take a look see, and
> remember that I got a set of plywood thickness bits from Grizzly as a
> Christmas gift.... Good chance to try 'em out making dadoes for the ply.
> HA!
>
> Okay, WTF? I have 1/2" plywood. One sheet is 1/2" right on the money.
> Okay.. odd, but okay.. The other partial sheet is 23/32... That's what I
> was expecting. The third partial is just *under* 7/16, and the last sheet
> is something that is none of the above, although it *IS* exactly 9mm.
>
> 'Scuse me, but how the FAQ is this? I don't want to cut multiple width
> dadoes - that's a recipie for disaster.
>
> Am I now to expect that 1/2 ply, er, 23/32 can't be relied upon, and I
> should expect something between 3/8" and a full 1/2"? This is NUTS.
> Especially at close to 50 bucks a sheet.
>
> How does your scrap bin measure up? This really is a pisser....
>
> John Moorhead
>

John Moorhead wrote:

> Am I now to expect that 1/2 ply, er, 23/32 can't be relied upon, and I
> should expect something between 3/8" and a full 1/2"? This is NUTS.
> Especially at close to 50 bucks a sheet.

Welcome to the wonderful world of imports.

--
dadiOH
____________________________

dadiOH's dandies v3.06...
...a help file of info about MP3s, recording from
LP/cassette and tips & tricks on this and that.
Get it at http://mysite.verizon.net/xico

If you've got different thicknesses of stock - ply or otherwise - the only way
to make good fitting dados is to cut them (or shim them to) slightly different
widths. Even if you have different thicknesses of ply, this little jig will
allow you to cut snug dados - of varying sizes, if necessary - very quickly. Try
doing that with a dado stack or special sized router bit...

I know it would be easier if ply was of consistent thickness, but sometimes it
just isn't. There can be thickness variations within a single sheet!
--
JeffB
remove no.spam. to email

"JeffB" <[email protected]> wrote in message
news:[email protected]...
> Having experienced your exact problem, and not possessing the "plywood"
sized
> router bits, I've been very happy with the router jig
> http://www.rockler.com/ecom7/product_details.cfm?offerings_id=10482 -
> manufactured by Accurate Woodworking Tools
http://www.accuratewoodtools.com/. It
> automatically sizes the dados to the exact thickness of the plywood (or
other
> stock) that you have, using a standard 1/4" or 1/2" router bit.
>
> No connection to either company, just a satisfied woodworker.
> --
> JeffB
> remove no.spam. to email

Well, that's all well and good, if all of your pieces are the same size (but
just not all 1/2" or 15/32" or whatever). When you're making a cabinet,
it's really tedious if all your dadoes have to be sized individually.
DAMHIKT.

todd

dadiOH says...

> John Moorhead wrote:
>
> > Am I now to expect that 1/2 ply, er, 23/32 can't be relied upon, and I
> > should expect something between 3/8" and a full 1/2"? This is NUTS.
> > Especially at close to 50 bucks a sheet.
>
> Welcome to the wonderful world of imports.

I'm wondering if you get more consistency with Appleply or real Baltic
birch. You know, the expensive stuff. I'm not surprised it would be a
problem with home center quality materials. But in their defense, these
materials are intended for construction, not precision woodworking.

bob wrote:
> Use the Dadowiz to cut every dado to exactly the width of the board that is
> going into THAT dado. Extremely easy to use.
>
> http://www.woodline.com/scripts/prodView.asp?idproduct=688

$159??? <G>

You can make a simple pantograph jig in 10 minutes that do just as well

It takes the dado width measurement right from the material, just like
the $159 + shipping version.

Barry

"John Moorhead" <[email protected]> wrote in message
>
> Okay, WTF? I have 1/2" plywood. One sheet is 1/2" right on the money.
> Okay.. odd, but okay.. The other partial sheet is 23/32... That's what I
was
> expecting. The third partial is just *under* 7/16, and the last sheet is
> something that is none of the above, although it *IS* exactly 9mm.

No insult intended, but where have you been hibernating? Imperial measure,
metric conversions and 1/2 dimensions in between both measurement systems
have been flooding the market for several years now. Not sure if that's how
it is down in the USA, but up here in Canada it's called Pot-Luck sizing as
far as I'm concerned.

Personally, I think all the router bit manufacturers made some kind of back
room deal to sell more router bits.

"John Moorhead" <[email protected]> wrote in message
news:[email protected]...
>
> I haven't had to get this creative with a ruler since I started measuring
> my dick!
>

Don't do that when I have just taken a drink of beer! I guess that is the
explanation for your last name.

Frank

I've not been WWing for so long, but I agree. I've already run into this
issue twice. I did get a nice tip from a magazine or online newsletter on
the same day I had the first problem. I can't remember what the outlet was,
and I know the extra work sucks, but it did work. Basically cut a slot in
the ply and insert a larger-than-kerf strip to expand the size on that edge.
It worked perfectly both times... both were shop fixtures so the innaccuracy
didnt mean so much.

Thats a work-around.. and no excuse for the problem, especially when, as you
say, you spend $50 a sheet. The alternative is to keep that micrometer with
you when you head out to buy the sheet goods.

Thanks.


"John Moorhead" <[email protected]> wrote in message
news:[email protected]...
> Folks -
>
> Okay, Sunday afternoon.... Just finished a glue up, and don't really want
> to start a finishing project... So, how about a "shop job"? Sure, he
> thinks - How about building that set of drawers for the bench? Maybe get
> the crap off of the bench and into some drawers? Maybe? Got enough
> poplar and pine on hand? Yep, good! Got 1/2" plywood for the gallery?
> Yep, good! Not so fast, bubba....
>
> Okay, I have several sheets of 1/2" ply... I take a look see, and
> remember that I got a set of plywood thickness bits from Grizzly as a
> Christmas gift.... Good chance to try 'em out making dadoes for the ply.
> HA!
>
> Okay, WTF? I have 1/2" plywood. One sheet is 1/2" right on the money.
> Okay.. odd, but okay.. The other partial sheet is 23/32... That's what I
> was expecting. The third partial is just *under* 7/16, and the last sheet
> is something that is none of the above, although it *IS* exactly 9mm.
>
> 'Scuse me, but how the FAQ is this? I don't want to cut multiple width
> dadoes - that's a recipie for disaster.
>
> Am I now to expect that 1/2 ply, er, 23/32 can't be relied upon, and I
> should expect something between 3/8" and a full 1/2"? This is NUTS.
> Especially at close to 50 bucks a sheet.
>
> How does your scrap bin measure up? This really is a pisser....
>
> John Moorhead
>

On Sun, 24 Apr 2005 19:55:33 -0400, "Upscale" <[email protected]>
wrote:


>Personally, I think all the router bit manufacturers made some kind of back
>room deal to sell more router bits.

Beat the conspiracy! Use the smallest size bit with a pantograph
style dado jig to cut them all.

We'll show THEM!!

Barry

On Sun, 24 Apr 2005 23:44:53 GMT, "John Moorhead"
<[email protected]> wrote:

>Folks -
>
>Okay, Sunday afternoon.... Just finished a glue up, and don't really want
>to start a finishing project... So, how about a "shop job"? Sure, he
>thinks - How about building that set of drawers for the bench? Maybe get
>the crap off of the bench and into some drawers? Maybe? Got enough poplar
>and pine on hand? Yep, good! Got 1/2" plywood for the gallery? Yep, good!
>Not so fast, bubba....
>
>Okay, I have several sheets of 1/2" ply... I take a look see, and remember
>that I got a set of plywood thickness bits from Grizzly as a Christmas
>gift.... Good chance to try 'em out making dadoes for the ply. HA!
>
>Okay, WTF? I have 1/2" plywood. One sheet is 1/2" right on the money.
>Okay.. odd, but okay.. The other partial sheet is 23/32... That's what I was
>expecting. The third partial is just *under* 7/16, and the last sheet is
>something that is none of the above, although it *IS* exactly 9mm.
>
>'Scuse me, but how the FAQ is this? I don't want to cut multiple width
>dadoes - that's a recipie for disaster.
>
>Am I now to expect that 1/2 ply, er, 23/32 can't be relied upon, and I
>should expect something between 3/8" and a full 1/2"? This is NUTS.
>Especially at close to 50 bucks a sheet.
>
>How does your scrap bin measure up? This really is a pisser....
>
>John Moorhead
>

I figure that the 23/32 was actually 23/64. Excepting that, my
experience is pretty much the same as yours.

Even buying from the same supplier, who is using the same
manufacturer, and where the pieces are coming from the same unit -
doesn't get you all the way home.

The usual solution is to not use a full dado but to create a
dado/groove of 1/4" or 5/16" in width and then machine a tongue that
is sized to fit that width.

This goes pretty quick with a good dado blade.






Tom Watson - WoodDorker
tjwatson1ATcomcastDOTnet (email)
http://home.comcast.net/~tjwatson1/ (website)

Lee Michaels wrote:

>
> "Tom Watson" <[email protected]> wrote in message
> news:[email protected]...
>> On Tue, 26 Apr 2005 02:09:12 GMT, Larry Kraus
>> <[email protected]> wrote:
>>
>>>It goes even more quickly with a radial arm saw. Laying the material
>>>flat on the table top is much more stable than sliding it vertically
>>>along a tall fence.
>>>
>>
>> Wouldn't tolerate one taking up shop space.
>>
>> Never saw one that could maintain even depth over a twenty four inch
>> dado.
>>
> LOL
>
> I like radial arm saws, but I know EXACTLY of what you speak.
>
> I have a friend who tried to cut a very hard peice of aluminium on his
> radial arm saw. It caused the arm to bend upward. If you tried to cut a
> 3/8' dado on a 9' board, the dado would start at 3/8' and end almost at
> the surface.
>
> So what this guy did was to cut the dado from both directions. Then cut
> down the sides with a hand saw. Then chisel out the rest.
>
> Not exactly fine woodworking.

What are you people _doing_ to those poor saws? It sounds to me like you're
trying to force the work. Let the saw do the work, feed it as fast as it
cuts. If it flexes 3/8 inch while cutting a dado then you need to _fix_ it
because it's _busted_.

--
--John
to email, dial "usenet" and validate
(was jclarke at eye bee em dot net)

"John Moorhead" wrote in message

> 'Scuse me, but how the FAQ is this? I don't want to cut multiple width
> dadoes - that's a recipie for disaster.

For the past few years I've found it necessary to make two trips to the
lumber yard when I buy multiple sheets for a large project. A digital
caliper goes along on the first trip when I pick out the grade, grain, etc,
and even note which stack the plywood I want is in.

Back at the shop I cut a dado in sample FF material based on the caliper
measurement (being sure to make project notes on the number, size, and
position of the cutters and spacers in the dado stack). Then it's back to
the lumber yard, using that sample dado, to check the fit, and select _each_
individual sheet of plywood.

The piece of dadoed FF stays on the dashboard of my truck until the project
is finished.

A necessary PITA these days if you work to any kind of tolerances where
multiple units must have the same measurement, and things like drawer slides
must fit drawers made long before a cabinet is put together.

--
www.e-woodshop.net
Last update: 4/17/05

Use the Dadowiz to cut every dado to exactly the width of the board that is
going into THAT dado. Extremely easy to use.

http://www.woodline.com/scripts/prodView.asp?idproduct=688

Bob


"John Moorhead" <[email protected]> wrote in message
news:[email protected]...
> Folks -
>
> Okay, Sunday afternoon.... Just finished a glue up, and don't really want
> to start a finishing project... So, how about a "shop job"? Sure, he
> thinks - How about building that set of drawers for the bench? Maybe get
> the crap off of the bench and into some drawers? Maybe? Got enough
> poplar and pine on hand? Yep, good! Got 1/2" plywood for the gallery?
> Yep, good! Not so fast, bubba....
>
> Okay, I have several sheets of 1/2" ply... I take a look see, and
> remember that I got a set of plywood thickness bits from Grizzly as a
> Christmas gift.... Good chance to try 'em out making dadoes for the ply.
> HA!
>
> Okay, WTF? I have 1/2" plywood. One sheet is 1/2" right on the money.
> Okay.. odd, but okay.. The other partial sheet is 23/32... That's what I
> was expecting. The third partial is just *under* 7/16, and the last sheet
> is something that is none of the above, although it *IS* exactly 9mm.
>
> 'Scuse me, but how the FAQ is this? I don't want to cut multiple width
> dadoes - that's a recipie for disaster.
>
> Am I now to expect that 1/2 ply, er, 23/32 can't be relied upon, and I
> should expect something between 3/8" and a full 1/2"? This is NUTS.
> Especially at close to 50 bucks a sheet.
>
> How does your scrap bin measure up? This really is a pisser....
>
> John Moorhead
>

On Mon, 25 Apr 2005 18:53:42 -0400, Tom Watson <[email protected]>
wrote:

>On Sun, 24 Apr 2005 23:44:53 GMT, "John Moorhead"
><[email protected]> wrote:
>
>>Folks -
>>
>>Okay, Sunday afternoon.... Just finished a glue up, and don't really want
>>to start a finishing project... So, how about a "shop job"? Sure, he
>>thinks - How about building that set of drawers for the bench? Maybe get
>>the crap off of the bench and into some drawers? Maybe? Got enough poplar
>>and pine on hand? Yep, good! Got 1/2" plywood for the gallery? Yep, good!
>>Not so fast, bubba....
>>
>>Okay, I have several sheets of 1/2" ply... I take a look see, and remember
>>that I got a set of plywood thickness bits from Grizzly as a Christmas
>>gift.... Good chance to try 'em out making dadoes for the ply. HA!
>>
>>Okay, WTF? I have 1/2" plywood. One sheet is 1/2" right on the money.
>>Okay.. odd, but okay.. The other partial sheet is 23/32... That's what I was
>>expecting. The third partial is just *under* 7/16, and the last sheet is
>>something that is none of the above, although it *IS* exactly 9mm.
>>
>>'Scuse me, but how the FAQ is this? I don't want to cut multiple width
>>dadoes - that's a recipie for disaster.
>>
>>Am I now to expect that 1/2 ply, er, 23/32 can't be relied upon, and I
>>should expect something between 3/8" and a full 1/2"? This is NUTS.
>>Especially at close to 50 bucks a sheet.
>>
>>How does your scrap bin measure up? This really is a pisser....
>>
>>John Moorhead
>>
>
>I figure that the 23/32 was actually 23/64. Excepting that, my
>experience is pretty much the same as yours.
>
>Even buying from the same supplier, who is using the same
>manufacturer, and where the pieces are coming from the same unit -
>doesn't get you all the way home.
>
>The usual solution is to not use a full dado but to create a
>dado/groove of 1/4" or 5/16" in width and then machine a tongue that
>is sized to fit that width.
>
>This goes pretty quick with a good dado blade.


BTW - The obvious question, which I neglected to address is:

"Do I then have to make a bunch of different setups to get the 1/4"
tongue, given that the material is all kinda different thicknesses?'

Nope. You machine the tongues with the alleged half inch material on
the vertical and the dado blade set with the lead cutter 1/4 (31/64")
away from the fence.

It goes quickly. Use a featherboard and a tall fence.




Tom Watson - WoodDorker
tjwatson1ATcomcastDOTnet (email)
http://home.comcast.net/~tjwatson1/ (website)

On Sun, 24 Apr 2005 23:44:53 GMT, "John Moorhead"
<[email protected]> wrote:

>Folks -
>
>Okay, Sunday afternoon.... Just finished a glue up, and don't really want
>to start a finishing project... So, how about a "shop job"? Sure, he
>thinks - How about building that set of drawers for the bench? Maybe get
>the crap off of the bench and into some drawers? Maybe? Got enough poplar
>and pine on hand? Yep, good! Got 1/2" plywood for the gallery? Yep, good!
>Not so fast, bubba....
>
... snip

>Okay, WTF? I have 1/2" plywood. One sheet is 1/2" right on the money.
>Okay.. odd, but okay.. The other partial sheet is 23/32... That's what I was
>expecting.

Don't you mean 15/32? 23/32 would be for 3/4?





+--------------------------------------------------------------------------------+
The absence of accidents does not mean the presence of safety
Army General Richard Cody
+--------------------------------------------------------------------------------+

On Tue, 26 Apr 2005 02:09:12 GMT, Larry Kraus
<[email protected]> wrote:

>It goes even more quickly with a radial arm saw. Laying the material
>flat on the table top is much more stable than sliding it vertically
>along a tall fence.
>

Wouldn't tolerate one taking up shop space.

Never saw one that could maintain even depth over a twenty four inch
dado.



Tom Watson - WoodDorker
tjwatson1ATcomcastDOTnet (email)
http://home.comcast.net/~tjwatson1/ (website)

"Tom Watson" <[email protected]> wrote in message
news:[email protected]...
> On Tue, 26 Apr 2005 02:09:12 GMT, Larry Kraus
> <[email protected]> wrote:
>
>>It goes even more quickly with a radial arm saw. Laying the material
>>flat on the table top is much more stable than sliding it vertically
>>along a tall fence.
>>
>
> Wouldn't tolerate one taking up shop space.
>
> Never saw one that could maintain even depth over a twenty four inch
> dado.
>
LOL

I like radial arm saws, but I know EXACTLY of what you speak.

I have a friend who tried to cut a very hard peice of aluminium on his
radial arm saw. It caused the arm to bend upward. If you tried to cut a
3/8' dado on a 9' board, the dado would start at 3/8' and end almost at the
surface.

So what this guy did was to cut the dado from both directions. Then cut down
the sides with a hand saw. Then chisel out the rest.

Not exactly fine woodworking.

On Wed, 27 Apr 2005 07:46:38 -0500, Jeff Cooper <[email protected]>
wrote:

>Hax Planx wrote:
>> I'm wondering if you get more consistency with Appleply or real Baltic
>> birch. You know, the expensive stuff. I'm not surprised it would be a
>> problem with home center quality materials. But in their defense, these
>> materials are intended for construction, not precision woodworking.
>
>It's been my experience with BB that the tolerances are very good.
>
>I just experienced this problem a couple of weekends ago with a birch
>veneer core plywood from Menards. I bought 4 sheets of 3/4" plywood
>(from a stack that I had them open) and two of the four sheets were
>24/32 and two were 23/32. I've never had this issue with BB (5x5 sheets).

You need to consider the source... If you're in the Eau Claire area
(and I have no idea just how far the Menard's epidemic extends,) try
Pigeon Creek Hardwoods on Hwy 12- cheaper than Menard's by at least
150%, and a whole lot higher quality. If you're in the Twin Cities,
try Youngblood's.

Menard's is nothing but trouble.


Aut inveniam viam aut faciam

On Mon, 25 Apr 2005 09:57:55 -0400, "Lee Michaels"
<leemichaels*nadaspam*@comcast.net> wrote:


>Your dado thickness guide is a keeper. I like that. Thank you sir.
>
>I do some metal work. Mostly fabrications out of squate tubing. Although
>there is far less size discrepancies in metal than wood, it is an increasing
>problem there too. Particularly in the corner shape. Which changes the time
>and skill required to do the fabrication.

You're not kidding there- we've got three or four steel suppliers at
work, and every single one of them has a different corner shape.
Doesn't matter all that much to the operations I'm performing, but it
sure does piss off the plasma cutter operators and the welders.

>Like you, I bring samples to the yard to check them against what they give
>me. And I submit samples each time I order. Even then, they screw up the
>order now and then.
>
>So I have already been doing this. I just did not think to apply it to wood.
><smacks forehead>
>
>
>
>

Aut inveniam viam aut faciam

"woodworker88" <[email protected]> wrote in message
news:[email protected]...
>I also ran into this problem with metal 1"x1" square tubing. Even
> though all the pieces were 1/16" wall, some had corners that were more
> rounded than others. When the pieces were welded, the guy had to
> fiddle around with the beads on some of them to get the edge flat and
> square.
>

And it is a problem if appearance is important. I was welding up gym
equipment. And a machine that has different tubing profiles within it looks
like it was put together by a back yard welder with recycled metal. It
doesn't look professional at all.

Another problem. As the wall thickness gets thicker, the corner gets more
rounded. Which means if you want to make part of the machine stronger, you
have to use the heavier gauge tube throughout. Otherwise, it looks crappy.
Which makes the machine much heavier and more expensive.

And talking to your metal supplier gets all kinds of protests that they have
no control over what the manufacturerr sends to them.

We settled on a fix to make the joints look good with the rounded profile.
We just stuck a peice of flat stock in the hole. Then weld as usual. The
flat stock was thick enough to fill the hole. When the weld was applied, it
just melted together with everything else. Not all that elegant, but it
looked good and was strong.

"John Moorhead" <[email protected]> wrote in message
news:[email protected]...
>

> Am I now to expect that 1/2 ply, er, 23/32 can't be relied upon, and I
> should expect something between 3/8" and a full 1/2"? This is NUTS.

23/32nds?
You mean 15/32nds, right?

Anyway - it is nuts...

Upscale -

Ho-kay.... Blame the victim - I've gotten used to 23/32" plywood which was
*apparently* at the time, supposed to be the *actual* thickness of the "1/2"
ply after it had been finish sanded. Fair enough... But *why* now, are
there a total of FOUR "sizes" of 1/2" thick stock? What kind of control at
the mill gives you 1/2", 23/32", 7/16" and 9mm all grouped under 1/2"
thickness....This is NUTS!

I think this follows the progression that 1" thick stock "means" somewhere
between 11/16 and 3/4" - ah, EXCEPT for Redwood. 1x redwood had been
somewhere between 11/16" and 5/8" except that now I get rough sawn boards
that are *just* over 9/16". At this rate 6/4 will really mean "veneer" in a
few years...

At the prices they're getting, I don't really care HOW thick it is, call it
1/2" and make it ONE thickness, between 3/8"
and a 1/2"... I'll deal with it, but for chrissakes, don't make me play a
shell game every time I want to knock together a gallery or box. Jeeezus!

I haven't had to get this creative with a ruler since I started measuring my
dick!

John


"Upscale" <[email protected]> wrote in message
news:[email protected]...
> "John Moorhead" <[email protected]> wrote in message
>>
>> Okay, WTF? I have 1/2" plywood. One sheet is 1/2" right on the money.
>> Okay.. odd, but okay.. The other partial sheet is 23/32... That's what I
> was
>> expecting. The third partial is just *under* 7/16, and the last sheet is
>> something that is none of the above, although it *IS* exactly 9mm.
>
> No insult intended, but where have you been hibernating? Imperial measure,
> metric conversions and 1/2 dimensions in between both measurement systems
> have been flooding the market for several years now. Not sure if that's
> how
> it is down in the USA, but up here in Canada it's called Pot-Luck sizing
> as
> far as I'm concerned.
>
> Personally, I think all the router bit manufacturers made some kind of
> back
> room deal to sell more router bits.
>
>

It goes even more quickly with a radial arm saw. Laying the material
flat on the table top is much more stable than sliding it vertically
along a tall fence.

Tom Watson <[email protected]> wrote:

>>The usual solution is to not use a full dado but to create a
>>dado/groove of 1/4" or 5/16" in width and then machine a tongue that
>>is sized to fit that width.
>>
>>This goes pretty quick with a good dado blade.
>
>
>BTW - The obvious question, which I neglected to address is:
>
>"Do I then have to make a bunch of different setups to get the 1/4"
>tongue, given that the material is all kinda different thicknesses?'
>
>Nope. You machine the tongues with the alleged half inch material on
>the vertical and the dado blade set with the lead cutter 1/4 (31/64")
>away from the fence.
>
>It goes quickly. Use a featherboard and a tall fence.
>
>
>
>
>Tom Watson - WoodDorker
>tjwatson1ATcomcastDOTnet (email)
>http://home.comcast.net/~tjwatson1/ (website)

On Tue, 26 Apr 2005 14:58:31 -0400, "J. Clarke"
<[email protected]> wrote:

>Lee Michaels wrote:
>
>>
>> "Tom Watson" <[email protected]> wrote in message
>> news:[email protected]...
>>> On Tue, 26 Apr 2005 02:09:12 GMT, Larry Kraus
>>> <[email protected]> wrote:
>>>
>>>>It goes even more quickly with a radial arm saw. Laying the material
>>>>flat on the table top is much more stable than sliding it vertically
>>>>along a tall fence.
>>>>
>>>
>>> Wouldn't tolerate one taking up shop space.
>>>
>>> Never saw one that could maintain even depth over a twenty four inch
>>> dado.
>>>
>> LOL
>>
>> I like radial arm saws, but I know EXACTLY of what you speak.
>>
>> I have a friend who tried to cut a very hard peice of aluminium on his
>> radial arm saw. It caused the arm to bend upward. If you tried to cut a
>> 3/8' dado on a 9' board, the dado would start at 3/8' and end almost at
>> the surface.
>>
>> So what this guy did was to cut the dado from both directions. Then cut
>> down the sides with a hand saw. Then chisel out the rest.
>>
>> Not exactly fine woodworking.
>
>What are you people _doing_ to those poor saws? It sounds to me like you're
>trying to force the work. Let the saw do the work, feed it as fast as it
>cuts. If it flexes 3/8 inch while cutting a dado then you need to _fix_ it
>because it's _busted_.


I've owned three radicalalarm saws, the most recent being an Italian
made Dewalt that was intended for cabinet shop use (It was
green-looked kinda funny in a Delta grey shopppe).

The deal on the most recent one was that it would crosscut to 25",
thus making it useful in a casegoods shop, where tops have to be cut.

That sumbitch wouldn't hold a dado to depth, neither.

The geometry of the damned saw is all wrong for doing things that
involve maintaining a given depth over the run of the arm.

It would only crosscut to within about a thirty-second, which I did
not feel was good enough.

I've owned them, I've used them, I've treated them nice - they still
suck.

The geometry is all wrong.


A buddy of mine has one of the old lumberyard style Dewalts, bulky as
Bubba amd heavier than iron mound dirt, and he set it on ninety and
tack welded it,


It still only cuts to within a thirty-second.


To me they are the Swiss Army Knife of fixed equipment - and suffer
the same problems.




Tom Watson - WoodDorker
tjwatson1ATcomcastDOTnet (email)
http://home.comcast.net/~tjwatson1/ (website)

On Sun, 24 Apr 2005 23:44:53 GMT, "John Moorhead"
<[email protected]> wrote:


>Okay, WTF? I have 1/2" plywood. One sheet is 1/2" right on the money.
>Okay.. odd, but okay.. The other partial sheet is 23/32... That's what I was
>expecting. The third partial is just *under* 7/16, and the last sheet is
>something that is none of the above, although it *IS* exactly 9mm.
>
>'Scuse me, but how the FAQ is this? I don't want to cut multiple width
>dadoes - that's a recipie for disaster.
>
>Am I now to expect that 1/2 ply, er, 23/32 can't be relied upon, and I
>should expect something between 3/8" and a full 1/2"? This is NUTS.
>Especially at close to 50 bucks a sheet.
>
>How does your scrap bin measure up? This really is a pisser....

I feel your pain... How about putting a rabbet on the edge of the ply
to get it to a consistant thickness as a technique? Not only makes
takes the guesswork out of the dado width, but the shoulders cover up
any little nicks the router might happen to make if you get a little
shaky at the wrong moment.

>John Moorhead
>

Aut inveniam viam aut faciam

"John Moorhead" <[email protected]> wrote in message
news:[email protected]...
> Folks -
>
> Okay, Sunday afternoon.... Just finished a glue up, and don't really want
> to start a finishing project... So, how about a "shop job"? Sure, he
> thinks - How about building that set of drawers for the bench? Maybe get
> the crap off of the bench and into some drawers? Maybe? Got enough
poplar
> and pine on hand? Yep, good! Got 1/2" plywood for the gallery? Yep,
good!
> Not so fast, bubba....
>
> Okay, I have several sheets of 1/2" ply... I take a look see, and
remember
> that I got a set of plywood thickness bits from Grizzly as a Christmas
> gift.... Good chance to try 'em out making dadoes for the ply. HA!
>
> Okay, WTF? I have 1/2" plywood. One sheet is 1/2" right on the money.
> Okay.. odd, but okay.. The other partial sheet is 23/32... That's what I
was
> expecting. The third partial is just *under* 7/16, and the last sheet is
> something that is none of the above, although it *IS* exactly 9mm.
>
> 'Scuse me, but how the FAQ is this? I don't want to cut multiple width
> dadoes - that's a recipie for disaster.
>
> Am I now to expect that 1/2 ply, er, 23/32 can't be relied upon, and I
> should expect something between 3/8" and a full 1/2"? This is NUTS.
> Especially at close to 50 bucks a sheet.
>
> How does your scrap bin measure up? This really is a pisser....
>
> John Moorhead

OK, I'll pile on. This happened to me not long ago, but for me, it was on
"identical" sheets that I purchased at the same time. I didn't realize
until I was about to glue up that I had basically two different thicknesses.
I had done my test fits from pieces that were from one sheet and then cut
all the dadoes based on that. I'm with the other comments...I don't care if
it's 15/32 or 12mm, just make it consistent within a reasonable tolerance.

todd

I feal you're pain (PITA actually). I just did the same thing today - went
to cut a couple drawers out of cut off 1/2 ply from my scrap bin. Didn't
bother to check it - all the stuff was from a recent trips to the borg. Two
different sizes I didn't discover until the drawers didn't go together
right. What as pisser. And of course there wasn't enough left to cut more -
truly Murphy at work.

jim bailey

"John Moorhead" <[email protected]> wrote in message
news:[email protected]...
> Folks -
>
> Okay, Sunday afternoon.... Just finished a glue up, and don't really want
> to start a finishing project... So, how about a "shop job"? Sure, he
> thinks - How about building that set of drawers for the bench? Maybe get
> the crap off of the bench and into some drawers? Maybe? Got enough
poplar
> and pine on hand? Yep, good! Got 1/2" plywood for the gallery? Yep,
good!
> Not so fast, bubba....
>
> Okay, I have several sheets of 1/2" ply... I take a look see, and
remember
> that I got a set of plywood thickness bits from Grizzly as a Christmas
> gift.... Good chance to try 'em out making dadoes for the ply. HA!
>
> Okay, WTF? I have 1/2" plywood. One sheet is 1/2" right on the money.
> Okay.. odd, but okay.. The other partial sheet is 23/32... That's what I
was
> expecting. The third partial is just *under* 7/16, and the last sheet is
> something that is none of the above, although it *IS* exactly 9mm.
>
> 'Scuse me, but how the FAQ is this? I don't want to cut multiple width
> dadoes - that's a recipie for disaster.
>
> Am I now to expect that 1/2 ply, er, 23/32 can't be relied upon, and I
> should expect something between 3/8" and a full 1/2"? This is NUTS.
> Especially at close to 50 bucks a sheet.
>
> How does your scrap bin measure up? This really is a pisser....
>
> John Moorhead
>
>