On 11 Jan 2007 11:51:02 -0800, [email protected] wrote:
>I am building a TV Credenza out of 3/4" Maple plywood (Premium Grade).
>It will be approx 65"L X @22"D X 23"H. My question is what would be the
>best type of joint to use on these pieces? I was thinking Biscuit
>joiner, but I don't have a Biscuit Joiner (or plate joiner). Any Ideas?
>Thanks a bunch!
Let's tell the truth about this, for once.
A biscuit joint is not a joint.
A biscuit joint is an alignment device.
A biscuit joint is a registration device.
That's it.
It has very little value in comparison to true joinery.
Get over it.
Regards,
Tom Watson (Fairly Unbalanced)
tjwatson1ATcomcastDOTnet (real email)
http://home.comcast.net/~tjwatson1/
Need a bit more info....
Joints for what pieces (side members to top, face frame to carcass
etc...)
Are you joining plywood edge to edge...
-nick
[email protected] wrote:
> I am building a TV Credenza out of 3/4" Maple plywood (Premium Grade).
> It will be approx 65"L X @22"D X 23"H. My question is what would be the
> best type of joint to use on these pieces? I was thinking Biscuit
> joiner, but I don't have a Biscuit Joiner (or plate joiner). Any Ideas?
> Thanks a bunch!
Need a bit more info....
Joints for what pieces (side members to top, face frame to carcass
etc...)
Are you joining plywood edge to edge...
-nick
[email protected] wrote:
> I am building a TV Credenza out of 3/4" Maple plywood (Premium Grade).
> It will be approx 65"L X @22"D X 23"H. My question is what would be the
> best type of joint to use on these pieces? I was thinking Biscuit
> joiner, but I don't have a Biscuit Joiner (or plate joiner). Any Ideas?
> Thanks a bunch!
No joints edge to edge. Sides to top and then shelves inside. From the
from it will be a simple rectangular box with 3 sections across. Each
section will have 1 shelf in it.
Nicky wrote:
> Need a bit more info....
>
> Joints for what pieces (side members to top, face frame to carcass
> etc...)
>
> Are you joining plywood edge to edge...
>
> -nick
>
> [email protected] wrote:
> > I am building a TV Credenza out of 3/4" Maple plywood (Premium Grade).
> > It will be approx 65"L X @22"D X 23"H. My question is what would be the
> > best type of joint to use on these pieces? I was thinking Biscuit
> > joiner, but I don't have a Biscuit Joiner (or plate joiner). Any Ideas?
> > Thanks a bunch!
No joints edge to edge. Sides to top and then shelves inside. From the
front it will be a simple rectangular box with 3 sections across. Each
section will have 1 shelf in it.
Nicky wrote:
> Need a bit more info....
>
> Joints for what pieces (side members to top, face frame to carcass
> etc...)
>
> Are you joining plywood edge to edge...
>
> -nick
>
> [email protected] wrote:
> > I am building a TV Credenza out of 3/4" Maple plywood (Premium Grade).
> > It will be approx 65"L X @22"D X 23"H. My question is what would be the
> > best type of joint to use on these pieces? I was thinking Biscuit
> > joiner, but I don't have a Biscuit Joiner (or plate joiner). Any Ideas?
> > Thanks a bunch!
[email protected] wrote:
> I am building a TV Credenza out of 3/4" Maple plywood (Premium Grade).
> It will be approx 65"L X @22"D X 23"H. My question is what would be the
> best type of joint to use on these pieces?
First, what are these pieces? Is it basically a box of just the
plywood, or does it have a frame of solid wood?
Second, what do you mean by best? Fastest, easiest, cheapest,
strongest, longest-lasting? How much weight does this need to support,
and will it get much abuse (i.e. play structure for kids)? Mortise and
tenon (either loose tenons or traditional) would probably be on the
stronger/longer-lasting side for a frame construction, and dovetails
are probably strongest for a box (tho I'm not sure how they'd do with
ply). Towards the faster/easier side, dowels or pocket holes are
fairly quick/easy methods if you don't want to buy a biscuit cutter.
Either of these would be facilitated with a jig (commercial @ $20-50 or
more, or shop-made). If you're just using plywood, and you wanted even
faster/easier, butt joints and a brad nailer would work, and you could
add rabbets/dados and glue to this method for more strength. I would
also think about a splined miter or a lock-miter (with appropriate
router bit).
What are your priorities for the final piece, and how much time and
money do you have to spend on it? The answers to these questions should
help guide your construction decisions.
Good luck and have fun, and let us know what works well for you,
Andy
[email protected] wrote:
> I am building a TV Credenza out of 3/4" Maple plywood (Premium Grade).
> It will be approx 65"L X @22"D X 23"H. My question is what would be the
> best type of joint to use on these pieces? I was thinking Biscuit
> joiner, but I don't have a Biscuit Joiner (or plate joiner). Any Ideas?
> Thanks a bunch!
With a router and a 3/4" straight bit you can route dados on the sides
and glue&nail the bottom and middle shelves into the dados. As far as
the top I suppose it's laid on top of the sides. Hence from load
bearing point of view any technique will work since the load is from
the top (as long as it doesn't fall apart when you lift the credenza by
the edge of the top).
DJ Delorie wrote:
> Buy a 5/32" slot cutter for your router. Make two marks 3/4" apart,
> route from one to the other - it's just right for biscuits.
A lot of the strength of a biscuit joint comes from the biscuit filling
the slot completely. Too deep/wide a slot is no good.
Using the router slot, will not let you do that unless you buy/make
biscuits with the exact radius of the slot-ends.
If it were me ....
Dados for the top to bottom section partions.
Dados for the side to side shelfs
Dados or Rabbits for the top to side joint.
How will you cover the exposed ply? Or will you "celibrate the joint."
I've seen the other posts that are suggesting alternates to not having
a biscuit jointer. I think this post is for and alternate to biscuits.
When building boxes out of ply materials, I use rabbits and dados. I've
also used simple butt joints (glued, screwed.)
Any other other methods?
-nick
[email protected] wrote:
> No joints edge to edge. Sides to top and then shelves inside. From the
> front it will be a simple rectangular box with 3 sections across. Each
> section will have 1 shelf in it.
>
>
> Nicky wrote:
> > Need a bit more info....
> >
> > Joints for what pieces (side members to top, face frame to carcass
> > etc...)
> >
> > Are you joining plywood edge to edge...
> >
> > -nick
> >
> > [email protected] wrote:
> > > I am building a TV Credenza out of 3/4" Maple plywood (Premium Grade).
> > > It will be approx 65"L X @22"D X 23"H. My question is what would be the
> > > best type of joint to use on these pieces? I was thinking Biscuit
> > > joiner, but I don't have a Biscuit Joiner (or plate joiner). Any Ideas?
> > > Thanks a bunch!
My friend owns a high end cabinet shop near Beverly Hills. He warned
me: "Whatever Biscuit Joiner you buy, use only Lamello Biscuits."
He said they are produced to exacting standards, and I've had good luck
them. In fact, now that the Festool Domino will soon be available here
in the U.S. I was considering it. But my joints with biscuits are
coming out so well, I'll save my $800.
I tried to break a few joints I'd made i n scrap 2x4s and couldn't.
Just cut your slots carefully.
Gary Curtis
My friend owns a high end cabinet shop near Beverly Hills. He warned
me: "Whatever Biscuit Joiner you buy, use only Lamello Biscuits."
He said they are produced to exacting standards, and I've had good luck
them. In fact, now that the Festool Domino will soon be available here
in the U.S. I was considering it. But my joints with biscuits are
coming out so well, I'll save my $800.
I tried to break a few joints I'd made i n scrap 2x4s and couldn't.
Just cut your slots carefully.
Gary Curtis
Thanks everyone for your input. Since it is difficult for me to
describe what I am trying to do. Look at the following like. This is a
sketch-up of what I am doing. I will leave the edges exspoed as I think
they look nice when sanded and covered with a clear enamel /laquer etc.
Plus, the naked edges will be close in color to my speakers and I
think it will help tie it together. THe casters are not preset in the
sketch-up, but they will be on the stand.
Thanks a bunch again!
all 3/4" Maple Plywood.
http://i10.photobucket.com/albums/a142/hammondc/chipstand.png
Andy wrote:
> [email protected] wrote:
> > I am building a TV Credenza out of 3/4" Maple plywood (Premium Grade).
> > It will be approx 65"L X @22"D X 23"H. My question is what would be the
> > best type of joint to use on these pieces?
>
> First, what are these pieces? Is it basically a box of just the
> plywood, or does it have a frame of solid wood?
> Second, what do you mean by best? Fastest, easiest, cheapest,
> strongest, longest-lasting? How much weight does this need to support,
> and will it get much abuse (i.e. play structure for kids)? Mortise and
> tenon (either loose tenons or traditional) would probably be on the
> stronger/longer-lasting side for a frame construction, and dovetails
> are probably strongest for a box (tho I'm not sure how they'd do with
> ply). Towards the faster/easier side, dowels or pocket holes are
> fairly quick/easy methods if you don't want to buy a biscuit cutter.
> Either of these would be facilitated with a jig (commercial @ $20-50 or
> more, or shop-made). If you're just using plywood, and you wanted even
> faster/easier, butt joints and a brad nailer would work, and you could
> add rabbets/dados and glue to this method for more strength. I would
> also think about a splined miter or a lock-miter (with appropriate
> router bit).
> What are your priorities for the final piece, and how much time and
> money do you have to spend on it? The answers to these questions should
> help guide your construction decisions.
> Good luck and have fun, and let us know what works well for you,
> Andy
I should also note that the shelves will be adjustable with holes/pins,
so, not joint will be necessary,
[email protected] wrote:
> Thanks everyone for your input. Since it is difficult for me to
> describe what I am trying to do. Look at the following like. This is a
> sketch-up of what I am doing. I will leave the edges exspoed as I think
> they look nice when sanded and covered with a clear enamel /laquer etc.
> Plus, the naked edges will be close in color to my speakers and I
> think it will help tie it together. THe casters are not preset in the
> sketch-up, but they will be on the stand.
>
> Thanks a bunch again!
>
> all 3/4" Maple Plywood.
>
> http://i10.photobucket.com/albums/a142/hammondc/chipstand.png
>
>
>
> Andy wrote:
> > [email protected] wrote:
> > > I am building a TV Credenza out of 3/4" Maple plywood (Premium Grade).
> > > It will be approx 65"L X @22"D X 23"H. My question is what would be the
> > > best type of joint to use on these pieces?
> >
> > First, what are these pieces? Is it basically a box of just the
> > plywood, or does it have a frame of solid wood?
> > Second, what do you mean by best? Fastest, easiest, cheapest,
> > strongest, longest-lasting? How much weight does this need to support,
> > and will it get much abuse (i.e. play structure for kids)? Mortise and
> > tenon (either loose tenons or traditional) would probably be on the
> > stronger/longer-lasting side for a frame construction, and dovetails
> > are probably strongest for a box (tho I'm not sure how they'd do with
> > ply). Towards the faster/easier side, dowels or pocket holes are
> > fairly quick/easy methods if you don't want to buy a biscuit cutter.
> > Either of these would be facilitated with a jig (commercial @ $20-50 or
> > more, or shop-made). If you're just using plywood, and you wanted even
> > faster/easier, butt joints and a brad nailer would work, and you could
> > add rabbets/dados and glue to this method for more strength. I would
> > also think about a splined miter or a lock-miter (with appropriate
> > router bit).
> > What are your priorities for the final piece, and how much time and
> > money do you have to spend on it? The answers to these questions should
> > help guide your construction decisions.
> > Good luck and have fun, and let us know what works well for you,
> > Andy
Tom Watson wrote:
> Let's tell the truth about this, for once.
>
> A biscuit joint is not a joint.
>
> A biscuit joint is an alignment device.
>
> A biscuit joint is a registration device.
Right
>
> That's it.
Wrong.
>
> It has very little value in comparison to true joinery.
A biscuit adds to the strength of the joint. No arguing that. It also
helps align/registre a joint.
But it is stronger than the simple butt-joint would be without the
cookies.
Is it elegant?
Nope.
Do a few carefully applied biscuits do as good a job as a tenon?
Yes.
See Miller for cites.
r
Tom Watson wrote:
> Let's tell the truth about this, for once.
>
> A biscuit joint is not a joint.
>
> A biscuit joint is an alignment device.
>
> A biscuit joint is a registration device.
>
> That's it.
>
> It has very little value in comparison to true joinery.
>
> Get over it.
>
>
>
>
> Regards,
>
> Tom Watson (Fairly Unbalanced)
And yet, there are those that empirically resist your conclusions,
refusing to "get over it". There are those of us living on the edge
that believe that the lowly biscuit, tool of the hurried craft/trade
person add strength to >certain< joints.
A good discussion brewed here long ago, but not out or my memory:
http://www.sawmillcreek.org/showthread.php?t=7651
Which led to a shopworn article that seemed to me to be well thought
out and was actually a controlled experiment:
http://www.woodworking.org/WC/GArchive98/Abstract/abstract1.html
However, we can see that the biscuit has it shortcoming... superior to
doweling in corner joints, but of almost not value according to this
treatise for the corner joint as it pertains to furniture making:
http://journals.tubitak.gov.tr/agriculture/issues/tar-04-28-5/tar-28-5-2-0311-1.pdf
I felt like the sum and substance of the above referenced materials
satisfied my own curiosity about the biscuit joint controversy long
ago. I didn't see any requests for money or blatant advertisements
soliciting funds at any of these sites, so I don't think there is much
need for conspiracy worries. Sadly, I was unable to find the MIT test
that was printed about 5-7 years ago where the compared biscuits,
mortise and tenon, dowel, and "loose dowel" joinery. Two or more
biscuits carried the day on all but mortise and tenon in solid wood,
but the biscuit prevaled in joining baltic birch.
I included the above links because I know this group has many
practicing engineers that would be anxious to see actual data, whether
they believed in the results, methods, conclusions, etc. or not.
For me, this was my test:
Edge jointed two pieces of 1X12 yellow pine 30" long with biscuits, and
did another set the same without biscuits. Ripped and glued the same
test materials as above out of 3/4" (nom.) cabinet grade birch ply.
Biscuits were set on +/- 6" centers. Glued with TB2, and waited a
week. Actually until the next weekend when my fellow scientists could
join me.
Put the panels between two sawhorses, resting about 1/2" on each edge.
Centered on the joint, I rested a piece of 4X4. the length of the panel
so that it would directly stress the joint. Not having the best lab, I
settled on cinder blocks (CMU) as weight to stack on the 4X4. Lots
were left from a deck job, so they were on hand.
In both cases the plywood and the panels held more weight (if memory
serves correctly it was two - three blocks) more with biscuits than
without. In fairness, while the glue joint cracked on the yellow pine
samples, neither gave way. The 1X12 broke in the field whether it had
biscuits or not. So in this case no conclusion was drawn except in the
case of the glue joint crack, which could mean that the joint with
biscuits which had not perceptible cracking was marginally stronger.
The plywood was the clear winner. It was smoothed over the jointer to
ensure a proper edge to join before glueing. The biscuit jointed edge
was significantly stronger (3 blocks?) than the edge glued material
that received no biscuits.
I am no fan of the biscuit; it has it uses. But to adamantly declare a
"truth" saying it is nothing more than an alignment tool is silly.
As always, your mileage may vary.
Robert
Lew Hodgett wrote:
>
> BTW, you are going to need a lot of open time to get all the clamps
> set in place. I'd use epoxy, unless you have a lot of help.
>
You keep mentioning epoxy. I have used epoxy in the past when building
torsion boxes.
Legless tables sticking out from the wall at a donut shop was one such
project.
I used Gougeon Bros WEST and found it hard to work with... very runny
and thin without much gap-filling ability. No matter how accurate I
made the lattices, I still didn't get a 'super sandwich'.
Vacuum bagging and regular adhesive worked better for me.
But... I still like the concept of epoxies.
Now, I am somewhat aware of microballoons and newer, more viscous
epoxies.
Can you give me a jump-off point, supplier, website of some outfit you
are familiar and happy with? When I DAGS, I get tons of info, but
virtually zero 'hands-on' reports.
I do know, that epoxies stick to solid surface materials like dog snot
to screen door.
TIA.
r
Robatoy wrote:
> I used Gougeon Bros WEST and found it hard to work with... very runny
> and thin without much gap-filling ability.
So why didn't you fill it? Gougeon recommend this (read their boat
building book - it's excellent) and they'll even sell you the varied
filler materials to do it with. They rarely recommend their own plain
product used unfilled for anything with any sort of gap.
Mind you, I do torsion boxes in a vacuum bag. So long as the skins are
stiff enough and the spacing close enough to avoid "starved dog", then
I get a good gap-free bond with any adhesive.
Andy Dingley <[email protected]> wrote:
> Robatoy wrote:
>
> > I used Gougeon Bros WEST and found it hard to work with... very runny
> > and thin without much gap-filling ability.
>
> So why didn't you fill it? Gougeon recommend this (read their boat
> building book - it's excellent) and they'll even sell you the varied
> filler materials to do it with. They rarely recommend their own plain
> product used unfilled for anything with any sort of gap.
Gougeon Bros are just up the lake a ways from me here and the WEST
stuff is available in a few of my dealers' stores, so I just bought
some and didn't really study the application that much. There have been
a few requests for kitchen islands with an overhang for stools which go
beyond the allowed dimensions for solid surface materials. I do not
like the look of brackets, so back to the torsion box idea.
>
> Mind you, I do torsion boxes in a vacuum bag. So long as the skins are
> stiff enough and the spacing close enough to avoid "starved dog", then
> I get a good gap-free bond with any adhesive.
I'm not sure what you mean by 'starved dog', but I am guessing that
you'll see the ribs if one uses a thin skin. I have been using 3/8"
Baltic Birch ply with poplar ribs 3/4"x 3/4" making 4" cavities.
Speaking of vacuum bags, 1/2" acrylic solid surface, such as Corian,
Wilsonart Gibraltar, Staron, Meganite vacuum form very nicely. The hard
part is getting the temperature 'perfect'.
Lew Hodgett wrote:
<snip>
>
> Fillers, OTOH, are another question.
>
> I use Pacific Coast Chemicals which cover the western US.
>
> Freight should be NBD, since UPS can handle it.
>
> Micro-balloons (Dic-A-Perl, HP500) come in a 30# bag and should be
> less than $30.
>
> Cab-O-Sil comes in a 10# bag and should be less than $90.
>
Micro-balloons and Cab-O-Sil are non-structural fillers generally used
for 'fairing' smooth transitions between adjoining surfaces (like
fillets between wings and airframes on aircraft). They will thicken
the epoxy but provide no real strength advantage (and could actually
weaken the joint, since they displace the resin).
For a true *structural* filler (that will also provide some thixotropic
(thickening) properties), use chopped fiberglass or kevlar (available
from various sources - would have to dig a little, but might could find
some) - and, even, cotton flocking. I've got some samples of 1-2mm
chopped kevlar 'flocking' that, added to epoxy resin at the rate of
1/2% (i.e. 0.5% --by weight) will *triple* the strength of epoxy. It's
that good (this per DuPont lit).
-- john.
(in my 'other life', I do rocketry and trying to find 30,000 feet at
Mach 3 will force you to find ways to make epoxy do things most folks
are unaware of).
Lew Hodgett wrote:
> Gougeon sells hand pumps for resin & hardener to insure proper mix
> ratio which I'm sure are very handy; however, I've never used them.
Aren't they also one-shot items? I remember they were for polyester
resins and kayak making.
I measure my hardener by eyeball, or with a S/H digital lab scale if
I'm mixing a lot or want to be accurate. Instant tareing is a wonderful
thing.
> 1Oz, 2OZ, 4OZ, 10OZ, 16OZ, 40+OZ cups (No Styrofoam)available at a
> restaurant supply house.
Mine are a soft "waxy" plastic - polypropylene ? Originally sold as
packaging for screws. If I leave the epoxy a day and then flex the tub,
it flakes clean off.
> Popsicle sticks or scraps from the table saw for mixing sticks.
My ubiquitous bamboo chopsticks. I only eat icecream in the Summer, but
I can go out for noodles all year round. I never leave our local noodle
bar without pocketing the chopsticks. They turn up in everything
afterwards - drive them through a dowel plate and they're great for
pegging tenons.
I'd add that microballoons are also usable as a structural filler. They
don't add strength per se, but they certainly lighten a large fillet
and improve the strength to weight ratio. Model rockets was where I
first used them.
As for Kevlar, I use this a lot as a filler material. I start with
offcuts of sheet material (I sew my own Kevlar clothing and luggage)
and then cut 1/2" diagonal strips. As it's a loose weave, these easily
tease apart into loose fibres and then get thrown in a bag in the epoxy
crate. Excellent stuff for strong fillets, or for repairing loose tool
handles.
Lew Hodgett wrote:
> However, we are talking about wood working here.
>
> The basic strength of epoxy far exceeds the strength of standard wood
> working adhesives so using some micro-balloons with the epoxy is NBD,
> IMHO.
If the strength far exceeds , then it doesn't really make a lot of
sense to use it -- all that 'extra strength' is, fundamentally, wasted.
Just use Elmer's or Gorilla, etc. (I would be inclined to agree this
may be overkill - but, then, to answer that question intelligently
would require a little more info into the application)
My point in responding was that one poster commented about the West
Systems being too thin - and then the followups about using fillers.
If one is going out to buy a filler, might as well go ahead and get/use
a structural one (assuming the cost is roughly the same). Cotton
flocking is amazingly inexpensive (not shown in below link) - but is a
pretty decent structural filler.
According to Fiberglast (see link), using Kevlar would be very little
cost differential than any of the non-structural fillers. But, again,
this may be moot (as you note) -- just use a more conventional
adhesive.
Several fillers here....
http://www.fibreglast.com/showproducts-category-Fillers-111.html
-- john.
Lew Hodgett wrote: lots of good stuff about epoxies.
I appreciate the discussion on epoxy quite a lot. I find myself in
situations like that the odd time where I need to glue aluminum, solid
surface material, wood, glass.. like a jeweller's display case
recently.
Composites are fun. I used to experiment with a lot of different
materials in the creation of woofer cones.
I have to ask: what's up with white oak and epoxy?
Again, thanks for the input.
r
[email protected] wrote:
> Thanks everyone for your input. Since it is difficult for me to
> describe what I am trying to do. Look at the following like. This is a
> sketch-up of what I am doing. I will leave the edges exspoed as I think
> they look nice when sanded and covered with a clear enamel /laquer etc.
> Plus, the naked edges will be close in color to my speakers and I
> think it will help tie it together. THe casters are not preset in the
> sketch-up, but they will be on the stand.
>
> Thanks a bunch again!
>
> all 3/4" Maple Plywood.
>
> http://i10.photobucket.com/albums/a142/hammondc/chipstand.png
>
In this case you need some kind of reinforcement such as a backboard.
Otherwise, with 3/4" ply, it's going to sag in the middle.
Robatoy wrote:
> I used Gougeon Bros WEST and found it hard to work with... very runny
> and thin without much gap-filling ability. No matter how accurate I
> made the lattices, I still didn't get a 'super sandwich'.
> Vacuum bagging and regular adhesive worked better for me.
> But... I still like the concept of epoxies.
> Now, I am somewhat aware of microballoons and newer, more viscous
> epoxies.
> Can you give me a jump-off point, supplier, website of some outfit you
> are familiar and happy with?
Gougeon is right out your back door and they have good tech service
which would make them a good choice for resin.
You want their standard resin and slow hardener.
Since you are buying small quantities, it won't be cheap, but the
price won't be too bad.
Fillers, OTOH, are another question.
I use Pacific Coast Chemicals which cover the western US.
Freight should be NBD, since UPS can handle it.
Micro-balloons (Dic-A-Perl, HP500) come in a 30# bag and should be
less than $30.
Cab-O-Sil comes in a 10# bag and should be less than $90.
You will be cold and in the ground before you use all of the above<G>.
HTH
Lew
"Robatoy" <[email protected]> wrote in message
news:[email protected]...
>
> A biscuit adds to the strength of the joint. No arguing that. It also
> helps align/registre a joint.
> But it is stronger than the simple butt-joint would be without the
> cookies.
> Is it elegant?
> Nope.
> Do a few carefully applied biscuits do as good a job as a tenon?
> Yes.
>
> See Miller for cites.
Miller who?
In article <[email protected]>,
<[email protected]> wrote:
>My friend owns a high end cabinet shop near Beverly Hills. He warned
>me: "Whatever Biscuit Joiner you buy, use only Lamello Biscuits."
>
>He said they are produced to exacting standards, and I've had good luck
>them. In fact, now that the Festool Domino will soon be available here
>in the U.S. I was considering it. But my joints with biscuits are
>coming out so well, I'll save my $800.
>
>I tried to break a few joints I'd made i n scrap 2x4s and couldn't.
>Just cut your slots carefully.
>
>Gary Curtis
>
There are cabinet shops near Beverly Hills?
Seriously, Lamello biscuits are certainly high quality but there are
several other brands that produce equally good results.
--
Make it as simple as possible, but no simpler.
Larry Wasserman - Baltimore Maryland - [email protected]
jcatora wrote:
>
> Micro-balloons and Cab-O-Sil are non-structural fillers generally used
> for 'fairing' smooth transitions between adjoining surfaces (like
> fillets between wings and airframes on aircraft). They will thicken
> the epoxy but provide no real strength advantage (and could actually
> weaken the joint, since they displace the resin).
Without question, aircraft applications are a different world. I
imagine Dick Rutan could provide a lot of info about those types of
application.
However, we are talking about wood working here.
The basic strength of epoxy far exceeds the strength of standard wood
working adhesives so using some micro-balloons with the epoxy is NBD,
IMHO.
If you have an application that requires more strength, add fabrics
such as knitted glass, carbon, Kevlar, etc; however, doubt you will
need such for wood working.
That's part of the "black art" of epoxy.
Lew
The basic strength of epoxy far exceeds the strength of standard wood
working adhesives so using some micro-balloons with the epoxy is NBD,
IMHO.
I agreed with this statement. However, the structural strength of the
bonding is greatly subject to the type wood, lumber or plywood.
In this case, we are talking about maple plywood. I may I missed some posts
but I do not know what type of wood is used for the core of this maple
plywood. In many instances, the core is made with softwood (not rated as
first class) and may have some void. The only hardwood maybe the top
surface. Very few manufacturers are making hardwood plywood with a hardwood
core without void.
If epoxy is used to bond Harwood plywood made with softwood core and unknown
voids mechanical fasteners will be required in order to have a good
structural bonding. In some circumstances, a solid wooden carcass/skeleton
is necessary.
As for aesthetic look rabbit and dado joinery with carpenter glue and metal
screws may well suit the bill for this project A matching wood tape could
be used the hide the plywood core.
"Lew Hodgett" <[email protected]> wrote in message
news:[email protected]...
> jcatora wrote:
>
> >
> > Micro-balloons and Cab-O-Sil are non-structural fillers generally used
> > for 'fairing' smooth transitions between adjoining surfaces (like
> > fillets between wings and airframes on aircraft). They will thicken
> > the epoxy but provide no real strength advantage (and could actually
> > weaken the joint, since they displace the resin).
>
> Without question, aircraft applications are a different world. I imagine
> Dick Rutan could provide a lot of info about those types of application.
>
> However, we are talking about wood working here.
>
> The basic strength of epoxy far exceeds the strength of standard wood
> working adhesives so using some micro-balloons with the epoxy is NBD,
> IMHO.
>
> If you have an application that requires more strength, add fabrics such
> as knitted glass, carbon, Kevlar, etc; however, doubt you will need such
> for wood working.
>
> That's part of the "black art" of epoxy.
>
> Lew
[email protected] wrote:
> I should also note that the shelves will be adjustable with holes/pins,
> so, not joint will be necessary,
Based on your sketch which basically describes an "H" laid on its side
complete with end caps, let me suggest the following:
Use dado construction to line up the vertical panels into the top and
bottom, then use adjustable shelf pins to support the shelves.
Leave the biscuits in the storage can for a future job.
BTW, you are going to need a lot of open time to get all the clamps
set in place. I'd use epoxy, unless you have a lot of help.
BTDT
Lew
Robatoy wrote:
> > I used Gougeon Bros WEST and found it hard to work with... very
runny
> > and thin without much gap-filling ability.
Further thoughts:
Gougeon sells hand pumps for resin & hardener to insure proper mix
ratio which I'm sure are very handy; however, I've never used them.
I use mixing cups (See below).
If you are going to mess around with epoxy, the following are almost
mandatory items.
Boxes of surgical gloves, 2" chip brushes, and plumber's acid brushes.
Strictly single use items.
Watch for the Harbor Freight sales and stock up.
1Oz, 2OZ, 4OZ, 10OZ, 16OZ, 40+OZ cups (No Styrofoam)available at a
restaurant supply house.
Popsicle sticks or scraps from the table saw for mixing sticks.
Home Depot furnishes me a lot of paint sticks.
Working with epoxy includes some "black art" which is the type and
amount of filler you use for a specific job.
Strictly OJT.
I almost never use just straight epoxy unless I'm laminating some
glass which is totally different than gluing wood together.
HTH
Lew
On Fri, 12 Jan 2007 21:14:14 +0000, marierdj wrote:
> The basic strength of epoxy far exceeds the strength of standard wood
> working adhesives so using some micro-balloons with the epoxy is NBD,
> IMHO.
Don't confuse the bond strength with the bulk strength. Epoxy in bulk is
fairlys strong, but when you add microballoons you turn it into something
approximating foam--that's the whole purpose of microballoons, to provide
a lightweight filler in applications where high strength is not required.
Effectively if you're using epoxy and microballoons to fill a gap you're
bonding two pieces of wood together with a piece of styrofoam in the
middle (yeah, chemists, I know that's not precisely correct) and no matter
how strong the bond between the styrofoam and the wood, it remains
styrofoam without a whole lot of strength of its own.
> I agreed with this statement. However, the structural strength of the
> bonding is greatly subject to the type wood, lumber or plywood.
>
> In this case, we are talking about maple plywood. I may I missed some
> posts but I do not know what type of wood is used for the core of this
> maple plywood. In many instances, the core is made with softwood (not
> rated as first class) and may have some void. The only hardwood maybe
> the top surface. Very few manufacturers are making hardwood plywood
> with a hardwood core without void.
>
> If epoxy is used to bond Harwood plywood made with softwood core and
> unknown voids mechanical fasteners will be required in order to have a
> good structural bonding. In some circumstances, a solid wooden
> carcass/skeleton is necessary.
Lot of stuff out there made with plywood and glue of various kinds with no
mechanical fasteners that has been holding up very well for decades.
While there are voids I think you are exaggerating their importance--the
typical voids in commercial plywood are going to degrade the joint a good
deal less than the microballoons.
> As for aesthetic look rabbit and dado joinery with carpenter glue and
> metal screws may well suit the bill for this project A matching wood
> tape could be used the hide the plywood core.
>
>
> "Lew Hodgett" <[email protected]> wrote in message
> news:[email protected]...
>> jcatora wrote:
>>
>>
>> > Micro-balloons and Cab-O-Sil are non-structural fillers generally
>> > used for 'fairing' smooth transitions between adjoining surfaces
>> > (like fillets between wings and airframes on aircraft). They will
>> > thicken the epoxy but provide no real strength advantage (and could
>> > actually weaken the joint, since they displace the resin).
>>
>> Without question, aircraft applications are a different world. I
>> imagine Dick Rutan could provide a lot of info about those types of
>> application.
>>
>> However, we are talking about wood working here.
>>
>> The basic strength of epoxy far exceeds the strength of standard wood
>> working adhesives so using some micro-balloons with the epoxy is NBD,
>> IMHO.
>>
>> If you have an application that requires more strength, add fabrics
>> such as knitted glass, carbon, Kevlar, etc; however, doubt you will
>> need such for wood working.
>>
>> That's part of the "black art" of epoxy.
>>
>> Lew
--
--John
to email, dial "usenet" and validate
(was jclarke at eye bee em dot net)
Robatoy wrote:
> I find myself in
> situations like that the odd time where I need to glue aluminum, solid
> surface material, wood, glass.. like a jeweller's display case
> recently.
NBD, just keep your 24 grit, right angle sander handy to rough up all
those funny surfaces before you epoxy them together.
> Composites are fun. I used to experiment with a lot of different
> materials in the creation of woofer cones.
Have nothing to offer.
> I have to ask: what's up with white oak and epoxy?
Don't know for sure, suspect it has something to do with the tannic acid.
Lew
[email protected] wrote:
> I was thinking Biscuit
> joiner, but I don't have a Biscuit Joiner (or plate joiner). Any Ideas?
Biscuits can be used if you have a router and the appropriate wing cutter.
Lew
joint
noun 1. the place at which two things, or separate parts of one thing, are
joined or united, either rigidly or in such a way as to permit motion;
juncture.
2. a connection between pieces of wood, metal, or the like, often
reinforced with nails, screws, or glue.
"Tom Watson" <[email protected]> wrote in message
news:[email protected]...
> Let's tell the truth about this, for once.
>
> A biscuit joint is not a joint.
>
> A biscuit joint is an alignment device.
>
> A biscuit joint is a registration device.
>
jcatora wrote:
> If the strength far exceeds , then it doesn't really make a lot of
> sense to use it -- all that 'extra strength' is, fundamentally, wasted.
<snip>
You must have missed the start of the thread.
Basic reason to use epoxy in wood working applications is "open time".
The fact that epoxy will stick to damn near anything and provides
increased strength are side benefits, not the primary reason to use them.
As far as fillers are concerned, Cab-O-Sil adds some strength, but
does absolutely nothing for vertical hang time and is a absolute bitch
to sand.
OTOH, micro-balloons, extend open time, provide vertical hang time as
long as you don't exceed about 1/2" per pass, without sagging.
None of the above means anything to anybody except a boat builder.
Some basic resin thickened as required for the application with
micro-balloons, which usually means hang time, will satisfy 90% of all
wood working applications, the basic exception being white oak.
White oak and epoxy are not compatible, need the purple stuff,
resorcinol for that.
As far as other fillers are concerned, don't see any application in
wood working or even building boats.
SFWIW, got a 10 lb box of 1/8" chopped glass when I started building
the boat. Must have at least 8 lbs left.
If I need added strength, I use the appropriate cloth and wet it out.
May not be a good approach for space ships, but I'm not building them.
Lew
"Robatoy" <[email protected]> writes:
> A lot of the strength of a biscuit joint comes from the biscuit
> filling the slot completely. Too deep/wide a slot is no good. Using
> the router slot, will not let you do that unless you buy/make
> biscuits with the exact radius of the slot-ends.
Profile-wise, it's not a perfect fit, but it's very close. I've never
had a problem with a biscuit failing because I cut the slot that way,
and I've found that using the router results in better board alignment
(table tops) than my biscuit cutter can provide.
The thickness of the slot is essentially exact, though. Finger
pressure or light mallet taps to seat the biscuits.
Buy a 5/32" slot cutter for your router. Make two marks 3/4" apart,
route from one to the other - it's just right for biscuits. In this
case, it might not work unless the joinery is always right at the edge
of the plywood (you can't route in the middle of a board)
Alternate idea: A shallow dado (maybe 1/16 - 1/8" and plugged pocket
screws. I usually do bookshelves this way.