JM

Jim Murphy

05/08/2004 9:50 PM

How to rip?

After lurking a while, I have begun to wonder if there's a right and
wrong way to rip. If you need a 1" wide piece, and have a 4" board, do
you set the fence 3" from the blade so the "waste" is the desired cut,
or do you set the fence 1" from the blade and let the 3" be waste.
(Assume that I'm taking kerf into consideration and setting the fence
based on the proper cutting teeth.)

Also, when you need to "extend" a board, for example, to put up chair
rail, and you scarf cut, is there any magic to the scarf compound
angle? I usually set up a 22.5° in miter and bevel and whack away. Is
there a preferred, professional angle set for scarf cut?

Thanks for all the help, y'all are great.

Jim
Raleigh NC


This topic has 19 replies

DB

Dave Balderstone

in reply to Jim Murphy on 05/08/2004 9:50 PM

05/08/2004 5:07 PM

In article <[email protected]>, Jim Murphy
<[email protected]> wrote:

> After lurking a while, I have begun to wonder if there's a right and
> wrong way to rip. If you need a 1" wide piece, and have a 4" board, do
> you set the fence 3" from the blade so the "waste" is the desired cut,
> or do you set the fence 1" from the blade and let the 3" be waste.
> (Assume that I'm taking kerf into consideration and setting the fence
> based on the proper cutting teeth.)

I'm in agreement with Leon. If I can safely get my push stick between
the fence and the blade, my keeper piece is there. Otherwise it's on
the outside of the blade.

Can't help with the scarf question. Sorry.

djb (who's out of the shop for a while with a broken 5th metatarsal in
my left foot. Damn kids and their footballs...)

DB

Dave Balderstone

in reply to Jim Murphy on 05/08/2004 9:50 PM

06/08/2004 9:38 AM

In article <[email protected]>,
Glen <[email protected]> wrote:

> My sympathies on your foot. I, too, am out of the shop for a few
> months, due to rotator cuff surgery.

A colleague had to put his golf clubs away for the season for the same
reason.

> Picked up three planes (a Stanley #4, an adjustable throat block
> plane and an old woodie) and I can't work on them to tune them up.

I hear you. I can't stand long enough to build the stool that would
allow me to at least sit at the lathe... <g>

> Believe me, I feel your pain. I wish you the best for a speedy
> recovery.

And you.

djb

Bb

"Brian"

in reply to Jim Murphy on 05/08/2004 9:50 PM

05/08/2004 5:55 PM

30 degrees on the scarf joint is standard. 30 degrees gives you a bond area
that is twice the area of a straight butt joint.

Brian.


"Jim Murphy" <[email protected]> wrote in message
news:[email protected]...
> After lurking a while, I have begun to wonder if there's a right and
> wrong way to rip. If you need a 1" wide piece, and have a 4" board, do
> you set the fence 3" from the blade so the "waste" is the desired cut,
> or do you set the fence 1" from the blade and let the 3" be waste.
> (Assume that I'm taking kerf into consideration and setting the fence
> based on the proper cutting teeth.)
>
> Also, when you need to "extend" a board, for example, to put up chair
> rail, and you scarf cut, is there any magic to the scarf compound
> angle? I usually set up a 22.5° in miter and bevel and whack away. Is
> there a preferred, professional angle set for scarf cut?
>
> Thanks for all the help, y'all are great.
>
> Jim
> Raleigh NC

Td

"TeamCasa"

in reply to Jim Murphy on 05/08/2004 9:50 PM

05/08/2004 4:35 PM

Again, I agree with Leon.

As for the scarf joint, in general, the longer the scarf joint the better.
However, for chair rail or base, a 45 works well for painted molding. A
simple butt with biscuits, splines or dowels will serve better. IMHO

Dave

"Jim Murphy" <[email protected]> wrote in message
news:[email protected]...
> After lurking a while, I have begun to wonder if there's a right and
> wrong way to rip. If you need a 1" wide piece, and have a 4" board, do
> you set the fence 3" from the blade so the "waste" is the desired cut,
> or do you set the fence 1" from the blade and let the 3" be waste.
> (Assume that I'm taking kerf into consideration and setting the fence
> based on the proper cutting teeth.)
>
> Also, when you need to "extend" a board, for example, to put up chair
> rail, and you scarf cut, is there any magic to the scarf compound
> angle? I usually set up a 22.5° in miter and bevel and whack away. Is
> there a preferred, professional angle set for scarf cut?
>
> Thanks for all the help, y'all are great.
>
> Jim
> Raleigh NC

LH

"Lew Hodgett"

in reply to Jim Murphy on 05/08/2004 9:50 PM

06/08/2004 1:52 AM

"Jim Murphy" writes:

> After lurking a while, I have begun to wonder if there's a right and
> wrong way to rip. If you need a 1" wide piece, and have a 4" board, do
> you set the fence 3" from the blade so the "waste" is the desired cut,

I don't.

> or do you set the fence 1" from the blade and let the 3" be waste.

I do.

> Also, when you need to "extend" a board, for example, to put up chair
> rail, and you scarf cut, is there any magic to the scarf compound
> angle?

A decent scarf is anything from 8:1 minimum to 16:1 max.

IMHO, scarf joints are definitely NOT a tablesaw operation.

You can use either a router or a hand power planer with the appropriate jig
to make scarfs safely.

See Fred Bingham's book, Practical Yacht Joinery for a rather extensive
discussion of scarfs.

HTH

Lew


Lr

"Leon"

in reply to Jim Murphy on 05/08/2004 9:50 PM

05/08/2004 9:59 PM

Your keeper piece should fall between the fence and the blade 99% of the
time. This way, you can cut the same width over and over to exactly the
same width.
If you cut very narrow pieces, in the 1/8" an narrower range, it would be
safer to have the keeper on the normal waste side.

Mm

MikeG

in reply to Jim Murphy on 05/08/2004 9:50 PM

05/08/2004 10:14 PM

In article <[email protected]>, [email protected] says...
> After lurking a while, I have begun to wonder if there's a right and
> wrong way to rip. If you need a 1" wide piece, and have a 4" board, do
> you set the fence 3" from the blade so the "waste" is the desired cut,
> or do you set the fence 1" from the blade and let the 3" be waste.=20
> (Assume that I'm taking kerf into consideration and setting the fence
> based on the proper cutting teeth.)
>=20
> Also, when you need to "extend" a board, for example, to put up chair
> rail, and you scarf cut, is there any magic to the scarf compound
> angle? I usually set up a 22.5=B0 in miter and bevel and whack away. Is
> there a preferred, professional angle set for scarf cut?
>=20
> Thanks for all the help, y'all are great.
>=20
> Jim
> Raleigh NC
>=20

Technically, for safety reasons, the proper way is to have the wide side=20
of the cut between the fence and the blade. Gives you more room around=20
the blade as you feed the stock.=20

However I don't know of many, including myself, that strictly adhere to=20
that principle. Especially if you are cutting repetitive sized strips=20
off of the stock and want them all to be exactly the same width. Say=20
three one inch strips from your four inch stock for example.

So, in short, there is a right way. However there is usually more=20
reasons to not do it that way then there is too. =20

--=20
MikeG
Heirloom Woods
www.heirloom-woods.net
[email protected]

SM

"Stephen M"

in reply to Jim Murphy on 05/08/2004 9:50 PM

06/08/2004 10:16 AM

I agree w/ dave.

I suspect that the scarf joint was invented before the biscuit. The first
time I tried this it was on a 1x4 piece of exterior trim (a pretty tough
environment). It held up perfectly for about 5 years. The structure was them
demolished so it saw no further testing. If you can, us some kind of spline
(biscuit dowel, whatever). The pieces become essentialy one piece of wood.

I find this works well for a coped molding as the difficult end can fiddled
with and then the butt end is just cut for and exact fit, them the spline
slot is cut.

I'm curious if others have found a problem with the spline approach as scarf
joints appear to continue to be conventional wisdom.

-Steve

"TeamCasa" <[email protected]> wrote in message
news:[email protected]...
> Again, I agree with Leon.
>
> As for the scarf joint, in general, the longer the scarf joint the better.
> However, for chair rail or base, a 45 works well for painted molding. A
> simple butt with biscuits, splines or dowels will serve better. IMHO
>
> Dave
>
> "Jim Murphy" <[email protected]> wrote in message
> news:[email protected]...
> > After lurking a while, I have begun to wonder if there's a right and
> > wrong way to rip. If you need a 1" wide piece, and have a 4" board, do
> > you set the fence 3" from the blade so the "waste" is the desired cut,
> > or do you set the fence 1" from the blade and let the 3" be waste.
> > (Assume that I'm taking kerf into consideration and setting the fence
> > based on the proper cutting teeth.)
> >
> > Also, when you need to "extend" a board, for example, to put up chair
> > rail, and you scarf cut, is there any magic to the scarf compound
> > angle? I usually set up a 22.5° in miter and bevel and whack away. Is
> > there a preferred, professional angle set for scarf cut?
> >
> > Thanks for all the help, y'all are great.
> >
> > Jim
> > Raleigh NC
>
>

b

in reply to Jim Murphy on 05/08/2004 9:50 PM

05/08/2004 8:36 PM


>> when you need to "extend" a board, for example, to put up chair
>> rail, and you scarf cut, is there any magic to the scarf compound
>> angle?
>
>A decent scarf is anything from 8:1 minimum to 16:1 max.


long scarfs are extra work to make look good on residential trim work.
the trim on a boat is structural- there the extra work is appropriate.




>
>IMHO, scarf joints are definitely NOT a tablesaw operation.

agreed.


>
>You can use either a router or a hand power planer with the appropriate jig
>to make scarfs safely.

or a chop saw <G>



>
>See Fred Bingham's book, Practical Yacht Joinery for a rather extensive
>discussion of scarfs.
>
>HTH
>
>Lew
>
>

b

in reply to Jim Murphy on 05/08/2004 9:50 PM

05/08/2004 8:43 PM

On Thu, 05 Aug 2004 21:50:51 GMT, Jim Murphy <[email protected]>
wrote:

>After lurking a while, I have begun to wonder if there's a right and
>wrong way to rip. If you need a 1" wide piece, and have a 4" board, do
>you set the fence 3" from the blade so the "waste" is the desired cut,
>or do you set the fence 1" from the blade and let the 3" be waste.

I generally assume that a board isn't quite the same width from one
end to the other. I'd set the fence at 1"






>(Assume that I'm taking kerf into consideration and setting the fence
>based on the proper cutting teeth.)

and then there's having to remember that....




>
>Also, when you need to "extend" a board, for example, to put up chair
>rail, and you scarf cut, is there any magic to the scarf compound
>angle? I usually set up a 22.5° in miter and bevel and whack away. Is
>there a preferred, professional angle set for scarf cut?

I was taught 30 degrees for trim.






>
>Thanks for all the help, y'all are great.
>
>Jim
>Raleigh NC

TW

Tom Watson

in reply to Jim Murphy on 05/08/2004 9:50 PM

06/08/2004 6:01 PM

On Thu, 05 Aug 2004 21:50:51 GMT, Jim Murphy <[email protected]>
wrote:

>After lurking a while, I have begun to wonder if there's a right and
>wrong way to rip. If you need a 1" wide piece, and have a 4" board, do
>you set the fence 3" from the blade so the "waste" is the desired cut,
>or do you set the fence 1" from the blade and let the 3" be waste.
>(Assume that I'm taking kerf into consideration and setting the fence
>based on the proper cutting teeth.)

I like to have the waste piece be the one that is on the side of the
blade that is farthest from the fence. I use an ice pick on the
skinny ones.
>
>Also, when you need to "extend" a board, for example, to put up chair
>rail, and you scarf cut, is there any magic to the scarf compound
>angle? I usually set up a 22.5° in miter and bevel and whack away. Is
>there a preferred, professional angle set for scarf cut?


Most trim carpenters use a forty five but I don't think they hold up
well over time. I believe the reason for this to be that the gluing
surface has too much end grain in it for a good bond over time.

What I've usually done is to clamp a temporary fence onto the SCMS,
that is basically a square piece of MDF, with some blocks glued on, so
that I can clamp the trim to it (I also glue on a piece of sandpaper
to the edge that the trim gets clamped to, so it doesn't want to slip
around so much). This gives me a fence that is at ninety degrees to
the regular fence.

On the SCMS I can get a long scarf that gives more of a face grain
gluing surface and joints cut this way seem to hold up quite well.




Regards,
Tom.

Thomas J.Watson - Cabinetmaker (ret.)
tjwatson1ATcomcastDOTnet (real email)
http://home.comcast.net/~tjwatson1

ON

Old Nick

in reply to Jim Murphy on 05/08/2004 9:50 PM

07/08/2004 10:30 PM

On Sat, 07 Aug 2004 03:05:57 GMT, "Hisself" <[email protected]> vaguely
proposed a theory
......and in reply I say!:

Oh God not you agaon!
*****************************************************
It's not the milk and honey we hate. It's having it
rammed down our throats.

Gg

Glen

in reply to Jim Murphy on 05/08/2004 9:50 PM

06/08/2004 11:06 AM

Dave Balderstone wrote:
<SNIP>
>
> djb (who's out of the shop for a while with a broken 5th metatarsal in
> my left foot. Damn kids and their footballs...)

My sympathies on your foot. I, too, am out of the shop for a few
months, due to rotator cuff surgery. Picked up three planes (a Stanley
#4, an adjustable throat block plane and an old woodie) and I can't work
on them to tune them up. Believe me, I feel your pain. I wish you the
best for a speedy recovery.

Glen

ON

Old Nick

in reply to Jim Murphy on 05/08/2004 9:50 PM

07/08/2004 7:14 AM

On Thu, 05 Aug 2004 21:50:51 GMT, Jim Murphy <[email protected]>
vaguely proposed a theory
......and in reply I say!:

remove ns from my header address to reply via email

>After lurking a while, I have begun to wonder if there's a right and
>wrong way to rip.

Sorry. Cna't help it (or help). Watch blazing saddles for a good
demostration. <G>
*****************************************************
It's not the milk and honey we hate. It's having it
rammed down our throats.

Hn

"Hisself"

in reply to Jim Murphy on 05/08/2004 9:50 PM

07/08/2004 3:05 AM

Check this site out for scarf joint
http://www.glen-l.com/supplies/pxman-apscarf.html

"TeamCasa" <[email protected]> wrote in message
news:[email protected]...
| Again, I agree with Leon.
|
| As for the scarf joint, in general, the longer the scarf joint the
better.
| However, for chair rail or base, a 45 works well for painted molding.
A
| simple butt with biscuits, splines or dowels will serve better. IMHO
|
| Dave
|
| "Jim Murphy" <[email protected]> wrote in message
| news:[email protected]...
| > After lurking a while, I have begun to wonder if there's a right and
| > wrong way to rip. If you need a 1" wide piece, and have a 4" board,
do
| > you set the fence 3" from the blade so the "waste" is the desired
cut,
| > or do you set the fence 1" from the blade and let the 3" be waste.
| > (Assume that I'm taking kerf into consideration and setting the
fence
| > based on the proper cutting teeth.)
| >
| > Also, when you need to "extend" a board, for example, to put up
chair
| > rail, and you scarf cut, is there any magic to the scarf compound
| > angle? I usually set up a 22.5° in miter and bevel and whack away.
Is
| > there a preferred, professional angle set for scarf cut?
| >
| > Thanks for all the help, y'all are great.
| >
| > Jim
| > Raleigh NC
|
|


---
Outgoing mail is certified Virus Free.
Checked by AVG anti-virus system (http://www.grisoft.com).
Version: 6.0.732 / Virus Database: 486 - Release Date: 7/29/2004

Ba

B a r r y

in reply to Jim Murphy on 05/08/2004 9:50 PM

06/08/2004 1:24 AM

On Thu, 05 Aug 2004 21:59:05 GMT, "Leon"
<[email protected]> wrote:

>Your keeper piece should fall between the fence and the blade 99% of the
>time. This way, you can cut the same width over and over to exactly the
>same width.
>If you cut very narrow pieces, in the 1/8" an narrower range, it would be
>safer to have the keeper on the normal waste side.
>


I use a long push BLOCK (NOT stick) for narrow rips, all the way down
to 1/8", between the fence and blade. The blade gets set to slightly
higher than the work, and it will cut a groove in the push block.

The push block is simply 3/4" MDF, with an MDF "handle" edge glued to
it, and mouse pad material glued to the bottom. It's about 4" wide x
12" long.

Barry

EP

"Edwin Pawlowski"

in reply to Jim Murphy on 05/08/2004 9:50 PM

06/08/2004 3:35 AM


"Leon" <[email protected]> wrote in message
news:[email protected]...
> Your keeper piece should fall between the fence and the blade 99% of the
> time. This way, you can cut the same width over and over to exactly the
> same width.
> If you cut very narrow pieces, in the 1/8" an narrower range, it would be
> safer to have the keeper on the normal waste side.

I agree.

If you want to cut a bunch of thin strips, make a guide block so you can be
consistent. Cut a piece of wood about 2 or 3" wide by about 6" long. Put a
3/8 x 3/4 strip on the bottom that will fit into the miter slot. On the
blade side of the block, put in a round head screw. Set it up so that the
distance from the screw head to the blade is the same as the desired width
of piece you want to cut. Clamp it in place well ahead of the blade. Now
you can use it a guide to set your fence for each cut. Just move the board
to the screw head, bring the fence into position and cut. repeat as needed.

TD

Tim Douglass

in reply to Jim Murphy on 05/08/2004 9:50 PM

06/08/2004 1:01 PM

On Fri, 06 Aug 2004 04:16:30 GMT, "Lew Hodgett"
<[email protected]> wrote:

>SFWIW, my first attempt at making scarfs were 16:1 made using a hand power
>planer and a scarfing jig clamped in a B&D Workmate.
>
>The whole thing was done outdoors.
>
>The strips were Doug Fir, 5/8"x1-1/2"x24ft cut from 2x12x24 construction
>timbers.
>
>Cutting those was an interesting exercise.
>
>Estimate that I made over a mile of cuts that day, filling a dumpster with
>saw dust.
>
>When I was finished, had 24 ft long strips, but needed 65-70 ft long strips.
>
>Only had 30, 3" C-Clamps.
>
>A few days and a gallon of TiteBondII later, had about 400, 72 ft long
>strips.
>
>Filled up a another dumpster with planer chips.
>
>Add about 5,000 deck screws and you get a mold that eventually turned into
>weenie roast fuel, once the fiberglass hull was complete.

Now *that's* a lot of work for a single use jig!

Tim Douglass

http://www.DouglassClan.com

LH

"Lew Hodgett"

in reply to Jim Murphy on 05/08/2004 9:50 PM

06/08/2004 4:16 AM

<[email protected]> writes:

> long scarfs are extra work to make look good on residential trim work.
> the trim on a boat is structural- there the extra work is appropriate.

On a boat, long scarfs are a structrual thing, so they have to be done
correctly or you end up with "hard" spots.

Whether you make a short scarf or a long scarf doesn't really matter as far
as time is concerned, but it does impact the amount of material needed.

Maybe I'm just prejudiced, but I've seen a lot of short scarfs on trim work
that tend to open up after a few years.

To me, that reflects back on the craftsman who did the job, demonstrating
for the world to see, a lack of pride, or maybe a supervisor who just didn't
give a hoot as long as they got paid.

You can't get there from here with a chop saw IMHO.

Might work for a base board molding, but those aren't real scarfs, IMHO.

Guess it just depends on how you look at it.

I look at my scarfing jig the same way I look at my sled.

Basic tools that are required before you open the shop door and turn on the
lights.

SFWIW, my first attempt at making scarfs were 16:1 made using a hand power
planer and a scarfing jig clamped in a B&D Workmate.

The whole thing was done outdoors.

The strips were Doug Fir, 5/8"x1-1/2"x24ft cut from 2x12x24 construction
timbers.

Cutting those was an interesting exercise.

Estimate that I made over a mile of cuts that day, filling a dumpster with
saw dust.

When I was finished, had 24 ft long strips, but needed 65-70 ft long strips.

Only had 30, 3" C-Clamps.

A few days and a gallon of TiteBondII later, had about 400, 72 ft long
strips.

Filled up a another dumpster with planer chips.

Add about 5,000 deck screws and you get a mold that eventually turned into
weenie roast fuel, once the fiberglass hull was complete.

Lew


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