After reading up on table saw jigs (sleds, aux fences, etc), the materials
most often recommended seems to be baltic birch, and maple plywood.
I found a source for baltic birch (which comes 5x5). The difference is
obvious from the plywood available at the local borgs, but they had other
(4x8) hardwood plywoods that seem to have a similar ply structure; how would
these compare to the baltic birch?
This same source also had about 8 bins each holding a different kind of
"maple plywood". Can anyone clue me in to the differences among the various
maple productions?
Also, how much better are these (specialty?) plywoods. For instance, is
1/2" baltic birch just SO much better as a sled base than, say, 1/2" MDF?
For fences (either rip or crosscut), I would think a good plywood would
stand up better than hardwood, due to stability. But still some authors
recommend using hardwood for fences (most notably on a crosscut sled). Is
it all just personal preference, and the choice of material just splitting
hairs?
/rick.
You most certainly will not find a consensus here. Hopefully you will
collect some replies and glean what works for you.
For me, I have had too many problems using any type of plywood for sleds,
fences, and zero clearance plates. Plywood often just won't stay flat over
time. MDF stays flat pretty well, but I find the edges too soft and flaky.
Bang a corner of your MDF sled on the saw table and you have an upset to
deal with. All of my current collection of zero clearance inserts are 1/2"
baltic birch, and it has taken a couple of years but they just ain't flat
enough anymore. Baltic birch might well be my LAST choice for a sled.
I am using more melamine these days. All my current sleds are melamine. I
have a couple of clamp on fences for the TS, again melamine. Next time I
make zero clearance inserts I'm gonna look for 1/2" melamine, although I
will have to find a project first because I will need the scraps to work
with. Melamine seems to stay flat no matter what. The corners will chip, a
weakness, but not as bad as MDF.
Just one humble correspondents opinion.
BTW, baltic birch is available in 4 x 8 as well as other sizes. Might that
be what you saw?
--
Bill Pounds
http://www.billpounds.com/woodshop
"RickS" <rick --dot-- s --at-- comcast.net> wrote in message
news:[email protected]...
> After reading up on table saw jigs (sleds, aux fences, etc), the materials
> most often recommended seems to be baltic birch, and maple plywood.
>
> I found a source for baltic birch (which comes 5x5). The difference is
> obvious from the plywood available at the local borgs, but they had other
> (4x8) hardwood plywoods that seem to have a similar ply structure; how
would
> these compare to the baltic birch?
>
> This same source also had about 8 bins each holding a different kind of
> "maple plywood". Can anyone clue me in to the differences among the
various
> maple productions?
>
> Also, how much better are these (specialty?) plywoods. For instance, is
> 1/2" baltic birch just SO much better as a sled base than, say, 1/2" MDF?
>
> For fences (either rip or crosscut), I would think a good plywood would
> stand up better than hardwood, due to stability. But still some authors
> recommend using hardwood for fences (most notably on a crosscut sled). Is
> it all just personal preference, and the choice of material just splitting
> hairs?
>
> /rick.
>
>
In article <[email protected]>, patriarch
<<patriarch>[email protected]> says...
> MDF certainly has a place. Flat, reliable and relatively cheap. Properly
> sealed, it's dimensionally stable, particularly if moisture and/or humidity
> isn't a challenge in your shop.
>
And there's always MDO. Especially nice for jigs you want to mark
settings on.
--
Where ARE those Iraqi WMDs?
"RickS" <rick --dot-- s --at-- comcast.net> wrote in
news:[email protected]:
> After reading up on table saw jigs (sleds, aux fences, etc), the
> materials most often recommended seems to be baltic birch, and maple
> plywood.
>
> I found a source for baltic birch (which comes 5x5). The difference is
> obvious from the plywood available at the local borgs, but they had
> other (4x8) hardwood plywoods that seem to have a similar ply
> structure; how would these compare to the baltic birch?
>
> This same source also had about 8 bins each holding a different kind
> of "maple plywood". Can anyone clue me in to the differences among
> the various maple productions?
>
> Also, how much better are these (specialty?) plywoods. For instance,
> is 1/2" baltic birch just SO much better as a sled base than, say,
> 1/2" MDF?
>
> For fences (either rip or crosscut), I would think a good plywood
> would stand up better than hardwood, due to stability. But still some
> authors recommend using hardwood for fences (most notably on a
> crosscut sled). Is it all just personal preference, and the choice of
> material just splitting hairs?
>
> /rick.
>
OK, Rick. Let's talk philosophy for a moment. Then take what you've
learned and make a few of your own decisions.
Sleds and fixtures need to be sturdy, flat and reliable in dimension.
Whether you are going to use them all day every day, or pull them off the
hook twice a year, the reasons to use a jig all pretty much require that
you can count on it for safe, repeatable results. Any material that
delivers that in your shop environment, in your use pattern, is a
candidate. Beyond those factors, it gets into personal preference.
MDF certainly has a place. Flat, reliable and relatively cheap. Properly
sealed, it's dimensionally stable, particularly if moisture and/or humidity
isn't a challenge in your shop. One of our stalwarts here called it
something like 'the first cousin of cast iron'. (he turned the phrase
better, but I'm not going to go look it up for the reference right now.)
Join it to the fence(s) properly, and use it in good health. David Marks
seems to use truckloads of the stuff for patterns and fixtures.
The last batch of BB I got seemed to have problems with staying flat. I
managed to 'encourage it' into square & plumb cabinets, but I wouldn't have
used it for a jig, where the twist couldn't be controlled. YMMV. Mine
usually does.
Hard woods for fences make a lot of sense, because they are reliable, and
easily fastened. I generally clamp a sacrificial face to mine,
particularly when I'm using it for mitered cuts. It works like a zero-
clearance insert on the table saw, and shows exactly where the blade will
cut. I use cabinet ply offcuts, because that's what I have. The vertical
grain douglas fir rails on my crosscut sleds all came from a really nice,
straight, kiln-dried 2x6 from the lumber yard. Ripped in half, I still
have material left. That's what I used, because that's what somebody at
the wood club said would work. Doug fir isn't a hardwood; just a hard
wood.
Here, finally, is the point. (you mean, he's finally going to make a
point?) Most any of these options are in use all over the wReck, most of
them safely. They most all of them would work for you. My guess is that
what you're trying to build is furniture, or cabinetry, or boxes, or
something. But jigs are just a means of getting to the goal. Find
something to get it done, with what you know now, with what's easily at
hand, and move on to the real goal.
Jigs that don't work can be used to heat the house, come winter.
Have fun. And remember, it's USENET. Opinions abound. Don't trust them
all. Even mine. Especially mine.
Patriarch