Thanks for the ideas, Dale.  
 
Does anyone have experience using a shooting board with a hand plane?  I
have a low angle block plain and am thinking it would be easier to get
everything lined up once to make the shooting board and then use it.
 
Ralph

  _____  

From: [email protected] [mailto:[EMAIL PROTECTED]
On Behalf Of Dale Leavens
Sent: Sunday, November 11, 2007 6:40 PM
To: [email protected]
Subject: Re: [BlindHandyMan] Bulletin Board Frame



Hi Ralph,

Cutting good mitres on a table saw is very difficult. There are a lot of
things to go wrong.

First is the precision of the mitre gauge. Then the fence of the gauge tends
to be pretty short, 8 inches or so it is fairly easy to find the work either
pulling along or pivoting just slightly when it meets the resistance of the
saw.

Then there is the question of the saw blade first being precisely parallel
to the mitre slot and being precisely vertical. Finally, depending on the
length of the stick being pushed through, are you able to hold it precisely
flat to the table? Any even small error is immediately doubled when you
marry the pieces together.

Many of these things can also apply to a dedicated compound mitre saw but
the work is fixed and there is a clamping mechanism to hold the piece down
to the table and against the fence. I noticed the other day that my mitre
saw is off vertical by a small amount. Not very much and certainly a couple
of years ago it wouldn't have mattered but I can detect it as being off over
the depth of a 3/4ths inch thick MDF board by about the thickness of a sheet
of typing paper. Depending on how the pieces lay up this could represent an
opening of the mitre of the thickness of a playing card, easily visible. If
you close it up then the frame won't sit flat on the wall.

Many wood workers use a fixed disk sander to tune up the mitre deliberately
cutting it a bit long then grinding it to precise length. They will also
mark each piece, never assume anything is square or that even your rabbets
are precisely parallel.

There are after market mitre gauges some with a triangular brace to stiffen
them further. The better ones are quite expensive. They are long and
therefore support work better and they have stops which can be positioned to
permit you to cut several identical pieces without having to measure each
one.

There are also sleds. Often these run in both mitre slots and carry the work
piece through the saw. Many people make their own and some even make a
series of them for specific angles. Turners for example will often build a
sled to cut 18 degree angles or something else so they can cut a 10 or 12
piece assembly to be glued together for turning on a lathe.

Commercially available sleds can be pretty expensive and I don't see many,
more often sliding tables.

This can get the 45 correct particularly if the blade is correctly set up
parallel to the mitre slots. Then there is the precision of the blade being
vertical. I check mine from time-to-time by standing a piece of waste on
edge, something about 2 and a half inches wide and setting the blade full
height. I run the piece through on it's edge cutting about a foot off the
end then examine what happens when I put the cut ends together but one
flipped over. If the blade is absolutely at right angles to the table it
shouldn't matter which way around the cut edges are approximated. You can
also lay one piece on the other with cut ends facing the same way then flip
one and see that the cut faces remain absolutely flush with each other. This
will pick up very small imprecision, much better than anything I can detect
with a square on the table and against the blade.

Finally I always dry fit mitres before attempting to join them. I have a
rather nice strap clamp my son got me a couple of years ago, I should buy a
couple of more, I use it for all sorts of square set-up. It has a fabric
webbing strap with a 90 degree corner on a threaded rod where the ends of
the strap meet and lock on to. There are three other 90 degree plastic
corners threaded through the strap. You position them on the corners, draw
the strap tight to the fourth corner device and lock them in then tighten
the lot by turning the threaded rod. Only trouble is that you cannot apply
nails but if the mitres are correct the fit will be correct.If the mitre
surface is adequate I will insert a size 0 biscuit and glue it up then pull
it together with the strap clamp.

Finally, there are mitre clamps out there. these come in different
varieties. some are something like a pair of vices stuck together at a
corner at 90 degrees to each 
other, you slide the two joining members into place with glue. Some have
holes big enough to tap nails through into the frame while supported in the
clamp and you set the nails while at it. Some are only half an inch high
jaws or less leaving room to nail.

You can also buy dedicated hand mitre saws sometimes called picture framing
saws. These can be bolted to a table or cabinet and have two clamps at
either side of a frame which holds a stiff backed saw. The clamps are
designed to present the wood to the saw at 45 degrees from either side, the
saw is suspended on posts and can then be lowered to the wood held firmly
straight and vertical like using a mitre box only you don't wear out the
kerfs in the box. The clamps can then be used to hold the mitre in place
while you glue and nail it.

I suppose you could use those so-called bow-tie connecters. This is a
technique where you cut a bow-tie sort of shaped recess across the joint and
cut a bow-tie shaped insert which fits tightly into the cut recess then
apply glue and tap it down pulling the joint together. This was a common
technique used a couple of hundred of years ago. Back then they hid the
connection under the joint where it wouldn't be seen but these days anyone
skilled enough to do that will usually put them right out front where they
are easily seen.

Hope some of this is helpful.

Dale Leavens, Cochrane Ontario Canada
[EMAIL PROTECTED] <mailto:DLeavens%40puc.net> net
Skype DaleLeavens
Come and meet Aurora, Nakita and Nanook at our polar bear habitat.

----- Original Message ----- 
From: Ralph Supernaw 
To: blindhandyman@ <mailto:blindhandyman%40yahoogroups.com> yahoogroups.com 
Sent: Sunday, November 11, 2007 4:19 PM
Subject: [BlindHandyMan] Bulletin Board Frame

My wife bought a cheap bulletin board for church that had a cheap metal
frame. I told her it would be no problem to make an attractive wood frame.
That was ignorance speaking.

There is nothing fancy. I want a flat frame with 45 degree beveled corners.
I have a rabbit around the inside edge where the bulletin board will fit. I
just tried to assemble the four pieces. Every corner has problems. I'm not
sure if they are open because I didn't have the boards snug when I fastened
them with a brad nailer. Or, they may not have been exactly 45 degree
bevels cut in the wood. Plus the surfaces on the front aren't completely
even with each other. 

I know part of my problem was trying to figure out how to hold the pieces in
the right place so I could nail them. 

Any tips or tricks for this kind of project? Using a table saw, how do you
get the bevels right?

Ralph

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