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Main Boards => The Bowyer's Bench => Topic started by: bbs383ci on March 27, 2012, 03:13:00 PM

Title: form material
Post by: bbs383ci on March 27, 2012, 03:13:00 PM
i have a binghams recurve and longbow plans, i need to some forms, i recently bought a very straight 2x8 to try it for the longbow since it is 1 1/2" wide, it was also treated i dont know if that makes difference, does anyone have a problem with a form like this twisting while it is in the oven, it not how do you stabilize it to keep it from doing so, or is there another alternative besides plywood for a form.

thanks
Title: Re: form material
Post by: dmikeyj on March 27, 2012, 03:51:00 PM
LVL lumber, MDF, Corian have all been used effectively.
Title: Re: form material
Post by: bbs383ci on March 27, 2012, 04:08:00 PM
do they make a 2" lvl
Title: Re: form material
Post by: bbs383ci on March 27, 2012, 04:27:00 PM
well i have called all of the places in my area that can get lvl and all they can get is 1 3/4" wide, do yall know of any place else that you can get this stuff from that has diffrent thicknesses available?
Title: Re: form material
Post by: Glunt on March 27, 2012, 04:53:00 PM
I would go with your board.  Natural grain is susceptible to  changing more so than laminated stuff but it may be fine.  I've seen a bunch of guys use a single board like that.

If it does start to tweak, you can add some runners down the side to make it behave.  I would pop it in the oven for a couple hours and see what happens.

If you grab some of that 1 3/4" LVL, you should be able to find some 1/4" stuff to add to one side and get 2" before cutting your form out.
Title: Re: form material
Post by: bbs383ci on March 27, 2012, 05:41:00 PM
Thanks ill try that
Title: Re: form material
Post by: Robertfishes on March 27, 2012, 08:19:00 PM
I live in a high humidity area So I would not use a board, I would worry about it twisting when heated, pressure treated wood will be more likely to twist..at least the PT Pine boards we have here in Florida, the PT wood here usually has a high moisture content.
Many guys use the LVL and it must be pretty darn good stuff. For the 1 1/2" form you can sand the 1 3/4" down to 1/1/2" if you have a big enough sander..I don't, but my neighbor has a CNC machine at his Cabinet shop that would do it..I use Cabinet grade birch plywood from the neighbors Cabinet Shop, I bought enough 3 years ago to make 4 form blanks, Then I found out about the LVL...Good luck with your builds!
Title: Re: form material
Post by: jsweka on March 27, 2012, 08:41:00 PM
You could get two 3/4 pieces of plywood and laminate them together with tite bond and wood screws.  Depending on how close the plywood actually is to 3/4, you might have to add another piece of 1/4 in the middle.
Title: Re: form material
Post by: Robertfishes on March 27, 2012, 08:54:00 PM
John, thats what I ended up doing on my 4 forms, I used my digital calipers and found I needed a thin piece..so off to Lowes with my digital calipers.. I went thru a bunch of thin pieces of plywood, paneling etc and found a wood door skin that was the right thickness to make the form 1 3/4" wide. I put the door skin in the middle of the stack. This is a 1 1/2" wide form I made using 3 pieces of plywood.  (http://i596.photobucket.com/albums/tt46/Robertfishes/firstlongbowdryrun.jpg)
Title: Re: form material
Post by: scottm on March 27, 2012, 09:42:00 PM
What about adding a 1/4" piece of ply or luan to the 1-3/4" LVL? Just a thought.
Title: Re: form material
Post by: Dmaxshawn on March 28, 2012, 07:13:00 AM
Dusty I'll send you a pm on the green screen.  I have a form that I don't use anymore. I'd be willing to send to you.  

Shawn
Title: Re: form material
Post by: bbs383ci on March 28, 2012, 12:56:00 PM
sweet thx shawn ill take a look.
Title: Re: form material
Post by: 7 Lakes on March 28, 2012, 02:31:00 PM
A piece of formica will take up the extra space you need, just rough up the smooth side before gluing.  That's for for a 1.5" form
Title: Re: form material
Post by: Bowjunkie on March 29, 2012, 06:04:00 AM
A concern with particleboard... it's not nearly as strong as plywood. I had a particleboard recurve form explode in the oven once. I never used the stuff again.

Now I only use plywood glued and screwed together, or LVL lumber.
Title: Re: form material
Post by: arrowlauncherdj on March 29, 2012, 11:45:00 AM
You can use particle board for the base form since it is very straight and sands nice. Then laminate it on the sides with some thin ply like 1/2" on each side dropping it down low enough to allow you to put on your washers to hold everything straight.  Also that adds a nice spacer for your air hose to keep it from pressing on your form hardware.
Title: Re: form material
Post by: johnny girardi on March 29, 2012, 01:00:00 PM
I have on my last bow forms used what we call microlam beams or gluelam beams. you can find then at 84 lumber,Menards by me not sure in Tx. These are multy laminated beams of soft whitewood.I just pick them up and look down board for streightness. they are only 1.75" wide.I never had one warp on me.