Plywood form question

[Bvas]

The BIL hooked me up today with some 3/4" plywood to build a form with. I need to build an 1-1/2" form. Problem is the plywood is actually 23/32". So if I laminate them together I will end up 1/16 narrow on the form.
I have steel banding strips that I could use as spacers to get proper thickness, but then I would lose that wood to wood glue bond.
Would just screwing the two halves together be sufficient?  Or should I use wood strips as spacers to maintain a glue bond as well?

[Walt Francis]

I would recommend using a wood spacer.   Most of the glass I purchased came slightly over 1.5 inches.  I use LVL's for forms and run them through the planner & thickness sander to match the thickness of the glass.

[kennym]

I like the wood to be glued and screwed on mine. Like Walt said, slightly over 1.5", a few thousandths at least.

[Crooked Stic]

On my 1 1/2 forms I use a 3/4 -1/2 and 3/8 plywood screwed and glued. Ir comes out a bit over 1 1/2 Most times I have to run it thru the drum sander to match the glass.

[kennym]

Heres a wild thought....

Make the form a bit thick, and then take a router with straight bit and your form pattern and bring it to the exact thickness you want for an inch down from the face. You have spacers under your lock straps anyway so a small step won't hurt anything.

[Trux Turning]

Originally posted by kennym:
Heres a wild thought....

Make the form a bit thick, and then take a router with straight bit and your form pattern and bring it to the exact thickness you want for an inch down from the face. You have spacers under your lock straps anyway so a small step won't hurt anything.

This is how I've done a number of my forms and it works out well.

[Bvas]

Originally posted by kennym:

Make the form a bit thick, and then take a router with straight bit and your form pattern and bring it to the exact thickness you want for an inch down from the face.  

Great idea!!

I been putting my forms in a vacuum bag... Saves a lot of time on screwing...

[Robertfishes]

I like to put alot of screws in my forms. I use tite bond 2 glue and I just don't trust this glue by itself. Make sure your plywood is not warped, I think it would be very hard to get a straight form if you start with "crooked" wood. I try to buy my Cabinet grade birch plywood from a local cabinet shop..but I did buy some from Lowe's once.I still use forms I built in 2009 that are straight.

[Walt Francis]

Kenny,

Good idea, I will give it a try on my next form.

I always put angle iron on all my forms, never had any issues with them warping.