Form Materials ?

[Forwardhandle]

Hi Fellas I know this topic has been posted before but figured I would asked, I went shopping for form material today for a Kennym form and hit some of the big box stores and started checking some of the so called true thickness numbers and they varied grately ,at any rate with any of them looks like I will need to drum sand the form quite a bit to get to 1 1/2 in. I dont have a problem with that but just time consuming, I was curious what every body else found for form material , I found some clear pine strait as a arrow and dead on the money it would make things a lot easer but herd it was a no,no ?

[T Folts]

I picked up LVL beams from a lumberyard. I ended up running them thru a planner. Then I sealed them after I made the form shape.
Look for dense stuff, not all are equal.
I looked a Menards but they felt weak/light.

Terry

[Pat B]

I use dimensional lumber(2x4,2x6) for forms.

[Crooked Stic]

3/4 1/2 and 3/8 plywood gets you real close to 1 1/2. Maybe a 1/16 over. The 3/8s may be hard to find though.

[Forwardhandle]

Im limited by what I can get local so Im ether going with ply wood & drum sanding to thickness or the clear pine and laminating 2  ,3/4  boards together but not sure how stable that would be hot box wise any body have thoughts on it I used it in my laundry room for cabinet facing and its been pretty stable for years ?

Go with plywood...  definitely...  My latest form I used 2- 3/4" plywood and two layers of Ram construction paper in between... You can it at Lowes or Home Depot...  I forget which one...  It is heavey duty paper made to lay on floors so they don't get damaged during construction... The paper will not sand evenly with the wood so I coated the edges with two coats of Polyurethane and it sanded even...  I know what you are all thinking...  Paper..??? We will see if it holds up...  I do not think that there will be a problem...  Just make sure you get glue right on the edges where you are gonna cut...  You should do that any way...  I will keep you all informed if there is failure in the future...

[monterey]

I have done something similar to Shredd.  For a 1.5" form, two pieces of 3/4" plywood with two pieces of roofing felt between to get a true 1.5".

The paper is probably a better solution but I have the roofing felt on hand.  

Whatever you use, measure all the components to be sure you will land on the width you are after.

I've wondered about the true dimension pine boards to.  It would simplify things. If you try it, please report back.

[Forwardhandle]

In the book american long bow I think Graff is the author he claims laminating the pine is more stable then the ply wood  I could give it a try and if it doesn't work out  cut it up for somthing else  I could hot box it prior to using it to make sure its stable .

[C. Johnson]

The 3/4" plywood sold around here is actually .688". Two pieces of that with a piece of 3/16 tempered hardboard in between will give you a full 1 1/2.

Also, though it's more money, the birch or other cabinet grade plywood is a full 3/4. (or 1/2)

[Forwardhandle]

Most of the better grade 3/4 plywood around here is 0.703 or there abouts  but I need to meausure all of them even some of the actual numbers on the tags are wrong  !

If you want your form to be super stable and purty at the same time...  You could also put some formica on it to make up the difference... I have seen one of the guys on another forum do this...

[Forwardhandle]

I'm leaning towards trying the pine I could joint some hard wood batten  strips  to screw to the sides making sure every thing is dead strait  I would be suprised if the form would have any alignment movement after laminating the pine and screwing the batten strips on  I bought the laminating press kit from Binghams and it has the Formica  top strip but that's a good idea Shredd for the side formica if you went that route,  I guess there is a lot of ways to skin the cat. just trying to take the path of less resitense.

[Forwardhandle]

Well went out and got the pine today the only down side so far is the cost is a bit more then the ply ! [/IMG]

[Forwardhandle]

[Forwardhandle]

[Crittergetter]

I just built a new form for a 64” bow with lvl. So far I really like it.
Starting another one for a new twist on my current limb design on my 3 piece this weekend. I’ll use lvl on this one also.

[Forwardhandle]

I was looking for the lvl beams here locally I didn't see any I think the clear pine will work out and simplify the width issue I'm starting the form next week end will see !