Text only | Text with Images

Trad Gang

Main Boards => The Bowyer's Bench => Topic started by: bsv on March 20, 2019, 11:37:41 AM

Title: bow form material
Post by: bsv on March 20, 2019, 11:37:41 AM
is mdf okay for forms I have access to all thickness at work.. Thanks Burt
Title: Re: bow form material
Post by: Flem on March 20, 2019, 12:03:10 PM
Mdf has real good compressive strength on its flat surface, not so much on the edge. I would guess if you used a stout piece of material on the assembled face, it would be OK. Hopefully somebody who uses a high pressure hose system will chime in.
Title: Re: bow form material
Post by: David Flanrey on March 20, 2019, 12:31:12 PM
I use LVL and run it through a planer or drum sander to get the thickness I want.
Title: Re: bow form material
Post by: bsv on March 20, 2019, 12:46:53 PM
My plan is the topless method I saw on here in a video,Steel plates on the sides with steel pins and mule tape with pressure hose..formica on the top of the form.we have a laser at work to make the plates. Burt
Title: Re: bow form material
Post by: bsv on March 20, 2019, 12:52:07 PM
when I think LVL I think I-beam shape,Can ya get LVL at home stores?
Title: Re: bow form material
Post by: JWheel on March 20, 2019, 02:20:10 PM
I've used 3/4" birch plywood glued n screwed together to make 1.5" thick....I think you may have problems getting formica to glue to the MDF surface.
Title: Re: bow form material
Post by: Crooked Stic on March 20, 2019, 02:57:59 PM
You are better of using LVL or 5 or 7 layer plywood. MDF not good with moisture. And I have seen pics of forms that broke under pressure.
Title: Re: bow form material
Post by: bsv on March 20, 2019, 03:26:52 PM
Thank-you I have found 2x11x8ft LVL for $47 bucks  :goldtooth: :goldtooth:
Title: Re: bow form material
Post by: monterey on March 20, 2019, 03:40:55 PM
Is the  LVL a true 2"?
Title: Re: bow form material
Post by: Crittergetter on March 20, 2019, 09:12:22 PM
I wouldn't trust mdf.
I use lvl and no complaints. I run it through the wide belt and get it down to desired thickness for both recurve and lb forms.
Title: Re: bow form material
Post by: skeaterbait on March 21, 2019, 06:23:02 AM
What is the difference between LVL and just gluing plywood together? Aside from with LVL the factory gets to worry about straightness
Title: Re: bow form material
Post by: bsv on March 21, 2019, 07:35:38 AM
It is not a true 2 inch but I will bring it down to 1.5 with Kennym"s method on his build-along
Title: Re: bow form material
Post by: Forwardhandle on March 21, 2019, 09:15:42 AM
That LVL sounds interesting I been using deminsional maple for my topless forms 2 peaces plied together perfect 1 1/2 " and face the top with .040 glass I really like the topless form now I got all the bugs worked out !
Title: Re: bow form material
Post by: bsv on March 21, 2019, 10:01:11 AM
this will be my first laminated bow but that style seems to fit me..
Title: Re: bow form material
Post by: jess stuart on March 21, 2019, 11:02:51 AM
I have several MDF forms for takedowns, made a bunch of limbs on them without issue.  I do reinforce the form with 3/8" plywood.  MDF mills very easy but does have some drawbacks, heavy, doesn't do well if wet, soft and can chip easily
I would not use it for a full length form  too heavy.  I think the LVL is the way to go, especially for a one piece form.
Title: Re: bow form material
Post by: Stagmitis on March 23, 2019, 04:47:40 PM
Every form I have ever made from LVL has twisted/warped whether using heat strips or hot box. String alignment became impossible and I tossed quite a few bows in the garbage before I figured it out. Btw, this twist is difficult to detect.  I only use cabinet grade 3/4 plywood and have had no issues since.
Text only | Text with Images