Trad Gang

Main Boards => The Bowyer's Bench => Topic started by: skeaterbait on March 26, 2019, 07:38:25 AM

Title: Foam padding
Post by: skeaterbait on March 26, 2019, 07:38:25 AM
I have read that some of you put a strip of foam on your form, assuming over and under the bow, to help compensate for any slight gaps that could cause bad glue lines. What type of foam do you use and where do you get it?
Title: Re: Foam padding
Post by: Crooked Stic on March 26, 2019, 08:03:23 AM
I have heard of using hard rubber. I use the rubber base  board from Menards cut in strips for pressure strips. When I make a new form I fill the voids with Bondo and sand down before the formica or whatever is used on the form face.
Title: Re: Foam padding
Post by: skeaterbait on March 26, 2019, 08:19:10 AM
That makes sense, thank you.
Title: Re: Foam padding
Post by: Forwardhandle on March 26, 2019, 08:53:26 AM
I use rubber strips for with aluminum  presure strips for wood lam bows but for glass bow forms if it's not right I make it right the foam or rubber would just cover up for the form problems I would think !
Title: Re: Foam padding
Post by: Flem on March 26, 2019, 10:14:10 AM
I have used EVA foam under bamboo, to even out the pressure because of the nodes. It was the stuff backpacking pads were made of. Now I guess they would be Yoga mats. :saywhat:
Title: Re: Foam padding
Post by: skeaterbait on March 26, 2019, 11:45:07 AM
I use rubber strips for with aluminum  presure strips for wood lam bows but for glass bow forms if it's not right I make it right the foam or rubber would just cover up for the form problems I would think !

I concur with that but once I get the riser fitted perfectly to the form (using a jig and sander), then add the lams, there is always a small area that seems to need shims. The issue being that they are so slight trying to chase them down could lead to more issues than I started with.
Title: Re: Foam padding
Post by: fujimo on March 26, 2019, 01:07:39 PM
when using a topless form, and rubber bands, for making boo backed bows, i took a strip of the hard insulation styrofoam, cut it the width of the form and about an inch thick.
i took a piece of wooden broom handle- wrapped some 60 griot around it, and quickly sanded a depression in the surface to match the boo.
lay up the bow, some saran wrap, then the styrofoam, then my backing strip, (which was a wood strip, slightly trapezoid shape- in order to spread the load right across the width of the bow evenly- i guess a half round piece of housing trim 1.5" wide would also do well).
 then the rubber bands.
the foam would pull down nice and evenly onto the boo- and get crushed/ depressed in perfectly at the nodes- and would apply great, even pressure over the entire boo surface.

the foam was not reusable- but a piece of foam goes a really long way!!
Title: Re: Foam padding
Post by: Bvas on March 26, 2019, 03:26:31 PM
I use rubber strips for with aluminum  presure strips for wood lam bows but for glass bow forms if it's not right I make it right the foam or rubber would just cover up for the form problems I would think !

I concur with that but once I get the riser fitted perfectly to the form (using a jig and sander), then add the lams, there is always a small area that seems to need shims. The issue being that they are so slight trying to chase them down could lead to more issues than I started with.

Lonnie, you should fit the riser with the back glass and lams in place.

But I’ve also been known to cheat :saywhat:  If I have a small isolated gap, I will put a piece of masking tape on the form where the gap is. If one piece of tape won’t do it, I keep sanding. But I have never been able to notice the spot where tape was used to fill the void.
Title: Re: Foam padding
Post by: JWheel on March 26, 2019, 03:27:17 PM
I've tried the yoga mat also but I wasn't convinced they helped much because the compress so much. I think I know what you're talking about when you say "rubber" strips...I've seen several Youtube videos where it looks like they use bout a 1/4" thick strip with a stiffer rubber density. It seems like it would even out low and high pressure spots during clamping but I've yet to find what I imagine it to be. Its definitely doesn't look like a foam....you got me interested now, I shall begin a search again...haha
Title: Re: Foam padding
Post by: Mark R on March 26, 2019, 03:38:49 PM
If its only a mini hint of lite I use masking tape build up as necessary, and for padding you can use double sided carpet tape and cork board.
Title: Re: Foam padding
Post by: Forwardhandle on March 26, 2019, 04:39:12 PM
I always put all the lams glass,carbon every thing that's under the riser then I tape 80 grit to the lams and scribe pencil lines on the bottom of the riser and shimmy the riser back and forth 1/4 " of center line it will rub the pencil off in the high spots and re grind tell it's snug ! It always works for me but I can run out of patients some days !