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Main Boards => The Bowyer's Bench => Topic started by: Meleon on June 07, 2016, 09:42:00 PM

Title: Pressure strip?
Post by: Meleon on June 07, 2016, 09:42:00 PM
Wondering what ya's ll use for pressure strips on the rubber band style forms?
 local big box stores in the hobby metal section only has 1/8 inch thick aluminium in the 2" wide that I need. Not sure if it flexible enough to make the bends of my recurve form. Not to mention its 15$ for 3'.

Is a pressure strip even required?
Thanks
Title: Re: Pressure strip?
Post by: KenH on June 07, 2016, 09:53:00 PM
I haven't used a pressure strip, and haven't had any problems. But my 2x4 is hair more than 1.5" wide, and the glass/lams are exactly 1.5".  Also, I use rings of bicycle innertube on through pegs at about 4" intervals, not a long "shoelace" crisscross rubber band.

You can see my setup in this post about my Scythian design:
  http://tradgang.com/noncgi/ultimatebb.php?ubb=get_topic;f=125;t=011534#000000
Title: Re: Pressure strip?
Post by: Mad Max on June 07, 2016, 10:04:00 PM
big jim has some good ones.
.040/.050 I think
Binghams are to thin.
Title: Re: Pressure strip?
Post by: mwosborn on June 07, 2016, 10:08:00 PM
Quote
Originally posted by Mark Daniel:
big jim has some good ones.
.040/.050 I think
Binghams are to thin.
x2 and they are only around 6 bucks.
Title: Re: Pressure strip?
Post by: jess stuart on June 07, 2016, 11:40:00 PM
If you don't use a pressure strip the rubber bands can put to much pressure on the limb edges causing the limbs to be cupped.  You can use something as simple as a thin piece of wood or a rubber pad to put pressure in the center of the limb, this will equalize pressure and prevent cupping.
Title: Re: Pressure strip?
Post by: bigbob2 on June 08, 2016, 01:10:00 AM
I went to plumbing supply outlet and got some strips of the relevant width of 20 gauge zinc anneal. Cost next to nothing.
Title: Re: Pressure strip?
Post by: mikkekeswick on June 08, 2016, 03:02:00 AM
Yep I use 20 gauge galvanised steel.
Title: Re: Pressure strip?
Post by: Kauz on June 08, 2016, 06:51:00 AM
Hello,
I use a cutting guide for wallpapering, made of stainless steel about 1/64" thick , 2" wide, available in different lengths (2 meters, 3 meters). It's quite flexible lengthwise, but stiff across width. I cut it to width with sheet metal scissors.
Title: Re: Pressure strip?
Post by: jess stuart on June 08, 2016, 09:42:00 AM
When using rubber bands I use a pressure strip that is not as wide as the width of the limb, this helps to put pressure on the center of the width of the limb.  For a 1.5" limb I usually use one strip about 1.125" and one about .750" wide and centered on the limb.  I have never had a problem with thick glue lines or the limbs cupping.  For the air hose method I use a metal strip the same width as my limb.
Title: Re: Pressure strip?
Post by: Carpdaddy on June 08, 2016, 01:33:00 PM
Some will remember this but this is what happened one of the times I forgot the pressure strip. One time and your a believer..
  (http://i939.photobucket.com/albums/ad238/tcj59/Next%20bow/594C36BE-45AB-4412-9772-768FAE70D98A_zps97hm7uae.jpg) (http://s939.photobucket.com/user/tcj59/media/Next%20bow/594C36BE-45AB-4412-9772-768FAE70D98A_zps97hm7uae.jpg.html)
Title: Re: Pressure strip?
Post by: Mad Max on June 08, 2016, 02:23:00 PM
It took a while to find this chart.
I used gauge steel all my life
Galvanized and steel sheet are different thickness for the same gauge, and has a max and min. thickness.

for 20 g. Galv. .0436/.0356
for me .030 esh is to thin


  (http://i1293.photobucket.com/albums/b593/osagemark/site%20window/gagechart.png) (http://s1293.photobucket.com/user/osagemark/media/site%20window/gagechart.png.html)
Title: Re: Pressure strip?
Post by: Meleon on June 08, 2016, 04:44:00 PM
Ouch that sucks. They where nice looking lams.
I've got some smooth rubber mat about 3/16 of an inch thick. I'm thinking I might cut some strips of it to use. (2, each being narrower like mentioned above)
You think that will work?
Title: Re: Pressure strip?
Post by: monterey on June 08, 2016, 05:31:00 PM
My last one off I used wood strips matching the width of the form.  I glued a 5/16" piece of polypropylene rope down the center.  Worked fine.

The next lay up will be with astrip of plexiglass about 3/16 along with the rope trick again.
Title: Re: Pressure strip?
Post by: Buemaker on June 08, 2016, 05:47:00 PM
http://tradgang.com/noncgi/ultimatebb.php?ubb=get_topic;f=125;t=012642#000000
Title: Re: Pressure strip?
Post by: monterey on June 08, 2016, 06:29:00 PM
What are "hard building plates"?   :confused:
Title: Re: Pressure strip?
Post by: passion for knowledge on June 08, 2016, 07:36:00 PM
Monterey.

You may be better off using Lexan.

A good place to pick up strips of 3/16" thick Lexan would be your local sign shop.

I know this, as I work in the sign business.

At the back of my shop there are bins full of offcut lexan.

99% chance you could pick up what you need for free, especially if you tell 'em what it's for. Seems like people think archery is cool, or something!

;-)
Title: Re: Pressure strip?
Post by: monterey on June 08, 2016, 08:45:00 PM
Thanks a bunch for that tip!   :thumbsup:
Title: Re: Pressure strip?
Post by: Krasus on June 09, 2016, 12:57:00 AM
I use 16 gauge 5052 aluminum strips.