A question for rubber band form users

[monterey]

I'm thinking of going to rubber bands on my LB forms and wonder what the options are for bands?  I see that bike tubes are mentioned but wonder about using automotive or truck tubes.

any and all suggestions on rubber band forms welcomed!

[Wolftrail]

I'm using an open type form with rubber tubes from an old bike.  I can get more than enough pressure using these tubes and never broke one yet. I find that you can get a good even uniform clamp with rubber . There is no looking back..........  

[breazyears]

If you have a local bike shop, they will most likely give you tubes that are no good.
 Every tube that I have got has 4 equally spaced lines running down the length of the tube, This makes cutting them into strips foolproof.
 I too have had nothing but success using tire tubes. However I have found that they can only be used once, as they tend to get covered in glue.
 When using them... have a staple gun handy. When the glue gets on them they become slippery and hard to tie off, I like to wrap the last bit of the length around a peg a couple of times, then staple it to the form.
 I use claps on the riser section.

[Nicon]

I use automotive tubes. They seem to be same thickness as bike tubes, but you get 10x more strips from car tube.
Rubber band form needs a pressure strip with a convex top. Bands tend to apply more pressure at the edges. I forgot to use a pressure strip once and the center of the limb was 1/16 thicker than the edges.

[KenH]

I use bike bands as round rubber bands about 1" wide, not long strips.  My forms have 1/4" dowels set transversely every 2" along the line of the bow and 3/4" down from the edge.  I get more than enough pressure that way for a good glue-up.  

I'm at a public computer right now, but will post a picture later today. But you can see one of my forms about 3/4 down this discussion of a Scythian style bow I recently completed:
  http://tradgang.com/noncgi/ultimatebb.php?ubb=get_topic;f=125;t=011534#000004  

I get all my tubes free from local bike shops just for the asking.  When I need a longer band at a riser, for example, I just loop two of my regular bands together and wrap off any excess band on the dowel.

A central pressure strip is an important addition, especially near the ends of radical recurves.  Otherwise the bands may cause the glue up to compress across the line of the limb forming a cup shaped end.  Luckily the first time it happened to me I was making a bow with pin nocks not side nocks and the curvature was cut away in the making of the pin nocks.

  [/url] [/IMG]

[monterey]

Ok, based on the great input received, am starting the process.  Am making up convex pressure strips and plan to steam bend them on a form that matches the riser fades.  Also have a handful of 7/16 dowel stock at the ready waiting for the form to be drilled.  

next a scavenger hunt for tubes.  Will look first for bike tubes and go to auto if necessary.

should I plan to use my thin metal pressure strips under the wood convex ones?

[breazyears]

Yes. Use the convex on top of your pressure strips.

[JamesV]

Most tire stores have tubes from tractor trailer or farm tractor tubes that are bad and will give you one. start down the center of the tube and spiral cut the tube 1 1/2" wide. One half a tube will give you over 100Ft X 1 1/2" piece

[monterey]

1.5" seems pretty wide.  Would 1" be effective?

[JamesV]

After 50 or so bows the rubber will be streached and  narrower. I double lace my bows to the form under a lot of pressure. I also spiral wrap the bow in 3 layers of streach wrap as tight as I can without breaking the streach wrap, this keeps everything from slipping after glue-up.

[monterey]

I like the stretch wrap idea!  Never occured to me and would not have without your mention.