backing strength of burlap.

[Mafort]

going to a fair and manning an archery booth in charlestown indiana. they Asked me to build the bows for the range. my question comes due to safety with the bows themselves. how strong is a burlap backing on a red oak board with good grain orientation and proper tiller? i planned on doing three layers for the backing considering i was unaware of the strength of burlap glued with titebond but i didnt want to bog the bows down too badly. These bows are going to be no more powerful than 30lbs @28.

[Eric Krewson]

I can't answer your question on backing because I don't have any experience with burlap.

I have a friend who mans an archery booth at a local SCA fair, he makes board bows for attendees to shoot, all of the adult bows are 6' long and low poundage. He makes the bows long on purpose, to stress the limbs less when a variety of people of all sizes step up to shoot them. He had much shorter bows for the small kids to shoot.

I made a lot of kids bows over the years, I bamboo backed every one of them for the safety factor and to prevent future lawsuits, just in case.

[Pat B]

Burlap is ok for a backing but there are better options IMO, and 3 layers is too much. That many layers will add too much excess physical weight only slowing the bows cast. Most soft backings are only good to help prevent a splinter from lifting, they won't prevent a break. If burlap is all you have, one layer is enough. Be sure you saturate the burlap well.
 Brown grocery bag paper is another option and will add less physical weight to the bow.

[Mafort]

Burlap is ok for a backing but there are better options IMO, and 3 layers is too much. That many layers will add too much excess physical weight only slowing the bows cast. Most soft backings are only good to help prevent a splinter from lifting, they won't prevent a break. If burlap is all you have, one layer is enough. Be sure you saturate the burlap well.
 Brown grocery bag paper is another option and will add less physical weight to the bow.

When you say saturate do you soak with water before applying the glue and onto the bow?

[bjrogg]

Wish Jawge was here.

I can’t really offer much advice but another option is silk ties, linen cloth. I haven’t tried any of them but I have seen a very sharp Osage that was backed with fabric with a nice pattern.

I’d second PatB. I would think three layers would add a lot of mass and really slow down your bow.

Like Eric says length is a friend when it comes to a bunch of different people who probably have never even drawn a wood bow before.

I guess the only backing I have used was rawhide and it needed to be rehydrated to make it flexible. Then I removed excess water with a towel. Then I put a liberal coat of straight wood glue on both the back of the bow and one side of rawhide. Then put the rawhide on the back of bow and rubbed the bubbles out. It is a pretty messy process that you might not want to do in your wife’s kitchen.

I would think that the burlap would be flexible enough without adding water. But I have never tried it

Bjrogg

[Pat B]

You could add water to allow the glue to soak into the burlap but remove most of the water so you don't dilute the glue, add glue to the back of the bow lay the burlap down and saturate the burlap with glue. Let this dry completely, maybe 24 hours to be sure before straining the bow.

[JW_Halverson]

On some of my early hickory board bows I backed them with 6 oz cotton canvas. I coated the limbs of the bow liberally with TBII or III, then used a rubber kitchen spatula to spread the unadulterated glue over the canvas strips. The first strokes were to lightly spread it across the fabric, but then I followed with firm strokes to wipe off excess glue and push it down into the weave of the fabric.

Immediately lay onto the limbs, clamp in the middle of the handle, and use your thumbs to press the fabric tight to the back of the bow. Squeeze excess glue down the limb and over the sides. Have a bucket of hot water and a little dish soap on hand, as well as an old bath towel. Keep a wet washcloth handy to wipe up excess glue as you go. Plunge your hands in the bucket of wash water often and quickly wash off the glue.

Easy peasy, messy as heck, clean up as you go.

[legend]

One question I would like to ask about a thin Linnen backing . Is it best to fix the backing on the limbs in the normal unbent bow or when the limbs are bent when the bow is strung ?

[bjrogg]

Apply your backing to unbraced bow.

Bjrogg

[legend]

Thanks for that answer bjrogg .

[Pat B]

Yes, the unbraced bow. You want the backing to put pressure on the bows back as you draw, holding down the wood fibers helping to prevent splinters from lifting.
 

[legend]

Thanks Pat . So by clamping the handle section down and slightly raising the tips into slight recurve as some others suggest , and then applying the backing might work also ?

[Pat B]

Yes. I have read that folks do that with silk backing. It put the backing in tension as the bow is relaxed. Bue sure the glue is completely before you mess with it though. What glue are you using?

[legend]

I will be definitely using Titebond 2 or possibly 3

[legend]

I have some really nice quality natural coloured  Linnen ribbon ( not rough looking like burlap ) which is relatively thin but strong and the exact width  of the widest part of my bow 1.5" , so Im hoping it will make a good neat and clean lookin job.