First long bow and a lot of questions.... :)

[DelawareDave]

I now have my first longbow in a rough shooting condition. Its made from a red oak board backed with a sheet of fiberglass fabric and epoxy.  69" knock to knock, and roughly 1 1/2 wide.  I was going for 45-50 lbs. draw weight but ended up at about 32 lbs..... :/ Witch brings me to my first question.  If I add another sheet or two of fiberglass fabric to the backing would that raise the draw weight and roughly how much?  Also my "set" right after d-stringing is 3.5" then 2.5" after a few min, is that a little excessive? and brings me to my next question if/when i add more fiberglass fabric can i clamp the bow strait are even a little re-flex?  would that help or hurt the bow?  thanks in advance

   

[Nim-rod]

I tried that fiberglass cloth backing thing before but it always ended up in the bow exploding. It is so tension strong that it overwhelms the belly and kapaow. Yours is on the light side so not sure if it will react the same. If anyhting I would think it would make the bow really sluggish.

[milehi101]

I have added glass to both sides of a week bow and it is still shooting and I did it a couple of years ago. I used the 2 inch tape available at places that sell fiberglass products.  I also used the West System slow dry epoxy system resin to attach the cloth and to smooth it. I then did the bow in camo.

[red hill]

Will your draw length allow for shortening the bow? Piking, or shortening, will add a few pounds.

As Nim-rod pointed out, the fiberglass will over-power the red oak. The experiences I've had with red oak board bows indicates excessive set. I learned on here that I was over-exercising the limbs which can lead to excessive set.

[DelawareDave]

Yes my draw length is only 29" so i could shorten the bow a few inches.  How much should i start with maybe 2" on each end?  also by over-exercising the limbs im guessing u mean i bent them to far to quick when i was tillering them?

[4est trekker]

Congrats on the first bow!  You're hooked now.  Here's some things that may help answer your questions:

There are two types of backings for wooden bows: those that add performance and those that insurance.  Those that add performance (e.g. hickory, bamboo, and sinew) will also allow for the induction of relfex and glue-up.  Those that add insurance (e.g. rawhide, paper, fiberglass tape) cannot be used to induce reflex or correct set.  Further, you generally only want to use one layer of these types of backings.  Imagine a tree having two layer of bark, where is along for the ride and will eventually give way.  I've seen too many bows ruined by adding two and three layers of fiberglass tape where one would be sufficient.

Now, in terms of your bow:  Red oak and fiberglass don't mix particularly well.  Red oak is not all that strong in compression and can be easily overpowered by a fiberglass, bamboo, hickory, or similar backing (all of which are incredibly strong in tension).  Without seeing more pictures, it looks like your bow is not doing a lot of work in the inner half of each limb.  This causes undue set in the outer portions of the limbs.  Generally 2" of less of set is a standard margin to work within for wooden bows.  Tillering past your draw weight, draw length, and/or profile problems can all lead to undue set, as can design (width, thickness, backing, length, belly profile, etc.).  

If I were you, I'd toss this one up to a successful beginning.  Get yourself another board/stave and make some shavings.  With a bow that is clearly stressed at 69" with your 29" draw, I wouldn't pike (shorten) it to gain weight.  You're liable to wind a 38 pound bow that shoots like a 25# bow if you do.

Build red oak bows flat and wide.  They make great pyramid bows.  Here's a link to a build-along I did of a simple red oak pyramid style:

 http://tradgang.com/noncgi/ultimatebb.php?ubb=get_topic;f=2;t=000122


Also, here's a couple pictures of a red oak pyramid bow that was heat treated and pampered during the tillering process.  It's also backed with butcher paper.  It's dead flat unbraced, but still took 1.5" of set.  That is, it started with 1.5" of reflex and settled to flat.  Thus, this bow has zero string follow with 1.5" of set.  Hope that makes sense  

 

 

[DVSHUNTER]

Nice job on your first bow. Mine came in at about that weight too.  Make another. 4est gave great advice as well. Keep on building.

[DelawareDave]

Thanks you very much for all the help.  I am definitely hooked on bow building!     I'm already planning my next two bows, and thinking about everyone i can build bows for.    

[razorback]

I live by the mantra, "weaklings need bows too"    I've supplied a lot of "weaklings" bows. That looks good for a first time bow. I have found with red oak that I need to leave more wood than I thought. You are on the right track and do one of 4est's pyramid bows. He, along with many others will offer you great advice, listen to all of it. Some may contradict each other, though that is just because there are so many ways to build a good bow. Get some practice and join the bow swap next year.
Good shavings.

[monterey]

I would shorten it up an inch at a time till you get where you want to be.  Now, just going by the pic, but it looks like it might be a bit whip ended.  The camera angle and lens could easily be the cause of what I'm seeing though.

[red hill]

Dave, what I meant by "over exercising" is when you pull the bow an excessive number of times on the tiller tree during the tiller process.  I was pulling between 50-70 times after each scrape session. By the time I'd finished tillering a bow it had been pulled until it was worn out!