Form trouble

[NYArrow]

Yesterday I started a HBO. I used 1/8" hick backing and 5/8" osage both 2" wide x 72" long. I was using a form from the PA forum. The form is laid out for a R/D bow with 1 1/2" of deflex and 2" reflex. This is measured from the handle. Total difference between midlimb blocks and tip blocks is 4". I roughed up my glue faces with a hack saw blade, cleaned down with denatured and applied epoxy. I then ensured all was lined up and began clamping. As you can see in the pic all went well except actually getting the wood to lay down on my deflex blocks. The force it took to get it down was so much I feared breaking so I stopped where you can now see. In the end I got about 1/4" of deflex and 2" of reflex. Hope it works out ok. For those that have made it this far in my post...I assume in this case I should have hand placed my reflex tips after clamping the handle and midlimb area. Is that what you guys do? It seemed like too much force on the wood to just clamp down as is. Or was the osage core of 5//8" too much to begin with?
 
 

 

[NYArrow]

Pictures didn't show in first post...

     

   
   

[Pat B]

Did you do a dry run with the lams and no glue to see how it would work first before glue up?  You said you used epoxy. What kind of epoxy did you use?

[Don Armstrong]

I normally get the bow tillered and then glue R/D in. If you just tried to glue a backing on a 5/8" board,I could see a problem getting it clamped down. I have only made 4 with R/D glued in so other methods would probably work.  Don

[Walt Francis]

I had the same problem with BBO and BBI’s so I started cutting my belly material then sending it through the thickness sander.  I turn them into a tri-lamb bow, but they hold their profile through tillering really well.  

Don, can you elaborate on your pre tillering process, it might wor better then what I have been doing.

[NYArrow]

I didn't do a dry run...obviously should have. I just assumed it wouldn't be a problem getting it to lay down. I used bow grip 100 two part epoxy.

[macbow]

2" wide the entire length is a lot of wood to bend.
I use bamboo usually but the hickory backing I treat the same way. I cut out the bows profile on the Osage, usually about 1 1/4 to 1 1/2 wide at the fades down to 1/2 inch wide at the tips. Then trace the backing from this and cut it down. Then the dry run and glue up.

Should be no problem finishing yours. It may end up with a little string follow when finished but that isn't a problem.
Ron

[Don Armstrong]

Walt, I start the bow just like I'm doing a normal self bow. Cut profile, glue handle on, taper with band saw. Start tillering till I get limbs bending about the same and then glue up. I draw the bow outline on my backing and cut out before gluing up, also. I have tillered a couple that I thought would be under weight, but after adding a hickory backing,I had to take weight off. I think Pat and osage does something along these lines. Someone on here suggested to do it like this. Don

[NYArrow]

Mac and Don both great ideas. The key I guess is cutting out the profile. It is a lot of wood to force into that shape.

[Don Armstrong]

It also makes tillering much easier, I think. I also think the R/D tends to hold better.  Don

[Roy from Pa]

2 inches wide is a lot of osage to bend. I cut my actual bow shape out of the boo and center the boo  on the wood and clamp it down. Then trace out the outline of the boo onto the wood. Then I cut 1/8 inch outside of that line on the bow wood. Bends a lot easier. I also start with 1/2 thick osage and taper it down to 3/8th at the tips.

 

[SEMO_HUNTER]

Man, look at all those bow blanks on the wall to the right of the bench!
Those are bow blanks aren't they Roy? Or rejects?

Sorry, off topic and I don't know anything about forms yet. I'm still working on building my first caul.
Good luck Dustin, I hope you get it figured out.

[Walt Francis]

Don, Thanks for the info.
Are you putting any deflex into the handle section or are you gluing on a straight handle?

Roy,
The method you use is close to the one I used in the past, I just had problems with the bows holding deflex near the handle when they came off the form.

[NYArrow]

Also just a little FYI, if you notice the center ratchet clamp. I purchased it and another from Harbor Freight and they are useless. The first time I attempt to ratchet down on something they gave way and are now junk.