Hello all.

After a few months of research and waiting for the fiberglass to arrive, I'm finally starting my first glass bow. As in the title, it'll be a 60" KennyM style. I have the form ready and already started working on the riser. I glued about 10 laminations using Elmer's carpenter's glue, then I'll grind it to shape and feather the fades.


Since I lack a lam griner (I'll get one in the future) I've made my lams with a planer and orbital sander and they came out pretty good. I'm shooting for a 40# bow so the stack should be 0.315". Converted to mm (easier for my to use) it's 8.04mm.

The glass I got is Bearpaw Powerglass, 0.8mm thick, 38mm wide. I have 1 parallel maple lam, 3.4mm thick. 1 tapered maple lam, tapering from 3mm to 1.6mm. That makes it about 8mm of total stack, which brings me pretty close. In edition, I'll use 8" long tip wedge made out of Ipe , about 3mm at the thickest point.

I plan on gluing the lams in the following order (back to belly):
Glass
Parallel+tip wedge
Riser
Tapered
Glass

That's it for now, I'll keep you posted on my progress. On the meantime, I'd like to know what you think.

Thanks,
Dor

Form with the riser clamped while the glue dries:
 

Parallel Lam:
   

Tapered Lams and tip wedges:
 

Tip wedge close up:
 

I like that riser glue up idea.Form fitting for sure.

I've been trying to find out where to get plans for a KennyM R/D. Can you point me in the right direction? Thanks!

Just contact KennyM here. Use the message system.

KennyM's form plans:
http://tradgang.com/cgi-bin/ultimatebb.cgi?ubb=print_topic;f=125;t=011684

By the way, I'll be using the rope and wedges method for keeping pressure. So if someone has good experience with it, I'd like to know how to use it right.

Are you using epoxy for the bow glue up? Glass and wood glue don't work too well, I hear. Never done it.

Next thing is if gluing the riser with wood glue, don't want too much heat curing the epoxy. It kills the wood glue at ? temp.

Like your riser plan for glue up!!

Oh damn! Haven't thought that through... Heat can cause the riser to delaminate!

I only got the smooth-on in the mail today, that's why I used wood glue for the riser... For the glass, I'll use epoxy for sure..

Any idea how to avoid riser delamination? (I guess I can cure the epoxy at room temperature, but I rather use heat. Maybe concentrate the heat on the limbs only?)

I think I would research the wood glue and see if I could find the max heat it will take and then only heat the whole bow to somewhat less than that. Smoothon is supposed to be good with room temp heat so if necessary that is what I would do, or make a new riser...

You can cure the epoxy at room temp. I've done about a dozen bows that way without any issues. One of my personal bows has around 30,000 shots ( estimated) thru it so far.

Ok... That's relaxing.. I've read that heat curing cause the epoxy to have more heat resistance, lowering the risk of delamination if left in a car or in a hot climate. Since I live in Israel and the summer can get pretty hot (at 35-37 degrees Celsius), I hope I won't have any issues.

Next time Put half of the stack for the back of the bow on the form add plastic rap and then glue the riser on top of that.

QuoteOriginally posted by Mad Max:
Next time Put half of the stack for the back of the bow on the form add plastic rap and then glue the riser on top of that.

This!..    Good Advice from Max...

QuoteOriginally posted by Mad Max:
Next time Put half of the stack for the back of the bow on the form add plastic rap and then glue the riser on top of that.

Good thinking Max. Probably get a better fit that way.

I would cure the riser parts at room temp. then it will get the heat on normal layup using smooth-on. And the half the stack idea is a good one.

Great advices so far.
The lable on the EA-40 can says that the mix ratio is 1A:1:B and that the curing time is 24hr at 23*C.
HOWEVER, the label also says that by mixing 2A:1B by volume, "EA-40 will achive greater heat resistance and improved physical properties".

Anyone tried it? Is it also true when  curing the 2A:1B mixat room temperature?

And while were at it, how much glue do I need for my bow (4 60" laminations + riser)? this stuff is pretty expensive and I don`t want to waste it...

If you have more wood you could glue up a new riser with the Smooth on..the smooth on is the right glue for building glass backed bows..I don't know about the wood glue? But I have read some where it could delam arround 145 degrees F or 62 degrees Celsius. I know you pay alot for materials and Glue..As far as cost goes it would be cheaper to build this bow once..it only costs $10-20 to make a new riser with smooth on..cheaper than having to buy one piece of fiberglass.

Oh, glad you finnaly got the glass and smooth on! We are so lucky here in the States to have the bow building materials close by.. I have only used 1:1 myself or 1.25:1, I use small 2 or 3 oz disposable plastic cups to measure parts by volume

For a 4 lam HH style bow I use 70 grams part A to 50 grams part B. I also don't use heat on riser but do 'cook' bow to 60 c for 8 hours.

A little more resin than hardner is good. some do go 2-1. Another thing I do now days is leave the parts under pressure for 2-3 hours before putting in the heat box. I feel all the bubbles etc. can get out before they may be trapped with getting things hot too quick.