Epoxy question

[DC]

Has anyone used West Systems G-Flex Epoxy? I called West Systems and he suggested that it would be the best of their product line for archery. As the name suggests it is flexible, it stretches 33% if I'm reading this chart right.
http://www.westsystem.com/ss/typical-physical-properties/

I've been using their 105/206 because I had a bunch left over from boat building. I've had no problems with it but I'm just about out of it and if I have to replace it I thought i would look around. I haven't found a source for Smooth-on up here(so far).

[PatM]

It is excellent. You can also get G2 by System Three at Lee Valley Tools.  I really like the System Three Gel Magic as well. Many of these are available a boat building suppliers.

[DC]

Thanks Pat. I've also used G2 in model boat building and it worked well there. I just wasn't sure it would take the bending. I'm beginning to think that anything that doesn't come in a double tube is probably good

[PatM]

 System Three recommends G2 as a bowmaking and lamination epoxy.

[DC]

I'll probably use G2 then, that 33% stretch scares me. Completely groundless but it just doesn't seem right. I've always thickened my epoxy with Cabosil when I'm using it for glue. I'll have to see if I can find anything about it's effects.

[ravenbeak]

Hey.

I have used a bunch of those.

Used a lot of g2 and really liked it.  It seemed pretty thick and less likely to run.  I did find you really needed to give it the full 24 to 48 hours as it set slow.
I then switched over to cold cure and liked it better.   Bit thinner when mixed.

Recently switched to west.  105 206 and really like it.  The. Pumps are so handy. I don't miss having to use the scale. 

Next time. I think I will buy the bigger jugs of 105 206

Cheers

[DC]

I have the pumps. They are handy. One shot is enough for one bow

[kiwijim]

I'm a big fan of West 105/206
It has better 'wet out' than Smooth On. When you the compare datasheets, West is significantly stronger. Also, when cured at 60 celcius west has the same heat deformation temp as smooth on cured at 80 celcius. Basically it is a better glue. It is runny though. I let it gel slightly before clamping so I don't squeeze it all out.

[willie]

I kind of like the wet out properties of the thinner resins. From the specs I have researched with systemthree, it seems thicker formulations all weaken the strength somehow. I have also found the adhesives to be slower curing to reach the same strength. Stretch properties may not necessarily be bad, it's the creep spec I would look closely at. cabosil is a good thickener, but at the expense of making the mixture more brittle than just straight epoxy.

I let it gel slightly before clamping so I don't squeeze it all out.

+1

[Hamish]

Historically the strongest wood glues for bowmaking were those with rigid glue lines, like urac and resorcinol. The most stressed point on a wooden bow glue join is at the dip area, and a flexible glue line can break down there, resulting in a lift or even the handle popping off. I only use proven glues on this area eg bowmakers epoxy, urac, resorcinol. Titebond 3 can fail, so can epoxies with a flexible glue line.

Full length laminations , ie back,core, and belly are much safer as the ends of the glue line are only exposed near the tips.
A more flexible glue line can safely work there.  Titebond 3, is my glue of choice. It is waterproof, cheap and does an excellent job there. Most decent epoxies will work too.

[Stoner]

I used G2 on a handle that failed when I moved from MI. to AZ. I liked it because of the non critical mix. Also used the west system on risers without any issues. Now I'll have to check into this flex west system. John

[mikekeswick]

Historically the strongest wood glues for bowmaking were those with rigid glue lines, like urac and resorcinol. The most stressed point on a wooden bow glue join is at the dip area, and a flexible glue line can break down there, resulting in a lift or even the handle popping off. I only use proven glues on this area eg bowmakers epoxy, urac, resorcinol. Titebond 3 can fail, so can epoxies with a flexible glue line.

Full length laminations , ie back,core, and belly are much safer as the ends of the glue line are only exposed near the tips.
A more flexible glue line can safely work there.  Titebond 3, is my glue of choice. It is waterproof, cheap and does an excellent job there. Most decent epoxies will work too.

x2