epoxy question

[Stick Bender]

Jeff make sure its smooth on EA-40 as the also make mold making material !

[upstatenybowyer]

Thanks SB. I made sure. 

[Bayou Ben]

I use uni bond 800.  It's a do it all glue in all wood applications.  It's cheaper than smooth on and cures fine @ 70 deg and above.  It's gap filling which is nice with spliced bows and laminates in general.  It doesn't have a great shelf life, but if you keep it in the refrigerator it will last a year if not longer.  I've heard good things about smooth on but never tried it. 
I've used weld wood resin too with good results, and that stuff is cheap (you can get it on amazon).  But it did start to clump up on me in a couple months and I could only get it in the dark brown color. 
 

[GlisGlis]

just a couple suggestions
do not thrust the cure time table.
your epoxy may be hard and workable but you will get the best performances after a significant amount of time.
It's a good idea to let your bonded pieces rest for at least a couple of days in a hot place.
Wrap it in black plastic bag and put in your car exposed to sun. 100F or more is best.


Be paranoid while mixing the two epoxy parts. that would make a great difference between a decent and an excellent bond.
Check the curing time and plan a solid mixing before use
 

[bubby]

With smooth on you can go up to two to one for a stronger mix, I've never done it but you can weight the mix on a digital scale to get your 50/50 mix. I have gone two to one before with zero problems but it won't last as long as going 50/50

[GlisGlis]

I was referring more at the care you put while blending the components than the ratio.

[bubby]

Yeah but you need the ratio right as well. I get mine all clamped to my caul and stick it in the cap of my truck, gets 125-130 easy here. I also wrap it with stretch wrap first then use my innertubes

[TorstenT]

I also wrap it with stretch wrap first then use my innertubes

Please excuse me, but what do you mean by ‘innertubes’?
The first thing that came to my mind would mean a constant 98 degrees, but sounds rather painful... 
(Just kidding, of course.. ..since English in not my native language, my vocabulary is very limited.)

[Aaron H]

Bicycle tubes

[bubby]

I use bicycle innertubes for stretch clamps, lots of guys do. Easy to get a consistent pressure on the bow when gluing up a lam, like a hickory backed ipe

[TorstenT]

Ah - I see... 
Do you just wrap the whole tubes around the limb or do you cut them open lengthwise first to get a wider strip?

[Pat B]

I cut the valve out and split the tube in half, lengthwise. I use it to wrap the pieces to be bonded. For a backed bow I use 1 half for each limb.  I also use rubber bands for holding tip overlays after gluing. I get good, even glue lines and no dry spots that can happen with screw clamps and some other methods of clamping. I doubt you could wrap with tube bands too tightly to adversely affect the glue joint.

[upstatenybowyer]

If your doing the glue-up on a caul, do you just wrap the tubes around caul and the bow?

[DC]

I do the wrap first, just around the bow and then bend it into shape on the caul. There is enough slip in the epoxy to allow it to conform. You might have trouble with this if you're using TB whatever, it grabs pretty quick.

[bubby]

I just cut the stem area out, I don't split the tubes, and I wrap around the caul, or at least to the caul. I wrap the bow with stretch wrap and this is two fold. It keeps everything where it is supposed to be, and keeps the epoxy off everything, the tubes the caul, any clamps you use, the seat in the truck when I hotbox it. You can also see the glue moving in the jointi wrap one limb both ways making a cross pattern then do the other limb. Make sure if you use a flat backer like a hickory strip lay a piece narrower than the bow down the center, then wrap the tubes, this keeps the backer from cupping if it gets too much edge pressure