Other than EA 40 ?

[m&m]

What other epoxy glues besides Smooth On have been used successfully in fiberglass wood laminate bows.

[onetone]

I have used G-2 from SystemThree for years. No problems.

[Jon Lipovac]

Man, I'm a big fan of Huntsmans. I get it from Mike at Rosewood Archery. Easy to mix and you can apply it with a thin foam roller.
What I like about it:
-More efficient use of the product
-Easy and fast application
-Consistent results
-I keep it inside the house before use, so it is the same viscosity every time. I think that helps with original tiller. I'm never off more than 1/8" tiller first time I string a bow.

The ratio is 100/42. I simply divide my total desired amount for a glue up by 142 and I've got my numbers for weighing it out.
65g total / 142 = 0.457
I then weigh out 46g resin & 19g hardner.

[m&m]

So is heat box required with these or you just glueing clamping and letting it cure ?

[Jon Lipovac]

To my knowledge, none of these epoxy’s ‘need’ to be cured in a hot box. It just takes a day or two to cure at 70* I’m guessing.
But a hot box at 120-130 degrees will have you cured in 1-3 hrs

[onetone]

G-2 does not require a hot box. It will cure completely at 70F and the higher the temp. the faster the cure.

[Buemaker]

Jon and onetone, what grit abrasive paper to you grind your lams with when using these epoxies, and is it necessary to mix in any fillers to make them thicker? One more, is the shelflife longer than EA 40? Thanks.

[Jon Lipovac]

Bue, I grind my laminations with 40 or 50 grit as I’ve seen 36 grit scratches under clear glass on some veneers. Then anything from 36-80 on overlays and 80 on tips overlays. Never felt like I needed a filler.


Not sure about shelf life comparison . I am gonna start using Kirk’s idea with the cauk tubes, in theory, the shelf life should be greatly extended.

[mmattockx]

Jon and onetone, what grit abrasive paper to you grind your lams with when using these epoxies

All of the epoxy manufacturers will provide recommendations on surface prep if you check their sites. Of course, that doesn't mean people will follow it... EA40 recommends 120 grit for prep and I doubt anyone here goes finer than maybe 60 grit at most, most are probably around 40 grit and it seems to work fine.


Mark

[Longcruise]

The sys 3 site says six months after opening for the G2

[onetone]

Bue - I use 60 grit for surfacing lams. I have never used filler, thinking that it would add to limb mass.

G-2 is lighter viscosity than EA-40 but I still use a notched putty knife for application. Used a feather file, like those used to sharpen Japanese saw blades, to notch the blade. The notches leave enough epoxy in place that there is some squeeze-out but it is minimal. The photo is of the knife I use for the narrow limbs on horse bows. Have wider ones for other bows.

In my experience, I think System Three is offering a conservative estimate of the shelf life. I have used it past a year without any issue.

[Buemaker]

Okay and thank you. I have been using 40 grit for EA 40, but wondered if you used different grits for the other epoxies.

[Mad Max]

I still use a notched putty knife for application. Used a feather file, like those used to sharpen Japanese saw blades, to notch the

I do it the same as you

[Noah70]

I‘ve used the G2 for many years, mostly for risers and overlays, due to its superior bond with oily exotics. I once ordered too much, had it over 1 year, and the resin (but not the hardener) went cloudy and granular. I thought it was scrap, but on a hunch I immersed it in warm water overnight and it was back to normal 24 hours later.  Worked fine with no issues going forward. 

[Stagmitis]

I use Unibond 800 for my wood to wood cores and handles unless I add a fiberglass insert then Ill use smooth-on . I think Unibond adds more performance since it has less creep than other glues.

But I may switch to West Systems G-fex 650 for the ease of applications.  Like Jon L. said this glue can be rolled on with a foam roller.

Years ago like many others I had  delamination issues using smooth-on. I remember contacting Binghams where I got the glue from and they asked  me to send them a sample which did. They denied the glue was bad and would not refund my money-Years later I found out they were buying the glue in 55 gallon drums and unfortunately their dispensing methods lacked quality control aloowing moisture to enter the glue. So, I think thats when smooth-on became questionable. Interesting to note that Black widow that was using Huntsman switched back to and is currently using smooth-on.

I use 50 grit for everything including grinding glass down if I need a different thickness.

In terms of heating any glue to cure Im a firm beleiver in doing so- I think if a bow is subjected to temperatures above what the glu is cured at there is a possibilty of delamination. I have my hot bow set at 150 degrees

[Kirkll]

There are a number of really good epoxy choices out there, and all of them should work just fine under the right conditions and applications. I messed around years ago when the big Huntsman promotion went public and tried some myself….I  Did not like the thin viscosity of the stuff at all and the way it soaked into some woods like a sponge, and I did not send any bows out using it until I tested it myself… that was one of the very few times that I had a limb delaminate on me, and that glue went into the hazardous wast bin.

The thing I love about EA 40 is how user friendly it is. I use a smooth putty knife myself and grind all my lams to 40 grit. The putty knife applies it very smoothly and fills the sanding grooves nicely.

Heating the glue prior to mixing makes a big difference, and thins the viscosity a bit, and mixing it thoroughly makes application a breeze, but you need to move right through the application process fairly quickly before it starts kicking off. Of all the different epoxies I’ve used, EA 40 has the best pot life, and has been the easiest to work with. I’ve used a lot of west systems epoxies on boats for years, and it’s good stuff. But for building bows I wouldn’t recommend it.

That doesn’t surprise me that black widow went back to EA 40…. The stuff is damn hard to beat.     Kirk

[Mad Max]

I use 80 grit and EA-40
120 is what they recommend