MT-13 Shelf Life

[Digital Caveman]

I have some MT-13 epoxy I want to use for a perry reflex longbow, but it was manufactured two years ago and the box says it has 'limited shelf life'.  I used it for a perry reflex bow last summer and the glue line had no issues, but the bow did break from an issue in the belly so I couldn't test it very much.  Would the glue be ok to use now?  I'm thinking that if it worked then it should be ok now, but I'd hate to be wrong.

Thanks,

[willie]

If it looks normal I would trust it. I have epoxy much older than that that I would use.

[bownarra]

MT13 is best for splices not laminating limb pieces? Get some EA40 if you are gluing a full bow up.

[Digital Caveman]

I don't have a hot box for EA-40 otherwise I would use it.

@Willie, What kind of epoxy do you use? is it supposedly 'limited shelf life'?

Thanks,

[willie]

system 3, they do not advertise "limited shelf life" though.  emailing the manufacturer would be more authoritative.
it would be interesting to see if they ask about the storage conditions over the last 2 years before they reply "you need to buy more". I remember one company replaced a lot of product that a distributor mishandled, might be the same outfit.

[bownarra]

You don't need a hotbox for EA40 It will set up just fine overnight in the house, around 20 degs is enough.
I've had issues with old Smooth-On glues.....if you want the definitive answer an email to Smooth-On would be adviseable. They are willing to help After all they wouldn't write that on the tins if it wasn't an issue?

[Digital Caveman]

Do you mean 20 degrees C. or F. ?

I had heard from Mike Yancy that EA-40 will cure without heat but not good.

Thanks,

[willie]

the mfg does seem to encourage a phone call if you have Q on their website. I do not know if ea 40  specifically has a required cure temp.  I have worked with epoxies in general on an industrial scale can offer a general observation.
Sometimes an application will have a slower cure than normal. More time is needed, or just a warmer environment for a longer time. Epoxy get progressively harder in a more gentle time curve than polyester, which is commonly said to "Kick" off.

I have heard it said that with epoxy, one should never expose a bow to a higher temp than what it cured at, so a hot box is necessary. I do not believe this. If you talk with them let us know please. There are guys that will do heat corrections on lam bows glued with epoxy, and those that will not. How much heat a well cured bow will withstand might be a question the mfg would hedge on saying much about to a new customer, but a conversation between engineers without a warranty implication being implied could be informative.

[Hamish]

"I have heard it said that with epoxy, one should never expose a bow to a higher temp than what it cured at, so a hot box is necessary. I do not believe this."

Willie, +1 from me.

[Digital Caveman]

The smooth-on site said their epoxies have a 24 month shelf life if unopened and stored at 73 F.  Mine is just over that, has been opened, and was colder for for a while.  I will probably use it on lesser quality lams in the near future.  I have three tropical wood lam projects coming up, so I will probably get new glue for those. 

My final question, has anyone here had issues with room temp cured EA-40 in perry reflex?

[bownarra]

It is more the shelf life I would be concerned about. I've used about 15 gallons of EA40 over the years and the only failures i've had have been with old glue. Anyway talk to Smooth-On they know their product better than us lot No matter how much experience we have MT-13 uses a very similar part A to EA40.

[Digital Caveman]

I just found out that Uinibond 800 is another gap filling laminating glue.  Anyone have any experience with it?  How does it compare with epoxy?

[bownarra]

Forget 'gap filling'......it is really a bit of a misnomer....If there are gaps inbetween your lams making lam bows might not be the best idea
Just use any decent wood glue and follow the instructions.....