1 Year in storage...

[querk1a1]

Well, Ladies and Gentlemen, I got my cozy back out from storage from uncle sam......my "Boat" bottom (ch 6) was intact and ready to have the contouring foam added when I left Georgia last summer and now it is in 5 broken pieces. At least the fuselage isn't ruined...... Hopefully I can get back to work. I think I have to throw out about 4 gallons of un opened MGS 235 and hardener. It has never been opened but it is about 4 years old. Should I keep it or toss it? Well glad to be back in a position to get back to work...

 

 

 

-Jonathan

[brainfart]

> I think I have to throw out about 4 gallons of un opened MGS 235 and

> hardener. It has never been opened but it is about 4 years old. Should I keep

> it or toss it?

 

There's no need to throw it out. The resin can be stored for many years and will still work. The hardener might be affected, depends on the packaging. Is it in plastic or metal containers? What does it look like? Did anything crystallize out? Has the colour changed? The amines need carbon dioxide and water to go bad. If no carbon dioxide or water can get into the container then the amines will not be affected. Discolouration might occur but it will still work. Once the hardener container is opened I wouldn't store it for years, but when originally packaged and well sealed it will last a LONG time. I've personally used some other MGS resin which was over ten years old and it worked like new, even though the hardener had turned reddish colour (which disappeared when it cured).

 

Of course, if you have any doubts buy new. Your life might depend on it. But experience shows that old epoxy resins still work ok. The reason the manufacturers give relatively short use times is 1) liability reasons and 2) they want to sell their products. They will never admit to you that the resin can still be used.

 

If in doubt, use the epoxy for something else or give it to some boatbuilders or other hobbyists. Or do some tests, but that means opening the original hardener container.

[Big Steve]

I concure with the previous poster. Dont throw the stuff away use it. OR give it to another builder. There are plenty of fairings, wheel pants,doors, and such on your plane that if it isnt super cured will still work just fine. If it concerns you dont build your wing out of it. It is hazardous waste dont throw it away give it to someone that will use it. Steve build on

[querk1a1]

Thanks guys, I feel the same way but I wanted to get a sanity check. All of the epoxy is still in the original containers (plastic or metal can) and has been in a plastic Bin. They are not open so I don't think there is any crystalizaton at least not in the resin containers that I can see and no discolorization.

 

-Jonathan

[Kent Ashton]

And I wouldn't throw away that contouring foam either (the white Clark stuff, right?). Use the pieces. It will be just fine. They are only to give shape to the fuselage.

-Kent

[brainfart]

Some epoxy RESINS might start to crystallize during storage, especially when exposed to low temperatures. This is not a reason to discard them, it's merely one of the components (bisphenol A diglycidyl ethers) separating from the mixture. By heating up the resin in a water bath and stirring and shaking the crystallized component can be redissolved and the resin will be good as new.

 

This is not valid for epoxy hardeners. If they show crystallization they most likely have reacted with carbon dioxide and should be discarded. They too might be ok and it might just be one of the components crystallizing, but most of the time it's a sign of them having gone bad so it's better to be safe than sorry and throw them out.

[Kent Ashton]

This is not valid for epoxy hardeners. If they show crystallization they most likely have reacted with carbon dioxide and should be discarded. They too might be ok and it might just be one of the components crystallizing, but most of the time it's a sign of them having gone bad so it's better to be safe than sorry and throw them out.

Oooh, a rich builder! ;-) I would use that kind of hardener (and have) for fairings, seats, armrests, wheel pants, ramps in the cowl, fillers, contouring. Lots of uses for it and I've never had any that did not cure hard.

-Kent