epoxy curing time

[mydauphin]

Originally Posted by thudpucker

I did that once! In Alaska, the stuff finally solidified. But it remained sticky on the outside.
Advice to me was mix a new batch on a warm day, cover the sticky stuff with the new batch, thinly. The new Batch will cover your hangnail pretty well.

If the epoxy does not cure fully, unlike polyester, adding another coat over it won't fix it. Structurally it will stay soft and it may Peel or delaminate.

A cool epoxy, that goes bad stays at chewing gum stage forever.

[PAR]

It's never good advice to cover a bad batch with another batch. You're just bonding to a bad batch which is self defeating.

The only good advice in that situation, is to grind down the bad batch, until you're back into good portions of the laminate, then apply more goo.

[thudpucker]

Good advice PAR, but for me you're some 25 Years too late.
Believe it or not, that Green F/glass coat made that boat look so good, that somebody stole it, trailer n' all.

[cthippo]

Originally Posted by mydauphin

Rule#1 with epoxys, if you can't keep temperature above 50 f for a 24 hour period don't mix it.
Good luck yip. Hope we don't have to answer the next question, how do I get this stick goo off. Give it 3days after you put heater before you panic.

I use System 3 with the fast hardener and it reliably goes off down to 36 degrees f. Of course, now that it's 70 degrees in the shop instead of 40 i've had some rude surprises!

[pauloman]

there are marine epoxies that will work and cure at freezing - I use and sell them every winter. That said, could be a mixing problem - off ratio etc, that sort of thing happens to everyone once they get past the beginner stage (it was never the new guys that fell from the rigging in the square rigger days, only the experienced guys)

paul oman - progressive epoxy polymers

[Charly]

Originally Posted by pauloman

That said, could be a mixing problem - off ratio etc, that sort of thing happens to everyone once they get past the beginner stage (it was never the new guys that fell from the rigging in the square rigger days, only the experienced guys)

paul oman - progressive epoxy polymers

Hey Paul, I made that very mistake this weekend, and on a part that would take a lot of effort to duplicate, to boot. I was mixing 24 oz batches-- two part resin to one hardner.I typically add 16 oz of resin first, and then the 8 oz of hardener. I don't know what I did this time, but now I have a sticky mess. So I have spent the last two hours with a scraper on it (it is 17 oz biax), with some vinegar, and it is very slow going. I am afraid a grinder would gum up real quick.

Anyone have any speed up tricks? Hope the OP doesn't have the same problem.

OH, and another question-- will vinegar, that is soaked in the wood compromise the bond (cedar strips) with a new batch of resin when it is cleaned up? Thanks

[tunnels]

Originally Posted by Charly

Hey Paul, I made that very mistake this weekend, and on a part that would take a lot of effort to duplicate, to boot. I was mixing 24 oz batches-- two part resin to one hardner.I typically add 16 oz of resin first, and then the 8 oz of hardener. I don't know what I did this time, but now I have a sticky mess. So I have spent the last two hours with a scraper on it (it is 17 oz biax), with some vinegar, and it is very slow going. I am afraid a grinder would gum up real quick.

Anyone have any speed up tricks? Hope the OP doesn't have the same problem.

OH, and another question-- will vinegar, that is soaked in the wood compromise the bond (cedar strips) with a new batch of resin when it is cleaned up? Thanks

The best trick i know is do the job properly !! take more care !!be accurate with you measuring !!!. mix well and mix even more !!
I really dont like working with epoxys at all .they are just a pain in the sit-upon !! stick smelly stuff !!

[Charly]

Thanks Tunnells!!!! Great Advice!!!! Also. Wear ya glasses!!!! When ya mix !!!

....and if I'd been weraing my glasses,. I would jave noticed that the OP is over a month old, so I guess (hope) his batch came out OK...


ANyway, will the vinegar soak into the cedar and mess up a new bond?

[yipster]

Originally Posted by Charly

OP is over a month old, so I guess (hope) his batch came out OK...

thx and luckely it did, i had a temp problem and it took a few weeks till the reaction picked up again with the temperature up but turned hard as rock
dont know whats your problem but might try to give it some heat, wont hurt me thinks?

Originally Posted by pauloman

low temps slow or stop the epoxy cure, but with warmer temps it will pick up where it left off....

[PAR]

Originally Posted by tunnels

The best trick i know is do the job properly !! take more care !!be accurate with you measuring !!!. mix well and mix even more . . .

That's helpful, now that's is down.

Originally Posted by tunnels

. . . I really dont like working with epoxys at all .they are just a pain in the sit-upon !! stick smelly stuff !!

I'm not sure what epoxy experience you have (not much apparently), but it's not smelly and easier then polyester or vinylester, particularly for the novice laminator.

I hope you managed to clean off the surface. Sometimes it helps to apply a talk or other powder to the sticky surface so the paper doesn't gum so quickly. Scrape the bulk off, then you know what's next.

[pauloman]

I am embarrassed to say that vinegar never seems to work for me - and I buy and test by the gallon - and I am in the epoxy business to boot! Guess my expectations for vinegar are just too high.

No clue on the affect of vinegar on wood etc. I suspect it is so weak it doesn't do much and that the water in the vinegar is more of a problem.

[lewisboats]

Vinegar is a neutralizer...it doesn't clean worth a crap. It keeps the epoxy from curing while you clean it with something else. Mineral Spirits is about the mildest of the chemicals that actually clean it up. Lacquer Thinner works the best I find but it is pretty harsh. If you have a large gooey mess...Heat and scrape the worst of it off then, if you want to re-epoxy the base material don't use vinegar...go at it with the solvents then let it all evaporate for a good long while. It would be nice if you could heat the area to help with the evaporation but solvents tend to be quite flammable so unless you can pump heat into the area from somewhere else...you'll have to wait for evaporation to take its course.

[Charly]

Thanks guys, it is coming off with a scraper, though slowly. Tunnels really does have the best solution. Reminds me of an old Billy Joe Shaver lyric "the hardest thing I learned there is there aint no easy way"