johnH20
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| posted on 13/6/20 at 04:12 PM |
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Does resin 'go off' with age?
I needed to do a small fibreglass job today, had not done any in quite while. I opened a new tin of PE resin and made up 100 ml with 2% hardener.
According to the tin this should be good for 20 -25 mins working time at 20 deg C. Mine went off in 5 mins! So I tried again with a 1% mix and the
same thing happened. The only clue is that when pouring the resin out it seemed to have a slightly lumpy consistency although when mixed this
disappeared. Never had this before and I am moderately experienced with fibreglass - I used to make surfboards in my youth.
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gremlin1234
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| posted on 13/6/20 at 04:26 PM |
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yes it does, sometimes the hardener is called accelerator
does the tin have a 'best before/ use by' date?
see also...
https://www.iso.org/standard/41680.html
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Mr Whippy
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| posted on 13/6/20 at 04:36 PM |
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yeah I have resin that will not even come out the can now  they certainly have a shelf life and if you buy resin from a boat builder supplier such
as West systems resin they tell you long long if will last.
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Irony
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| posted on 13/6/20 at 05:18 PM |
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It certainly does, also if you find resin that's only half rock hard and the other that looks fine, it's more than likely all no good as
it won't harden properly at a later date.
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motorcycle_mayhem
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| posted on 14/6/20 at 10:00 AM |
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Styrene is the both the solvent for the resin and the actual resin itself... it will quite happily cross-link if it's left a while. You'll
end up with a resin with a variation of cross-linked units, some large, some small. Stirring it all in won't change that.
Add the rest of the peroxide to the can, set it all safely solid and send it to landfill.
Buy a new batch.
With a 'normal' activity MEKP catalyst 1-2% will be ample in the summer, or what we in the UK call summer... gives you about 30 minutes
working time.
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