A
ark
Guest
I used some of this today(for the first time) and was surprised that it did not harden at all over a period of 4 hours. Is this normal?
Pye_End
Well-Known Member
What temperature?
oldsaltoz
Well-Known Member
What ratio of resin to hardener?
matelot
Well-Known Member
Yes - its temp dependant. But unlike poly resin it will always harden in the end.
At yesterdays ambient I would expect up to 24 hours and it wont fully cure right through to its ultimate hardness for a few days. But its bl**dy good stuff for structural repairs. Inclined to amine blush so if you are overcoating remember to wash it first and then abrade.
At yesterdays ambient I would expect up to 24 hours and it wont fully cure right through to its ultimate hardness for a few days. But its bl**dy good stuff for structural repairs. Inclined to amine blush so if you are overcoating remember to wash it first and then abrade.
vyv_cox
Well-Known Member
Coincidentally I laid up a small repair patch inside a box yesterday using the same stuff. I did the job at about 1500 and left an inspection lamp turned on inside the box. At 2000 the layup was pretty much hard, whereas the used brush and left-over resin were still liquid. As has been said, curing is very temperature dependent with a recommended minimum of 5 C, not much better than it was here yesterday.
A
ark
Guest
Thanks for the replies. The mix I used was one part resin to five parts hardener. I later tried a test batch with a higher ratio of hardener but that was the same. I also tried a heat gun on the original batch but this just made it run off the vertical surface I was working on. It was a fine sunny afternoon but I did not have a thermometer so maybe it was just too cold.Will have to wait till I go back to the boat to see the result and will report back.
boatbuilder
Well-Known Member
I hope that your ratio of mix is a typo, or it will never work.
Do not change the resin / hardner mix as it is a reaction not a catalyst as in poly.
Do not change the resin / hardner mix as it is a reaction not a catalyst as in poly.
A
ark
Guest
Phew you had me worried there. Not a typing error but brain malfunction. /forums/images/graemlins/confused.gif
RAI
Well-Known Member
I've always found small batches of West epoxy takes 24 hours to harden, especially if it's spread out. Conversely, a large batch hardens in the pot and gets indecently hot very quickly. So I mix a bit, apply a bit, mix a bit and apply a bit .... all in the same mixing jar. I conclude that the hardening process is very temperature dependent as well as being exothermic.
A
ark
Guest
Went to the boat today and pleased to say Mr West's gunge has turned into a perfect repair. Thanks all.