Thread: Disaster with Epoxy - Help!

Is it just sticky on the surface or is it still all gooey?

Epoxy can quite often still be sticky to touch, even after a week of curing, just sand as normal, it will be hard underneath.

But if it is gooey under squishy still, you'll have to dig it out and re do it.

Steck

Have you allowed enough time for the stuff to go off. Usually a large amount of it requires a longer time to harden.


Regards Mike

I don't agree with Mike, a larger amount of correctly mixed epoxy takes less because the heat given off during the chemical reaction cures it quicker. That's why when we are coating large areas, we get it out of the container quick smart. It can get far too hot to hold!

None the less, how long has it been there?

Is it Epoxy or another form of casting resin? I'm sorry to ask, but many people refer to anything that has two parts as "epoxy".

If it's epoxy and you did mix it correctly, try some gentle heat for a bit. Either elevate the room temperature with a heater, or use a hair dryer on low.

If you have a slow catalyst it could take some time!

For cleaning, use solvent for the brand of epoxy that you used. You could try acetone. Either way use gloves and don't breathe.

Good luck,

P

Its been on the timber for about 6 hours now and it is still just a sticky liquid with no sign of setting.
It's been a warm day here and it's still 28 degrees outside.
I guess it'll be a lot of wiping and scraping and scrubbing tomorrow.
The can says "Diggers Fibreglass Resin". I am one of those who calls any 2 part resin Epoxy. It is actually Unsaturated polyester resin in styrene/methyl methacrylate solution. Does that make it epoxy?
I have used this stuff before and it usually goes off pretty fast.
I am hoping that it won't wreck the holes for filling later and that I can remove it completely from the surface??

Originally Posted by steck

It is actually Unsaturated polyester resin in styrene/methyl methacrylate solution. Does that make it epoxy?

No, that makes it polyester resin.

It's completely different to epoxy in pretty much every respect!

You'd better check, but from memory acetone is the solvent. And unlike epoxy, it probably won't go off from here! sorry!

Cheers,

P

I'd set it aside for 48 hours and hope it may go off, you may have been a bit light on the hardener. Acetone is the best to shift it, if it remains gooey.

Polyester resin uses a catalyst, not a hardener. Because of the tiny amounts involved it's vitally important to measure it out accurately. If it hasn't gone off after 6 hours I doubt it will at all.

Mick

Here we are 14 hours later and some of it has almost set. Some is still gooey.
I measured the catalyst with a syringe so it was exact. And I know I mixed it thoroughly.
Has any one heard of the catalyst or the resin going off on the shelf?

Originally Posted by steck

The can says "Diggers Fibreglass Resin".

I think this is part of your main problem, you should have been using Casting Resin. The fibreglass is really made to be applied it layers with cloth whereas the casting resin is more designed to for doing blocks or filling holes.

Sounds like not enough catalyst, but this stuff will go off in air even without catalyst, just it takes time. If you find it sets but still sticky, you can burn off the sticky residue - I use one of those small cigarette ligher blow torches. Be careful though, it can flame up.

So much to learn!
Thanks to everyone here. I do appreciate all the input. These forums are a great place to pick up that extra bit of useful knowledge!

Yes polyester resin will go of eventually without any catalyst... like several years!
If you have put any catalyst in it, it will go off eventually. I've messed it up before(changed brands without reading the...)and it took about a week to go off.
Dai Sensei is correct, casting resin has some sort of filler medium in it, straight polyester resin(no matting) will crack while curing if thicker than 6mm or so.(epoxy can too, but its more tolerant because of its flexibility)

I've stuffed up the mix as well, and let it sit for a few days and it did eventually go off. Polyester resin is easier to get around here and for smaller holes seems to be ok for most things I fill.

Originally Posted by steck

Its been on the timber for about 6 hours now and it is still just a sticky liquid with no sign of setting.
It's been a warm day here and it's still 28 degrees outside.
I guess it'll be a lot of wiping and scraping and scrubbing tomorrow.
The can says "Diggers Fibreglass Resin". I am one of those who calls any 2 part resin Epoxy. It is actually Unsaturated polyester resin in styrene/methyl methacrylate solution. Does that make it epoxy?
I have used this stuff before and it usually goes off pretty fast.
I am hoping that it won't wreck the holes for filling later and that I can remove it completely from the surface??

Correct catalyst for Polyester resin is MEKP or Methyl Ethyl Ketone Peroxide check that the catalyst you used is this substance. Those dodgy hardware typr fibreglass kits often do this due to quality control.
Fibreglass resin comes in many types mostly relating to its intended use ie submerged or not and a seasonal rating ie Summer or winter temp ranges.
A summer rated resin requires less or a dilute catalyst where a winter rated one requires more catalyst to go off in the same time.
Other problem is even if it goes off it will look like crap. Fibreglass resin is optically poor and tends to cure a cloudy greenish or yellowish color. Not at all attractive . Epoxy is not much better though.
Sam Maloofs book has some good methods for filling voids in timber that both look good and stabalize the fault. Inserting small pieces of timber and or creating a paste out of fine sawdust and a clear non foaming Urethane glue works well.
Also if the void is stable it is often better to sand it internally and make no further attempt to hide it rather make it a feature.



Ross