Gooey Epoxy results.

[rregge]

Glued up one of the last planks for my Arctic Tern last weekend, went to take off the clamps the next morning and yuck. The epoxy never dried. Tried to wipe up the mess and test glue a sample, you guessed it, it didn't harden.

What did I do wrong (messed up the mix I suspect)?

What do I do now.

Help

Russell

[BrianR]

Russ - this happened to me recently. It turns out I carelessly messed up the ratios of the epoxy. I think I did one pump from each bottle (resin and hardner), forgetting that I should have had two pumps of resin to one of hardner.

I had to scrape off the old stuff with a scraper, and do it over. I found that a head gun applied to the mess I made helped the process.

Also, make sure you sufficiently mix the stuff - seems you can never be too thorough. Good luck.

[JimConlin]

The only time I've had a case of gooey epoxy, I had an off-ratio mix. The pumps I was using had gone out of calibration. My hardener pump was calibrated by means of an internal spacer that limited the stroke. It had somehow slipped out of position.
It's good to check 'em occasionally.

[CC1968]

I'm new here so hello ALL; but what I've seen thus far this Forum has to be the best of the best. Lots of great posting and info. On mixing epoxy ... I use West but I've tried others too. I find the plastic medicine cups great for small amounts like 30 grams is the least I mix. It has never failed me yet and it really doesn't take much longer than their least expensive pumps. I transfer it to a 16oz cup to do my filler mixing. This year I invested in their $250+ pumps but I haven't ventured into them yet; I will this summer to install some deck-bridge teak.

[jhl]

At the risk of insulting you, (not my intent) make sure you didn’t reverse you’re “A” and “B” components in your ratio.

PS: This recommendation rendered from personal experience!

Jim :cool:

[Bruce Hooke]

Gougeon Brothers sells a solvent for cleaning up UNcured epoxy. This might be helpful for removing the gooey mess you've got. Be careful with a heat gun if there is good epoxy in the area because too much heat will do in the good stuff.

[Bob Perkins]

Plain old white vinegar will clean up uncured epoxy remarkably well.. And it is cheap.

I use a digital kitchen scale (inside of a ziplock bag) to measure out large batches of epoxy, which I pour from the bottle.

I use the pumps for small batches, which I check the calibration of every now and then.

Finally - many tend to undermix the epoxy (Systems 3's #1 support issue is related to not enough mixing time). I took some training from System 3 guys. They said 2 minutes (while watching a clock) which seems like forever - but I never had a bad batch this way.

I often cheat and go a minute+. After you have mixed enough of it, fully combined epoxy gets a *feel* IMHO and you know it is ready.

Good Luck,
Bob

[John Meachen]

I have always believed that the use of pumps was only really suitable for moderately large mixes.Not only that,but they commit you to the one mix ratio.For years I have been looking for digital scales that read in 0.1 gram increments as these can be used with any mix ratio and very small quantities.A month or so ago,I saw some in a sale at an electrical hobby shop for a very modest price and bought them.I now feel better equipped to deal with small mixes.The only other source I had seen was a market stall that also sold unusual pipes and other smoking paraphenalia.....

[Peter Page]

Is weight ratio the same as volume ratio?

[Don Maurer]

According to MAS, the epoxy mixture can be off as much as 20% and it will still cure properly. It just takes longer. If you suspect you messed up the mixing ratio, you may want to leave your work clamped a day or two longer. It may save a lot of work.

[John Meachen]

Peter, I have never yet found an epoxy that was sold in any form other than a kit containing the right quantity of harderner for the resin.Usually,the weight of each is labelled in grams and a little arithmetic gives the mix ratio.There may be exceptions and i would be interested to hear of them.

[JimD]

Originally posted by Peter Page:
Is weight ratio the same as volume ratio?Nope, and epoxy is always sold in volume ratios. But as long as you stuck to the manufacturer's proscribed ratios it wouldn't really matter. And as others have said, failure of the epoxy to kick is virtually always a goof up in measuring. If you don't like the smell of all that vinegar you can use acetone, which is not only smelly but toxic as well.

[mariner2k]

Not to drive a point too far home, but....the ratios must be correct and mix, mix,mix well. If your adventurous you can clean the uncured with acetone, toluol, laquer thinner but watch your liver. They are absorbed through skin.