Epoxy question?

I did some epoxy repair work yesterday morning, and this evening the Epoxy is still tacky.

Not sure if I made the wrong mix or if the humidity is doing it.

My question is: will holding a hot air supply on it such as a hand held hair dryer help speed up its drying?

Any other suggestions?

Thanks in advance


Shop Light
I have used a shop light to help resins cure. Just don’t put it too close. I think the light helps as much as the heat.

I have had it stay tacky for 12-16
hours in high humidity/cold temps. The shop light is a good recommendation for gentle heat.Unless you reversed the ratio, which I have done.

Epoxy doesn’t "dry."
Drying occurs when solvents evaporate. Epoxy cures through a chemical reaction.

I hope you wore gloves when you applied the stuff, right?

If it does not cure correctly and remains gummy, you can strip it by applying generous amounts of white vinegar. Or even soaking newspaper with white vinegar and laying that over the unkicked epoxy.

Hair dryer may work…
Hit it for a while every so often. It may take a few days.

Something went wrong …

– Last Updated: Jun-11-08 10:13 PM EST –

....... in the mix ?? If it's something important you were working on , remove and redo with brand new fresh components (suggest not using the same stuff you just had a failure with , may be to old) .

Maybe you put in on too thick w/o filler material ??
In any case it sounds like you didn't achieve proper cure temp. for intial set .

What did ya do ??

…can help - I’ve seen it help cure epoxy that was still “cheesy” days after the initial application. Heat is also good - gentle heat, for long periods - I’ve placed several light bulbs beneath a kayak and shrouded it with an old plastic tarp to help with overnight curing in a cold basement…

You can also dissolve it with…
…denatured alcohol. I find the odor to be a lot less obnoxious than vinegar. Moreover, vinegar neutralizes the epoxy so it cannot cure, alcohol dissolves and removes it.

Possibly not well-mixed
I always measured my Part A and B accurately when doing epoxy work. Our climate is dry, my workroom heated by portable oil-filled radiators.

Yet one time one area remained tacky for days. Eventually, it did dry and harden. I suspect that the mix was not homogenous–the tacky spot probably had an overabundance of Part A (resin) while somewhere else the stuff had too much Part B (hardener). It’s a tricky thing to mix thoroughly without whipping in lots of bubbles.

I suggest that you wait a few days before doing anything. If it’s still tacky, you might try mixing a small amount of new epoxy with slightly higher ratio of hardener in it, then putting that on top of the tacky stuff.

Thanks all
I’ll try the gentle heat first, and if that doesn’t work I’ll try the alcohol.



Alcohol and acetone
are solvents. Have some toxicity issues that vinegar does not have.

Sunlight is also a good suggestion.

I avoid acetone…
…as it’s noxious, penetrates and dries your skin quickly and it’s too volatile, evaporating before it dissolves the epoxy completely. OTOH, denatured alcohol is pretty benign stuff, as long as you don’t drink it. It’s simply ethanol - the “active ingredient” in alcoholic beverages - with enough methanol added to make it undrinkable.

Adding hardener won’t help
"Fixes" like that tend to cause more problems than they solve. What you’ll end up with is one poorly cured layer over another, creating twice as much work to fix it. The best remedy is to remove the uncured material and start over. Additionally, if you mix epoxy with excess hardener, the result is actually a softer cure, not a harder one (counterintuitive, but true). The resulting epoxy will be rubbery and weak compared to properly mixed epoxy. Any deviation of more than 10% in the mix ratio is likely to cause problems.

Ethanol is not much safer …
Ethanol is an excellent solvent for penetrating skin and carrying dissolved toxins into your blood stream. Think of all the drugs that are dissolved in ethanol that you buy over the counter. Make sure you wear gloves. The toxicty of ethanol itself is lower. But it could easily transport the hardner into your system the chemicals in epoxy systems are not something you want circulating in your blood. Breathing ethanol fumes is much less dangerous than breathing acetone.

Yea it’s probably not mixed well…
I had a similar problem when we got a sharp cold spell and my garage got very cold after I did the layup. I ended up using heat lamps and a thermometer to cure the resin, but I still think I made an error in mixing. I suggest using the ipod and mixing for a good 5 minute jam type song.

I got an very funny email from Patrick when I explained what had gone wrong with a recent project and asking him for help. Something like … I know how to do things right … I don’t know how to do things wrong.

Scrape 'er Off And Try Again…
Many of us have had that same frustrating experience. Two years ago, I was replacing the marine plywood flooring in my antique 1960 Lone Star 16 sailboat. It was a stressful hit and miss project using only the remaining rotten fragments for templates and no off the shelf parts available. I was using West System products with the calibrated 5:1 proportioning pumps in the epoxy & hardner. For some stupid reason I pumped the large epoxy pump 5 times to a single pump of the hardner. After 24 hours of staying tacky a call to West’s 800 number quickly helped to solve the problem. I was apparently so stressed from the project that I forgot the simple basics…1 pump on each container will give you the exact 5:1 ratio.

All that you can do is to swallow your pride and follow West’s damage control instructions. First, gently scrape off the tacky, wet, goo with putty knives (I used the plastic ones) then wipe off all of any remaining goo with acetone and rags.

Wear gloves and it’s NO PROBLEM
No one should work with epoxy without gloves on, whether you’re applying it or removing it. That one simple precaution removes any concern regarding using denatured alcohol as an epoxy solvent…that is unless you’re brain-dead enough to be working in a small sealed room.

HA did somethin similar
your ratio was right ! West’s pump system is one to one BUT the ratio is 5to 1. I just did this yesterday-ha!Took it all off an I like the redo better than the 1st attempt !

More than you might need, but…
In an attempt to get as much info available to as many people as possible…read these manuals if you are wanting to use epoxy in your build, and are unfamiliar with it’s use. They don’t take long to read and you are really going to educate yourself. This is a great place to start to familiarize yourself with the materials, terminology, and potential trouble shooting.




The following site is the full West Systems site…this has info on other products and some trouble shooting tips and pointers. Problem solver guide is under user information.