epoxy issue -- advice needed

I glassed and epoxied the hull of my boat yesterday morning, and when I went to trim the fiberglass this morning, it became clear that there's one section near the end that is still sticky.  My guess is that I screwed up the ratio of hardener somehow -- maybe by not stirring quite enough or not getting a full pump from the dispenser.

Should I just give it more time and see if it hardens?  If it does eventually harden, is there any negative consequence?

If not, what do I do? I can't imagine getting much expoxy off without totally messing up the fiberglass underneath.  Would it help to apply a thin layer with extra hardener?




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RE: epoxy issue -- advice needed

Definitely give it a while longer. It could be a temperature thing (that end of the boat is colder, that batch of epoxy was colder, etc.), not just the mix. You could also try gently warming it with a heat lamp or hair dryer to get it to kick. But just waiting an extra day or 2 is the easiest and cheapest thing to do. If it doesn't harden you can always do the annoying stuff then.

If it's really a bad mix, putting a layer of good on top is not a good idea. You'll just have a hardened crust over a soft mess.

What kind of boat and where is the bad spot?

Good luck,



RE: epoxy issue -- advice needed

Thanks for the response.

It's a Shearwater Sport Sectional, and the sticky section is about a 8 inch stretch on the side near the bow (but not including the keel line).  Having spent a little while looking at epoxy sites, my guess is that I was at the end of the container of epoxy and scraped the sides of the container to get the last of it, and wound up picking up some epoxy that hadn't been fully mixed..It's tacky -- leaves a mark if i press -- but not super soggy

If i do need to remove it, it sounds like applying heat to soften and then scraping is what is needed.  Is there any way not to shred the glass, or should  I just try to take it all off and apply a fresh layer of glass there?

RE: epoxy issue -- advice needed

   You'll get lots of advice on how to recover from uncured epoxy when and if the time comes, and it might, however...

The good news is that you're reporting that the epoxy has hardened somewhat.  That does mean that it might harden up copletely with heat and time. I agree with Laszlo. Nothing too extreme or too long, maybe 100 degrees for a day or two. Check it periodically, let it cool before you decide if it is hard enough or not. 

If that doesn't do it, you're probably in for some recovery effort. You will have to remove the glass in that area. Heat it with heat gun enough to peel up past the edges of the bad area, slice it off with a knife,  scrape while warm to remove as much epoxy as possible, push the rough glass edge down into the goo, let cool, sand, fair in a new patch of glass.  Your fixed area might be invisible from 12 inches away.  You can do this now if you don't want to wait to see if things harden up.

RE: epoxy issue -- advice needed

Ok, I think I'need to replace the glass -- I gave it another 24 hours with a space heater running and this section is still sticky.  So, two questions:


1) You say "fare in a new patch of glass" --  is there a description of what that looks like somewhere?  Any advice on making the edges less obvious?   Is it better to overlap the remainign glass or try to abut it?

2) You suggest just scraping up the old expoxy. -- this is the bottom layer, so it's soaked into the wood. Some older posts suggest using alcohol or vinegar to try to remove the "bad" epoxy -- thoughts?


thank you!

RE: epoxy issue -- advice needed

I would strongly recommend calling the tech support lie for the brand of epoxy that you are using.  I suspect that they will tell you to physically remove the bad epoxy/glass then put a patch overtop as discussed above.  They will definately have the best recommendation for which solvent to use to clean up the wood.  When you patch the glass, you definately want several inches of overlap.  If you do a butt seam with the glass, it will be a weak spot in the hull.  As far as cosmetics, paint is your friend.     

RE: epoxy issue -- advice needed

 Hi ELB, 

ditto to what mark says about contacting tech support for their best advice on how to remove uncured epoxy.  fwiw, i have had to do it once and the boat came out fine with no need to paint.  i seem to recall that after removing the epoxy as suggested i was, with a light sanding, basically just having a fresh start.

repairs like this use the concept of 'feathering in'.  there is an article on the clc site which is useful:  https://www.clcboats.com/shoptips/epoxy_and_fiberglass/surviving-catastrophe.html

in summary, when you pull the old glass off, you will create an edge that is like a scarf joint.  so you will gradually over 1/2 to and 1 inch go from your good glass/epoxy outside of the repair zone to a feather it down to the bare wood.  your epoxy patch then goes over the bare wood and the feather zone. where now it starts to double up.  

once the epoxy cures and is sandable, you then block sand that doubled up part back to only one thickness of glass thick....but you have feathered it in like a scarf joint and it is plenty strong for this and not 'doubled up'.

anyway, i hope that helps.  if your glass is properly wetted-out and the underlying surface is not damaged or discolored, you cannot detect this repair....it will just look like wood with clear glass over it.




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