I made a small repair to my Merlin this weekend but one of the pumps to my epoxy wasn't working. I guessed at the 2:1 ratio and obviously got too much resin and not enough hardener because after 24 hours it still wasn't completely hardened. Is this really long dry time going to effect the strength of the epoxy or the repair at all?

JD

I know all about epoxy problems, unfortunately not so much about epoxy solutions. My pumps crapped out on me too. I had one section that would not completely harden, was tacky to the touch for a day or two. I scraped it off the best I could then put another layer on.

Hold out for advice from the more experienced, but I would consider scrapping it off and trying again.

epoxy is a chemical cure requiring a relatively precise ratio, it doesn't really dry. Too much or too little hardener and it may never cure. You could try and heat the area and see if it helps, but you may have to strip it and re-do it.

I would also suggest some heat to the area. But as mwd says it may be easier to strip it off/out and start again. I have the same problem with a bentshaft paddle I made. One spot the size of a quarter hasnt set up over a year. In the middle of the blade/back side. Poor mixing job, got in a hurry. Its a carbon fiber blade.
Winter project.
CB

ditto all of the above. Scrape it off and do it again, you will sleep better.

I do not like pumps. It is better to mix resin and hardner (by volume) in one calibrated container (resin first and then hardner). After the 2 parts are in, mix a full 2 minutes (scraping sides and bottom).

I then transfer the mix to a second clean container and mix again

Do I sound paranoid? Yup, I scraped once and vowed not to make the same mistake again :)

I would second this. We did not use the pumps. Actually had cups that we mixed it in. Worked really well. I am certainly no expert, but the guys that helped my daughter and I through some of these things have built a couple dozen between them, they don't use the pumps either.

You can also measure by weight, at least with West System. Most epoxy products are measured by weight but the manufacturers give us pumps instead. Just weigh out your 2:1 or whatever the ratio is supposed to be for the brand you are using.

The epoxy problem on your repair will never cure if it's already been 24 hrs. If you can't scrape off the problem repair you can try applying some straight resin or hardener (which ever one you think you goofed on) over the uncured epoxy. This will allow the epoxy to cure enough on the surface to sand and finish.

Tom

I checked last night and the epoxy has now cured. Might have been the cool temps and a slight oops on the 2:1, but looks like all is well. Thanks for all your help guys, really glad I won't have to scrape it all off and redo it.

JD

Good to hear.

or maybe Bruce Kunz is watching over his flock of Merlins