i have had a high degree of sucess doing epoxy repairs…but say 20% of the time the repair becomes gummy…and well impossible to sand …a nightmare…i beleave my mixing ratio is on target …i use fiberglass hawaii epoxy and fast hardner…i have been told that im using too much hardner thats what causes it to gum up…true or false…whats up? mahalo…
I use FH epoxy for repairs all the time. Small amounts (less than 100 gms) have to be weighed. Below 70 F, you need to heat up the resin so that it will mix properly with the hardener. Just put the small amount of resin you’re using in a cup and put that in some hot water for a while. Harbor Freight has several digital scales, $20 for the cheapest. I got one and haven’t had any gummy epoxy problems since.
Small batches are hard to measure correctly by volume. A tiny mis-measurement can be off by a huge amount in terms of ratios.
I’ve never worked with FH epoxy, but typically, not enough hardener or not enough mixing makes it gummy. Too much hardener makes it rubbery.
Temprature is also critical, if the temprature is too low the resin doesn’t set up properly, try heating the resin (not the hardner) and heating the work area if you life in an eara with low temps.
I grabbed an affordable digital scale off of Ebay and have started using that to measure out small batches.
I had no idea that you could use too much hardener…good to know.
For small batch measuring, scales aren’t accurate enough. And too much hardener does make it rubbery. Guess how I know?
For small ding repairs, Fiberglass Hawaii sells syringes. Only about a buck each. Measure the hardener first, because the resin is soo thick it will goo it up and you can’t reuse it for the hardener
When you get a scale make sure it is digital with a gram function. The one I have is good for 5 lbs and can be switched between grams, ounces, lbs, and kilos. Put the scale on grams for small repairs. I used to use a syringe but found that the small dixie cups work great. Pour the hardener into the cup and dispense from the cup into your resin.
I was having problems with my leash plugs pulling out from improper mixing of the small batches. Now that I have the scale I can mix up a 4 gram batch of resin for an ofishl super plug and get it to kick without waste.
Where was this post last week when I was setting a leash plug!!! Grams, why didn’t I think of that! better precision for smaller batches!
MAHALO… FOR ALL the very, very helpful response!!! thanks so much for the great tips!!! i must say this web-site is amazing…looking at the projects that you guys are doing is well… BLOWING MY MIND!!!..the quality, and craftsmanhip,and just pure talent that is out there is so inspireing…im STOKED…ALOHA