This is my first time using epoxy, I usually use PER which cure rock hard but when I switch to epoxy that I bought off ebay, it gets flexible feels like polyurethan, is it this epoxy that I am using or are all the epoxy don’t get hard like PER resin?
I would say that it the epoxy you have used or how you have used it. All the epoxies we use cure rock hard. However if the ratio is wrong or it hasn’t been post cured hot and/or long enough it can be soft or crumbly.
I’m sure if you post up what the resin is, someone will have used it and could tell you more.
^ I agree you have to post cure most of the epoxies to get them rock hard
And they can expire.
http://www.aeromarineproducts.com/carbon-fiber-epoxy.htm
that’s the epoxy I used. Has anyone use them before?
Maybe it has only been a day. How long does it takes to get complete cure?
most epoxies are ready for demolding after 24h cure in room temperature, but again it’s depends the specs of the specific epoxy
I use an epoxy for repair work that cures at room temp and does not require post curing / tempering. It can be de-molded after 24 h but it takes 7 days to fully harden. It feels hard after a day but is still slightly tacky and will smear when sanded. Maybe you need to wait a bit longer or temper it.
Cheers
I just took out some left over 2 days cured epoxy out of the cup, this is bendable and will not crack feels like rubber, as for PER it feels like glass hard. It’s for the overlay part, I am just affraid I won’t be able to sand it after.
Don’t bother post curing I’ve made monocoque’s for motor cycle and never post cured,and never had any problems,you should source a respected supplier,it took me a while to source different epoxys for different applications,also your problem could be a number off reasons, had a similar problem and thought I had not weighed out resin correctly,left it for another 3 days,and all was fine ambient temperature plays a big part in curing times.
are you using a accurate scale to measure? If you mixing by volume and not by weight then more than likely your not mixing by the right ratio. Your scale should measure by a 10th of a gram. Most epoxies need a post cure to be fully cured.
Which epoxy do you guys recommand for overlay jobs?
This is a very dangerous statement on it’s own. We use a resin that has pot life of 72hrs and never cures without heating to 80C. You need to do what the manufacturer recommends.
tingc911, I noticed on the manufacturers website they give mixing ratios by volume. Also have you tried to contact them with your problem? We call our resin supplier quite often to get their advice.