Epoxy Help Needed

So i have an epoxy Santa Cruz that had someone run into the bottom of it. I cleaned the gash out and sanded the area around the repair. I have done many polyester repairs but few epoxy. So i mixed the 2 part resin with some q-cell to fill in the huge gash. Well after 3 days it still wasn't cured and had a rubber bouncy ball feel to it. I took a dremel and cut it all out, but now I wanted to ask some advice before i attempted it again. Is there something i am doing wrong, should i add more hardener? Thanks so much

If it’s that big a gash the first thing you should do is square the hole off and fill it with a piece of EPS foam, and reshape the foam to match the contours of the board before you glass over it.  The stuff is super cheap at any of the home improvement superstores.   You can glue it in with Gorilla Glue or its equivalent.  


Filling a big gash or hole with a bunch of resin is not a great plan to begin with because it just gets hard and stiff and creates a stress point for the foam around it, leading to more dings or even a break.   


As for the resin, you have to be really accurate with your measurements to get the ratio right.  Because you were using the resin to fill a large gash you’re lucky the pooled resin didn’t get hot, otherwise it could have melted the foam.  The interiors of those boards use a very liteweight foam.   

additionally, if it feels rubbery after a few days, you probably already put too much hardener in the mix in the first place…more hardner will likely cause a repeat.

you need to measure your epoxy ratios to the gram if possible, especially in small batches where a little stuck to the sides of the cup can skew the ratios dramatically (as a percentage of overall ratio)

not knowing what kind of epoxy you are using, here are some things that i've learned here on Sways and by experience:

epoxy is not like polyester resin where you can adjust the hardner to tailor the time it takes the resin to kick. the mix ratio has to be followed exactly whether it's 1:1 or 2:1 or whatever, follow the instructions. also, the reaction that occurs with epoxy is different from polyester. polyester is a catalysed reaction and epoxy is something else that i can't remember right now. bottom line is, epoxy needs to be stirred THOROUGHLY. when you add the q-cell, it's a good idea to mix it in with the resin real well, then add the prescribed amount of hardner for however much resin you used then mix it all together. the rubbery resin that you describe is probably a result of either not following the mix ratio exactly or not mixing thoroughly enough. as for fixing the ding, after you get the epoxy thing straight, it's usually just like fixing any other ding. the only thing to remember is that if the pool of epoxy is deep, it will heat up and might melt the eps. to combat this, you can do the pour in a cooler environment like maybe at night or you can do the repair in halfs. if you're doing a small repair, you probably don't have to worry too much about that though. it might be a good idea to have a couple ziplock bags full of ice though to put on and/or under the board in the area of the repair if it starts heating up.


EDIT: oops, yah, what they said^^^

Hey thanks everyone for the advice i usually try to figure things out on my own but epoxy is just a pain in the butt for me haha

You should fix it sell it and shape yourself one. LOL

Hey Mgarbutt


once you get used to epoxy you wont go back! just get some good measuring cups!



Not measuring cups… a gram/oz. electronic scale!  When I switched to a scale my mixes were MUCH better.

AND… I can mix any size batch, down to 6gms for little patches!  Yea!


I actually did shape the board i am fixing, but this is a buddy of mine's board so i am just trying to help him out. It's a beautiful rob face Santa Cruz Pumkin Seed five fin, the second time he rode it some idiot dropped in and put the nose of his board right through the face graphic on the bottom. The kid is only 12 and I felt really bad for him so I am trying to do the best repair i can and even try to color match the graphic back. I will look into a scale rather not take any chances this second time around haha.But thanks again for all the advice hopefully all will go well.

To  add another voice to this  thread… Scales, Scales ,Scales , If you weigh the epoxy mix as per  manu. instructions, it will harden properly first time, everytime…

These are the ones I use, super cheap, I buy 3 at a time when they go on sale for $10 each… I’ve used expensive postal scales, but these are better and way cheaper…http://www.starfrit.com/Products/kitchen/Gadgets/Kitchen%20Scales/93016.aspx?sc_lang=en

i found these rubber cake frosting spatulas at IKEA for less than $1 and bought a few. They are perfect for getting every last drop of resin or hardener out of those plastic, 1 pint measuring cups. Get at least two- one for hardener and one for resin. I need a similar tool for the little 1 oz cups. Those 1 oz cups suck because they have raised graduation markers on the inside of the cup. There’s always a few drops left inside those.

I use yogurt cups and sour creem containers ,etc, anything as long as it’s properly washed out…

I used to buy  mixing comtainers from the glass/epoxy supplier… Stupid!!!  You.re going to buy the food anyway, why not re-use the  container it came in…