I’ve got bubbles coming up on both fin boxes I installed today!!! Big half dime sized bubbles coming out of just one spot. Same on both boxes. It’s slowing down as the resin hardens. Exoterm??? I’m I screwed???
EPS 2lb, Resin research CE, Pro box fin boxes, 75 degrees. I put 6oz patches at the bottom of the routed holes and wrapped roving around boxes.
Make sure that workshop is at constant temperature and board has been allowed to normalise - it is just expansion of the air inside sealed board coming out the only place it can.
One way to avoid this, if you can’t control the temp and keep it constant, is to “seal” the inside of the routed hole with resin and microballoons, or even spackle, before you install. You can also do a two staged pour, which helps… do half the pour, let it kick, mix up a new batch and do the second pour.
My router spins so fast the bit gets hot and melts the surface of the foam on the inside of the hole… which seems to help, too.
If you have pin holes that go all the way to the foam, and you may, you’ll need to drill them a bit bigger and fill them. If you have BIG holes and no resin in them, you may have melted the foam around the plug. Bad news. What you don’t want to do is keep pouring more resin in. It just makes it worse! Wait till it kicks, then fill in the voids when it cools.
IF THE ROOM IS COOLING YOU CAN EXPERIENCE THE PROBLEM OF THE RESIN BEING ‘SUCKED’ INTO THE FOAM. iT WOULD BE ALMOST IMPOSSIBLE TO SEAL THE HOLES FROM THE INSIDE SO IF YOU CANNOT MAINTAINA ASTABLE TEMP. THEN THE VENT HOLES MAYBE THE WAY TO GO - HOWEVER YOU THEN HAVE THE PROBLEM OF SEALING THE VENT HOLES!
I hope your foam didn’t melt. I like epoxy resin. I just don’t like to use epoxy to set boxes in eps. Too hot, melt throughs, bubbles, etc. I’ll probably get flamed for saying it. Mike
I think it is resin draining through the EPS and air replacing the resin. Not related to temperature. Wouldn’t happen if the hole was sealed. Remember, you can pour a cup resin through an unsealed EPS blank.
When I switched to EPS / Epoxy I ran into all kinds of weird problems. I coined the term "epoxy weirdness" but it didn't catch on..... Out gassing, temp , 2 part pours.....some really good posts so far....
did I tell you about the time I had a major melt down?
Howzit Panhandlekook, Are you pouring the in just 1 spot and not different spots. Pouring from just 1 spot lets the resin fill evenly and displaces air as the hole fills. If you fill in one spot then move to another spot you trap air nd it takes time for the air to reach the surface. This is one thing that I remember FCS stressing in it' installation instructions. Aloha,Kokua
Did a few different things to see what would work.
I tried to stabilize the temp in the shop and let the board “normalize”. Then I installed the last finbox (longboard 10"). Still bubbled. As soon as I saw the bubbles I drilled the vent holes in the deck where the leash plug will be. The bubbles stopped. Like magic.
I drilled the hole for the leash plug and sealed it with fastnfinal. poured and installed the plug. No bubbling.
My smallish A/C and lack of insulation doesn’t allow the shop to stabilize enough to go without sealing. For me, sealing the routed holes is the easiest solution.
Agian, thanks for all the help guys. I will post some pics later.
“I drilled the hole for the leash plug and sealed it with fastnfinal. poured and installed the plug. No bubbling.”
Well , there you go, not outgassing or temperature. Just plain old drainage into the EPS. As Laravat says, a little colloidal silica will thicken it and keep it from draining.