I am having a problem setting fin boxes(loxbox, probox, longboard single fin boxes) in EPS foam blanks using RR epoxy (fast hardener). The problem is heat from the curing epoxy melting the foam. I know I would have better luck using the slow hardener, but I really do not want to have to buy additional hardener just to set fin boxes. I use a factory jig to route my holes for the boxes. Is anyone out there having the same problem or is it just me? Has anyone tried to set fin boxes using an epoxy putty like “Marinetex”? Thanks, Jim
Aloha Jim:
I just sent you a PM about one possible solution that people have successfully used with ProBox, which is to use a larger bearing on the router bit reducing the gap around the box and hence the volume of resin. We have these router bearings if you can’t find one locally. It is 5/8" instead of the standard 1/2" on a 1/4" shank.
-Robin
Are you using straight resin or adding some filler like milled glass? I haven’t had any problems with filled epoxy, but haven’t ever used straight resin.
Aloha! I put FCS plugs in my last styro, and after I machined the holes, I let the board chill in the air-conditioned shaping room for a couple of hours, and then installed the plugs. I didn’t want to chance it, and I put the things in at night. I used the standard milled fibers, which actually made it harder to fill the holes. I think that next time I’ll just use straight resin. So far, no problems, except everyone I show the thing to wants to buy it from me! Aloha…RH
Howzit Rick, Sounds like you are adding to much milled fibers to the epoxy which will thicken it to the point where it doesn't flow easily. I add milled fibers til the resin starts to show bubbles then let it sit over night so the bubbles will disapate and leave you with a nice creamy flowing resin. JD used to make his mix thick then thin it with styrene to make it runnier but I feel that weakens the resin. After Talking with the new FCS rep he told me that installers that tweak the install do the best installations they've found. Aloha,Kokua
Aloha Kokua! Different situation with epoxy, especially installing the plugs in EPS. I use the same formula when installing plugs with pu/epoxy, but the nature of styro calls for a lot thinner batch due to the sponginess and absorbtion of the foam. Heat from the reaction is the culprit, the styro is more heat sensitve than pu. Plus, there’s no way to adjust the resin/catalyst ratio with epoxy. Also, there is no way to pre-mix the fibers with the epoxy resin before mixing the catalyst. Although the processes are similar, epoxy is a different kind of system. Slow hardener would be a plus, but regulating the temp. is about the best way to deal with it. Also, for all you styro/epoxy users- make sure you don’t use Additive F when dealing directly with raw styrofoam, more danger there. Aloha…RH
Yes, you can soak in chopped fibers with epoxy. Or cabosil. Or tint. Anything.
I measure my epoxy hardener in medical dixie cups. Lots of graduations on them. If I’m adding any of the aforementioned to epoxy, I pour a batch of resin plus some extra in a large plastic mixing bucket, graduated to ounces.
Say I want 8 ounces. I pour to that, and mix in my whatever. Once its mixed, I note what the level rose to - say 10 ounces (a 20% increase). I pour out 2 oz into a dixie to hold for extra (especially if its tinted) so I know it’ll be the same. Then pour 1.6 oz hardener into another dixie & mix that into the bucket (4:1 on the original, minus the 20% increase due to additive which I then poured off with the backup resin). 1.6 will be exactly the amount of hardener I need to make the resin go off, nevermind the additive - even though the 2 together add up to 8 oz in my bucket. Works every time.
Howzit Rick, Think I'll just stick to poly. But what's good is you are learning the ins and outs of epoxy and you'll be the go to guy.Aloha,Kokua