Hi all. Sorry for the question that has probably been answered before but my search didn’t come up with much.
I’ve been fixing my own surfboards for many years, but always have a problem blending epoxy repairs. Even with my best sanding effort, there is often a line between the new resin and the old. I’ve read about “faring” and “blending with a razor blade,” but I have no idea what this actually means in practice. I seem to be able to blend patches just fine with PU repairs.
Repairs are one of the many reasons Epoxy just plain sucks. If you want epoxy repars to blend in you really need to let your final coat of resin reach its full hardness before you final sand it. You also have to use extra care not to heat it up as you sand. Wet sanding the final coat helps a lot with this.
Thanks. Yeah. Part of it does seem related to how soft epoxy stays for so long. Also just thicker. I haven’t been thinning the resin out, and I wonder if that would help.
I am guessing it is your resin. A quality surfboard epoxy resin witll get the job done and a fast set hardener will get it done quickly. With greenroom resins and west coast fast hardener I can get a ding water proof in 15 mins and perfect sanded repair in 90 minutes. I have a bunch of ding repairs in the works and I will take some pics. Using peel ply on the rails will also make a perfect lamination and filler at the same time ready for sanding and final coat of epoxy if necessary. attached a rail and fin box replacement with epoxy resin
yes lowell. If there is a huge gouge you have to sort that out first and can use peel ply for that also. But especialy on rails, the peel ply will make the gouge repair close to perfect, sand then make water tight with peel ply and wet our fiberglass. I have a mutiple ding repair I will be doing soon and the piuctures will explain it better. The peel ply should be bigger than repair and then tape over peel ply. On huge repairs on flats I would use peel ply and throw board in bag for the repair. Thats How I did the fin repair one.
Anyone who needs some peel ply just pm me and I can send. It is very inexpensive. I buy by the roll
Posts go from “it can’t be done” to a guy who does it perfectly! If someone says “epoxy sucks” it means they don’t know ho w to use it.
The only thing I can add is that epoxy takes heat to fully harden. As easy as a dark cloth over the work on a sunny day for a handful of minutes. Let it chemically cure for a day, then warm it for a bit. Makes sanding a lot easier. Also, since you are fairing in two different cures ( the original and the repair) a rubber sanding block will even out the pressure. Sandpaper on your fingers will sand the softer fresh repair more than the old hard cure.
When you mix your epoxy mix it well. Go slowly but blend it well. Get all those molecules lined up with a partner in there.
Depending on how fast you work with the resin and familiarity with gel times, what I like to do is: let it just barely start to warm up in the cup (or I use it the moment I know it’s about to start warming up). You dont want it to get HOT hot, or not leave yourself enough time to work with it, but I found (at least with my heat/humidity) it helps to get the resin to cure a little faster, uniformly, and to full sanding hardness within a reasonable amount of time. Once you spread it thin on your repair the thermal reaction loses some of its intensity and the overall reaction takes longer. BUT as some of you may know, if you leave a bunch of resin in the cup it can get really hot, boil, and smoke, and so on, so don’t do that!
