What type of fiberglass resin is best to use on a Hobie comtip repair?
Bill 404 21SE
Does this help?
Prindle 18-2 #244 "Wakizashi"
Prindle 16 #3690 "Pegasus" Sold (sigh)
AZ Multihull Fleet 42 member
(Way) Past Commodore of Prindle Fleet 14
Resin Research Composite Pro 2050 + 3100S. West Systems starts to soften at 105 degrees F, which is about half the temperature of a black part in the sun. The Resin Research product is lower cost and much higher performing.
The other well recommended product is Adtech 820, these folks have everything you need for the repair: https://www.sollercomposites.com/Epoxy.html
I would paint it white or at the very least clear coat it. The latest 1k rattle can paints, either Rustoleum auto enamel or krylon do nicely.
I've been using the Jamestown branded resin, "Total Boat", which is a 5:1 resin and have been very happy with it. I suspect Gougeon Brothers packages it up for them It also responded exceptionally to post-curing at 300F for 15 minutes when I was making carbon fiber bar backers for a hull repair. Very predictable, but exact same technical info (hardness, etc.), just seemed to harden better than the old West I knew.
They both have the same tech data, however. The Tg value is what tells you when it'll start to fail at what temperature (about 125F for West and Total). You'll pay a bit more to get into the 175 degree range and really need to post-cure it to see those benefits. I'd repair using epoxy, whatever brand you pick as you're making a glue joint, not a chemical bonding joint. That means, wash with soap and water thoroughly first, then wipe with acetone, then sand the parts to get a good "tooth" for the epoxy to get a hold of, then wipe with acetone again before epoxying it.
I found that a temperature gun/thermometer is really handy along with a scale, even though I use metered pumps as sometimes you get air bubbles. Most times the pumps are pretty darned accurate. I mix up the resin, take a temperature reading of the mix stick through the resin immediately and then keep mixing and taking temperatures watching the temperature climb and the color of the resin change from cloudy to water-clear(ish). Takes more mixing than you'd think. Somewhere around 92-95 degrees is when I go to work, if I've been mixing for a while.
Like above, there are better resins for cheaper, and you do have to paint all epoxies as they are not inherently UV resistant.
So, uh what happened Bill?