I’m on my third different epoxy resin now. Here are some observations:
Fiberglass Hawaii 4:1
Seemed to work fine, sets up very fast, yellows big time. This is the first epoxy that I used and has therefore had more time to be tested in the water. After 8 months I have gotten a few dings after I broke the leash and it bounced around on rocks and coral. Nothing major, zero pressure dings (2 layer 6 oz S cloth). Hard to work with the metal cans, and they rust on top. Have to clean before mixing batch or else you get dark stains from top of can.
U.S.Composites medium set thin resin.
Made a handfull of boards with this stuff. Takes forever to set. 6 hour flip time was a real pain in the ass, but they do have a faster hardner. After several months not much sign of yellowing, but have also used tint on most boards so that may be hiding or hindering the yellowing process. By the way, I have been coloring my boards during the gloss coat phase. That works great as long as you don’t sand the gloss coat too much. I used pumps on the plastic bottles and like the control of the pumps, even if using mettered buckets, it’s much easier to get exact measurements. Surfed one board for a few months now. Again, no pressure dings yet, same glass schedule. Havent been pounded yet like the fiberglass hawaii boards so not sure how strong yet.
Resin Research fast 2000.
Just finished hotcoating my first board with this. The lam went off really fast, maybe 80 degreee F outside, little less in garage. After messing with 2 logos on bottom I barely got 1 layer of 6 oz. S cloth on before it jelled. Not quite so hetic laming top using 2 layers cloth, but it does go off fast. No time to spare. I only mix for a count of 120 (about 2 minutes). and as always I microwaved resin 2 seconds per oz resin. This stuff is thicker than US Composties. (1000 vs 600). Still have to do the gloss coat after sanding this afternoon. One problem I had on hot coat was lots of air bubbles. I did hit it with the heat gun while it was setting up and I could see the bubbles poping, but it was late and I had no natural light, just a 250 watt haligen (bright). It was hard to tell if I should continue with the heat or not. I was afraid to over do it, but can see now it needed more with the heat gun. I didn’t have to use the heat so much with US composites to draw out the bubbles. I’m hoping the gloss coat works out better and will post the results. Again, comes in plastic bottles which is good. I wish I had another set of pumps to put on. I could use my old pumps (if they fit) but worry about mixing resins and hardeners trapped inside pumps.
Check out photos of bubbles. They cover the entire deck. A few less on bottom.
I haven’t used the first two, got lucky with RR as my very first pick. If I may offer a suggestion, how about not nuking the RR before using it to lam? I’ve heard of doing that for a hotcoat, but it wets out well enough with the add. F that I don’t think it really needs to be thinned out by heating it for laminations.
I just did a bunch using the fast hardener in 70-80 degree heat, and found that I was just barely starting to thicken a little after lamming a 7’8" and fiddling around with patches at the nose and tail, then by the time I got the next two boards lammed, the first one was about cured enough to handle.
Note: Laminating a board while the temperature is rising is the best way I know to create off gas bubbling.
Suggestions: If you are working in 80 degree weather do these things. Use slow hardener & put the board out in the sun and get it nice and warm. Then bring the board in the shade a few minutes before you start laminating. Don’t heat the resin. Just mix up enough to do the flat surface when you get them in good shape. Mix a second batch to do the rails and roll them clean. There’s no reason to mix up a full batch. Give yourself time to work like a gentleman. I always do my work with two batches cause I do lousy work when I’m stareing at a rapidly approaching deadline.
For the record: sealing the board with resin prior to laminating is a grand idea IMHO. At 80 degrees I see no reason to accelerate curing by heating the resin. I have never used additive “F” for the lamination process, because I can see no advantage to using it until it’s time for the finish coating. Adding Alcohol to the resin seems a needless complication IMHO. Dust and dirt is your enemy, no doubt. These are just my own preferences after doing seven boards. So I can hardly call myself an expert.
i had some problems with pinholes, and it seemed to go away with those small changes to my routine.
contamination was definitely never a problem.
problem one was that the lam was pulled too dry…enter the cheater coat…problem solved.
heating the resin isn’t to accelerate the curing process…it’s to thin out the resin. when the resin is heated, it flows much more smoothly over the board. subsequent coats went on much better. probably not a necessity for the hotcoat…but definitely for the gloss. just the same…it can’t hurt.
and with a little splash of dna…the alcohol surfaces and evaporates…things lay down nice and flat…with no pinholes…and requires minimal (if any) sanding. not too much, though…just a splash.
Ya know, my short term memory is so bad that I can’t recall if I nuked my lams the last few times or not. I had to wait a couple of weeks for the rr to arrive so I kind of lost my recollection. It seems that I did nuke them though…I’ve been using 6 oz S cloth which I think is a little harder to wet out. What kind of cloth have you been using?
I have been heating up my blanks before I do my lams, so my outgassing problems have been less lately. I am a dawn patroller so working into the night on falling temps just doesn’t cut it for me. My problem with slow hardener is the super long flip time and the extended time the sticky resin has to become a bug magnet. I’ve added a bug zapper recently and that helps. But I really like the 2 hour flip time. I think I’ll try again to not heat the resin for the lam, but this happened on the hot coat. As far as two batches go, I appreciate the suggestion but I already spend a small fortune on those metered buckets, unless I reuse one. That may be worth a try.
I just got done sanding and it turns out not to be bubbles at all. It appeared to be sharp little chuncks of resin. I don’t think it was dust, but it may have been. I just don’t have a dust free environment, but never had this problem before. Sanding it smooth and came out great. Came across a couple of pin holes that should fill in on the gloss coat.
One thing that was way weird last night was when I was hitting the resin with the heat gun I kept seeing little flashes. Almost like flames but not really. I couldn’t tell if it was the reflection of the heat gun tip in the halide light or what. I’m usually working with some natural light but it was after dark when I was hot coating. I don’t know what to think about these chunks, but it seems to have sanded smooth and not effected the final product. Just stoked it wasn’t a million pin holes.
I think I’ve got to work on a cheater coat. How much resin do you mix up for your cheater? Do you find it makes it harder to cut your laps do to the longer wait for the chaeter to harden before you can flip your board?
Just another example of different resins. I glued in my boxes with left over Fiberglass Hawaii epoxy. Due to the V the center box has to be set deeper and then be filled in with resin. You can see how yellow it is. The lam and hotcoat in this photo is with rr resin. This is the same board after being sanded down.
I think I’ve got to work on a cheater coat. How much resin do you mix up for your cheater? Do you find it makes it harder to cut your laps do to the longer wait for the chaeter to harden before you can flip your board?
i mix up about an ounce per foot. with additive F in the lam and a sharp utility knife, i don’t have any problem getting a good cut.
I use the US Composites resins for setting up plugs and boxes as it goes off very slow and no real risk of exothermic reation (slow and medium). Its cheap but has good adheasion qualites. I talked with them about using it as a lam resin and they were not comfortable giving me the OK on that. It has some amber tint to it, but fine when pigmented.One resin I used that had surprisingly good qualities in laminating was “Dura-Clear” from Chafin in Texas. it was lower viscosity than RR and showed very few airs in the lam. Its a little thin for a sanding coat – but ok. Wondering about how it sets up long term.
I talked with them about using it as a lam resin and they were not comfortable giving me the OK on that.
I’ve used us composites for lams and had no problems with it. I can’t imagine why they were not sure if you could lam with it.
Most of these guys are not into experimentation – they supply boat/marine interests – “don’t know, don’t go,” is their thing. US comp epoxy is used to put together boats (I used it in my boat) so, it is probably structurally fine for a surfboard.
These are just my own preferences after doing seven boards. So I can hardly call myself an expert.
I think I rode number 2 or number 3 and it already looked professional to this non-glass-shop eye. I think it helps when there are true professionals with thousands of lams under their belts a few feet away.
hey, just a side note…the FiberglassHawaii 4:1 is a really generic epoxy…made to be used and then painted over, its supposed to be brown, like Marine Lam PE resin.
the FH 2:1 epoxy is the surfboard epoxy…try that.
its non blushing and clear…use the fast hardener, it starts gelling in about 15-20 mins like a regular PE resin.