I would love to hear from ya... do you like it on the deck, on a compsand, a coil ?
Why slow hardener.? With a 55 gallon drum you use maybe 2- gallons of slow to get the job done on veneesands or whatever you call them. On coils I use charmin. The 2040 is used between the skin and the foam, long cure only if necessary for the specific job. (huge board, doing both sides simultaneously, multiple boards, working alone, no temp control in shop etc).
The type of resin by flex rating is personal preference. Are you looking for some set in stone cook book answer? Fast is where it is at, flex choice is a great way to sell epoxy.
So to answer your question, It works slower.
you looking for some set in stone cook book answer?
You also use slow in very hot conditions. I actually like using slow a lot. A lot of laminators use slow in FL in the summer. Some use it because they like working slow with no anxiety. The boards I built in the WMD thread were laminated on the outside with slow ..... it was damn hot when I did those.
2040 is for more flex. Use it if that's what you like to ride or if your building a board that's for a novice and your looking for durability. Add more glass. The thing will take a shot and not look back.
Some of the more experienced guys who have been building epoxies for a long time like to use 2020 or 2040 on the bottom of the board and 2000 on the deck. They say the board has a livlier feel that way. I never noticed a big difference but then everyone is different.
Yeah I remember using the long cure, old formula, in California 1997. Post lam at 20 minutes everything is fine. Check on it at 40 minutes and gas off delams the size of tennis balls. I called it my Anti-Phazer boards but the Willis bros had issues with the new design name.
Yeah for CA fast is better for sure.
A few note to add to the info trail, as I used 2040 with fast hardener to lam (once) and to hotcoat (twice) for the first times. This was the first thread that came up when I googled up "resin research 2040 lamination."
My normal is RR Kwik or 2000CE (sometimes fast, sometimes slow), and I generally have found that Composite Resource epoxy is the most dependable for hotcoats (regardless of temperature, but I have often gotten bad results in hot/humid/rising-temp conditions with all types of resins when hotcoating). That combination has yielded a couple of boards then went through horrendous upkeep -- e.g. heavy use for 6 years always being left in a car with the windows up, including in Summer, with leaks in the board, etc., so that now the bottom looks like a golf ball , yet the board still shows no delams and is still being ridden.
First, in a joint glassing project, with very careful handling (gloves always, after the foam was final sanded, and tried and proven prep, including a squeegee coat before the final hotcoat), myself and another board builder used 2040 for the final hotcoat. Results there were OK -- a handful of fisheyes and low spots, despite being careful about temperature and conditions. Very good result, overall, but there was some corrective fill work to be done before sanding.
After that, based on that good experience, I tried to hotcoat with 2040 on a board I'd already waxed, ridden, and then stripped (of wax) and resanded, to hotcoat again. I have done this before with CR epoxy, without problems. This time, with the 2040 (medium amount of pigment -- I had a cosmetic reason for wanting to add pigment to the hotcoat, beyond it likely being better to sand later), I got massive and numerous fisheeyes. I scraped the board off, let it cure, wiped it down with both acetone & DNA, allowed it to dry and tried again. Again, fisheyes everywhere, in all the same places as before. No noticeable positive effect from having squeegee coated, or from wiping down with the solvents. Then I mixed 9 ounces or so of CR epoxy (4.5 of hardener) -- this was for a 6-8 Minisimmons, big boy type of planshape, brushed it on, and got a nearly flawless hotcoat.
Upshot: I might use 2040 to hotcoat again, but not for a board that has had any type of exposure to anything but perfect/routine prep conditions, and probably would aim for cooler and only-cooling temps. It's because I'll likely only use 2040 sparingly in the future that I decided to try lamming with it, because now I have a lot of 2040 relative to the amount I intend to use in the near future.
The relative low viscosity of the 2040 also made me want to try it for lamming a recent board. I was doing an 8-1 x 21 x 3 midsize with 6/4 deck, 6 bottom w tailpatch, Aerolite S-cloth for both 6's. I'm using Aerolite because I changed cloth sources (to Graphite Master, whose service I can't recommend highly enough, so far), and among their offered cloths, this seemed to be the one I should get. I actually liked what I got from Fiberglass Supply as S-cloth as "6 oz" (I think it was technically 5.6 oz?) better. It's less stiff to work with, and wets out better (meaning more readily). That difference in wet out between the cloths is also what made me want to try 2040 for lamming. If any one knows of an S-cloth available from GM, that I might like better, please please please throw me bone.
Anyway, I did get the easier and quicker wet-out I was looking for -- fewer missed bubbles, etc.. I was working in cooler conditions, backyard lamming, without controlled temps -- daily temps varied from 40s overnight to high 70s, low 80s during the day, so the lower viscosity was really useful. It was probably low to mid 60s when i was actually lamming, then no higher than 70, more consistently in the low to mid 60s then in the low to mid 50s overnight. The surprise came three to five days after I lammed. I did a fill coat (also with 2040, and with a small amount of Q-cel and white pigment in the mix), sanded, and then hotcoated with Composite Resource this time, instead, so it was new CR over 3-5 day old lams. I did only 1 hotcoat per day, first the deck, then the bottom, then sanded. After sanding, I took the board out to do a wipe-on sealer coat, and after the bottom coat a quarter sized pressure ding had magically appeared near the rail, midboard. I thought, ****, how the **** did that happen? I carried on and figured maybe it was due to temperature changes and the board sucking/trying-to-expel air? Then, when I was done with the sealer coat, and was putting fins in, I saw that 2 or 3 less prominent but definitely significant new pressure dings had popped up (or rather "in").
Clearly, the lam was still soft, and most likely the pressure dings were from fingers gripping the rails while turning the board over. I had sanded the laps flat, but without burnthroughs to foam; I stopped a tiny bit short of flat, sanding the laps. These "dings" were where the deck laps would have been.
I did *not* "bake" the board after lamming or hotcoating. Indeed, it mostly stayed cool and out of the elements, either in my bay or in racks protected from the sun. Temps were as mentioned above. I've let it take two more full days to cure further, all in the back of my car, so temps are a bit warmer than they would be in the insulated bay during the day, and probably a bit cooler overnight.
The treatment up to now is about the usual, other than variation in time of year, when lamming with 2000, CR, or even UV Poly, but the point the lam is at now, maybe 6 or 7 days after the bottom lam went down (I lam bottom-first, hotcoat deck-first), is way behind any of those under similar conditions.
I'll probably bake it in an outdoor metal shed today, to make sure it gets at least one exposure to temps over 80 degrees before riding it.
I can report on durability results after that if anybody wants details.
In the past three years I've been working with Homegrown Trailers near Seattle... We build the exterir skin (front / top / rear) with 1/8" bending ply... That is glassed with RR epoxy... In those three years I've hand laminated, top coated (x2) and final coated about 20,000 sq. ft. of fiberglass... I have hand stirred epoxy for over 100 hours... It's a lot...
Besides cleanliness, temperatures above 65 F and a mixing time of 3 minutes per batch... THE MOST IMPORTANT THING after correct ratios and timed stirring is to let the epoxy "rest" in the cup for 5 minutes... Get the chemical reaction going...!!!...
We are doing 256 sq. ft. (8' wide x 32' long) at a time, using eight 500 gram batches ... The resin is mixed by weight... Resin weight x 1.44 for hadener... Mix - Rest - and Apply... We apply the resin from the cup with a foam roller, and tip-off with a brush...
This method was developed with a lot of input from Matt Weaver at Fiberglass Supply...
Nice. I have seen a few of those around in the NW.
rr2040 is long elongation to break low stiffness modulus resin so you ended with a flexible thouger skin that is, on eps foam, easy to dent but harder to "open dings". more skin is (flexural) stiff less it dent, for increase flexural stiffness increase thickness and/or use stiffer (higher modulus) materials.