ok seems like some intellegent and experienced people here . finally glassing after a pretty cold winter. ive allready messed up my mix for my bottom lam…it went off way to fast for my first try …so i spent days sanding and stuff ,sow i think its saved but not near perfect. and never will be. but im not giving up on it yet, any tips on mixing the lam? oh by the way this is a very cool site dont you think? i do. oh yeah ,i think it is a good idea to try a test right …? like say a ounce and maybe 1 cc of cat. and wait see how how long it takesthen mix according to the outcome. and when i get to the hot coat does it really have to mix to go off real fast or do i have some time? oh yeah its about 6’11" .
Hey bob a few things you must pay attention to: - temperature greatly affects the gel time of polyester resin. A few degrees can make a difference. try to keep the room at between 70 - 75 degrees. - larger batches of resin gel faster than smaller ones. So when you test your gel times you’ll need to account for this when mixing up larger quantities. - hot coats, gloss coats, tinted resin have additives which lengthen gel times some. Here are some quantites I’ve found work fairly well For laminates: 40 oz resin - 9cc MEPK 60 oz resin - 12cc MEPK For hotcoats 20 oz resin (with 20cc surface agent) - 10 ccMEPK For gloss coats 20 oz gloss resin - 12cc MEPK you may want to reduce the amount of catalyst for your first lam job, it won’t hurt anything, just may take a little longer to gel - but I wouldn’t go much below 7cc MEPK to 40 oz resin. The above amounts are based on a temp of 70-75 degrees F. (Not only the air temp but also the resin temp). I wouldn’t set off a batch at any lower temperature. Have fun! your first board will be a big learning experience, so your second should be much better! Good Luck, have fun, and be careful! Chet http://www.x-place.org/miniatures/
Sorry that should read 40 oz resin - 9cc MEPK 60 oz resin - 12cc MEPK I have no idea where that link came from??? Miniature Hell?? Huh? what? who’s that? somebody there? ahh!? aaahhhhh! http://www.berlin-gmbh.com/
Hey bob I wondered onto your post from a day or so ago - the guy instructing you on 1.5 to 3 inches of resin is winging it way too much to give you advice - might be hitting the sauce a bit too much too. - jk For your board size - I’d mix 40 oz resin (minimum) for the single bottom layer of glass (4 or 6 ounce weight cloth) and go with about 8cc MEPK catalyst. This should give you 20 - 25 minutes gel time. Make sure you wet your laps - this is very important! Mixing up extra resin for your first time is not a bad idea also - better to have too much than not enough. when you get to laminating the deck with two layers glass - use a minimum of 60 oz resin with about 11cc MEPK catalyst. This should give you slightly more time than the bottom lam above. Again temperature is really key! Good luck - read your warning lables and use the proper protection! if you need further assistance post again, check the archives, or email me at -Chet
Bob, I posted the other day only realizing afterwards how useless a depth measurement is (our workers in the factory measure VISUALLY (and w/amazing accuracy) and catalyze according to the given amount). Chet’s right, small samples are useless AND temperature is a HUGE influence on catalysis. I measured (we use graduated buckets for our epoxy work) the basic minimum amount we use to be about 20oz. for a 7’0" bottom with 4oz. We shoot that with 10cc at 70F. We won’t glass if it gets below 65F (we have heating). Humidity also affects the gel time (higher humidity=less stable batches). The resin gels just as the job is done; about 8 minutes. I figure it will take about 25 minutes for a beginner and 40 oz is a good safe amount leaving a lot of margin. You could keep the MEKP at 10cc but it does make sense to back it off a bit like I am seeing (8cc). Overall it seems like you have the chemical measures pretty well established; I cannot emphasize the influence of temperature. I always vary the catalyst throughout a day of laminating; it’s amazing how sensitive resin is when trying to really do things right. Good Luck.
here’s a question… Say its around 65 degrees ambient temp, and thats what your resin is at. if you put it into a bucket, then filled a larger bucket with hot water, and floated the bucket of resin in the bucket of hot water, and stirred until it reached a consistant temperature of around 70 degrees, then added the catalyst, would the resin stay warm enough until gelling to glass consistantly?? if so, i think that might just be the ticket for people who dont want to use UV resin, yet have colder temperatures to deal with.
yep Dannyboy, that’s half the battle. Good to heat the room too. We microwave our resin to get the viscosity just right…
Use uv cure - I find it much much better than MEKP - less health hazards too!
UV resin. NO MEKP! NO WORIES ABOUT THE COLD NO WORRIES ABOUT GEL TIME NO SUN NEEDED…just daylight!
yep i figure uv would be good , but i allready have regular resin, and dont know where to find a large enough ammount of sun cure. so much for that. when somebody said a large ammount gels faster than just a little bit, well see i do the test on a scrap af foam with a peice of glass so when a small or large ammount is mixed would the ammount in the bucket really matter?