I got to jump in here .. I've bought the resins from home depot, autozone, and Oriely's, when I was in a pinch ... but ya Got to look at the dates on that stuff, the polyester resin only has about a two month shelf life, it's on the can, after that, it's unpredictable, and the vynal ester the same, but even shorter shelf life, if it's not shaken often, it starts thickening up with-in itself. If you try to slow down the kick time by reducing the amout of mekp, you may have to go through the take if all off and do it again deal, that sucks ! and it Does make a difference on the percentage of the peroxide in the mekp, it comes with 2% or 4% by volumn, for cool or warm weather use, most general purpose mekp is 2% .. ( I think)
I don't measure the stuff really, I been doing this for a long time, just kinda guess what it takes, temp, humidity, and sunlight still surprizes me, I just look how much resin I think I need, squirt plenty of mekp in it, and get it applied, I don't have much patients, get-er-done, on a floor ... cutting the mat to fit first is a Must, lay it out, don't staple it down, then roll it back to apply the resin, pour some on the project, brush it uniform , lay the mat back in place, then pour the resin on the mat, brush it kinda uniform, then use the plastic 3/8" or 1/4" roller, depending on the weight of mat used, to distribute it evenly, then brush tip it, in a hurry. Depending on the season, I get 2% or 4% mekp from the distributor I buy from, "custom composits" here in Okc, they use so much resin, I know I get fresh resin when I buy it, and on the same note, I buy my gel coat from Florida, from an out-fit that goes through a couple hunderd gallons a week, I know it's fresh .. it makes a difference. I don't use the resin with the wax already added, because I most generally do multipul lay-ups, and I don't want to sand it between lay-ups, but I still scuff it up some, if it has wax in it, it dries to a slick finish, and ya got to grind or sand that off to do another lay-up, just put wax (surfacing agent) in the finish coat, I don't even do that on a floor, or a transon job, I grind it smooth anyway.
I've never concidered myself a pro, and I've taken a lot of flack from others, that call themselves so, on my proceedures, but I do what works for me, and my advice to others, just get fresh product, test your skills on small areas, and then hurry up, 15 minutes is a long time when you are working with resins in warm humid conditions.
