whats a good amount of cat to use that wolnt give you to short of a gel time or to long of a gel time for about a quart of resin. i am trying to get better with my glassing skills but every time i use mekp i always mix to much in or to little. can you please help a fellow craftsman before wilma dominates my home .(i pray to god it doesnt)
-lex
till then i am gonna continue searching. . . …
The stuff I use states clearly on the lable the required mixing ratios.
1.5 - 2% of MEKP to Resin measured by volume.
If you are using polyester resin you are never going to get a long working time (15-20 mins max) in my experience, however with that said gell time is totally dependant on the outside tempature.
try suncure or epoxy
Hot and humid? Try about 7 cc’s, if it’s cool use a little more. If it doesn’t kick and the sun’s out, take it outside after it gels a bit. Should kick it the rest of the way. Or, if it doesn’t kick, mix a “hot” batch and apply to the lamination and squeege in.
Thanks gents 7ccs worked out GREAT for me i had ample time to get laps perfect and spread the different colors i will post a pic of the board when i am done. . .
-lex
Open this link, there is a chart of MEKP by volume. Print it out and nail it to your wall where you glass:
http://www.fiberglasssupply.com/pdf/miscellaneous/MEKPChart.pdf
All polyester resins are not created equal as far as gel time. The mekp reacts with a promoter, usually cobalt naphthenate, so the amount of promoter in the resin has a effect on the gel time. If you stick with one brand of resin you will get a feel for how it work with different amounts of catalyst and at different temperatures.
viejo…
You are absolutely correct. Not all resins are the same nor are the types of MEK-P. Generally speaking, the MEK-P should be mixed at .8 % to 2 % by weight or volume. the difference is so small between volume and weight it should not make a difference. Its always a good idea to do a test coupon and time your gel time. Room temperature and resin temperatures make a big difference in the gel time of either poly or epoxy. Another thing to keep in mind is that polyesters like to grab onto moisture. If you have high humidity, your end result can come out a bit gummy… Test the resins first! This is always a good practice, until you have used them enough and know what to expect in a given circumstance.
Ken