im a little confused about the following. what is a cheater coat, a laminate, a hot coat? i hear it all the time but i have no idea what the???
Cheater coat. - American term. This one is mainly epoxy, but relevant for a badly airy polyester also. When your glass job has kicked off but not fully cured, squeegee in another mix. This is a second hit to get pinholes. Depending on your skill, choice of resins and conditions, a cheater coat may or may not be necessary.
It also gives a bit more bulk for the scuffing…In epoxy its necessary to lightly sand the laminate pre filler coat. Epoxy filler coats can be applied wet on wet, but a scuff between the layers gives the best bond and the nibs of pointy glass are knocked off a little. With a cheater coat, you’re less likely to knock the tops of the weave right off.
After the scuff the filler coat will sit really flat, no nibs, like a really good gloss coat, so if you do it well and don’t over-sand, you can get a polish straight off the filler coat.
Laminate- Glass job.
Hot coat.- Same as our “Filler coat”
Hot coating gets it’s name by the amount of hardener you put in the polyester (quite a bit). Too much hardener and the resin will start smoking! You also add surfacing agent when you hot coat with polyester. This is also known as a sanding coat.
Cheater coat (to the best of my knowledge) refers to brushing on a second layer of epoxy (sanding coat) while the lamination is still tacky. You could call this hot coating as well but the amount of hardener for epoxy stays the same. You don’t have to use surfacing agent for epoxy sanding coats, but some people prefer it. Epoxy is not as adhesive as polyester which is why if you want to put a sanding coat on you have to brush a second layer on either before the epoxy is completely cured or after the epoxy has been completely cured and scuffed.
A laminate is just glassing a board with fibreglass and resin.
Josh, Dean, all good, but doesn’t cheater coating make a little mess on the rails since you are not able to tape? Do you just coat the flats? Do you still come back with a fill coat? This seems particularly true on the bottom lam where you would be unable to sand the lap. thx
A cheater coat can be used for many different reasons. Some use it to fill in aired out boards. Some use it to check to make sure they don’t have any air. We occasionally use it if we think a stringer might suck down the resin. We mainly use it just before we do the final bottom hotcoat to fill in a little bit of the weave to give a flatter looking bottom. We use a lot of the heavier weave glass like 8 & 10 oz and we have found that a thin layer of lam before the final bottom hotcoat give us a smoother finish.
When its for the stringer we just run a bead down the middle.
When its used to flatten out the bottom we have already hotcoated the top so we just tape along the hotcoat edge and then shoot a thin layer of lam resin running off the bottom. Right after we shoot the hotcoat layer using the same tape off.
I hope that helps.
Hope this isn’t a full on hijack as it is about resin terminology confusion:
When someone (in reference to epoxy) says they use X ounces of resin to glass one side do they mean total of resin plus hardener or do they mean the resin itself before they added the hardener meaning really 1 1/2X ounces total?
I use squeegee for a cheater coat…it helps force resin into pinholes and the thinness prevents dribbles on the rails, and yes, its done as well as a filler coat.
well, that makes sense (thin coat), thanks