Before the Hot Coat

Hey there.  Just joined the site after lurking for a bit.  Shaping a 5’4" fish (second board, first was about 10 years ago), was wondering and it makes sense to me; I do sand the complete board before the hot coat?  Correct?  Thanks for the help.

Hey cattle dog, what you need to do is mix up a small batch of hot coat(lam resin with wax in styrene added) and brush a strip about 3" wide around your rough edge on the lap on the bottom of your board and a little around the rough bits round nose and tail. Let that go off and then sand with rough paper anywhere from 40 to 80 grit is fine. You then need to hot coat the deck and run that down the rail. That will start to drip so just run your brush around the rail right underneath the board. Let it go off then sand the rough hot coat on the bottom of your board and key up the rail up to about the rail apex.then tape off the rail mid way and build a tape ‘dam’ around the tail area where you want the harder edge and then hot coat the bottom. When that’s kicked pull the tape. You’ll need to leave it till it’s hard to sand the whole board.


Just slap your hotcoat over your laminated fiberglass.  Polyester laminating resin is designed to accept subsequent coats without sanding.  Be sure to use hotcoat resin - it comes with a wax solution additive mixed in and should cure tack-free.  You will need to sand that before adding any additional gloss coat resin.

Epoxy is a little bit different.  Please advise if you are using epoxy.  Or refer to Stingray's excellent instructional thread on how he does it.

EDIT... "Incorrect" refers to the original poster's question, not to the helpful tips provided by Thirdshade.  He and I were apparently answering the original question at the same time.

Thx, but what if the laps need a little work?  Will the hot coat fill all in?

It depends on how bad it is. If you can open up and/or flatten any lumps or airbubbles before you hotcoat then do so. If it’s super crazy bad, then shoot a hotcoat paste around the laps and sand into it. This will help you sand into it without gumming up and wasting a bunch of sand paper. After you’ve cleaned all of that up then paste the rails, nose and tail with lam resin and brush. Let that kick (but not completely) and then slap your hotcoat on the deck. Thirdshade and johnmellor covered the rest.

Ahhh, the laps.    When I was doing glassing, I would use a sureform blade to take down the tags and bumps on the lap line, and then ‘‘baste’’ the lap line with some more lam resin, as a filler in the lap area.      After setting up, the normal hotcoat would be applied.     It made for a very good sand job, with little chance of a sand through.     Very important when doing volan cutlaps.


I tape off my bottom for the edge, brush lam resin over the laps and into the taped off edge. Creates a buffer between the hot coat and the weave.

Then for a light hotcoat you can just paint the lap like thirdshade said and then sand to flatten and take out bumps. If weights not an issue I just hot coat the whole board.


Same here.

After my squeegee technique improved, I rarely had to bust out the surform.


Hey there.  Just joined the site after lurking for a bit.  Shaping a 5'4" fish (second board, first was about 10 years ago), was wondering and it makes sense to me; I do sand the complete board before the hot coat?  Correct?  Thanks for the help.



 In California you can buy pre-mixed "Hot Coat". Also known as "Sanding Resin" or "Fill coat".  After you do a perfect Lam job you can lay out your Hot Coat without sanding anything......that's that.....

.....If you are using Resin Research Epoxy Resin......this thread might help...........Stingray.........


Where I made reference to sanding I only do the basted laps. That means my final hot coat is flatter and easier to sand. It adds a little time as it’s an extra stage but for a non pro it’s an easy method for achieving a good result. A friend who runs a small factory showed me that way.


The key word in that phrase being “perfect”. :wink:

What Bill and Sammy said.  I might add that the weight of glass being wrapped also matters.  6oz. will leave a bigger ridge than 4oz. and also may show more weave when doing a sanded finish etc.,etc.  Glassing is the ultimate love-hate relationship.  "baste"