Hotcoat Glass on fins

General Discussion
1

First post. I’ve used this site alot for reference but have a question I haven’t seen in the archives.

What’s the best technique to hotcoat glass on fins. I’m using PU resin. I apply the hot coat to the fins while hot coating the bottom of the board but always get alot of bumps and ridges that are a pain in the ass to sand out. I’ve tried applying the hot coat to the fins before doing the board so that the resin wasnt to thick going on and that didnt get rid of the horizontal lumps I get on the fins. I always dread sanding the fins. Any little tricks or techinques to help with apply hot coat to fins and sanding?

2

do the fins with the board on edge

fins horizontal

do whats facing up then flip and do the other sides

3

I do all at one time…it should go fine if you leave the right amount of resin…maybe one more brush pass just to make sure you dont have excess?

 

4

I do what Ken does especially since I glass on large D fins. An extra step but worth it.

5

Ok makes sense. Thanks!

6

And how do you get the glass patches to go so clear? I saw a Dick Van Straalen board the other day and his build ups were totally clear. My build up is always milky because i have to sand into the cloth to clean up the bumps etc.??

7

 

Properly laminated fins should not have bumps. Gotta trim the edges of the cloth real neat and tidy, then after they’re lammed on, you hot coat and sand.

8

     Howzit Sammy, I always start with brushing the resin on the fins so by the time I get back to that area whenfinishing the bottom all the excess resin has run down the fins and pooled at the bottom and gets brushed off as I am doing the final stroes on the bottom seems to work for me and the hot coat is esy it's the gloss that you want to be really right on . Aloha,Kokua

9

Another tip; use a small orbital sander, again with the fins horizontal; cleans em up real fast and much more control.

10

I had the same problem with the cloth showing through at the base of the fin. I now will keep the cloth cleaner on glass-ons, to make it look nicer, but will you still see the cloth?

 

Are the steps I am taking correct?

  1. Lam. the board both sides

  2. Glass on fins

  3. Hotcoat

  4. Sand

  5. Hotcoat if necessary.

 

11

As Kokua said do fins first, so if there are and any sags or puddles they brush out when doing the flats, and importantly-always brush away from edges never toward.

12

…I think the fella was confused, and really wants to talk about a polished gloss coat or a sanded gloss coat.

The ridges that can occur when you brush the resin on the flat sides, etc; so, resin on resin and not filler resin (to the weave)

13

ghettorat what do you mean always brush away from edges? are you saying to brush from trailing edge to center of fin, then from leadin edge to center of fin? if so, what does that do or prevent?

14

There was another thread on here about the right angle grinder.  The tool has made for a much faster cleaner process to do glass ons. 

After laming both sides, glass the fins on.  After cutting excess glass take the grinder and go to town on the thing.  Get it clean and close without taking off any glass.  I baste the bottom laps and the fins then prep with the small orbital sander.  At that step I won't worry as much about the cloth as much as getting the area smooth.

Then final hotcoat and sand.  If there was any weave I'll try to catch it on the last hotcoat.  The glass ons always get the small orbital.  If you prep was good the final sand should be weave free.

For the baste and final coat I'll cheat and add a touch of surfacing agent with wax just to make it sand fast and easy.

15

I learned how to hot coat old school from Kurt Augsburger who did a lot

of Harbour boards back in the day.  He always did the bottoms first as Kokua

says.  Recently, I watched another production glasser hot coat the deck first

and do the fins at the same time.  This sheets off the fins with a drip or two

which can be cut off at gell stage but makes the fins really smooth.  Then the

board is flipped and the bottom and base of the fins hot coated.  This eliminates

the need to spend time in sanding at the base of the fins to remove pooling resin.

The process is duplicated if you are doing a gloss/sanded gloss. This to me is important

if you are doing a complex bottom around the fin area. Like the man says, there are

always two ways to skin a cat..... Hope this helps, just my 2c.

BKB

16

     Howzit surfteach,there was a time when we always did the bottoms first but later I started doing the decks first and then the bottoms since there was quite a bit of prepwork to do on the bottom to get the sharp edge and then there was 3 fins or a fin system to deal with. I have done some bottoms first even recently and I would tape off the fins so the when I shot the upside down fins there was a fine line that I couls reverse tape off when I did the bottom. But if there were a system on the board then no fins to tape and hotcoat. That was in the days before we had such hard edged rails and the hotcoat seam was in midrail. The main thing is to do it so the fins have no drips or runs in them and when you get it down with hotcoats you can apply it to your glossing of the board. Aloha,Kokua

17

…I do not see the other way to skin the cat…I mean, the logical and obviously way if you have fins, is to do the deck H coat first, because you have:

bottom lamination, flip and deck lamination with laps, so hot coat the deck, it s not practical flip again and h coat the bottom, plus, the deck can have tiny bubbles if its too dry or develop a dry lamination.