Author Topic: Fill Coat / Hot Coat procedures for production  (Read 8471 times)

newleafsup

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Fill Coat / Hot Coat procedures for production
« on: November 29, 2015, 01:49:54 PM »
I have a question about the fill coat and hot coat. I have been building boards for the better part of 5 years now and have been lucky enough to build boards for a living for the last 2 years full time. I myself have been mostly self taught (not any sup builders in my area on the Gulf Coast) and I always apply the fill coat then sand the entire board with 80 grit to flatten the board and clean up the laps, then apply a thin hot coat and sand the entire board once again. I am wondering if production guys fill coat then lay a hot coat once it gels and only sand the board once. I am trying to cut time in the sanding room as well as cut costs on using twice as much sandpaper and want to simplify the process so when I put in place a sander (at piece rate) it will be staright forward. I know alot of us on here are diy'ers but it would be great to hear from some production guys. I can see getting away with a fill and hot coat in one shot on 4 oz. cloth, but is the 6 oz. a different beast being a coarser cloth? Thanks in advance.
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PonoBill

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Re: Fill Coat / Hot Coat procedures for production
« Reply #1 on: November 29, 2015, 02:07:03 PM »
I lieu of a production pro answering, I've seen how high production boards are made, and they generally get sanded after fill coat and then just polished (buffed) after hotcoat. This seems to be standard for Asian boards. I think that explains the kind of wavy top coat you sometimes see. I try to minimize sanding out of laziness. I don't sand or buff hotcoat except on the bottom, where I prefer a non-gloss finish, so I do a once-over with 220. I certainly don't do production, in fact I've never built a board from scratch.
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supuk

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Re: Fill Coat / Hot Coat procedures for production
« Reply #2 on: November 29, 2015, 03:00:57 PM »
i am by no means doing production stuff but have done a fare few big boards over the past few years and are  totally self taught other than internet resources but i believe that the end quality shows in a sum of the quality through out every step of the process.

The trick to sanding is not in the sanding but in a good tight lam that doesn't hardly need sanding and fill and hot coats that come out crater free every time and then you doing very little sanding however that said there is still more sanding than anything else in building a board and epoxy is 5x harder than pe to sand.

I have found a good sander and good paper at least makes it semi pleasurable. I would always blend the lap before doing any fill coat so that you are not burning through back down to the glass as it makes it less likely for that to happen when sanding the hot coat but thats just me and I still have a lot to learn.

The method most production boards seam to be is just cover it in a thick q cel mix thats very easy to sand and then just stuff a load of paint on it to cover up all the ruff work.

Dwight (DW)

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Re: Fill Coat / Hot Coat procedures for production
« Reply #3 on: November 29, 2015, 03:08:28 PM »
I am wondering if production guys fill coat then lay a hot coat once it gels and only sand the board once.

You are correct. But the factory called the fill coat a cheater coat. Lap touch up sand, then hot coat, bake, final sand.

Make sure you use the sand paper from Portugal. Rhynolox Indasa

TallDude

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Re: Fill Coat / Hot Coat procedures for production
« Reply #4 on: November 29, 2015, 03:09:35 PM »
For what it's worth, here is some Swaylocks chatter on the topic. http://www.swaylocks.com/groups/cheater-or-not
Like Supuk says, a tight lam will save you a ton of sanding.
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karl

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Re: Fill Coat / Hot Coat procedures for production
« Reply #5 on: November 29, 2015, 10:19:39 PM »
And a well shaped core will help with tight lam, even hot/cheater, and easier sanding..

bajasurf

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Re: Fill Coat / Hot Coat procedures for production
« Reply #6 on: December 09, 2015, 02:56:16 AM »
Its my big bitch.  Sometimes i hate epoxy, heck most of the time...

I have tried everything, and all suggestions and what somewhat works for me is a fill coat with brush, and then a hotfoot as soon as it starts to set up, slightly sticky.  Works most of the time, last time it was so-so.

I might go with poly over epoxy next time.  A buddy of mine does it that way and it works fine as long as you sand the epoxy with 100 grit and then apply the poly, and poly is a joy to sand after trying to sand epoxy.

magentawave

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Re: Fill Coat / Hot Coat procedures for production
« Reply #7 on: January 17, 2016, 10:07:18 PM »
Its my big bitch.  Sometimes i hate epoxy, heck most of the time...

I have tried everything, and all suggestions and what somewhat works for me is a fill coat with brush, and then a hotfoot as soon as it starts to set up, slightly sticky.  Works most of the time, last time it was so-so.

I might go with poly over epoxy next time.  A buddy of mine does it that way and it works fine as long as you sand the epoxy with 100 grit and then apply the poly, and poly is a joy to sand after trying to sand epoxy.

Yeah, epoxy is a beeotch to sand compared to polyester. A polyester hot coat over epoxy? Interesting. I didn't think that was possible but I 've been hearing about some people doing that on surfboards. What is the longevity of those boards - and especially on sups? In other words, does the polyester stay stuck to the epoxy?
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bajasurf

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Re: Fill Coat / Hot Coat procedures for production
« Reply #8 on: January 18, 2016, 04:31:19 AM »
If the epoxy fill coat is sanded correctly, it will stick just fine.  A buddy does it this way with his prone and SUP production boards and he doesn't have any problems with it..

I have heard of chipping(poly) flaking off on some boards that didn't have a good bond..

I have 2 boards over a couple of years old, that I used poly over epoxy, and so far I love it..

Its a mechanical bond, so the epoxy fill coat  sanding needs to be rough, so they poly has something to grab on.  Check out Swaylocks, some swear by it other swear against it.

Dwight (DW)

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Re: Fill Coat / Hot Coat procedures for production
« Reply #9 on: January 18, 2016, 04:40:49 AM »
Not all brands sand the same. Try another. Always sand after baking. Mine sand great.

magentawave

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Re: Fill Coat / Hot Coat procedures for production
« Reply #10 on: January 18, 2016, 10:23:50 AM »
Is this what you do?

Laminate with epoxy > hot coat with epoxy > sand with 100 grit > fill coat with polyester
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surfcowboy

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Re: Fill Coat / Hot Coat procedures for production
« Reply #11 on: February 01, 2016, 07:53:32 PM »
I wanna pitch in for the bake. Even if it's just in a car (be careful in hot climates!) I make sure my boards get a couple of afternoons in the car and they harden up nicely.

I am getting better hotcoat but I'm still fighting small craters. I'll report in over on the haterade thread. I might avoid a gloss coat and just get to finish this one but I gotta sand into it and see.

supuk

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Re: Fill Coat / Hot Coat procedures for production
« Reply #12 on: February 02, 2016, 04:28:29 AM »
Geting the hot coats down flat is key I'm geting prity consistent results now and using a good sander and even more important good paper sanding realy is not a issue for the benefits of a full epoxy build. I could never put poly over epoxy. If you have every had to repair them you will soon see the frustrations. Sanding a hot coat flat with 120 or 180 on a 8' board only takes 10mina side if that. I'm still just doing a squeegee cheater coat left to tack then a brushed coat and may get one or two small fish eyes tops which I just drip resin on 30-1h or so in when I go back to catch the drips

bajasurf

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Re: Fill Coat / Hot Coat procedures for production
« Reply #13 on: February 02, 2016, 07:19:57 AM »
10 minutes a side, thats not me.  I sand for at least a hour or more each side and rails with Epoxy.  Way too much work.. Start with 80 then go up from there..  Cutting the top coat takes so long.

The repair is the same when using poly over epoxy.  Just repair with epoxy like normal.  I have had any issues with repairs so far.


supuk

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Re: Fill Coat / Hot Coat procedures for production
« Reply #14 on: February 02, 2016, 08:06:05 AM »
10 minutes a side, thats not me.  I sand for at least a hour or more each side and rails with Epoxy.  Way too much work.. Start with 80 then go up from there..  Cutting the top coat takes so long.

The repair is the same when using poly over epoxy.  Just repair with epoxy like normal.  I have had any issues with repairs so far.

That's per grit normally start at 120 or 220 but the higher grits don't take long.

I would never put epoxy over poly ether so that makes feathering in impossible without having to sand the area right back and then hot coating  with poly and I would rather not mix the two.

 


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