Author Topic: How many coats of Epoxy  (Read 5587 times)

Offline captainfogfish

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How many coats of Epoxy
« on: December 09, 2014, 07:44:29 AM »
So as it says how many coats on the exterior bottom and sides , I've read a few posts on the subject and methinks if I ask 10 people I'll get 10 answers . So here's my take on the subject , the sides are covered in 8oz , ply pre wetted and cloth filled /wet out not saturated leaving the weave still showing but no bare spots , lumps or bubbles .The bottom will be 12Oz Biax treated the same way , so as they are or will be completely covered in Epoxy and well bonded to the ply and are fully water proof I don't intend putting on another coat to fill the weave as all it will do is add weight and cost more in Epoxy . The plan is to use Jotun Paints High Build Primer this will fill out the weave and leave a smooth finish ready for top coat after a quick blast with  the R.O. sander then topcoat with Jotun Marine paint . Wotcha think guys , good plan , bad plan . I'm back off shore next Tuesday for Xmas  :'(  so won't be painting till after new year but I'm hoping to have it already to paint when I get home
     Eddie

Offline Dave Wright

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Re: How many coats of Epoxy
« Reply #1 on: December 09, 2014, 09:09:37 AM »
I'm an amateur so I have no idea what the professionals do. I fill the weave with however many coats it may take, sometimes with a little silica in the final coat. Seems to me, if you don't fill the weave then you'll be roughing up glass fabric if you do any sanding. Also, good primers are often at least as expensive, if not more so than epoxy.

Offline Dave

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Re: How many coats of Epoxy
« Reply #2 on: December 09, 2014, 01:27:47 PM »
Eddie, I put on 3 coats of epoxy after the glass so that the weave was invisible and completely filled.  Then I knocked the shine off and put 3 coats of system 3 primer.  Maybe overkill but as I recall it was per the manufacturer's recommendations.  If your high build primer is two-part epoxy then maybe you'll be OK with skipping the weave filling coats, but I agree with Dave Wright on this especially on the bottom of the hull.
Dave in Homer
GA26 (FABDFH)

Offline captainfogfish

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Re: How many coats of Epoxy
« Reply #3 on: December 10, 2014, 03:00:02 AM »
I'm an amateur so I have no idea what the professionals do. I fill the weave with however many coats it may take, sometimes with a little silica in the final coat. Seems to me, if you don't fill the weave then you'll be roughing up glass fabric if you do any sanding. Also, good primers are often at least as expensive, if not more so than epoxy.

Aye Dave , my Two Pack High Build is free but I think I'll put on another coat of Epoxy any hoots if nothing else it will protect the fabric from sanding damage
   Eddie

Offline tananaBrian

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Re: How many coats of Epoxy
« Reply #4 on: December 10, 2014, 08:56:18 AM »
Eddie, I put on 3 coats of epoxy after the glass so that the weave was invisible and completely filled.  Then I knocked the shine off and put 3 coats of system 3 primer.  Maybe overkill but as I recall it was per the manufacturer's recommendations.  If your high build primer is two-part epoxy then maybe you'll be OK with skipping the weave filling coats, but I agree with Dave Wright on this especially on the bottom of the hull.

Same here ...3 coats of epoxy, very light sanding between coats to remove little nits, mosquitoes and bugs, and a bit of the ridges in the epoxy (shape of the glass) ...but without getting into the glass.  2 coats of a high build primer is fine, but a 3rd coat might be called for if any weave or scratches are still visible.  Dave's boat has a very nice paint job....

If you want to minimize fairing, do your best job between the waterline and sheer, second best on outside of house and cuddy, and do an 'adequate' job on all other surfaces (basically just smooth out rough edges, sharp bits, etc).

Brian

The Great Alaskan - Professional performance - Easy to build! - https://www.glacierboats.com  ><((((º> ¸.·´¯`·.¸¸><((((º> ¸.·´¯`·.¸¸><((((º> ¸.·´¯`·.¸¸><((((º>

Offline David Nolan

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Re: How many coats of Epoxy
« Reply #5 on: December 13, 2014, 02:56:47 PM »
Use quick fair or make your own.    It will use less and you can trowel it on and fill the weave.     Sands quick too.     

If I was a fairer, that's what I'd do.    It works well


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