epoxying/varnishing timing

I am about to embark on the sanding/epoxying/varnishing part of my build, and I would like to understand the timing better (since I can't wait to get the boat done!).

I've read that I can do a coat of MAS epoxy inthe morning and another one in the evening. How many coats on non-fiberglassed wood people usually do? How long should I wait before sanding the final coat? And how much time between varnish coats?

I assume I'll have to do inside and outside separately. I don't see any way to coat the entire boat in one pass.

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RE: epoxying/varnishing timing

on the epoxy over wood, no glass....i would go with at least two coats.  this way you have the second pass to pick up any bits you missed on the first coat.  doing these coats with a little foam roller  https://www.clcboats.com/shop/products/boat-building-supplies-epoxy-fiberglass-plywood/boat-paint-varnish-finishing/foam-roller-covers.html makes it easier to get a thin coat on easily and then tip it with a foam brush.

make sure to do your epoxy work for the first coat when the temperature is decreasing over the cure time to prevent outgassing.  the wood breathes...so when you epoxy coat it you want it inhaling so it doesn't put bubbles in your epoxy.  if the wood is heating up, it will try to exhale.

this can be a one day operation.  do the first coat at night (so it gets cooler as the night moves on), then the next coat the following morning.   i usually give it a day before sanding if you are at a good temperature range  (above 70 degrees).   you are only sanding lightly to take off any rough spots.  it is very easy to sand through...so you may need a third pass to address any sand-throught just addressing the sand through with a foam brush and a little epoxy.

on varnish.  again, follow the directions on the label.  but if it is nice and warm you can get a morning coat and evening coat on.  i would avoid trying to do more than two coats a day.



RE: epoxying/varnishing timing

   >> and then tip it with a foam brush. <<

Pay attention to those foam brushes. The ones I got from the hardware store began to come apart in the epoxy, leaving little black lumps in the coat. Discard the brush and get a new one at the first sign of deterioration. Fortunately I learned this on an interior part of my boat that's all sealed up now.

I don't know if the foam brushes CLC sells have the same problem or not. I've been doing mainly paint & varnish since I switched to them.

RE: epoxying/varnishing timing

Use your pull saw to cut those foam rollers into sections, then cut the sections in half lengthwise, glue on a handle. Much better tool for 'tipping' rollered-on epoxy to reduce/prevent bubbles than the foamies that can start to disintegrate. The cut-up rollers work as well for tipping varnish too.  

RE: epoxying/varnishing timing

   Thank you all for the responses. The project feels manageable time-wise.

By the way, how do you guys apply varnish? With rollers? With foam brushes (the way CLC suggests)? Something else?

RE: epoxying/varnishing timing

the methods described  on the CLC website and their videos work well (with foam brushes) and that is how i approach it. 

per the comments above,  it is very important to use foam brushes/rollers that are compatible with the step (varnish or epoxy or paint) and the stuff you get at the local hardware store often is not. 

i usually buy my rollers and brushes from CLC ...the pricing is good.  or i use another marine supplier like jamestown....who know that they are selling to marine users who are working with marine paints, varnishes and epoxies.  its cheaper to buy in bulk so estimate the entire project and save on shipping.   

the right quality/specifications are important and most general hardware stores would not be able to tell you the formulation of the foam they are selling.   even though i have a local hardware store and have run out of brushes (and they had foam brushes), i waited for an order of known quality to arrive from CLC.

if you do use from a supplier who does not know the details of what they are selling, consider doing some test work


RE: epoxying/varnishing timing

   Yeah, since this is my first build and I am clueless otherwise, I got essentially all my supplies from CLC. If things go wrong, I'd better blame them than myself :)

RE: epoxying/varnishing timing

   Regarding the time between varnish coats, this question is actually answered on the Interlux Schooner Varnish product page:

55°F (13°C) 16 hours
70°F (21°C) 12 hours
85°F (29°C) 8 hours

So yeah, two coats are doable in a day at 70º and up.



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