Refinishing wood components: Is epoxy necessary?

Thread starter #1
I have stripped my rudder, tillers and daggerboard and am ready to refinish, but I'm finding conflicting advice on what to refinish with.

Some suggest using a good quality varnish, starting with a couple of thinned coats to penetrate the wood and finishing with five or six at full strength, sanding in between. Other posts say you need a coat or two of epoxy on the wood prior to varnish.

I suppose epoxy is harder than varnish so it may be slightly more dent-resistant, but on the other hand it's an inconvenience and additional expense here.

What's the popular wisdom? Is the epoxy layer really necessary?

I'm also confused about varnish quality. Some commenters argue that you have to spend the big bucks on pro-grade varnishes, and others suggest mid-grade is sufficient. Is the level of UV protection the key difference, or are there differences of hardness and water resistance as well?

Dave
 

Wayne

Member Emeritus
#2
I have stripped my rudder, tillers and daggerboard and am ready to refinish, but I'm finding conflicting advice on what to refinish with.

Some suggest using a good quality varnish, starting with a couple of thinned coats to penetrate the wood and finishing with five or six at full strength, sanding in between. Other posts say you need a coat or two of epoxy on the wood prior to varnish.
All of the above are possible. I think you are getting bombarded by personal preferences. We all know best what we, ourselves have used.

Transparent Epoxy … toughest of the coatings. It takes some learning over and above the usual varnish application and epoxy needs a varnish top coat for UV protection so it will last.

A How To from the strip kayak builders gives a good look at the process.
http://www.laughingloon.com/epoxy.html


Varnish is the traditional coating.

[from the recent Daggerboard Restoration post ]
Varnish options range from less expensive household products, like MinWax’s Helmsman to more expensive “marine” spar varnish, such as Z-Spar Captain’s.

The difference, as you move along the scale, is the level of UV protection contained in the varnish formula and the amount of dry coating you get from each layer you apply.

Varnish comes in two types, phenolic (oil base) and polyurethane. The popular type is polyurethane because it’s less finicky (temperature, humidity, thinning) to apply and requires fewer coats to achieve a lasting finish.

To browse a catalog that contains a good assortment of brands with their descriptions, visit Jamestown Distributors on-line. Even if you are going to buy locally it provides some arm-chair shopping.
http://www.jamestowndistributors.com

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Do they all work, yes, the question is for how long and with what attention to touch-up maintenance. My marine varnished blades will get a refinish this year after 10+ years of seasonal 3 times-a-week sailing.

Paint ... You can even paint if you don’t mind loosing the “bright” (transparent view of the woodgrain) look.
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#3
Re: Refinishing the centerboard

Just a heads up that I used this polyurethane based product on my centerboard last weekend, and it came out great. Like many on this board, I found everyone's personal recommendations on wood refinishing to be really confusing. Bottom line is that this product below was recommended by Jamestown Distributors as a quick and easy solution, and the final result looks great. All it took was about 15 minute of sanding with a palm sander with 120 grit paper, and a disposable china bristle brush. In fact, I wrapped the brush in foil, and stuck it in the freezer after each use such that I could reuse it again, without having to go through the cleaning process every time. There is no sanding required in between coats, and no thinning. Just open the can, give it a quick stir, and put in on. You'll need to wait 24 hours between each coat, but after 3 coats in 72 hours, the final result looks great. At about $40 bucks (including shipping and handling and a $3 hazmat fee), this stuff is pricey, but after 3 coats, I barely used 1/5 of the can. And this stuff supposedly stays good for years - I'll put 1-2 coats on in the forthcoming years. Anyway, a heads up to anyone else who found teak/wood refinishing options seemingly simple from the outside, but extremely confusing once you start actually exploring the process...
 

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#4
You can not varnish over epoxy. Or maybe you can, but there is no point. Varnish is designed to penatrate the wood. Epoxy will create a barrier. The varnish won't adhere to the epoxy well.

If you want the wood to look amazing, use varnish. If you want a hard, protective finish use epoxy. I'd lean toward the epoxy, as I'd expect the varnish to get scratched badly on a 'fish./
 

Wayne

Member Emeritus
#5
You can not varnish over epoxy. Or maybe you can, but there is no point. Varnish is designed to penatrate the wood. Epoxy will create a barrier. The varnish won't adhere to the epoxy well.
Ten years ago I said the same thing, however. . .

It's a brave new world...


Finish Coatings by WEST System Epoxy
The function of a finish coating like paint or varnish [polyurethane varnish works best] over an epoxy barrier coat, is to decorate the surface and protect the epoxy from sunlight. In doing so, the finish coating extends the life of the epoxy moisture barrier, which, in turn provides a stable base that extends the life of the finish coating. Together the two form a protective system far more durable than either coating by itself.



If you want the wood to look amazing, use varnish. If you want a hard, protective finish use epoxy.
Wooden Kayaks.com
I build these boats out numerous narrow strips of wood carefully fitted together by hand. The wood is then contoured to a smooth, fair surface and covered with a layer of fiberglass saturated with epoxy resin. This composite construction provides a stiff, rugged shell that lets the beauty of carefully selected wood glow through. The epoxy provides a clear, waterproof protective shell over the wood that requires only minimum maintenance.

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#6
And, to add one more note to my previous comment, that polyurethane product has a tung oil base, which eliminates the "varnish-over-tung oil" process, which was yet another one of the many options.

Also, I'm sure the epoxy base option is the best long term bang for the buck, but boy is West Systems epoxy pricey.
 
#7
I've used both methods and I recommend epoxy with varnish on top. For one thing it is much faster than putting many coats of varnish on your boards. Put a heavy coat of epoxy on, sand it smooth and then another and sand, and that will be thicker than 10 coats of varnish for a base. Then a couple of coats of varnish will do a nice job to make it look nice. With the last coat of varnish un-sanded, or minimally sanded for maximum sheen. Next time I plan to put the last coat on with thinned varnish to see how smooth I can make the final coat--anyone here tried that? I think that will be the perfect method.

I can tell you that over time, the epoxy coating might get a bit dull in spots from it's final sanding--my priority was smooth not gorgeous. That held up for year after year of abuse. I have one rudder from my first refinish, that is ten years old and while it could take another thin coat of varnish to look perfect, I most likely will leave it alone as it is still smooth as silk.
Smoother is faster.
 
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