View Full Version : stain/varnish/poly/epoxy - I'm confusing myself
04-19-2006, 02:14 PM
Hey all, I need some straightening out on a few terms and some tips on order of operation. I have some bench seats cut with luan plywood as the top. I bought some west epoxy (105) at west marine. I was going to stain the seats, epoxy them up and put them in but came up with a few questions.
My research has me confused. Previous threads discussing stain said the epoxy will eat the stain. The wood doesn't need the stain so I might just skip it.
Next question is what is varnish? West Systems page says the epoxy can be used with varnish. Why would I want to do this? How does varnish compare to the polyurethane I put on my interior trim (I'm not proposing using poly, just curious.)
In what order are the above put on? Stain (if used), epoxy then varnish? The boat is stored indoors so UV resistance isn't a huge concern (or is it?)
Lastly, what is the shelf life of an open can of epoxy?
04-19-2006, 02:46 PM
Probably easiest to have the epoxy colored, that way you both avoid the step of staining the ply, plus the epoxy should adhere better to non-oily-stained wood.
The Varnish gives the epoxy a much better gloss/glow/look, and is essential to keep the UV from trashing the epoxy -- get a varnish with good UV additives.
I'm at this step right now -- I've used CPES to coat some boat parts, now I'm varnishing them to protect them, even though the boat will be trailer-sailed and stored indoors.
Epoxy doesn't store well for long periods of time, but can last for several years in some cases.
My two cents worth:
Yes, the order is stain, epoxy, varnish. First stain (or preferably not unless you feel you absolutely have to change the colour) with a water based, non-sealing stain.
Then epoxy, then topcoat with a uv blocker of your choice. Traditional varnishes work well. So does Cetol if you don't mind the look of it. Poly topcoats work as well depending on the product and its uv blocking ability. But you absolutely must coat the epoxy with an effective uv block.
04-19-2006, 06:12 PM
Epoxy, stain (Minwax Gel Stain), varnish
I have had wonderful results with the Minwax line in general, but for this combination, the Minwax Gel Stain - works wonderful over the epoxy because it is designed to be used to faux finish fiberglass and metal doors and the like. It is also the consistency of mayonnaise, so I can put globs of two colors on a plastic lid and even mimic grain patterns.
Keep in mind that I reserve stain for repairing scratches, gouges, or other damage, and for blending in repairs. If you ever start to stain a large area or a whole piece of something, say to yourself, "Wood is not supposed to be monochrome." Repeat until the urge to stain goes away.
As an OC (Obsessive Compulsive), I often catch myself trying to get something too perfect and have to remind myself that if I want monochrome, I need to open a can of paint.
04-19-2006, 06:59 PM
concordia...if you were to apply a very thin layer of gel stain over cpes, then varnish, would appear too monochromed or would it just help even out the wood? How does the stain hold up under the sunlight?
I ask because I am very close to this stage. I have 75 year old somewhat blotchy wood. I plan on a tsp scrub, then....?
Just trying to get the best finsh possible. BTW what color did you use?
04-19-2006, 07:36 PM
Ok Grasshopper ...
Mahogany gel stain.
The varnish you use is going to determine UV resistence. One word: Epifanes
The wood I spent the most time on is interior, and my project is in an enclosed warehouse, so I have no comparison.
I am trying to post some pictures, but: a) my DSL connection is blinking and webpages are dragging; b) I have pictures of exactly what you are looking for, but I am trying to import them from another computer, upload, post, etc.; c) I am leaving in the morning to crew / race so if I can get this to upload in a couple of tries ok, if not, I've got to get packed and it'll have to wait until I get back.
P.S. In the whole time I've been typing this, Similes have been appearing one by one so I've got something really wrong with my connection...
04-19-2006, 08:34 PM
I hate to be the grinch, but i can't ignore that the seats are made with lauan ply. If so, i'd suggest paint. It'll save you some effort and some money and will protect the rot-prone lauan better and be easier to maintain.
If you still are prepared for the effort, initlal cost a long-term maintenance of a varnish job, there are many schools of thought on this subject. Some folks have religious fervor on the merits of CPES as a varnish base and some think it's snake oil and that thinning the first coat or two of varnish is an OK start.
Most of us like the marine varnishes from the boat shops and there are probably more votes for Epifanes than for the others, though it's a bit trickier to apply. The expensive boat varnishes have more UV filters than hardware store varnishes and therefore last longer in sunlight. If you're on a budget, the West Marine house brand is fine.
The adhesion of epoxy over stain is iffy and a strong argument can be made for avoiding stain altogether. It's easier to get an even stain job over some kind of sealer, whether it's epoxy or a conventional finish.
Epoxy resin and hardeners have good shelf life - years. Over time , the resins get more viscous and the hardeners darken, but they'll still cure.
I've found epoxy over luan does quite a good job of protecting it, especially above the waterline.
04-19-2006, 08:46 PM
There really aren't any reasons to ever use stain on a boat. Well, maybe I suppose on an interior finish under limited circumstances, but otherwise, no. The thought that by slathering stain down one will somehow even out the "blotches" and so on, is seductive, but always ultimately disappointing. You stain a blotchy surface and you will simply have a blotchy surface the color of the stain. If wood is to be finished bright, it should be finished natural. If that is not possible for whatever reason (e.g. mahogany, once yellowed is pretty much going to stay that color), paint it.
04-21-2006, 01:08 PM
Thanks all for the help. I've set down the stain can and I'm backing away slowly. As for the luan, I'm not going to sweat that, it'll be well coated with epoxy, top, bottom, sides and screw holes. This won't get wet very often as the boat is garage stored and transported under a cover.
Have a great weekend.
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