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What to cover a woodie?

Posted:
Tue Apr 21, 2009 1:04 pm
by Von Pook
May I ask, what is everyones opinion on exterior seal for a woodie? Epoxy, spar, etc? Thank you all.

Posted:
Tue Apr 21, 2009 2:37 pm
by b.bodemer
I used spar urethane but my td is garaged. I used a satin finish.
When I helped my friend Kate build her td last summer she decided on epoxy followed by spar urethane. She had it in a garage for the winter.
Barb

Posted:
Tue Apr 21, 2009 4:29 pm
by MushCreek
I've never built a tear, but I've been working on boats for many years. I'll echo the advice for epoxy, coated with a marine (UV resistant) varnish. Epoxy has superior bonding properties, but is attacked by UV. Coating it with varnish gives you the best of both worlds.

Posted:
Tue Apr 21, 2009 5:56 pm
by tk
Just got the June issue of Fine Woodworking yesterday and was going to post this information anyway. Just as well put it here. They did a test of outdoor finishes. I haven't read the whole article, but the only finishes that appear to be worth considering (of those they tested) are Epifanes High Gloss Marine Varnish-seven coats-$45/qt. and Smith & Co. Penetrating Epoxy Sealer-three coats-$42/qt. topped with Epifanes Marine Varnish-five coats-$45/qt.
My main observation that I could distill at a glance is that 'you get what you pay for.'
Best,
Tom

Posted:
Tue Apr 21, 2009 9:20 pm
by doug hodder
I've built 2 woodies, epoxy and auto clear on both. I've had really good results with it. If you want to go varnish, the Epifanes is absolutely wonderful. Varnish can take more maintenance, but if you take care of it should last a long time for you. On a nice older restored boat, most are done with the Epifanes or in a varnish, because if it is to be judged, you get points knocked off for auto clear, it's just not original. Doug


Posted:
Wed Apr 22, 2009 12:48 am
by Von Pook
Hey Doug, two big questions for ya, (1) how did you make the curved trim, and what speed of hardener do you use for the epoxy? Would a faster set speed be better for the walls, or a slower thinner layer work better? I must admit, I like the glow of your tears. That kinda sounds sick in a way


Posted:
Wed Apr 22, 2009 1:31 am
by doug hodder
I used a marine grade mohagany, 6mil, laminated on a 5/8" ply. Dyed with colonial red aniline for the sides. Buried it with like 5 coats of epoxy, then shot the clear over it. For the curved trim, I made up cardboard templates and then traced them onto the 5/16 maple, cut them out with a band saw and sanded the cut edges. Thing is, you have to make sure all the hard edges 90 degrees, are eased so that they will not cause any epoxy or finish to crack on the hard edge...it will. I also sealed all the trim before I applied it on the back side. I used a thickened epoxy so that I got some squish on it and it sealed up all the joints where it was bonded to the sides. Smoothed the squish out with a finger.
I did up the sides with the dye and epoxy before I installed them, much easier to do when they are laying flat. Then I cut the doors and installed the walls.
I use West System epoxy. The 207 hardener is what is used for 'brightwork' like this. It isn't speed rated but is what they call a "special top coat" hardener". It has some UV resistant agent in it, but still needs to be top coated with something. It's made for showing off bright wood work.
My opinion...all the layers of epoxy need to be put down thinner, using a roller and tipped off, pre-sanded prior to the next coat. A great top coat is dependent on what's underneath. The more layers you lay down, the deeper the finish you end up with. Outside of the automotive clear, anyone can do this, once the epoxy is done, it's up to you how you top coat it. Can't spray clear?...then do the varnish, but get a REALLY nice brush to do it. The real glow that you refer to comes from depth in the finish, epoxy/ clear or varnish.
It ain't easy, time consuming, you're going to do the sanding on the epoxy anyway regardless of what you put over the top, the advantage of an auto clear in my opinion is that I can spray 2 coats of clear in an afternoon and it'll look as good as tons of time doing the varnish....but some experience and equipment is the advantage. I think the results are pretty nice. All of this is just what I've done. Doug

Posted:
Fri Apr 24, 2009 12:41 pm
by Todah Tear
I used Helmsmen Spar Urethane from Lowes or Home Depot. When you apply it, make sure it is not a humid day or you may have areas that come out kind of cloudy. If it's not too hot of a day and it is humid outside, warm your garage with a little heater.
The finish comes out clear and holds up very well.
Todah

Posted:
Fri Apr 24, 2009 2:45 pm
by Mauleskinner
I'm sealing mine with West Systems epoxy, using the hardener with UV protection (#207 maybe?), and then I'll put spar varnish over that.
I've got a couple of Adirondack chairs with just spar varnish, and I can't quite seem to get consistent sealing with that, so I'm doing the epoxy sealer.
David

Posted:
Fri Apr 24, 2009 3:22 pm
by Von Pook
What is the difference between spar varnish and spar urethane?

Posted:
Sat Apr 25, 2009 6:06 am
by Rock
Not enough to worry about. Polyurethanes are a sub-set of varnishes. They both varnishes.
Eric