Spar varnish questions...

[Eric Adams]

My TD will be natural wood and I am going to coat the outside in Spar Varnish. I have never used it. Do I:

Put on a thick coat, 4-ought steel wool it, re-coat, steel wool, coat, etc... ??

Is it better to brush or roll it on? I can't spray it because of my workspace. I will have to brush or roll. If rolling, what kind of roller?

thanks!!!

[SteveH]

Eric,

I'm not going to tell you how to get a good finish because I'm not worth a crap at it, but I will tell you not to roll it. If you want any chance of a good finish you will want a good quality brush. Years ago I had a boat with a lot of mahogany in it and I had good luck refinshing it using a foam brush.

[Arne]

If I was doing a large area, I might use a roller to apply it, and a foam brush to drag out the material and air bubbles. I do this a lot with epoxy resin on kayaks.... it gets the material on more evenly and quickly, and the dragging fixes problems left behind by the roller.

[Terbeau]

From my boating days with way too much varnished wood...you need at least six coats of varnish (well sanded between coats) for a durable, protection layer. You must fill all the porosity of the wood grain. Failure to do so leaves places for water to inter the wood and cause the varnish film to lift, allowing more water in. That is how varnish fails. If you look at a well kept boat or yacht with varnished trim, the varnish will have a glass-like surface. That's not just to impress...it is the best way to keep the varnish entact. Any place there is a crack or ding is where the varnish fails.

Of course, if you store your TD inside, then the varnish will not need to be of that high quality finish for it to last. But leave it out in the weather and sun, it will need redoing about every six months...at least in SoCal weather.

Ralph

[DestinDave]

Also from my boating background... I recommend at least 6 coats to get a nice "glass" finish with the 1st coat thinned 50/50, the 2nd thinned 70/30 and all following coats 90/10 or 100% varnish. I prefer a good varnish brush but marine stores carry foam rollers made for varnish. If using one of these rollers, "tip" it out with a clean dry varnish brush to get any bubbles and lap marks out. Sand well between coats with successively finer grit papers and clean well. I use acetone or denatured alcohol to remove all dust. Acetone will soften the varnish slightly so be careful with it. After 5 or 6 coats you will really start to get a nice glassy finish. I would carry teak finishing out to 12 or 13 coats with wet-sanding the final 3 or 4 coats but that's probably over-kill here. One word of caution though - all blemishes (scratches, blotches, stains, etc.) will be amplified under the varnish so spend the time to make the surface ready for the varnish. Unless the sun beats the hell out of the varnish, maintenance consists of a light scuffing and application of another coat maybe once a year. FWIW - I like Epiphanes or Schooner brands.

[Steve Frederick]

FWIW...
I coat over fiberglass, so the issue of sealng the wood fibers has been resolved. I'm not concerned about sealing the wood from moisture, just adding some "bling" and U-V protection for the epoxy.
If you go over raw, or stained wood, use a thinned 50/50 coat of varnish. Use #300 or #400 grit wet/dry paper between coats. I quit using steel wool 'cause it can leave bits of metal behind.
After that, Roll out the next/first coat. Use one of those black foam roller covers meant for varnish or adhesives. Tip off the surface by dragging a dry, or barely damp, foam brush accross the finish to remove any bubbles in the finish. Sand with #300 or #400 grit.
Do two or three coats like this, sanding with dry paper between coats. I stop after 3 or 4 coats. You could do a wet-sanding between the last two coats, although, for something like a camper or a boat, I think it's overkill!
If you want the best finish, go with automotive clear-coat. The thing is, you'll have to build up a base with epoxy, wet-sanded between coats, to get a really smooth job. Check out Doug Hodder's wooden runabout for an axample of a great finish!

Hey Doug, what did you use?

[doug hodder]

Hey Steve.... I use West System epoxy with #207 hardener. It is for top coat finishes, not for structural glueing. I laid it down with a foam roller 3 1/2" and then dragged it off with a roller cut in half held in a spring clamp. On my boat I laid 6 layers of epoxy down with sanding inbetween. This was done because I striped the deck with automotive pinstriping and wanted to build up the epoxy so that you couldn't feel the tape. I wet sanded inbetween coats using finer paper the more layers I had built up. I finished up with 600 grit, and then shot it with Transtar automotive clear coat. I wet sanded that from 800-2000 then hit it with the polisher and a fine compound and wool bonnet, using a spray bottle with plenty of water so as not to burn the finish. There is no cloth on the top deck. It's way time intensive, but it has great uv protection and won't need the maintenance like varnish. West System has a roller that I think works better than the typical home depot ones. The foam doesn't separate from the roller, if that starts to happen get a new roller, when rolling don't go too fast as this will whip air bubbles into the epoxy. you don't need to go to these extremes to get a great finish, but I wanted something that I could show, and a lot of depth on the finish. I got it! Doug Hodder

[asianflava]

I was thinking of putting epoxy on the exposed wood, though probably not as many coats as you. Can you have a stain or something under the epoxy? Oil based, water based?

[doug hodder]

Yes you can stain or much more preferred dye, and lay epoxy directly over the wood. Don't use any oil based stains however, I haven't done it but West System recommends against it. You'll have too much money into the project to cut a corner and use some oil based stain from the hardware store and have a problem. I used anilin dyes on my boat, water based, comes in lots of colors, and you can mix them to get the exact color you want. I doctored mine up, and saved the recipe, as well as a sample. Check out www.woodworker.com , go to their stains and dyes. Dyes work great because you can work them with water and a sponge to get the exact color you want if you have an area that is too dark. They are compatible to overlaying with epoxy. Use the top coat hardener. Make sure all sand scratches are out of the wood and that it is completely sanded to the same grit. If going over a soft wood, you may want to lay down a spit coat of 50/50 lacquer and lacquer thinner. Spray it thin or wipe on with a cloth so that it doesn't seal up completely. Most important of all is to do a test patch on some drop wood prior to doing it on the project. The lacquer will help stop excessive penetration of the stain/dye especially on end grain. This shouldn't be a problem if you thin your dye out prior to application. Test first, test first, test first!!! alcohol based dyes are also acceptable... just my experience, doug hodder

[campingboy]

From my many hours working on the bright work on sailboats, I would recomend trying Sikkens Marine Cetol. We have been using this product for about 4 years now and are very happy with it. I will be using this on the side of my Tear.

[mikeschn]

Hey Doug,

I tried some water based stain on my Benroy, and it was splotchy. I ended up painting over it with white paint.

Could I have this kind of a problem with the dye that you are talking about? I am thinking about finishing the inside of the Lil Diner, and wonder if I should try dye?

Mike...

Yes you can stain or much more preferred dye, and lay epoxy directly over the wood. Don't use any oil based stains however, I haven't done it but West System recommends against it. You'll have too much money into the project to cut a corner and use some oil based stain from the hardware store and have a problem. I used anilin dyes on my boat, water based, comes in lots of colors, and you can mix them to get the exact color you want. I doctored mine up, and saved the recipe, as well as a sample. Check out www.woodworker.com , go to their stains and dyes. Dyes work great because you can work them with water and a sponge to get the exact color you want if you have an area that is too dark. They are compatible to overlaying with epoxy. Use the top coat hardener. Make sure all sand scratches are out of the wood and that it is completely sanded to the same grit. If going over a soft wood, you may want to lay down a spit coat of 50/50 lacquer and lacquer thinner. Spray it thin or wipe on with a cloth so that it doesn't seal up completely. Most important of all is to do a test patch on some drop wood prior to doing it on the project. The lacquer will help stop excessive penetration of the stain/dye especially on end grain. This shouldn't be a problem if you thin your dye out prior to application. Test first, test first, test first!!! alcohol based dyes are also acceptable... just my experience, doug hodder

[darkroomsource]

I just used two coats with a steel wool sanding in between. However I just read an article in a wood magazine about getting a great finish. It said to cut the varnish with thinner, 1 part thinner to 3 parts varnish, and use a rag to apply, and a 400 grit between coats. I'm going to try that on the areas I've been updating and re-sanding.

[Steve Frederick]

I bought a HVLP/Gravity spray gun. I was wondering if I could spray spar urethane??? I think I'll try it, or automotive clear coat on my 'Diner..Any thoughts??

[purplepickup]

I bought a HVLP/Gravity spray gun. I was wondering if I could spray spar urethane??? I think I'll try it, or automotive clear coat on my 'Diner..Any thoughts??

Steve, these are some white oak planks in the bed of my pickup that I sprayed with a harbor freight hvlp gravity feed gun. I used Minwax Helmsman Spar Urethane, satin finish. I did it about 10 years ago but I think I thinned it about 10% with mineral spirits. The gun I've got has a 1.4mm nozzle and I crank up the air pressure to about 45 or even 50 psi at the gun to get it to atomize nice.

[Steve Frederick]

I bought a HVLP/Gravity spray gun. I was wondering if I could spray spar urethane??? I think I'll try it, or automotive clear coat on my 'Diner..Any thoughts??

Steve, these are some white oak planks in the bed of my pickup that I sprayed with a harbor freight hvlp gravity feed gun. I used Minwax Helmsman Spar Urethane, satin finish. I did it about 10 years ago but I think I thinned it about 10% with mineral spirits. The gun I've got has a 1.4mm nozzle and I crank up the air pressure to about 45 or even 50 psi at the gun to get it to atomize nice.

Yeah!! That's the gun I got!! I also got a bigger compressor, The took my first one, two weeks old back, gave me credit towards the bigger (3.5-hp/60gal) unit.
My finish of choice so-far, is Minwax Helmsman gloss. Nice and clear. good uv protection. Never thought of satin. Looks great on your truck!! Maybe I'll practice some..