Interior-polyurethane or varnish

preserved_killick · Post by **preserved_killick** » Tue Nov 20, 2007 12:07 pm

I commonly see varnish as the most common building-type wood finish for interior woodwork. Why not just use inexpensive and easy to apply polyurethane? Is there really a difference once finished?

For example, the book entitled "The Brightwork Companion" suggests something like 10 coats of varnish on a cabin sole. Why not just use three coats of fast drying polyurethane and be done with it?

http://www.castlewholesalers.com/MINWAX ... thane.html

If UV degredation is not an issue, why use varnish?

-Jeff

Post by **Tim** » Tue Nov 20, 2007 1:24 pm

Use what you like. I prefer a satin interior finish, but you're right that there is not a large appearance difference between oil based satin polyurethane and oil based satin varnish, and the satin varnishes don't have the UV protection of the gloss to begin with.

And you don't need 10 coats on a cabin sole either way. All you get from that is the possibility of increased life--and if you want to get the absolute flat, high gloss, no-wood-grain-showing look, you need a high number of coats to allow you to flatten the finish without sanding through.

From a practical standpoint, I have found 2 coats of gloss and one coat satin to be a long-lasting and attractive finish on interior components.

We all know how well polyurethanes work for interior wood flooring. It'll work on your boat too, if you prefer it. I like the amber look of oil-based finishes, but if you like the clearer look of the acrylic, use those.

preserved_killick · Post by **preserved_killick** » Tue Nov 20, 2007 4:04 pm

Tim, do you find that you get the same build with varnish as with polyurethane? Two coats straight varnish equal to two coats oil based poly?

I've been using a commercial two-part water based polyurethane called BonaKemi Traffic on the floors of my house with great success. Proven to be extremely durable both in abrasion resistance and flexibility. I'd love to use this on the boat, but I also don't wish to have it fail somehow and deal with the mess.

-Jeff

jollyboat · Post by **jollyboat** » Tue Nov 20, 2007 6:00 pm

Jeff, I have never worked with water based polyurethane so cannot add much to that, however, I do use an oil base polyurethane on my Tritons interior and exterior woodwork and am pleased with the outcome of the finish and durability.

LazyGuy · Post by **LazyGuy** » Tue Nov 20, 2007 6:24 pm

A boat builder explained to me that I should use either varnish or oil on a boat because it is much softer and pliable than polyurethane. Poly is fine for houses because they don't move. Yes they expand and contract with temperature and moisture but not like a boat. The softer varnish is much better for a lasting finish on a boat.

The Brightwork Companion talks about 10 coats of varnish but if you follow their instructions, the varnish is applied in a thin coat and you sand about half of it off, apply another coat, sand half of it off, rinse, repeat.... so it really isn't much thicker than most people applying 3 or 4 coats with a light scuff in between.

It is all a matter of opinion. It is your boat. If you like the look of poly, and you are happy with the result, go with it. One in a hundred people are going to look at it, raise the corner of their lip and ask "Why did you use polyurethane?" The other 99 are going to complement your work.

suntreader · Post by **suntreader** » Wed Nov 21, 2007 1:07 am

Funny this came up, I just loaded up some pictures from the first varnish going into my project.

I had the poly vs varnish debate as well, read everything I could on it. I have used gallons of poly in the house, 1400 sq ft of white oak floors for starters, and most of the future as well. I decided to go with spar varnish for the boat however. The difference in the look is substantial, but both are nice. Varnish has an amber tint to it and looks more liquidy to my eye, poly is more like a plastic coating, less color imparted to the piece, but thicker and less clarity.

I was all set to order some Epifanes varnish but at 1/4 the cost the hardware store brand won out. No one I know would be able to tell the difference (me either) so as much as I am a sucker for a boat on the label I went with the cheap stuff.

I did try the water based polys a few years ago and absolutely hated the stuff. I've heard it has improved lately and is now pretty good but I haven't gotten around to trying it again.

The following pictures are of the panels that go outboard of the quarter berths. I had intended to cut new pieces for these because the fasteners had rotted out big chunks of the ply around them. After some consideration I figured that the shelf fiddle above and the cushion below will hide the problem edges and the panels will match the rest of the boat.

Originally I had planned on satin or "rubbed effect" for the interior wood finishes, but now that the gloss coats are on I don't think I'll be able to dull it down, it just looks too good! The interior glass will be in satin so that should take down some glare and provide a nice contrast.

For not being a high priced boat, this Islander has some nice materials in it. The interior is all doubled sided 3/8" ribbon mahogany plywood. I couldn't tell before because of the condition of the old finish, but when stripped down and refinished this plywood is amazing. The pictures don't show it well, but the grain is iridescent, light dances around it as it moves across, really a sight. The pictures were taken with four coats on, I will probably do another tomorrow. The can of varnish says two to four coats. I really wish these pictures came out better, the wood isn't nearly that dark in person.

Now that I think about it I have the cut outs from the cubby openings in these panels, maybe I could throw some poly on there and compare.

Dave

CharlieJ · Post by **CharlieJ** » Wed Nov 21, 2007 4:07 pm

I have poly on my house floors also- Miniwax brand for floors.

I have Zspar 2015 on the interior of the boat. The main thing I dislike about poly is that it isn't all that easy to repair. I find varnish much more forgiving to touch up. And I know Tim dislikes epoxy under varnish because it's tough to remove if you need to do so- well poly is just as tough to get rid of.

Also as pointed out- poly is a very hard finish- spar varnish is softer, so it does give better- has more flex.

Frankly I don't much care for it on boats and don't use it on customers boats at all- we use Z Spar 2015 exclusively on those.

As an aside, I would never ever varnish a sole, particularly with high gloss varnish. I about killed myself once on a varnished sole- ended up flat on my back staring at the over head, while the boat merrily sailed along with the autopilot driving- who knows what would have happened had I hit my head and cold cocked myself. And I was wearing topsiders too.

Rachel · Post by **Rachel** » Thu Nov 22, 2007 5:58 pm

CharlieJ wrote:... while the boat merrily sailed along with the autopilot driving- who knows what would have happened had I hit my head and cold cocked myself.

Maybe you'd be writing to us from the South Pacific ;-)

On topic: I remember that the fellow with the Westsail 42 posted some nice-looking photos just after he'd coated his companionway stairs (and maybe the sole?) with Ultimate Sole (the glossy but supposedly grippy sole "varnish").

Has anyone got an update after living with Ultimate Sole for awhile?

JonnyBoats · Post by **JonnyBoats** » Thu Nov 22, 2007 8:19 pm

Has anyone got an update after living with Ultimate Sole for awhile?

We have used Ultimate Sole on the sole of our LeComte NorthEast 38, but we have not re-launched the boat yet so I can not give you much or a report. It does seem good so far.

CharlieJ · Post by **CharlieJ** » Thu Nov 22, 2007 9:48 pm

Yep Rachel- and I talked to him about it and it does SOUND great. But you know me- I don't recommend stuff I have no personal experience with.

That's why we haven't said anything about the Bristol Finish we used ( or LAURA used) on the mast. we don't know how it'll do yet.