Which first? Spar Varnish or Poly?

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Forum topic by Kean posted 06-26-2013 12:10 AM 1287 views 0 times favorited 10 replies Add to Favorites Watch
View Kean's profile


74 posts in 2556 days

06-26-2013 12:10 AM

Topic tags/keywords: question finishing

I’ve got a piece of camp furniture that I will be finishing with spray on spar varnish, but I want to use a heavy brush on polyurethane on the feet in case of water runoff through the pavilion. My question is, which should I apply first, the Spar varnish or the Poly?

-- Kean - It's all fun and games until someone loses an eye.

10 replies so far

View RonInOhio's profile


721 posts in 2859 days

#1 posted 06-26-2013 12:15 AM

Not sure. I do know that epoxy is another product to consider for the feet. My guess would be the extra protection poly or epoxy would go on first,then the spar.

View Grandpa's profile


3259 posts in 2670 days

#2 posted 06-26-2013 03:37 AM

I would think spar on the top.

View nailbanger2's profile


1041 posts in 3138 days

#3 posted 06-26-2013 12:30 PM

Maybe I just haven’t seen it, but isn’t all Polyurethane for interior use only? Whatever you use for the feet should go on first.

-- Wish I were Norm's Nephew

View Fred Hargis's profile

Fred Hargis

4983 posts in 2488 days

#4 posted 06-26-2013 01:37 PM

Spar varnish is a “long oil” formula, which simply means it has more oil in the mixture they cook up for the varnish. The long oil formula allows it more be more flexible, good for stuff that’s outside. But for what you’re doing it’s not going to be enhanced with another coat of “polyurethane”, which in most cases is just oil based varnish, but not the long oil formula (several other types of finish are now called “polyurethane” as well). You can do what you want, but putting a more rigid finish (regular varnish) on top of a softer (spar varnish) one usually spells trouble.

-- Our village hasn't lost it's idiot, he was elected to congress.

View Kean's profile


74 posts in 2556 days

#5 posted 06-26-2013 03:14 PM

Just got off the phone with Minwax. They say the two products (Minwax Helmsman Spar Urethane & Minwax Gloss Polyurethane) are fully compatible and the only consideration for which to apply first is recoat time. They recommended doing the brush-on poly on the feet first, then the spray-on spar on the rest.

BTW: I’m not actually planning on putting the spar overtop the poly, but I’m assuming some overlap where they meet.

-- Kean - It's all fun and games until someone loses an eye.

View bobasaurus's profile


3443 posts in 3179 days

#6 posted 06-26-2013 03:23 PM

The helmsman spar urethane is basically just a better polyurethane… more flexible to resist cracking, UV resistant, and waterproof than normal poly. I would just use it all the way for outdoor furniture.

-- Allen, Colorado (Instagram @bobasaurus_woodworking)

View pintodeluxe's profile


5654 posts in 2808 days

#7 posted 06-26-2013 03:55 PM

The spar I have been less than thrilled with. We had someone tape a notice on our front door with scotch tape. The finish peeled right off. We’re not talking packing tape, just household variety scotch tape.

I have great luck with Deft Poly on our new door. It sprays well too.

-- Willie, Washington "If You Choose Not To Decide, You Still Have Made a Choice" - Rush

View gfadvm's profile


14940 posts in 2685 days

#8 posted 06-27-2013 01:44 AM

Fred in the #4 post has a great explanation of the difference in these finishes. The Spar holds up well to water exposure but not so well to sun exposure.

If this is not “fine furniture”, maybe dip feet in some of that coating that tool handles are dipped in. That should provide a lot of protection and will not wear off on the pavilion floor like spar or poly.

-- " I'll try to be nicer, if you'll try to be smarter" gfadvm

View Grandpa's profile


3259 posts in 2670 days

#9 posted 06-27-2013 01:55 AM

About 25-30 years ago I was in our local lumber yard looking for a finish to put on something. I was talking to an old finish man that had his knees go out. This was before you could knee replacement at the corner store. His knees went bad and he needed an easier job so he got this job. He knew his finishes though. He told me that polyurethane varnish was basically all the same. The more you paid the more little polys you would get. The more poly the harder the finish. In those days the best was probably Verathane. It was $18 to $20 a qt. back then and the other brands were $12 to $14 a qt. The Verathane proved to be worth the cost.

View Earlextech's profile


1161 posts in 2685 days

#10 posted 06-27-2013 08:09 PM

Spar the whole thing – forget the Poly. If you’re concerned about a larger amount of water hitting the feet then just double or triple the spar in that area.

-- Sam Hamory - The project is never finished until its "Finished"!

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