Differences between spar and poly

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Forum topic by Thuzmund posted 12-04-2016 10:36 PM 821 views 0 times favorited 12 replies Add to Favorites Watch
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151 posts in 1776 days

12-04-2016 10:36 PM


I did some fun serving boards for a local cider house in NY. They are “flight” boards for sampling 9 small glasses of alcoholic cider.

The finish I chose has turned out to be problematic. I did equal parts spar urethane, BLO, and turpentine because I like traditional stuff, like this old finish recipe. I also thought that spar would allow the wood to expand and contract if water got into it, like during washing.

About a month later, they are unhappy because the finish is wearing away and has begun to look white and hazy. I feel very embarrassed and told them I will make it right. My first choice will be going with straight polyurethane—no spar, maybe a little thinner to make it wipe-able.

I know finish discussions can be crazy (I’ve read about a hundred so far!), so I wanted to confirm a couple things I’ve heard. What do you think:

- I think spar is flexible, but not as hard and durable as polyurethane. While it may do well with water contact, I think the finish is scrubbing away when they wash the boards.

- Many say it’s better to get finish in the wood than on top of it. (I did try my best to soak the wood, but also did three coats on top of that). Would a thinner finish, and more soaking, be less prone to dulling and hazing?

- My last question: are there any finishes that folks would recommend for use in high-abuse environments like a restaurant? I give explicit instructions: no dishwasher, no super-hot water, and no soaking. Otherwise, the only issue is frequent washing and drying. For instance, what do folks think about just oil as an option under these conditions?

My original thinking was:

- Oil—will dry out too quickly with frequent soap and water, and I don’t think they would like to have a regimen of oiling for their boards. But in retrospect I am willing to rethink this…

- Poly—Tough, but inflexible, I would expect cracking. I have heard that poly clouds in the presence of water, but I haven’t been able to clarify if this is only while it cures, or if water after curing is acceptable (as in, both water from outside and water that’s soaked into the wood).

- Spar—Not rock hard, but we’re not talking about steel wool scrubbing here, right? Looks like the sponge scrubber was too harsh though. I chose it because it was flexible and made to be in contact with water.

- Premixed salad bowl finishes, etc. —Just the same as my home concoction but in a fancy jug. I’ve seen no evidence at all that they contain ingredients beyond my own mix. Maybe if I wanted to get fancy I could use Tung oil, for instance.

So that is why I chose spar/BLO/Turps for the finish.
Any experience would be great.

-- Here to learn

12 replies so far

View Loren's profile


10477 posts in 3795 days

#1 posted 12-04-2016 10:41 PM


um. refund their money or get them to sign-off
on a spec-sheet of a specific poly.

View Loren's profile


10477 posts in 3795 days

#2 posted 12-04-2016 11:37 PM

Marine epoxy finishes like System3 may suit
the needs of the client.

View Thuzmund's profile


151 posts in 1776 days

#3 posted 12-04-2016 11:43 PM

Yes, I think there is a second lesson in here about when to make a sale and when to pass. I knew this was a special situation of high wear, and maybe should have either found a workable solution together or I should have offered them test pieces, etc. I wanted it to be a soft finish, which was an aesthetic decision taking precedence over practical design decisions. Take a note from me, kids!

The job was an idea from a friend who works at the place, and the business embraces a local/handmade side…but just not to this degree! :)

-- Here to learn

View Loren's profile


10477 posts in 3795 days

#4 posted 12-04-2016 11:53 PM

They may be putting the boards in the dishwasher…
ridiculous. Many finishes, even shellac will withstand
years of wipe-downs with damp cloth, but I doubt
any wood finish can take a dishwasher cycle.

View mrbob's profile


182 posts in 716 days

#5 posted 12-05-2016 12:11 AM

If it is going into the dish washer, some of the most damaging/aggressive detergent. To my understanding Spar is for UV rays thats all.
I would use a wipe on non film finish and put one person in charge of there cleaning and refreshing of the finish.

View corelz125's profile


542 posts in 1123 days

#6 posted 12-05-2016 03:24 AM

Hard to put all the blame on you I’m sure at the end of the night they don’t give a second thought how they clean them

View Fred Hargis's profile

Fred Hargis

5095 posts in 2640 days

#7 posted 12-05-2016 12:46 PM

Some basic varnish info. Varnish is a finish that is made by cooking resins with a drying oil to form a new compound called varnish. The resins are normally urethane (or polyurethane), alkyd (my personal favorite), or phenolic (Waterlox). Spar varnish is called a long oil varnish, that means there is more oil in the mix when it’s cooked….that gives it the increased flexibility. So, the only difference between “spar poly” and “poly” is the long oil feature, and it is indeed softer (flexible). Adding BLO to it makes it a danish oil finish, and less durable. It is no more water resistant than regular varnish, but the flexibility allows it to move with wood a little better…it was invented for the spars on sailing ships. So your assumption about the spar moving was spot on, but in my opinion you won’t find a find a finish that will stand up (for long) to what they are doing (the dish washer thing). they (again, IMHO) will have to adjust their care of the trays…or move on to a plastic or other material.

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

View ChefHDAN's profile


1133 posts in 2997 days

#8 posted 12-05-2016 01:06 PM

I HATE HATE HATE, flight boards, they are only cared for by the better employees and as was said above, I PROMISE you they’re getting dropped in to bus bins with other bar ware and washed “however” by whomever has the detail. That said, the one thing I found in my bar was that the flights were not SUPER popular and at most 3 to 5 per shift would sell & from our opening purchase I had about 50 of the things, so I made sure the majority were not in rotation and scrapped them as they began to look crappy.

If I were to make flight boards knowing what the useage velocity is I’d go with a mineral oil finish to keep it simple, and train staff to rinse them and wipe them dry with a towel following use. If the cider house is doing crazy sales for the flights, (9 is a huge one) it might not work for them but in my location it would not be a huge deal to have one of the staff add oiling the boards to weekly side work.

-- I've decided 1 mistake is really 2 opportunities to learn.. learn how to fix it... and learn how to not repeat it

View Lazyman's profile


2527 posts in 1535 days

#9 posted 12-05-2016 02:04 PM

If you think need a film finish, you might consider an epoxy or epoxy bar top finish though that might be too expensive. I have actually tested just a regular 30 minute epoxy adhesive on a tool handle and it worked okay but I am not sure how it it will handle repeated wet/dry abuse. Try it on a test piece and run it through some abuse tests to see if it fares any better than the poly. Frankly, just about any film finish may not last more than a few months under that kind of regular abuse so you might just consider a salad bowl type finish and just give them a bottle to refresh it when needed. Howard’s Feed and Wax would be relatively easy and inexpensive. That way, if they don’t do the maintenance required, it is really not your problem (anymore).

-- Nathan, TX -- Hire the lazy man. He may not do as much work but that's because he will find a better way.

View Thuzmund's profile


151 posts in 1776 days

#10 posted 12-05-2016 05:24 PM

These are great responses! Very helpful to know more about what makes Spar Varnish different from other types.

I think it would be a great idea to run abuse tests and post the results. I’ll put that on my to do list for this forum.

-- Here to learn

View ArtMann's profile


1081 posts in 963 days

#11 posted 12-06-2016 05:44 PM

My experience with consumer grade spar varnish, like Minwax brand, is that it is no better than just plain old polyurethane. It has poor weather resistance. If this is a commercial environment and the piece requires frequent washing, I would start investigating epoxy. Even a commercial grade of spar varnish obtained from a marine supply store is unlikely to hold up to commercial treatment.The penetrating oil finish you are talking about will only penetrate a few thousandths of an inch and will not provide much water protection. There is a reason that cutting boards almost always come with instructions to apply mineral oil or some other non-toxic oily coating frequently.

View Thuzmund's profile


151 posts in 1776 days

#12 posted 12-10-2016 05:24 PM

Yes and as someone said, a small bottle of the oil used is a nice way to soften the blow of “someone has to keep oiling this.” Especially if it’s in a nice pretty bottle for them. :) This experience has really changed my view of spar—as a woodturner I put Spar/BLO/Turps on more than half of the stuff I make. But most turnings don’t get treated like cutting boards or serving trays (frequent washing, scrubbing). So I learned to think about what they will do on their end and make time for a conversation about finishes specifically with the customer.

-- Here to learn

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