Shopsmith Forums

After some more research online, and taking in the advice here, I purchased a gallon of Varathane Diamond water-based flooring polyurethane (satin finish). I found some references which indicated this product has excellent durability for shelving.

- Chris

Yes, That's good stuff. I've used quite a bit of it. It seems a little more runny than the Varathane not specifically for floors, but it works just fine on vertical pieces, with a little care. BTW - I use foam brushes - easy to clean up in the sink and re-use.

I spent most of the morning using a foam brush to get a single coat on only 30 out of the 88 slats. That's for the birds. I'm borrowing an airless sprayer from my neighbor.

- Chris

Okay, another question for the collective...

Each shelving unit has 11 slats, 1x4 boards cut to 32". If I use one screw centered per end, is cupping a concern with polyurethaned 1x4s? Cupping is the only reason I'd need to consider two screws per end, because otherwise these screws won't see any real loading forces.

- Chris

chrispitude wrote:Okay, another question for the collective...

Each shelving unit has 11 slats, 1x4 boards cut to 32". If I use one screw centered per end, is cupping a concern with polyurethaned 1x4s? Cupping is the only reason I'd need to consider two screws per end, because otherwise these screws won't see any real loading forces.

- Chris

Yes, cupping on flat sawn boards is always an issue especially if their location is subject to humidity changes. It's best to use 2 screws per board, even with 4 inchers. Polyurethane finish will slow down water vapor absorption, but will not stop it. (if you put the board on with the end grain frowning rather than smiling, the cupping will raise the center of the board rather than the edges.)

Concerning your time applying the finish.
1) We didn't know you were in a hurry!
2) I just don't know how water based poly will work with an airless sprayer. It would have to be thinned a bit for use with a HVLP sprayer.
3) As a rule of thumb - for most projects, a woodworker should plan on 50% of the construction time for finishing. That is 50% construction and 50% finishing. If you can get by with less time getting a good finish, it is a gift.

I also wood recommend 2 screws per board.

Since you know the screws will offer no structural support why not just drop in a 2 nails at each end? Their only function is to hold the slats in place, as far as bowing goes I doubt if it is a real concern. Besides this is just storage so if the slats do bow do you really care?

If were me I would probably use my brad nailer and shoot a few brads in each board and be done with it.

Have you figured how your going to mount the whole assembly to the ceiling?

Ed

Hi Ed,

Pictures of the ceiling mounting to come - hopefully soon now!

Today I got all the shelving slats sprayed with the Varathane with the borrowed paint sprayer. This was a real nice contractor-grade sprayer (Titan 440i) from a contractor friend of mine.

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I laid out a canvas painter's tarp in my driveway, and laid out the slats in three rows. I angled the slats so that when I sprayed from the sides as I moved up and down the aisles, I would also get coverage on the sides of the slats too.

This is the first paint sprayer I've ever used, and I never fully appreciated just how thirsty these things are. After getting the sprayer primed to the point where polyurethane was coming out of the gun, I used nearly a quarter of the gallon can (at $50 per gallon)! After the first coat, I was down to about halfway:

[ATTACH]1869[/ATTACH]

I sprayed two coats on the bottoms and two coats on the top. The gallon can lasted just long enough - to the point where during the last coat, we had to pour water in the polyurethane gallon can just so the sprayer could push the last of the polyurethane through the line!

The boards came out great:

[ATTACH]1870[/ATTACH]

Before each coat, I used my 2-stroke leaf blower to blow away the accumulated plant and leaf matter that fell on them. I have a 5" random orbital sander which is also borrowed from another friend of mine. I zipped it quickly over the top sides between the first and second coats (literally three seconds per board) to take out some of the roughness. I am extremely happy with how the job came out. My only regret is that I didn't have enough left for one more coat on the topside, but it'll get the job done.

- Chris

chrispitude wrote:...I sprayed two coats on the bottoms and two coats on the top. The gallon can lasted just long enough - to the point where during the last coat, we had to pour water in the polyurethane gallon can just so the sprayer could push the last of the polyurethane through the line!

The boards came out great...

Hi Chris,
That is super! Airless sprayers work great, and the clean-up ain't bad when you are using water based products. BTW, running water in the line to finish out a spray job is standard operating procedure. You did great!

Hi Chris - The spraying project worked out great for you. Thanks for the photos! - Glad it worked so well, and you have friendly neighbors.

If you are going to be happy with only two coats, then I will be too! However, you should really think about coating over those sanded off whiskers. These "whiskers" were actually surface wood fibers that were raised by the water. Those fibers have been sanded off (broken) and are not presently sealed with poly.

Have you figured the square footage of both sides, edges and ends of the slats? You may have gotten average coverage. I was also surprised to read of the volume needed to fill the discharge hose. Hadn't thought about that! - But will in the future, if I ever use one of those sprayers. You just don't run across that with an airless sprayer.

Yes, it is sometimes surprising to find the cost of applying a finish coat. Many of us, after building small projects, using only a quart or so, forget about the required volumes to get full coverage on larger projects. I've used a gallon or more on a number of projects using a brush.