polyurethane

[Rmartin]

Were're all looking for the hardest longest lasting finish right? Well, as the old saying goes, you can't get there from here. Until they come up with a substance that can be applied in one coat which will never wear (I'll be the first in line), it's going to be a trade off between time and durability.

I'm willing to put in the time to get the longest lasting finish, but which one is that? To find out I asked the experts. I spoke to the people at Deft and Minwax, and Minwax Krylon division. Each one told me the same thing.

Polyurethane is the hardest longest lasting finish available on the market today.

That is what I use. Although I do not follow their recommended procedure for applying. The experts say to sand only to a 220 grit. Pfft. Who's going to do that? They are more concerned with the finish sticking to the wood rather than the look of the wood. We all sand to a higher grit, that's a given. But if you sand with MicroMesh, you run the risk of your finish not adhering to the wood properly.

This is my method:

1. Sand to a 600 grit
2. 4 coats of wipe-on poly (thinned poly)
(on the lathe with lathe turning, takes less than 10 minutes)
3. 3 coats of spray-on In/Outdoor Helmsman Spar Urethane
(off lathe, one hour between sprays, no sanding)
4. After 24 hours, sand lighty 600 grit with grain
5. 1 Coat spray-on poly
6. After 24 hours, sand lightly with wet Micro Mesh

Polyurethane vs. Laquer

Laquer will dry faster and finish can be completed if time permits in a single day. Cures faster. Poly cures very slowly. While a pen with a poly finish can be handled within 24 hours of final sanding, it does not produce it's hard shell (hardest substance available according to the experts) for 30 days.

 

[RussFairfield]

Tes, a Polyurethane can be harder than lacquer, and it can be the hardest finish we can put on a pen short of encapsulating it in Plexiglass; BUT whether it is either of these things depends on the Polyurethane finish we use.

If hardness can be equated to durability, then Enduro, a waterborne polyurethane that is favored by pen makers, is the hardest commercial product we can put on a pen. CA glue is a close 2nd. All other polyurethane products, including everything made by Minwax, will fall short of either CA glue or Rnduro in hardness, and most of them will have problems with <b>color, clarity, or application</b>.

These 3 properties of color, clarity, and application are important to most of us for a pen finish. We don't want the "polyurethane blue haze", and we don't want a finish the turns orange and brittle with age. We do want to see the colors of the wood and enhance them if possible, and not mask them with a dull or muddy haze.

 

[jeffj13]

Good post with lots of good information.

However,if hardness is the primary concern, it is my understanding that there are other varnishes that are harder than poly. Rockhard Tabletop varnish comes to mind.

While hardness is important, it is not the only thing of importance. Clarity of the finish is also key. Polyurethane tends to be amber in color. It also contains more solids than lacquer, which would tend to "muddy" the finish to a small extent. Poly will also yellow over time.

I do have a question about your technique. Since poly does not dry all that quickly, how are you able to put 4 coats on in 10 minutes?

jeff

 

[DCBluesman]

In general, when we talk about finishes for pens, we talk about clear finishes. Behlen's Rock Hard is YELLOW. It WILL change the color of the wood. Been there, done that.

 

[Rmartin]

I agree Russ, a water-based poly is probably better. But it's very thin, and takes nearly double the coats. I have used it on furniture because of the easy clean up, but I've had problems with the high humidity in my area which can cause water-based poly to whiten. Also, I use Minwax because it's easy to come by where I live. I'm sure there are better brands, and in no way meant Minwax was a superior brand. Saying that, I have pieces of furniture that are thirty years old which are as clear as the day they were made using Minwax products. I probably shouldn't have mentioned a brand. I have no dog in the brand fight.

Jeff,
I'll look into Rockhard products, but the people at Deft and Minwax told me poly was a harder substance than laquer or varnish. I agree poly can amber wood. On dark grain this can ruin a blank, but I actually like the slight coloring, sorta like a light honey maple stain will give on light colored woods. I should have mentioned I use a sanding sealer which will greatly reduce ambering.

How can I add several coats in a few minutes?

I would equate it to using a friction polish without the wax. The thinned down poly mostly evaporates. I use a dry paper towel between the wet paper towel poly coats. I feel it creates a good surface for the spray to adhere.

I appreciate the comments. I'm always looking for a better way.

 

[Rmartin]

Russ, I read your articles on finishing. Very informative. I particually like the idea of barewood with a light wax to get it started.

 

[alamocdc]

Every polyurethane that I've used in woodworking over the years definitely has a yellow tint. Worse, polyurethane tends to yellow further with time and UV. The only polyurethane I'm aware of that doesn't yellow is the three part type used to clearcoat cars.

 

[Rmartin]

I suppose poly will yellow over time, yet I think that's true of other finishes as well. Ask a cabinetmaker what type of finish he/she puts on interior drawers. I get that there's a bias against Minwax because they are like the Walmart of finishes. I've used Minwax stains and finishes for 30 years on furniture and have found them to be consistent and inexpensive. With pens, I'm looking for something entirely different. At this point, if someone told me peanut butter applied during a full moon works I would probably try it. The spray on poly I'm using right now is a spar urethene which according to the manufacturer is formulated for exterior handrails and other outdoor applications. I'll let you know in a couple of years whether it holds up or not.

 

[Blind_Squirrel]

Try peanut butter (natural, smooth, NOT chunky) and apply it during a full moon. []

 

[wdcav1952]

Or, if you use the chunky, make sure it is Jif. Then use your skew to level out the finish. Smells better than sandalwood, IMHO! []

 

[beamer]

Choosy turners choose JIF.

 

[jeffj13]

Originally posted by Rmartin
<br />I suppose poly will yellow over time, yet I think that's true of other finishes as well. Ask a cabinetmaker what type of finish he/she puts on interior drawers.

If you are implying that cabinetmakers use poly inside of drawers, this is typically not true. Most cabinetmakers/woodworkers avoid oil based finishes inside of drawers because the smell lingers for a long time. Even if poly is used on the outside of a piece, shellac or lacquer (or sometimes unfinished) are the finishes of choice inside a drawer.

jeff

 

[Rmartin]

No, I wasn't implying cabinetmakers use poly on the inside of drawers. We don't put any finish on the inside of a drawer!

 

[almer]

I also make and refinish some pool cues,most of us use auto clearcoat sprayed on cues,i use durachrome clearcoat,i will spray some pens when i spray my next cues and post my crappy pics.I know its not feasable to buy this stuff in small amounts as it has a shelf life and is expensive.When a cue is sprayed we polish with 3 grades of auto compound,swirl remover.

 

[stevers]

Nice research Richard. I actually use Wipe-on-Poly myself. I sand to 400 or 600, depending on the material. Apply two or three coats and sand if necessary. I am happy with the results so far.