Microbubbles in Waterlox

[Matt Roth]

This is my first try with Waterlox, I'm finishing a culry walnut/curly maple kitchen table lazy susan. I have a applied three coats of Danish Oil, and let them dry for a couple weeks. Yesterday, I used a rag to apply a coat of Waterlox. It went on even, but I immediatly noticed lots of small bubbles in the finish. I thought they might go away as it dryed; no such luck!

How do I fix this and how do I keep it from happening again?

Thanks!

[Henry Ambrose]

Did you shake the Waterlox? If so, try again but -STIR- it.

Also, I don't think another finish under Waterlox is a great idea unless you are sure it is compatible.

[Matt Roth]

I shook it like it was for James Bond. I'll try stirred next time! Minus the bubbles, it looks great over the Danish oil. How do I get the existing bubbles out? Do I need to sand and start over?

[Scott Holmes]

Wipe-on should never leave bubbles, even if you put it in a paint shaker to mix it.

Wipe-on should be applied as thinly as the kid that wipes the table in the fast food joint with a damp rag...

It could be ait escaping from the pores of the wood. A seal coat of shellac would have been a good move. light sanding and a seal coat may be the ticket now may not need the seal coat of shellac now that the Waterlox has sealed the wood.

[Henry Ambrose]

I shook it like it was for James Bond. I'll try stirred next time! Minus the bubbles, it looks great over the Danish oil. How do I get the existing bubbles out? Do I need to sand and start over?

Yes, sand it.

[Howard Acheson]

What "Waterlox" product are you using? Waterlox is a brand name for a number of finishing products.

As said, it sounds like you are not using the proper application technique when wiping on your finish. The wipe-on technique was developed to virtually eliminate the possibility of bubbles.

Here is the technique as described by the guy who sort of developed it and popularized it.

QUOTE

There are a number of suggested application regimens that are totally subjective. The number of coats in a given day, the % of cut on various coats, which coat to sand after, when to use the blade and a whole host of other practices are all minor differences between finishers. There are some things that I consider sacred when applying a wipe-on finish.

First, you can use any full strength oil based clear finish. Polyurethane varnish or non-poly varnish is fine.

If you are making your own wipe-on the mix is scientific - thin. I suggest 50/50 with mineral spirits because it is easier to type than any other ratio and easy to remember. Some finish formulators have jumped on the bandwagon and you can now get "wipe on" finish pre-mixed. If you use a pre-mixed, thinning is generally not necessary. But making your own is cheaper and you know what's in it.

The number of coats in a given day is not important. Important is to apply a wet coat with an applicator and merely get it on. Think of a 16 year old kid working as a busboy at Denny's you have sent over to wipe off a table. Sort of rub/swirl the the material on like you would if you were applying a paste wax. Don't attempt any straight strokes. The applicator should be wet but not soaked. The applicator can be a non-embossed paper towel shop towel, half a T-shirt sleeve or that one sock left after a load of washing. Once applied,leave it alone. The surface should not be glossy or wet looking and, if applied correctly, there should be no "brush stroke" type marks. If you have missed a spot, ignore it - you will get it on the next coat. If you try and fix a missed spot you will leave a mark in the finish.

Timing for a second coat involves the pinkie test. Touch the surface with your pinkie. If nothing comes off you are ready for another coat. If was tacky 5 minutes ago but not now, apply your next coat just as you applied the previous coat. Remember, you are wet wiping, not flooding. After applying the second coat, let it fully dry for 48 hours. Using 320 paper and a sanding block lightly sand the surface flat. Now, begin applying more coats. Do not sand between coats unless you have allowed more than 24 hours to elapse since the prior coat. The number of coats is not critical - there is no critical or right number to apply. For those who need a rule, four more coats on non-critical surfaces or six more coats on surfaces that will get abraded seems to work.

After your last coat has dried at least over night you will have boogers in the surface. You should not have marks in the surface because you ignored application flaws. You may have dust, lint and, if you live in Texas, bug legs. Use a utility knife blade at this point. Hold it between your thumb and forefinger, near the vertical, and gently scrape the surface. Gentle is the important word - no harder than you would scrape your face. If you start scraping aggressively you will leave small cut marks in the surface. After you have scraped to the baby butt stage gently abrade the surface with 320 dry paper or a gray ScotchBrite. Clean off the surface. Now, leave the area for two hours and change your clothes. Apply your last coat with a bit more care than the previous coats and walk away.

An anal person is going to have a tough time with this process. Missed spots have to be ignored. Wet wipe, don't flood. Scraping to babies butt smooth means scraping no harder than scraping a babies butt. Ignoring any of these will leave marks that are tough to get out. Getting these marks out requires some aggressive sanding to flatten out the surface and starting over.

Jim Kull

END QUOTE

Finally, It works better to use a gloss varnish for all coats except the last. The flatteners in semi-gloss and satin tend to rapidly fall out of suspension when the finish is highly thinned. If you want a non-gloss finish, use it only on the final coat or two and be sure to stir the material frequently or you will end up with cloudy streaks.

[Matt Roth]

Thanks guys. Without a doubt, I put too much on; I like the table wiping analogy. I'll sand and try again.

[Matt Roth]

You guys got me on the right track, thanks! I sanded and wiped on coat 1 of the waterlox. So far so good! I just got carried away the first time and put it on WAY too thick. I'll be more patient and apply several thin coats in the same manner.

[Howard Acheson]

Glad it's working for you. Wipe-on is technique that is virtually foolproof when the proper technique is used. Many think of it as just a different way of brushing. It's not like brushing at all.

[Glen J. Peterson]

I realize I'm late chiming in, but here goes. I've used Waterlox Original for several years on many projects with good results. The application technique I learned was quite different from what I've read above. For the first coat I flood the surface using a (cheap disposal) brush to apply. I let it sit for about 30 minutes and then I wipe it completely dry. This is important. I rub it completely dry with no wet spots, especially in the cracks between mating surfaces. Let it dry for 24 hrs. Subsequent coats are applied with 0000 steel wool. Let it sit for 10-15 mintues and completely wipe it dry with clean rags. It will need several coats. I'm currently finishing a pair of bureau's with 8 drawers each. It's very important to wipe it dry after applying a coat. If you don't wipe it completely dry you get shiny spots that look like varnish. This is particularly noticable in the little crevices. I learned this technique at CT Valley School of Woodworking. The only downside is that you are left with lots of oily rags, which are a fire hazard. I let them sit in hot soapy water over night, rinse them out, and then use them for general shop rags.

Just yesterday I had lots of micro bubbles using the Waterlox. They seem to occur because when I apply the product with steel wool after the first coat I'm both "sanding" and applying finish. For example, the brueaus have wooden knows and I spend some time rubbing them with the Waterlox and steel wool so they will be smooth to the touch. Since I completely wipe off the finish so that it's "dry" there is never an issue with bubbles.

Here is a photo of one of the dresser tops after 3 (or perhaps 4) coats using the method above. I'm starting to get a bit of a shine. The tops are 3/16" veneer cherry over baltic birch ply and banded in solid cherry. I put on another coat after I took the photo. I haven't been out to the shop yet this morning, but I think one more coat and I'll be done.

[Howard Acheson]

I expect that your method will produce a smooth, bubble-free surface. But, it is a method that is exceedingly wasteful of a finish. The first coat will virtually completely seal the surface. Subsequent coats will not be absorbed at all and over 90% of the finish you apply after the first coat will be completely wiped off when you wipe the surface dry. You are only building an almost microscopic film on subsequent coats. Most of what is a quite expensive finish is being left in your wiping rag.

[Scott Holmes]

You indeed are wasting alot of finish... Your method works but it is not very effeceint. It sounds like a process that is a cross betwen an oil/varnish application and a wipe-on varnish application.

Waterlox is not an "oil finish" it is VARNISH made from tung oil and phenolic resins. So it's an oil-based finish. You would get better results making an oil/varnish blend or a wiping varnish.

As for your use of steelwool... see reason #2 below...

3 reasons why I say never use steel wool on bare wood or between coats…

Reason #1 Poly does not stick well to itself or anything else for that matter that is why they tell you to sand between coats. Steel wool abrades the finish; it does not give enough "tooth" for poly to adhere well. 220 sand paper 320 at the finest.

Reason #2 you will leave shards of steel wool behind; then you will top coat it. Now you have steel wool IN your finish when water vapor gets to it, and it will, it will RUST - IN YOUR FINISH.

Reason #3 Many steel wool products have oil to keep them from rusting so now you have oil on your surface... bad idea.

[Pete McMahon]

Glen,
Who taught you that method at the Ct Valley school? Re-read Scott's response to this method. It's wasteful and silly.
Read the side of the Waterlox can, it has directions that are easy to understand.
Using steel wool between coats of anything is asking for problems. Your oily rags are just part of the problem. Varnish soaked steel wool is no day at the beach either.

You should print out some of these responses and send them to the person who taught you this. They know nothing about finishing.

[Prashun Patel]

I wouldn't say Glen's method is 'silly', but I agree that Waterlox is an expensive finish to use like an oil/varnish. I like in-the-wood finishes for many things, and I use that wipe on/sit/wipe completely off method wherever I can.

There's no reason you can't use a straight varnish, or wiping varnish like an o/v blend. The only thing the oil does is increase the open time. It might be more of a workout to wipe off Waterlox if it starts to tack up, but it can be done.

I also disagree that after the 1st coat, the flood/wipe off method does nothing but waste. Sometimes it has taken me 3-4 coats to get an even sheen to the piece and to eliminate all dull spots.

I do agree with the experts below that steel wool's not the best choice here for rust and contamination purposes. I also don't like the idea of reusing oily rags. Soaking them in soapy water overnight will not remove all oil, and it will prevent it from drying. Once the water's removed, remaining oil will dry and cause the rag to possibly heat up.

I say use disposable rags for oil application, and then dispose of them (properly); don't reuse.

[Pete McMahon]

Let me re-phrase.. It is silly for an "instructor" to teach such a method. This is how wives tales get a foothold and passed along as doctrine.

After the first coat, IMO, flooding is wasteful and not required. Flowing the Waterlox varnish is more economical in time, material and cleanup. Let the varnish do the job it was designed to do. Besides, it normally takes multiple coats of Waterlox to build enough of a film to eliminate dull spots. If flooding is desired use one of the cheap thin ones like Watco or Minwax antique oil that were specifically designed for that purpose.

That was good advice on the rags; once they have been contaminated they shouldn't be reused.

[Henry Ambrose]

Sanding in the finish is a good technique to help fill the pores and build a surface film. You have ot give it plenty of time to dry though. But for sure do not use steel wool for this.

You can wipe on Waterlox as described above and get very fine results. If you want "build" try spraying - Waterlox sprays great. (gotta have a good respirator)