Waterlox bubbles and pitting

[Jim Clelland]

I'm having issues with Waterlox Sealer/Finish and Waterlox Satin Finish (both VOC Compliant).
The end goal is to get a Satin Finish, but I'm having the same issue with both Satin and the Sealer/Finish. (Sealer/Finish illustrated here).

Application goes well and is virtually bubble free, then over the next 1-2 hours, micro bubbles magically form in the film, many of which expand to varying
amounts seeming to push away the finish from the bubble in a circle, leaving a dry mark, often leaving a mark in the center and a depression.
See attached image for some examples. Some of them just stay as micro bubbles in the finish.

Wood is Beech Butcherblock. This begins happening when Waterlox is fully absorbed into the wood around the 3rd coat. For example this is the 6th coat of Waterlox.
Spoken to Waterlox and they've been of little help and don't have any ideas except to spray it (which isn't practical in my case).

I've tried a variety of things with no luck:

• Following WL's protocol
• Good brush, foam brush and paint pad (paint pad provides the best bubble free application (at the start), foam brush is 2nd to that)
• With the Satin, I stir, the Sealer/Finish I don't shake or stir
• Product is clean. I've tried 2 different batches of both products. It happens with new product straight out of the can
• Air temperature is 71F and static, bubbles don't seem to come from the grain
• Tried thinned and unthinned, same result. Thinned with MS, 10%, 20%, 50%. Also tried Satin/Sealer/Finish 50/50.
• Sealer/Finish has lesser visible effect than Satin (Satin, the dulling agents seem to get pushed out further).
• Using real Mineral Spirits, not Paint Thinner. (verified on the MSDS that I'm getting plain mineral spirits, also tried 2 different manufacturers)
• Tried with sanding and without sanding between later coats. Tied 220, 320, 600. Also tried the 3M Maroon pad.
• Cleaning with rag dampened with mineral spirits after sanding and let dry before next coat
• Waiting 24 hrs between coats. Air exchange is good, air not blowing directly on surface.
• I'm about $400 into product so far

It seems to me that either the bubble is expanding and pushing the film away (however the bubble doesn't expand, just the circle around the bubble), i.e. some surface tension issue,
or there's some residue on the surface (but I wipe off everything, with a clean lint free cotton rag damped with MS).

Is it possible that MS is not compatible with the VOC Compliant (I've noticed on the MSDS for Waterlox VOC Compliant, it doesn't have much MS in it) and it's causing it to push away?

Any ideas? Been at this for 2 months and beginning to have nightmares about the stuff.

[Andy Giddings]

Does the same thing happen using the same process on another piece of wood (ie not from the same batch)?

[Jim Clelland]

Does the same thing happen using the same process on another piece of wood (ie not from the same batch)?

Not yet, it's my first WL project, but a good idea to outrule process versus wood. It's standard Ikea butcher block. I should add. I sanded it down to bare wood (i.e. removed the initial coat of mineral oil), before starting with the WL.

[Adam Herman]

"however the bubble doesn't expand, just the circle around the bubble"

that sounds like fish eye, not bubbles, which is a completely different animal.

I would try wiping down the whole thing with xylene or similar and then a good sand and clean off. use a new rag and wipe a coat on. fisheye is where the coating will not stick because of a containment. I have waterlox on my island top of reclaimed bowling ally and did not have any problems with the finish itself.

because of your continued problems, i may suspect the MS as well.

[Andy Giddings]

As Adam states, it does look like contamination. I do find it strange that this is only happening after three coats of Waterlox. Something else you might try if you have another type of finish available and some of the beech left, try a different finish. If it exhibits the same issue this would indicate there is something going on with the beech and nothing to do with the finishing process.
Is the Ikea block definitely untreated when it's supplied to you? The only block I can find on their US site is oil treated Bamboo

[Jim Clelland]

that sounds like fish eye, not bubbles, which is a completely different animal.

I get both appear within the finish as it's setting (they're not there immediately after application), they develop. Some of the bubbles develop into
"fish eye", and some of the bubbles remain as bubbles. The ones that fish eye, the bubble disappears in the center, but leaves a mark, the ones that don't develop, the bubble is
in the finish.

I would try wiping down the whole thing with xylene or similar and then a good sand and clean off. use a new rag and wipe a coat on. fisheye is where the coating will not stick because of a containment. I have waterlox on my island top of reclaimed bowling ally and did not have any problems with the finish itself.

Do you suggest using a rag damped in Xylene when cleaning the sanding dust off too?

because of your continued problems, i may suspect the MS as well.

I've tried 2 different MS's, but it maybe they're getting them from the same source.

[Jim Clelland]

As Adam states, it does look like contamination. I do find it strange that this is only happening after three coats of Waterlox.
Something else you might try if you have another type of finish available and some of the beech left, try a different finish.

I'll try that

Is the Ikea block definitely untreated when it's supplied to you? The only block I can find on their US site is oil treated Bamboo

It's this: http://www.ikea.com/us/en/catalog/products/40274960/ (but in beech, they discontinued it last year so it's no longer listed on their website).

It ships with 1 coat of mineral oil on, I sanded it down to bare wood, and cleaned with mineral spirits and let dry before applying the first coat of Waterlox.

[Prashun Patel]

I suspect problems with mixing the sealer finish with anything. The voc compliant formula is even less friendly to mineral spirits than the original formula. That is not a scientific finding - just my observation after one can. So ymmv.

[Andy Giddings]

If it comes with mineral oil already on it, Jim, I suspect that to be the issue. Oil will penetrate Beech very well as its more porous than a typical cutting board material (Maple for example). Might be wrong but you may never extract the oil completely and that will cause issues with the finish. See this thread on Mineral Oil and does it dry? http://www.sawmillcreek.org/showthre...-quot-Dry-quot

[Jim Clelland]

If it comes with mineral oil already on it, Jim, I suspect that to be the issue. Oil will penetrate Beech very well as its more porous than a typical cutting board material (Maple for example). Might be wrong but you may never extract the oil completely and that will cause issues with the finish. See this thread on Mineral Oil and does it dry? http://www.sawmillcreek.org/showthre...-quot-Dry-quot

It mentions on the Waterlox website, it's okay to apply over mineral oil provided the cross hatch test is okay. However, I stripped it down anyway till there was no color left from the oil as I didn't want to take a chance. Also did it again more aggressively later with 60 grit to take off a batch of waterlox failed coating. There's a possibility there's a bit soaked into the grain, but nothing visible, but they didn't initially soak the wood heavily either, it was just a light coating to prevent warpage by the manufacturer.

[Jim Clelland]

I suspect problems with mixing the sealer finish with anything. The voc compliant formula is even less friendly to mineral spirits than the original formula. That is not a scientific finding - just my observation after one can. So ymmv.

I've tried it thinned and unthinned. (The photos are unthinned).

What are you thoughts about wiping the sanding off with mineral spirits? Would that be enough to cause incompatibility? I sand, vacuum, wipe off with paper towel with mineral spirits, and then a lint free cotton rag dipped in mineral spirits, then wipe with a dry rag, then let the surface completely dry.

I've got some other solvents on hand. I've got DNA (Bio Fuel, in Canada so DNA is hard to find), but MSDS says it's Ethanol and they use Ethyl Acetate for denaturing (which is also used in Fish Eye Additive). Also Isopropanol 99%, Acetone and can get Xylene. Just not sure if any of those would damage the existing coating or create bonding issues.

They tell us that Mineral Spirits is the thinner to use, however the low VOC doesn't have much mineral spirits in it, unlike the original formula (but can't get original here either, so stuck with Low VOC).

[Brett Luna]

No clue if it'll make a difference in your case but I thin WL with naphtha, usually 2:1. It takes more coats and isn't intended to build much of a film but it really reduces recoat time.

[John TenEyck]

They look a lot like fisheyes to me. I would try cleaning with Xylene after sanding then applying a coat or two of Sealcoat shellac before starting with Waterlox.

John

[matt romanowski]

I am having the same problems as you for the last week. I didn't try thinning at all today and think I found out what is going on. I believe the bubbles are from solvent popping. That is when the solvent starts to evaporate in the middle of the film but can not get out because the surface has already evaporated. I'm guessing your in the Northern part of the country where the humidity is pretty low right now?

I had trouble with heavy coats and was going crazy looking for dust. I did my initial coats with a foam applicator and had trouble. Sanded down with 320 grit until it was perfectly smooth and put a new coat on this morning with a good varnish brush. Same issue with the bubbles started to happen. I started to wipe the surface down with a rag figuring I couldn't make it worse and the thinner film laid out much better.

My initial applications were very close to their suggested coverage rate. I'm doing a 38"x72" walnut table. With the apron and legs, I figure it's about 40 sf and I used a quart in 4 coats (they say a quart should be 156 sf).

I would suggest either getting the humidity and temp to the 45% and 75*F range, or put on thinner coats. For me the temps are going to be around 60-65F and 30% humidity, so I'll go with thinner coats.

[Jim Clelland]

They look a lot like fisheyes to me. I would try cleaning with Xylene after sanding then applying a coat or two of Sealcoat shellac before starting with Waterlox.
John

Take the finish back to bare wood, or sand level; xylene,sealcoat then WL. I.E. If Shellac on top of waterlox okay?