I just finished putting on my second coat of Waterlox satin over Waterlox gloss. All were wiped on after thinning with about 30% mineral spirits and 24 hours between coats. The waterlox people specifically say that sanding between coats is not needed for adhesion. Tonight I noticed (to my horror) that the varnish can be easily pulled off with Scotch blue masking tape. The varnish seems sufficiently hard (no gumminess at all).
Do you think more cure time is needed? I should note that under the gloss varnish is one coat of Zinnser seal-coat (de-waxed shellac). This was allowed to dry several hours before the first coat of varnish.
I have not yet tested to determine if the satin is lifting off the gloss or if both gloss and satin are lifting off the shellac. I will give it a day or two then test.
Anyone have any experience with this type of problem?
This is on a floor, so stripping the whole thing back is not an easy proposition.
Replies
I can't help with your problem, but I recommend you contact Waterlox directly. I have spoken with them, and they have always been exceptionally helpful.
MLB,
How long was it between the 1st and 2nd coats of waterlox? In general, varnish will adhere to a varnish undercoat if no more than 24-48 hours elapse between applications. After that, you should scuff the first coat to improve adhesion. Varnish does not "burn in" (redisolve) in multiple coats.
This is true of most varnishes. Waterlox is an oil/varnish mix and the oil may have interfered with adhesion. It is really necessary to know what is lifting from what.
The shellac is unlikely as the problem.
If the finish is lifting, stripping the floor is the only remedy. More cure time is not going to help. However, I really question using Waterlox as a floor varnish.
Rich
Per the folks at Waterlox, their varnish consists of a much "stickier" molecule. I was told by Jay Hawkins that you can go back any number of years later and put new over old. In my case, each coat was put on at 24 hour intervals.
I used this on another floor several months ago with no problem. The difference there is that I used full-strength coats brushed on. This time I thinned then wiped so that I could control the build to avoid the finish being too thick (cosmetics).
I have been using Waterlox to improve my ability to spot-repair down the road. I am now thinking of going back to my old stand-by; Deft-oil with asphaltum.
What I am trying to achieve is a very dark floor, thin-film finish, repairability. I first applied a water-based stain (Homestead Trans-tint). I then followed up with Minwax oil-based pigment stain. I applied one coat of shellac as a barrier to prevent lifting the stain with the wiping varnish. Then applied the wiping varnish.
mlb,
"I used this on another floor several months ago with no problem. The difference there is that I used full-strength coats brushed on. This time I thinned then wiped" . . .
. . . and apparently have learned that altering the brew significantly changes its behavior.
It won't be the last time a wood worker alters a proprietary mixture of complex resins, solvents, catalysts, accellerators, retarders and who knows what else, only to find it doesn't work as the manufacturer intended.
You still need to determine between which layers you've lost adhesion. I'd bet it's between the gloss layer and the satin layer. I'd also bet that scuffing the first varnish coat will solve the problem. But that's something you prolly don't want to do on such a large job. Going back to your original technique is a good idea.
Rich
Rich,
Having investigated a bit more, I don't think thinning the varnish was the problem. I did a yank test with some tape and it appears that everything yanked off except the stain. My guess is that with the heavy coat of stain I had applied that I gave it insufficient time to dry before the shellac barrier coat. It dried at least overnight and was not gummy, but still probably not dry enough.
I have since bit the bullet and stripped the whole d#$% thing! Took me about 45 minutes with a carbide paint scraper to pull 90% of the finish. Two hours with 60 grit on the ROS later I am past all traces of top-coats. I'll need to put about 4 more hours into sanding to be ready for my second go-round.
Here is my plan (after testing on flooring samples): Trans-tint dark walnut (or similar) in water to establish the dark color the "artistic director" wants. One or more coats of Deft/Watco dark walnut to color any pores missed by the water-base stain and also to pop the grain a bit. Then follow up with more clear top-coats to provide sufficient protection. The top coats will probably consist of more watco or similar. I don't want a thick-film finish.
Several years ago, I refinshed several floors with nothing but Watco and Deft. I was very happy with the protection afforded by the thin-film finish. I was even more impressed with the ease of repair and renewal.
mlb,Well, there's nothing like experience. I would have thought it very unlikely, but if you've been happy with that floor coating, go for it! It certainly is easy to repair. But I've had a similar finish fail on the arms of a frequently-used rocking chair in 6 months. Rich
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