Lacquer over Stain Adhesion Problem
Walnut hand sanded to 220
I can mark and even remove the lacquer with my fingernail. It comes off in tiny flakes like an old finish. I have been using Behlen lacquer for 30 years, never a problem. I don't usually use Minwax. How do I fix this?
From contributor L:
You need to wait a minimum of 3 days with warm temps before you can topcoat MinWax with a lacquer product.
From the original questioner:
Should have mentioned I waited 24 hours before sealing the stain. Can says 8 hours.
From contributor R:
It does sound like your stain wasn't dry... but you did wait long enough. You'll get a lot of crap about using the Minwax but don't let it get to you. I know a lot of finishers who do, at least on the occasional job.
It really doesn't matter what caused it. It's done and I think you'll need to strip it. 220 is also finer than I would go, 180 tops. That can also cause adhesion problems.
From contributor E:
Talked to the Mohawk guy (makers of Behlens). He was extremely helpful, said they recently changed the formula and it is hard not to spray it on too dry. He thinks that is the major portion of the problem. I remember having a hard time getting a wet coat down. Probably the first coats were sprayed quite dry before I caught on. He thinks if I sand back and use a much retarded heavy coat on top, there is a good chance it will melt down to the stain and bond. Certainly worth a try!
From contributor R:
Good luck with that, but I'm thinking you have too many mils on there for the retarder to work. Check a door before doing all of them.
From contributor D:
My finisher says that the darker the stain is, the longer it takes to dry, with Minwax. The can is way off - 2 to 3 days for walnut or darker.
From contributor Q:
Be careful using excessive retarder additive. Too much opens another can of problems.
I agree it's best to strip and do over. The rep is trying to help make the save, but the odds are you chase more time down the drain or at best are left wondering if problems will show down the road.
Depending on the scale of the project it could be as simple as washing down with acetone or even lacquer thinner.
Also agree - don't sand finer than 180. We go 120p -150p at most in my shop.
You mentioned the dry spray - This could be a cause of poor adhesion. You need proper wet coats so that you get a chemical bond between them. So get your mixture and equipment settings worked out and practice on some scrap plywood.
I don't like 2 coats of sanding sealer either. 1 is adequate. I realize that lacquer sanding sealers are industry standard products and 2 coats is long held standard. But what most reps don't tell you is the additives which make it easy to sand also compromise adhesion and transparency (if only a little). Vinyl sealer is a better choice over standard lacquer sealer.
My money is on the dry spray as source of adhesion trouble. However I wouldn't use Minwax because the dry time is not very manageable and there are numerous other materials that are predictable and achieve better results. I don't rule any product out for use if I understand what it is - how it performs - and it gives the best result.
Minwax is popular and available and I realize finishers who are not further along the learning curve need simpler solutions. I don't judge anyone but just want to encourage you that there are many more better ways to achieve your colors and get much more control and satisfaction with your work.
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