Old Finish (or Stripper) Bleeding Through New
Deficiencies in stripping and cleaning can cause problems with re-finish coats. July 18, 2008
Question
I'm stripping some cherry cabinet doors. When I apply the new topcoat, a clear substance appears on the surface and will not dry. Is this bleed-through of the old product, and how do I eliminate it?
Forum Responses
(Finishing Forum)
From contributor A:
Did you use a paste stripper? If so, it sounds like it could be incomplete removal of the wax which is in paste strippers.
From contributor C:
I agree, if the coating feels sticky and stays glossy, wax is probably the culprit. Wash the finish with scotchbrite and VMP naphtha and wipe with clean cloth a few times. Let dry and recoat and see if this eliminates the problem. If so, then one of two things are in order - either remove the entire finish or work around it by building up those areas of contamination with spot coats of finish. If it's bad all over, I would just strip with solvents and again scrub the surface with naphtha a couple of times and wipe dry and reseal the surface. One surface only till you know for sure it's been eliminated, then proceed with caution.
From contributor T:
I agree, however I might use a little hotter solvent such as acetone when scotchbriting. You might also try a 000 ought steel wool while removing that last application of stripper. All strippers are different and all have that perfect window of application removal time. Try one door at a time and find that perfect window to remove it. Leaving it on too long or removing too soon can cause inconsistency in stripping results. Never try to strip 10 doors at a time. No two projects strip the same.
From contributor C:
If you're looking to remove finish as well as the wax, then acetone, toluene, mek, and other polar solvents will do just that. If you're just trying to remove the wax under the finish or on the wood without removing any finish, then a non-polar solvent is your best choice. The old adage "like removes/dissolves like" always holds true.
From contributor R:
In addition to what's been mentioned already, make sure that all the original finish has been removed. Some of these newer finishes are almost impossible to remove with chemical strippers and even though they look as if they have been removed, they are still present. When you apply a new finish, it won't adhere to the older finish that's been left on the wood surface and it will give you the same look as what you've been seeing. Sometimes it helps to sand a surface with 100 grit paper before you lay on or dip the piece into the stripper. That opens up the surface film and allows the stripper to get a better bite.
