Recoating Over an Existing Finish
Finishers advise on a cautious approach to recoating cabinets without sanding down to bare wood. August 21, 2006
Question
I have a customer who wants to change the color of a small kitchen. The cabinets are oak with a clear finish but I'm not sure what type of finish was used originally. My thoughts are to light sand and put medium brown glaze stain over them then put three coats of WB. My question is whether or not it is ok to do this procedure or do I need to strip the doors and start on fresh wood? Any advice would be great.
Forum Responses
(Finishing Forum)
From contributor A:
You might want to consider using blond shellac as a barrier or adhesion or primer coat. It will stick to anything and anything will stick to it.
From the original questioner:
I was considering using one coat of Zinnser sealcoat then continue on. What product do you recommend? The old finish is in very good shape except for a couple spots where it is peeling. That will have to be stripped and redone.
From contributor B:
The first thing you need to do is to clean and dewax the cabinets. Use the back of a door to make up your complete start-to-finish sample. The sealcoat will work. It is commonly used as a sealer for water base coatings. If it works on the back of the door, you’re good to go.
From the original questioner:
That’s exactly what I was going to do on the backs and have them sign off on the color. I was actually considering refacing them but with waterbornes as good as they are I think the refinish will work.
From contributor C:
I would try this - it has worked for me. Somebody correct me if I'm wrong in suggesting this, and please tell me why. If you were to scuff them, spray MLCampbell white vinyl sealer over the original material, scuff the sealer when dry, apply your MLC glaze, 20 min later apply another coat of sealer over the glaze, wait till sealer is dry and scuff, then your normal 2 coats of finish.
It worked for me on a cherry job that looked unbelievable after we completed it. It looked totally different and like a whole new kitchen. We even did the crown and light rail in place with an HVLP gun in the house with a fan in the window. The only problem was the portable compressor condensation which was solved with a new small portable air dryer.
From contributor A:
The only problem is the compatibility of the vinyl sealer with an unknown sealer. Some finishes for example poly will crinkle and turn loose if you use a vinyl sealer especially if it is not dust thin.
From the original questioner:
Compatibility with the original coats is my main concern. Your solution with vinyl is great, but I'm not 100% sure that it will hold over time. There is probably 98% chance that it will, but with my luck I will find that 2% error factor. Shellac sealcoat will pretty much adhere to anything, and my 2nd issue is that I use Target WB finishes - breathe easy. Thanks for your tip.
From contributor B:
Your right, compatibility is the main concern whenever you’re recoating over the unknown. Why not take some time doing some tests first to see if it’s an evaporative or a reactive coating that is on there now? How about doing a start to finish sample on the back of a door, and then doing a cross hatch adhesion test to see if it’s bonding? Think twice, and finish once.
From the original questioner:
I will do a test on the backs of the doors and have them sign off. How soon can I do the cross hatch adhesion test? I know the differences between coatings but do not know how to test first to see if it’s an evaporative or a reactive coating. I will use Zinsser sealcoat as my primer then glaze then topcoat with WB.
From contributor B:
Take either denatured alcohol or lacquer thinners and rub the coating. If it softens it, then it’s an evaporative coating. If it doesn't affect it, then it’s a reactive finish.
From contributor D:
The other problem with using solvent finishes is that they are very prone to fisheye from cleaning product and cooking residue. This is one area where WB's rule the roost.
From the original questioner:
I just did a 25 foot workstation for a hospital 100% waterborne on desk tops and tops - this will be the true test for WB. Ended up with about 6 coats.
