Recoating Old Cabinet Doors

Adhesion, compatibility, and durability are concerns when applying new spray finishes to old cabinets. March 3, 2006

Question
I have a repeat customer who wants cabinet doors re-sprayed. They are Kraft-maid and they don't need stripped or re-stained, just top-coated. They are 15 years old and the top-coat is wearing. My question is with ML Campbell products, should I put vinyl sealer on first or can I put Krystal right on top?

Forum Responses
(Finishing Forum)
From contributor S:
Do a light coat of vinyl sealer. Then you can do your Krystal after scuffing the vinyl sealer. Do not expect to get the high performing durability of Krystal with this recoat.

Here's why. Your new topcoat can only be so many dry mils thick because for Krystal you cannot have a total coating weight that exceeds 4-5 dry mils. An application of Krystal that is 1-2 dry mils has nowhere near the performance and durability of a Krystal coating system that is through-and-through 4-5 dry mils.

You do not know the amount of existing dry mils of finish. I suggest that you clean your areas to be recoated with a mixture of TSP and water. Rinse with clean water. Scuff real good with 280 grit or 320 grit stearated sandpaper. Lay down a thin coating of vinyl sealer (you can shoot anything from unreduced 25% solids to something cut in half at 12% solids). Scuff with 320 and lay down one coating of Krystal.

Now you are done. No guarantees on the behavior of your new coatings or its durability or performance. The only aspect of the whole operation is that you can predict how you want it to look in the end, not even how long the coating will last.

I should have mentioned first that if your original coating is wearing in such a way that it is starting to degrade, chip and peel then you are too late for a recoat. Degraded finishes should not be recoated. They should be stripped.



From contributor D:
It has been my experience that the best way to do what you are looking to do is to use one of the self cross-linking WB urethanes that are on the market now. I do a lot of this work and with the solvents, you always have to worry about adhesion to the old finish and worse yet what kind of products have been applied to the surface that are either going to inhibit adhesion or cause incurable fisheye. The WB urethanes excel in this area also and the other benefit is if you also need to do the face frames and end panels, you can do the onsite with less hazard than CV or pre-cat.



From contributor M:
You should first think about thoroughly cleaning the doors. Always remember adhesion comes first before compatibility.


From contributor O:
I would advise not taking the project unless you can 100% guarantee adhesion. I'm not saying this to help your client but you. We recently refinished some coffee tables that had been coated and polished with silicone for 15 years. Do you know what to clean them with – nothing. Do you know what will stick to them - nothing. I don't want to be negative and I'm assuming you are a conscientious finisher but in this situation all bets are off.

I wouldn't try cleaning them with anything lest you push what's there around and make it worse. Your best option in my opinion is to choose a waterborne you want to use as a topcoat and apply it correctly (light scuff with 320 or even Scotchbrite unless you're using a urethane which may require a sealer and a heavier grit sanding). If it fisheyes you will know within a few minutes if not instantaneously and at least you'll have a decent chance at wiping it off with a really wet rag.

The only problem here could be that the contaminants migrate over 24 hours and you won't have time to wipe. I'd like to tell you to just go for it and maybe you will and if so I hope you don't have a problem. If you're at all worried by my suggestion (which I make because it happened to me and caused me grief) that adhesion could be a problem then at least brief your client and do a test. What's the worst that could happen? You could end up having to match/replace every finished surface on the kitchen.



From the original questioner:
I'm seen a couple posts here referencing WB. I didn't think you could put WB over lacquer. I'm assuming they are some sort of a solvent base finish now. Am I missing something?


From contributor D:
I have been putting WB over solvent and varnish for quite some time and have never had an issue. On the other hand every time I tried to put solvent over old solvent I had nothing but headaches. That’s just my experience though. Contributor M is exactly right. You need to thoroughly clean and prep the doors before spraying.


From contributor M:
Recoating is not new in finishing - recoating has been around for decades. Most furniture restorations are recoats. You cannot take anything for granted, nor can you assume what the coating is that you will be recoating. You need to spend a little time investigating what the coating really is, and what coatings will be compatible to recoat.

Using "softer" solvents like retarders in the new coating can be a big help in preventing wrinkling and separation in the recoat. There are plenty of areas where you can do your testing on the cabinets, and barrier coatings are another option you can consider. Recoating is not for every shop. If you’re going to do recoating, you need to do your homework on each and every job you do.



From contributor R:
I can only address cleaning the old surface. You must remove any oils, waxes and anything else that was smeared on these cabinets over the years or you will have problems. I use a product made for the automotive industry to clean off everything. The auto guys use it to clean off body panels before refinishing. It will remove everything - wax, tar, oil. The product I use is made by Dupont and is called Prep-Sol.