Toning out Prefinished Cabinets?

Finishers discuss the feasibility of adding one or two more coats to pre-finished imported cabinets in order to adjust the color. April 17, 2010

I was recently contacted by a guy who is bringing in pre-finished cabinets from overseas. He wants them toned from natural to a bundle of different colors. They are all alder and approximately 90% are finished with a CV, the other 10% with lacquer (which variety I know not). My Gemini rep said that if I sprayed vinyl sealer on them I'd have problems, but I want to tone them out in vinyl and then recoat both varieties with CV. Any thoughts? He is after different wood tones, not opaque colors.

Forum Responses
(Finishing Forum)
From contributor D:
Sounds to me like a recipe for disaster. It could be UV lacquer topcoat, in which case you are hooped. I suggest you pass.

From the original questioner:
I will not take on the project unless I can put out a quality job, but having said this, the fellow is bringing in containers of thousands of cabinets and it is worth it to me to exhaust all my options before simply saying it can't be done.

From contributor J:
Talk him into sacrificing a few - for certainty's sake - and run some trials which you will subject to all the usual tests (adhesion, checking, resistance, etc.). Or have him get his supplier to divulge the finish spec.

From contributor R:
Contributor D is trying to save you quite a bit of frustration and some serious finish failures down the line.

Keep in mind that a catalyzed finish has a mil thickness threshold and if you add more finish to an existing finish (tone, color change, etc.), you will add to the mil thickness. This will cause many problems for you, the importer of the cabinets, and their customers. These problems may not appear immediately, but you can bet your bottom dollar that they eventually will appear. If at all possible, get a couple of sacrificial cabinets as suggested and run some lengthy in-house tests.

Too bad you can't get the cabinets shipped to you in the raw stage and finish them to whatever color the customers want.

From the original questioner:
Thanks, everyone. I will definitely get some bones to work on before moving forward. I have already seen the spec sheets on these, and I know a reliable finish can be achieved, as another company in my area is doing the same thing with great results. The majority are finished (as mentioned) in a CV. I am not sure what lacquer is used on the rest. If it is a UV cure, I'm probably screwed, but I would be pretty surprised if it was.

On a basic step by step level, assuming that I am dealing with CV and some lacquer other than UV cure, and taking into account mil thickness as a very real factor to durability and life, is there a problem with scuff sanding, sealing (while toning), and coating with CV?

After another few conversations with the Gemini rep, he said that his main concern was wrinkling the vinyl sealer if I didn't use the catalyzed variety, which makes perfect sense. I realize that I am just making a mechanical bond here - just want to make the strongest one possible.

Also, believe me when I tell you that I have mulled the value of getting in neck deep on this job many a time and I do appreciate the experienced advice on the matter.

From contributor D:
I would hate to hear that you ran into a huge headache. I don't know how to do what you want. However, if you can do it and make some money, that would be great. There was a guy in Edmonton who mentioned this sort of thing to me about two years ago but he had raw doors. I was too busy to be interested but I was also quite a bit cautious. I bought pre-finished import birch and it was a disaster, so I was probably thinking about that when I first read your post. Too bad you can't get them raw!

From contributor E:
Could you maybe use shellac with some NGR mixed in as a toner, then spray another coat of CV over top? They say shellac works as a barrier for just about anything.

From contributor M:
Will you be able to tell which is lacquer and which is CV? Do you plan on scuffing the finish before coating? Have you considered using a 2k urethane (a little more forgiving on film thickness and wrinkling)?

From the original questioner:
I will definitely be able to scuff sand, and I will know in advance which cabinets have which finish on them.

I haven't looked into 2k urethane. I'm not very experienced in spraying that. I did consider recoating in a hard lacquer called Ultralac by Gemini, but I came to the conclusion that since I would be tinting the sealer rather than the top coat, I wouldn't have much problem if there was an area that I needed to retouch.

As for shellac under - I've never tried it, but I've heard you should never use shellac under CV. Does anyone have experience with that?

From contributor E:
Now that you mention it, I have heard not all CV will go over shellac. No reason you couldn't go over the shellac with lacquer, though.

Another option: get a hold of a Positector (I think that's what they are called) and measure the dry film thickness of the existing coating. You then know how much additional film you can add. Since you are only toning the cabinets, you can thin out the CV a lot, as all you need it for is a little binder in the toner coat. Then spray another ultra thin coat over top of the toner coat. If you know the current film thickness, you can then figure out how much extra you can put on before exceeding the recommended film thickness.

From the original questioner:
Thanks - it's certainly worth testing the shellac idea. The only thing I want to do is make sure there is enough coating over the toner that I won't have to worry about fingernail gouges and touchup! I will also check into some type of dry film tester.

From contributor E:
They are really expensive... $600 and up depending on the model. My local MLC rep has one. Try your local coating reps to see if one of them has one that they can bring by to measure for you.

From contributor L:
I agree with the idea of seal coat shellac tinted with Transtint dye to get the color you want, and then topcoating with your preferred product. One way or the other the finish will probably outlast the Chinese cabinets anyway.

From the original questioner:
Thanks. Do you have any experience spraying CV over shellac? I think it should be okay but I've never done it. Also, with shellac, would I need to get all my toning in one coat, or can I build it up?

I laughed reading your durability comment... That was the first thing I thought of when the guy called me!

From contributor B:
Your best option will be 2K polyurethane. The main concerns with other systems would be excessive film build, blooming or wrinkling. If they are UV cured finished, I would recommend an Isolante sealer.

From contributor R:
The longevity of a finish and one reason for its failure can be traced back to the foundation coat. Shellac is not a very good foundation coat due to its inability to withstand any sort of moisture. Putting any finish - oil or lacquer or conversion varnish - on top of a poor foundation (shellac) will most likely cause problems for you down the road.

From contributor J:
I agree with contributor R about the shellac thing. If you need a barrier coat for contaminants, then shellac. But you need a bond coat, probably something catalyzed, that can carry the toning agent as well.

From the original questioner:
Thanks - that was exactly what my first thought was on shellac. I have never used it for anything - I've just always found a better alternative. I've used a bunch of 2k polys but I've had big time problems tinting it to anything besides a completely opaque color.