High Gloss White Paint on MDF

Finishers offer several approaches to achieving a high-gloss white finish on MDF cabinets. March 9, 2008

I have a customer who wants a contemporary kitchen with what they call "white lacquer." The finish is found on a lot of the European cabinets. It is a mirror gloss white over MDF slab doors. I am trying to get some advice on how to do this over MDF. Poly is what I think makes sense based on the few conversations I've had, but I would love to get your feedback.

Forum Responses
(Finishing Forum)
From contributor J:
"Wet look" acrylic polyurethane by Milesi spa. It is the glossiest gloss I have ever seen; you really can't tell if it is wet or dry. I hope you're set up for such a job, though; otherwise it will be a nightmare.

From the original questioner:
How so? And what are the steps you take to get this look - do you buff/wet sand, etc.? Thanks.

From contributor C:
High gloss will show every little imperfection there is. Yes, MDF has its share. I say a few good coats of primer, sand smooth on last coat of primer, then a couple of good coats of the finish.

From contributor M:
Everyone is right. Gloss will show everything. Prep, prep, and more prep will be your best bet. I would use Becker's surfacer and then top coat with gloss Matador.

From contributor J:
The look you are trying to achieve will require you to wet sand and polish, no matter what material you use. I find the acrylic urethane easiest to use, and glossiest, but Becker is a great product also. The quality of the end product always starts with preparation. Prep it perfectly and you will be good to go. The urethane is a high build, so that will take care of most imperfections in the MDF.

From contributor R:
Use Becker Acroma. But remember, the glossier the finish, the harder it will be to hide the dust, etc. I use 40 degree sheen most of the time. I've done higher, but it shows everything.

Here's my process. Prep sand MDF on the machined surfaces up to med 3M sponge. Apply one healthy coat Becker White Surfacer. Sand with medium 3M sponge when dry. (This is the hardest sand.) Don't worry about sanding through. Make nice and smooth all over. Apply second coat Becker White Surfacer. Sand when dry with *worn* med sponge or good finer sponge. No sand through this time. Make nice and smooth. Spray front of door with good coat of white or tinted Becker Madator. Let dry. Scuff with fine sponge, lightly. Do final coat of Becker Madator. Back, then front. Front gets two coats. I spray with a Deviblis gun with a Binks pressure pot. It gives good control over how much and how fast you put it on. To get a perfect finish, you have to spray on the ragged edge of getting a run or a sag on the final coat. Doors come out nice when spraying flat, but if you have to spray large panels or vertical pieces, it will take practice and patience.

From contributor M:
I can't explain it any better than that. Contributor J's way is great too, but, I would try to stay away from buffing; you won't make any money doing that.

From the original questioner:
So if I'm getting this right, you guys just prep the stuff glass smooth, and then sand between the topcoats, but the final coat doesn't need buffing with this product?

From contributor J:
I have done several high gloss jobs off the gun. But make sure that is what the customer wants. You described a polished finish. There is a difference between polished and off the gun. Get a sample and have it signed. The only jobs I have done in the past 10 years were off the gun and polished (buffed) - I never wet sand anymore. You usually only wet sand if there are dimples or defects in the finish. The compounds these days will sand (buff) out any orange peel you may have and bring it to a mirror shine.

From contributor E:
I am with contributor J on this one. I've sprayed the high gloss 2k poly by Milesi and it is glossier than anything else I've sprayed out of the gun. It covers great and you can build the mils without worrying down the road. I've used it on open grain conference tables made from mahogany and didn't need to use any filler. So it should fair well on MDF.

From contributor F:
Why would anyone use mahogany if you want a full fill high gloss white?

From contributor P:
Becker surfacer (primer) and Matador (or Bernyl Strong) are conversion varnish and won't buff out as easily as 2K poly. If you're not planning to buff the finish out, either is a good choice. On MDF, you should be able to get away with one coat of primer except on cut or routed edges. Level sand with 320 (e.g. Abranet), and you're ready for the topcoat.

From contributor E:
Contributor F, you are quite right. I used the clear coating system on mahogany. I've sprayed the white on other stuff.

From contributor D:
I mostly play with cars now instead of furniture, but off the gun and polished are two different worlds. Off the gun looks good until you color sand and buff. This looks exactly like a mirror, not a fun house mirror like off the gun does. Factory paint on a Mercedes isn't as good as color sanded and buffed is. When you get into the high gloss world, there are many different versions of perfection.

I've designed furniture with knock down fittings specifically so that I could polish it, which is impossible if something is assembled, as you can't polish into the corners. All of my living room furniture is 844 Quinacridone Violet tinted Automotive Acrylic Urethane clearcoat over MDF that is a purplish burgundy color that's amazing, and it's all been color sanded and buffed to a true mirror like finish; you could shave looking into it. The amount of time I took to do this was infinite, but I wanted something completely unique for my personal furniture, which it is. If it takes you X amount of time to build something, it will take you 5X to finish it to the level of perfection I'm describing here. The only way this is possible is by using Minifix, Rafix and Confirmat connectors and assembling everything after the components have been polished flat.

From contributor I:
Could you explain what you mean by "color sand"? Thanks!

From contributor D:
Color sand is an auto body term first used with respect to acrylic lacquer automotive finishes which are no longer used today. It's the use of fine sandpaper (either wet or dry) to remove all imperfections from the painted surface. Back in the day, this was done with CAMI 600 grit wet-or-dry wet paper; now it's done using 3M 260L P1200 finishing film dry on a random orbit sander. We've gone from lacquers to urethanes, but the term lives on. Basically, color sanding is simply sanding the paint smooth prior to buffing. The entire process is referred to as color sanding and buffing.