High Gloss Finishes

Advice on formula choices (including automotive clear-coat urethanes), polishing methods, and finishing schedules for a drop-dead glossy clear finish. December 9, 2010

After an outsourcing relationship went bad, I had to do a white and black gloss job on four small pieces. I tried to do the job with Target Coatings products, then ICA 2k waterborne polyurethane. I was not able to get a satisfying polish with either product. I cannot get rid of the sanding marks. I have tried many types of sandpaper, compounds and pads without success.

Any advice? For level sanding, what kind of paper, compounds, and pads work for you?

Forum Responses
(Finishing Forum)
From contributor D:
For pads, start with wool and finish with foam - first orange foam, and finally black foam. For compounds, use Menzerna 2L, Paste 16 and if needed 106FA.

From contributor J:
Where did you purchase the ICA? What was your overall opinion of the product? I have been spraying waterborne for a few years now, but have not settled on a pigmented product yet.

It has been my experience that you should let the finish cure some more after leveling, before the final polish. The marks could be from the finish still being too soft. Waterborne takes a long time to get hard.

From the original questioner:

Thanks. Contributor D, what brand do you recommend? Contributor J, I am still in the process of choosing my products. Contact ICA North America. Should be easy to order. Their white basecoat and topcoat is nice. The gloss product is kind of strange. I need to do more testing.

From contributor D:
Brand of what? Menzerna for the polishes. The wool and foam pads can come from many sources: 3M, Lake Country, American Buffing, Buff & Shine, S. M. Arnold and others.

From the original questioner:
Thanks - I did not know there is a color standard for pads. I thought you were referring to some particular brand. I'll buy some new pads.

From contributor W:
Rubbing to make high gloss finish is very tough work. The small imperfections will show clearly in this finish. You need to make sure you get the level surface from the beginning when you prepare the raw wood. Your finish needs to be thick and dry enough before you start the rubbing process.

Do your leveling with wet sanding. Start with the 800 grade sandpaper and go to 1200. When you buff, start with a white colored pad and end with the foam buff pad.

From contributor B:
Call your Festool rep. They have everything you need for solid surface polishing, including a schedule of what grits to use.

From contributor R:
Stroll on down to an auto showroom and take a gander at an automobile finish. Nice and shiny. Automobile finishes have made a tremendous leap in the past few years, thanks in part to the White House's desire to lower VOCs.

At one time wood finishers had the opinion that an auto finish was too brittle, difficult to apply, difficult to sand, difficult to polish, and difficult on the pocketbook. Not so any longer. By the time a wood finisher has applied a traditional wood finish, then waited and waited and waited, our counterparts around the corner are getting ready to polish their automobile coating.

When you add up all the waiting and the labor and the down time and the other numbers that enter the equation, the bottom line is that all that wasted time is money you haven't made. I think the application of auto finishes can cross over and become beneficial to us wood finishers.

From contributor D:
As an auto guy, I've been trying to beat this fact into these wood guys' heads for years. What wood do you work on that's as flexible as a urethane bumper cover? Automotive clear coat is the way to go for high gloss finishes on anything.

From the original questioner:
I am trying to figure out how to do it efficiently. Take the guy who was outsourcing my jobs, or the big finishing shops in my area - there is no way these people are going through four fine sandpaper grits, then 2-3 compounds, then whatever else.

No, it doesn't look like painted glass, but it is glossy, though a little wavy. I am trying to find a way to do a good enough finish when painted glass is not possible. I cannot put my mental health at risk each time a customer "needs" a gloss finish.

From contributor D:
Here's how you do it. This would be for something like a table top.

1) Use whatever primer you like. Polyester works well.

2) Bury the thing in acrylic urethane clear coat. With acrylic urethane, there is no thickness limit, but you have to be careful about shrinkage and solvent pop, so you have to let it flash between coats and wait a day before you start polishing. Here in Arizona we set stuff out in the sun where it will get to 170F. Acrylic urethane loves heat, the more the better.

2) After you've got on about three coats of clear, you level the surface with P400 grit paper. The best way to do this so that the object gets the flattest is with a long DuraBlock and file board paper, and hand block it.

3) If that ain't cutting it, using a hard and perfectly flat DA pad and an 8" Mud Hog (National Detroit 900) or equivalent. You use P400 stearated paper to get the thing as flat as possible.

4) Back into the booth for two more coats of clear. If you're doing this right, things should look really good at this point. Clear goes down on flat sanded clear much better than it does on raw material or primer. If you're really good and have a great booth, the off the gun surface at this point might be good enough.

5) Start with P800 6" 3M 260L finishing film on a 3/32" random orbit sander (I like AirVantage but Dynabrade or Hutchins is fine) and flatten out the urethane wave again. Once again using a hard DA pad.

6) Move up to P1200 3M 260L finishing film and go over the P800 and make sure you've removed the P800 scratches. Use a soft DA pad. 3M calls these Painter's Pads.

7) Next we use P1500 3M Trizact Clearcoat finishing discs wet (spritzer bottle) on the same random orbit with a soft DA pad.

8) We're looking really shiny now.

9) Next we use P3000 Trizact moist (spritzer bottle) on a large throw DA (3/8") with the soft pad and we're looking shinier still. 3M recommends the large throw on P3000 Trizact as it speeds the process up and since Trizact is used wet, there isn't the threat of pigtail scratches that exist during dry sanding. I use a $29.95 C-H sander from Wal-Mart for this operation as it has the big throw, it's cheap, and it works.

10) Rotary buffer time. Wool pad and Menzerna 2L. This gets rid of any stray pigtail scratches (which will be there, trust me).

11) Wool pad and the Paste 16. You're near mirror surface at this point.

12) Black or orange foam and P106FA and it's sunglasses time.

I've done this for decades and there is no other way to achieve this level of perfection. If shiny and wavy is good enough, you can skip sanding steps, but you'll see the difference.

From the original questioner:
Wow, I wasn't expecting that. I won't be able to try your schedule with what I've got now, but will try it for sure as soon as I can. I really appreciate you offering that kind of info.

From contributor B:
Now you have to figure out how much you need to charge for all that work to make money. Your average wood purchaser will most likely require a 911 call when he hears what it will cost him. And my buddy contributor D does know what he's talking about.

From contributor C:
I've had decent results with Becker's Matador. I've sprayed an 80 degree sheen, then buffed it out with a buffing wheel and used progressive (cutting/buffing/polishing) 3M compounds. It's still a little wavy, but every client I've done it for is happy and it saves you wet sanding. I've always used it on an MDF substrate with two coats of Unisurfacer primer and 3 coats of colour. Wait a day or two before buffing.

From the original questioner:
Thanks! The biggest mistake I made was my pads. The pad choice seams at least as important as the compound.

From contributor A:
Wow! You guys go to a lot of trouble to get a mirror finish. I concur with using auto clear (not sure if you have Autothane Stateside), but after three coats of build - sealer, base, topcoat - cut back with P400, finish top coat, then buff with any auto cut paste. The result is the same as any newly polished car. Mirror finish. No scratches, nothing, and it works equally well on teak, mahogany, pine or cherry. You just have to be patient and allow flash off between coats - 5 minutes?

From contributor M:
If you're using solid wood, try scraping it with a cabinet scraper after sanding. This will remove sanding marks and leave your surface looking shiny - perfect for finishing with oil.

From contributor Z:

Great timing for this post, as I'm trying to resolve my problems to get a brilliant finish over MDF. If the client wants white or black, no problem - I use a 2-component polyurethane. But with colors I need to use automobile lacquer. My steps have been:

1) Two coats of primer
2) 3-5 coats of top coat
3) Polishing with foam pads, 360-1000
4) Buffing with 3M compounds

My problem is with the drying time on the top coats. I'm having to wait 5-7 days before I can polish, before my fingernail doesn't leave a mark. I lay down 3 coats, wait 24 hours before another 2 coats. At 3 coats, the polishing goes to the primer. Thicker coats require more drying time. I've tried a clear coat of lacquer after the three, but I'm still at the drying time. I'm at my wits end. I'm limited to one brand of automobile NC here in Mexico. I'm thinking that I should go back to Dupont acrylics which I tried several years ago and had problems with, but perhaps their formulas have changed since then.

From contributor D:
Use acrylic urethane clear coat and automotive urethane or polyester basecoat. Lacquer is no longer used in American automotive refinishing.