Painting - Painting MDF

Hey guys,

Not sure this topic fits here but here goes. I've built a box, made from MDF that I'm wanting to paint. The problem is where. I've tarped off a small area in the garage to limit the dust as I'm after a mirror like finish. After 3 coats of primer and 2 coats of high gloss laquer, I'm not happy. There is still a ton of dust that is finding it's way onto the finish.

I don't have a full time paint booth. Any suggestions for a guy who paints every once in a while?

Are you sanding between coats?

Yes. Just seems whatever I do to limit the airboarne dust just doesn't work. I was hoping there was a trick to it. Maybe I have to built a more semi-permanent closet with a fresh air fan blowing in and another blowing out. Switch the fans on for a few minutes before painting to help clean the air?

I bought a Honeywell Air Purifyer recently. It's actually the smaller one which had the best review and it uses a large HEPA filter that never needs to be replaced and a charcoal pre-filter that does need to be replaced, but it works really great. Since I've been running it, I hardly see any (if any) dust particals floating around in the air. Maybe you could buy one of these.

Interesting avenue. How much volume of air are you cleaning? Do you have it running while you're spraying?

Gee, I wonder if you could ask an autobody shop to paint it for you... Although I don't know if auto paint would work on MDF.

SirWired

In dusty conditions, you definately would NOT want to run any sort of fan into the room. All it will do is pick up and circulate the dust. A dust collector would help... even Shadeladie's suggestion of the air purifier might help since it would also filter the air.

Occasionally I will run an exhaust fan out a window when needed to draw air out of a room. Not sure that would help if you're not in a very clean environment to begin with. Have you made yourself a small paint booth out of plastic?

How bad is the dust? Is it feasable to buff it out?

I'm not using it for painting or anything, just have it in my house (the one I have is recommended for a 200 sq. ft. area) but thought I'd mention it since it seems to be working well for catching dust.

What about the sprayer you are using. It must be a HVLP for what you are trying to achieve. The paint, are you thinning it down? Or are these spray paint cans at the big box stores? Did you vacuum the entire garage floor THROUGHLY! Including the ceiling, walls or joists? These last two sentences are the key.

you said you were using lacquer. what brand? many good brands have retarders you can add that will slow the dry time, allowing some of the over spray dust to melt back in. The gun is important as well. What is it? is it HVLP off of a turbine, Airspray, HVLP off of a compressor, Complaint, Airless, AA? a cheap gun system tends to have more over spray. (which is the dust you are getting on the film) if you are using a spray can, there really is not much you can do.

Great knowledge here guys, thanks. I've now realized that what I want to accomplish cannot be done with my "equipment".

You caught me, I'm using off the shelf spray cans. I honestly didn't think about the gun and it's importance. The second strike against me is the shop I'm painting in. Ironic that I do a lot of wood working but very little painting. I have been painting in the same space I cut my material. I simply tarped off a small area to paint in.

So, come spring (little tough working in -25!) I'm going to build a small, 5x5x7, collapsible enclosure for painting. I'll think about how to clean the air in the enclosure. Perhaps an air purifier. The problem as mentioned is I cannot draw air in from the outside as the shop is littered with dust.

Next question, how much do you think it will cost a guy for an effective gun setup? I'm not looking at premier quality, just something that will produce good results.

Thanks a million guys, I feel out of my league!

If you already have a big enough compressor, you can get into a decent gun setup for around $400. You should have a compressor that can keep up with the CFM requirements of the gun, figure around 8-9 as a lower end.

I would highly suggest a paint store. You will find much better equipment and service. And better products then the off the shelf spray cans. A good lacquer for MDF will give you an excellent finish, better then a paint in some respects.

Thanks again. A little late to add to the Christmas wish list. Guess I'll have to wait until the new year!

Have a good one!

You could built enough thickness, then rub out the finish.

As in sand the final coat?

Not with sandpaper! Sometimes just rubbing/buffing the paint with a soft cloth will remove minor blemishes. You could also use a wax or rubbing compound if it's suitable for the finish you used.

I like the idea of a wax. That might help achieve the high gloss look I'm after.

I used a laquer. Think a wax would be suitable?

you could rub a wax on it, but then you can not ever put more lacquer on it.