Painted MDF - Bail out or Fix it?

[Statsman1]

Hey...

It's taken me the better part of 4 weeks to very slowly build a cabinet.  I've been making it up as I go, so to speak - I borrowed some of LuSid's plans (via Saint's BYOAC Bible), some Supercade CP ideas, and then...well, it's my own idea, and once it's done, I'll try to post some pictures.

Anyway, I'm painting the cabinet which is made of 3/4" MDF.

I went ahead and primed it with Kilz, and now I'm 3 coats of paint into it.  And I'm a little worried, as the paint is not coming out as I'd hoped.  This far into it, I would have thought that the paint would not allow the primer to show through, but...it's still kind of visible through the paint (it's a dark burgundy).

I was scanning through the posts about painting MDF, and there's a lot of talk about sanding, and such, that I didn't do...and perhaps I should have, but it's too late now.

I can let the current coat of paint dry, then sand the heck out of it tomorrow night and try painting it again, if that would help.  I don't want to rebuild this, I can tell you, so I'm hoping that there's a way to salvage this.

Any suggestions would be appreciated!

[Necro]

First, DON'T sand that sucker inside the house.  The MDF - if you sand down that far - will get everywhere.  And be sure to wear a mask.

Now then, my suggest would be to get a random orbital sander and sand the crap out of it with decreasing grit sizes until you get the sucker smooth.  Maybe reprime, but only if your seeing MDF. 

Then do a coat of paint, light sand, coat of paint, light sand, repeat.  I did 4-5 quick light coats to get the inside of my cab a nice dark black over the white Kilz primer, so that's not unexpected.

Also, something else that's going to come into play is what your using to paint it.  I found a sponge brush worked the best and would recommend that.  A regular brush kept leaving streaks and was making it textured.

Last thing, make sure to mix/stir your paint well before using.

(Note: Most of my cab painting was done inside my cab to make the entire inside black so...I wasn't going for an external finish.  However, I've done a few other wood projects and the above has always worked for me in the past)

[Statsman1]

MDF is a dust machine, and luckily I wasn't doing it in the house - I was doing it inside the garage.  And that MDF dust gets EVERYWHERE.  Wasn't wearing a mask, although I probably should have been.  That's what I get.  =)

If I'm doing the sanding now, it's just PAINT, right?  Shouldn't be a big problem, but I will wear a mask anyway.

Will sanding it remove all the paint and put me back to square one?  I don't mind priming it again, it sure beats building a new top.

I was using a 4" sponge roller for the paint, but I used a brush for the Kilz primer, and I suspect that's were the problems began...the strokes must be coming through.

And by decreasing grit sizes, you mean going from something really coarse DOWN to something really fine, right?

[Chadwick]

Yep, that's what he means.

Your biggest issue is that you are using about the worst color.  Anything in the pink to red range is going to take many many coats to cover well.

My assessment is that you just need more coats of paint.  You do not need to sand that hard between each coat either, just the final coat.

If you want it shiny after you are done painting, get a can of clear spray lacquer and coat a few times.

Good luck.

[Statsman1]

"The worst color" is exactly how it was described to me when I bought it.  I should have listened, but it matches the monitor I'm using, and I'm stubborn.

I think I might use what I've got (right now, I'm calling it "burgundy woodgrain"), and build a new one and do it right from the beginning, and swap it in when it's done.  It's getting too close to the holidays to sweat this, and my wife will be happier for it (I want drums for Christmas, you see).

Thank you for the tips, you guys. 

[dkubarek]

When working with MDF you should apply a solution that's one part wood glue and one part water to the ends (where it's not quite finished). Otherwise it soaks up tons of paint. But it sounds like you have color problems everywhere, so maybe that won't help much.

[Statsman1]

1 part glue and 1 part water - any particular glue?

I read in a couple of places that I should have done that sort of thing, but it was too late.  The funny part is that this should have been the easiest part, and instead, it's giving me the most headaches.

I like MDF because it's hard and tends to stay straight, but when I do this again, I might use something else.