How to base coat MDO so it looks GOOD

[android606]

I know there's a similar thread to this, but I have a little different twist.
I think it would be very, very helpful if someone experienced could give a real step-by-step about this.

I have a customer that needs 10 4x8 sheets of MDO. He wants them base coated a very specific shade of yellow (to match his store), so I bought a gallon of custom tinted Syn-Lustro oil based paint from Dunn-Edwards.

I've only been doing this about 2 years, and up until now, I've never had a sign bigger than a single sheet of MDO. Furthermore, I've never dealt with yellow. It seems that most people either want a relatively dark base color, or they just want to leave it glossy white, the way it comes from my supplier.

Here's my usual procedure to coat MDO, arrived at mainly by trial and error:

1) I get Rust-oleum oil based paint, or 1-Shot lettering paint. If I need a custom color, I get oil based "Syn-Lustro" from my local Dunn-Edwards paint store.
2) I recently started de-glossing the surface with a Scotch-Brite pad.
3) I apply the paint with a 3" natural bristle brush I get from the paint store.
4) Sometimes, I'll thin the paint a bit and apply a second coat.

Usually, that works fine. It doesn't look *perfect*, but it looks pretty darned good, and the customers like it.

I have had the worst time trying make this particular job look good. This yellow is just a nightmare. I've tried brushing it; every brush stroke shows. I tried spraying it with an automotive sprayer; every spray stroke shows, and the paint either runs, or it comes out rough and matte looking. I used a small white foam roller; it looks like it was applied with a sponge.

It has occurred to me that my technique probably sucks, all of my paint jobs are probably full of brush strokes, and the dark color just masks them so you can't tell they're there.

So, what am I doing wrong? Is it my choice of materials? Should I actually be using latex or something? Do I need a different brush, roller, or sprayer? Is yellow just a pain? Am I doing everything wrong? It seems like everywhere the paint overlaps, the yellow is very noticeably darker.

Manufacturers of everything from cars to kids toys seem to be able to put a perfect coat of paint on just about anything, so why is it so hard to get the same results on a specially prepared white piece of MDO?

As I said before, I think step-by-step instructions, with a complete list of tools and materials would be extremely helpful to me, and probably to many others.

Thank you for your time,
Andrew

 

[OldPaint]

anytime you paint yellow, iam a suming its a light colored yellow...its is really transparent.
try this: scuff with scothbrite, then COAT OUT WITH KILZ which is white. get it laid on the board so it covers completly white. let dry scotch brite it, then apply your paint with a foam roller......with plenty of paint....so it covers the white KILZ... also do this on a horizontal set of saw horse....

 

[Columbia Signs]

We paint and use about 3 units a month of ½" MDO (about 200 sheets). You can give me a call and I will tell you how to make it look like a sheet of glass.

Mon - Fri shop # 360-696-1919 or try my cell 360-772-5555

Cody

 

[Letterbox Mike]

Are you using prefinished MDO or something like Omega Board (I ask because you mentioned deglossing the surface)? Scotchbriteing the surface is a good idea in either case, I've never bothered priming prefinished materials like that. I've never tried the paint you're using so I don't know for sure, but you might try adding 10-15% of a flow enhancer like Penetrol. I do not mean thin the paint, thinning changes the consistency of it and will show brush strokes more, a flow enhancer maintains the body of the paint, just helps it slow out or smooth out better. I get the best results with oil based paints bu pouring a good sized puddle on the surface and rolling it out from the center using a high-quality foam roller. Spread the paint out to get a nice even coat, then using a new clean roller very lightly drag the roller across the surface, using NO PRESSURE on the roller at all. This will help evenly distribute the paint, but may leave a ton of tiny bubbles. My last step is to drag a 3" or 4" high-quality foam brush across the surface, again, no pressure whatsoever. This will pop all of those air bubbles. It takes some getting used to but once you get the technique down you will have a flawless glass-smooth surface.

If you're having bad luck spraying, I suspect your paint it overly thinned or your technique is not good. Thin as little as possible, I typically thin 1-Shot with their Reducer 6000 (not sure if it would work in the paint you're using) no more than 10-15% to spray. I adjust my spray gun to use as little material as possible, and spray numerous very very light mists of paint. If you're getting runs you're putting too much paint on at a time, if you can see your strokes, you need more coats. The easiest mistake to make when spraying paint is to try to put too much paint on at a time.

You might consider spraying satin Porter acrylic paint as well, thin 10-15% and spray a bunch of light coats. We've been switching over to this paint over oils and are having tremendous success with it. It's alot easier to work with and clean up, and the durability is fantastic.

 

[Columbia Signs]

I've never tried it that way. I'm sure there is a bunch of ways to make it look good.

Our way takes only 1 coat of primer and 1 coat of paint. Take a look at the pics...... 1st one is of a white board (oil based paint) and the 2nd pic is of a yellow / grey (water based paint). It's all in how it's applied.

I have to be carefull who I tell. My compitition is dying to figure out how we get our boards so nice.

anytime you paint yellow, iam a suming its a light colored yellow...its is really transparent.
try this: scuff with scothbrite, then COAT OUT WITH KILZ which is white. get it laid on the board so it covers completly white. let dry scotch brite it, then apply your paint with a foam roller......with plenty of paint....so it covers the white KILZ... also do this on a horizontal set of saw horse....

 

[signtologist]

try the black foam rollers for oilbase paint and use a pms book to find colors that are custom they are easier then using some tintable paint.
if all else fails buy a new can of paint

 

[smdgrfx]

We use Matthew's paint system and spray with automotive type spray guns. We have no problem spraying yellow on a primered board. Two coats and we're done. It takes about 15 minutes of work total. The rest is dry time. You can shoot it vertically or horizontally. Just depends on how much room you have. Both ways work for us.

 

[ChicagoGraphics]

Instead of using prefinished MDO use MDO thats just primed and use a 9" foam roller sleve, roll it on at first with a hefty in a criss cross pattern. Then go over the whole sheet lightly without any paint on the roller in even strokes overlapping the last about 1" stright up and down. You should get a glass like coat on your MDO. I allways used Ronan fast dry enemel without any problems.