Finishing Question

[mrmoray]

Hey gang,
I'm building some built-in cabinets that will just be painted when I'm done. So they are a combination of MDF & poplar. (I'm not near good enough to work with real wood yet) I'm getting close to being ready to paint, which I'll do with HVLP. I'm thinking I should prime/seal the cabinets first, but I'm not sure what to use? With the final finish just being paint, is there anything in particular I should use, or will any old primer be sufficient in this case?

Thanks,
Mike

[JimD]

Poplar is real wood - just less expensive than most. It is also a good choice for the frame of doors that will be painted.

Both of your materials take paint well and should not bleed through. For softwood, I always use a Kilz type primer and that is what I keep around so it is what I would use. For your materials, you do not need this type but it would not hurt anything either.

I finish raised panels prior to glue-up. If you've already glued the doors up don't worry about it, MDF doesn't move nearly as much as solid wood. If you haven't, I think this is still a good practice. If you finish after glue-up and are using a solid wood panel that is fairly wide, you are likely to get an unfinished edge showing at the time of the year that the panel sees the lowest moisture level in the air. I also finish the inside edge of the frame while finishing the panel. Then I sand the frame flat at the joints after glue-up and finish the frame. I also put a last coat on the panel when the last coat goes on the frame.

Jim

[JoeyGee]

I'm no expert on painting, but I do know a good primer is an essential step to a great finish. I would not skrimp on the primer.

Also, make sure you pay special attention to the MDF edges. They will suck up A LOT of paint if not primed correctly. A lot of people use drywall compaound on the edges, and then sand it smooth.

[Wood_workur]

I'm no expert on painting, but I do know a good primer is an essential step to a great finish. I would not skrimp on the primer.

Also, make sure you pay special attention to the MDF edges. They will suck up A LOT of paint if not primed correctly. A lot of people use drywall compaound on the edges, and then sand it smooth.

an alternative to the drywall compound is glue size- a 10:1 ration of water to glue. it is the consistency of milk, and makes mdf less water soluble.

[cabinetman]

As to what to use for primer, if the finish paint is an oil base paint, I would use an oil primer. Likewise, if the finish coat is water based, I would use a waterbased primer. A waterbase primer and finish coat will dry faster than an oil base, and some of the ones on the market are very durable. As for mixing chemistry between primers and topcoats, you should read the labels to see what combinations are compatible. For example: oil base primer and water base top coat, or the other way around.
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[JimD]

I could have put this in my first post but I like tinted resisthane for spraying. It only comes in white and black, however. It is a water based lacquer so it dries fast and it is very durable - it is rated as suitable for kitchen cabinets. Your primer needs to be the same color as your top coat, however, because while it is tinted, it remains somewhat transparent (although I did manage to cover MDF with three heavy coats). I get it from Hood finishing by mail order. About $35/gallon delivered. Their website will let you get information but I have to call them to place the order.

Jim

[eddy merckx]

Hey Mike

I just finished painting a pair of cabinets with my HF HPLV sprayer. It's very different from a clear finish because you can see every tiny flaw. After doing some reading and experimenting, I found that the best thing is to spray a layer of primer, then fill the voids with Bondo. Sand and recoat. Repeat as necessary. When it all looks good, you're ready for the paint.

The best paint for cabinets is supposed to be Satin Impervo, an oil based enamel. I didn't want to deal with the chemicals though. I used Behr latex enamel from HD, thinned around 10% with water. It worked super, although it will run if you're spraying a vertical surface. I ended up spraying all surfaces horizontally. Spraying horizontally also allows you to lay on a thick coat for even flow out. The latex dries in under an hour, so it's not too time consuming to do it that way. Being latex, cleanup is with water and no off gassing (at least not from the paint).

My cabinets are now mounted next to trim work which is painted with Satin Impervo. The latex looks at least as good.

Eddy

[Pappy]

I've used Impervo and it's sister exterior paint, Iron-Clad. Excellent paints but slow to cure.

[lakkdainen]

Hey Mike

I just finished painting a pair of cabinets with my HF HPLV sprayer. It's very different from a clear finish because you can see every tiny flaw. After doing some reading and experimenting, I found that the best thing is to spray a layer of primer, then fill the voids with Bondo. Sand and recoat. Repeat as necessary. When it all looks good, you're ready for the paint.

The best paint for cabinets is supposed to be Satin Impervo, an oil based enamel. I didn't want to deal with the chemicals though. I used Behr latex enamel from HD, thinned around 10% with water. It worked super, although it will run if you're spraying a vertical surface.

That's the same unit as the Rockler, correct? I received the Rockler one for Christmas, and haven't had a chance to use it yet. Typical latex works well though in reality when thinned? It seems like any time you mention latex and HVLP in the same sentence, you get a 3 Stooges "Niagra Falls" kind of reaction from some people. You're the only person I know who has actually *done* it though, so I'll take your word, and any other tips/advice you have on it...

[JimD]

There is a little piece on the tips and tricks link on another post here about thinning latex with Resisthane (a water based lacquer) for reduced viscosity and improved durability. Might be something to try. My painted cabinets have been white so I used melamine particle board where possible and I painted with tinted resisthane and got good results.

Jim

[crokett]

I second the recommendation to fill the MDF edges with drywall compound. I've done this a few times and it works very well. If the edge is profiled, after the drywall compound is dried I sand it pretty close then do a final scraping with the router bit that made the profile. I tried the glue trick once but ended up with a few ridges, etc that were tough to sand out. Plus I think the primer goes over the drywall compound better than the glue - no flashing.