Finishing with a foam roller?

[KLF]

I have to hang several (4) doors at my office, all of which are birch veneered fire rated doors. We want to keep the natural wood finish, not painted. I'm planning to put on 3 coats of spar urethane, that's a lot of finishing, even with a wide foam brush. Wondering if I could use one of those 6" wide foam rollers, with a tight foam insert. I was thinking I could thin out the urethane a little, so it will "self level" and not leave a stippled finish that the foam roller sometimes causes.

Anybody ever try this?

[RayintheUK]

Yes, I tried it and for the same reason. Wish I hadn't - disaster - mostly due to air bubbles. For the same reason I tend not to use foam brushes either - a good-quality real bristle brush is the tool in my opinion - worth the (admitted) extra effort.

Ray.

[jziegler]

What about a lambswool pad or a mohair roller like are reccommended for finishing wood floors? Seems like that would work OK on a door, and no thinning of the urwthane should be needed.

Jim

[Jeffrey Schronce]

One of the 6" wide latex paint pad applicators from the big box stores would work. You know the ones with the 1/4" white bristles and usually red handles. It will leave slight streaks, but they should self level with out addition of thinner. As others mention I would use a good brush here, a 4" if time is a concern.
I think most roller applications are doomed to fail due to the nature of the application. Foam definately would be a problem with bubbles.
Could this be the time to invest in one of the $60 or so HVLP's on the market?

[KLF]

One of the 6" wide latex paint pad applicators from the big box stores would work. You know the ones with the 1/4" white bristles and usually red handles.

Yeah, I know that type you're talking about, I have one in my painting supplies.

Could this be the time to invest in one of the $60 or so HVLP's on the market?

Oh geez... I wish you hadn't said that. I've been looking for a project to justify buying one of those, and there's air available in the next room.

[Jeffrey Schronce]

Yeah, I know that type you're talking about, I have one in my painting supplies.



Oh geez... I wish you hadn't said that. I've been looking for a project to justify buying one of those, and there's air available in the next room.

Some nice Porter Cable HVLP guns on sale at Amazon right now . . . .

[Jan]

Ray has it right. Buy yourself a good natural bristle brush. Purdy is a good brand. Something about 3 inches wide should do it. Spar varnish is a good choice as it dries slower than ordinary varnish. If it's still not slow enough you can use wiping varnish or add Penetrol to your spar varnish.

The advantage and disadvantage of oil base varnish are the same thing; it's slow drying. If you need to sand do it somewhere other than where you're finishing. Varnish will collect dust nibs for hours after it's applied.

Stir the varnish thoroughly before using it and measure what you're going to need into a clean container. Then recover your can of varnish or it will skin over. Use the more expensive mineral spirit because paint thinner is often recycled and contains whatever. Mineral spirit also doesn't smell as much.

Before you spray any varnish remember that it's slow drying. The overspray will gum up everything in your work space.

Jan

[JimD]

I successfully applied Minwax water based poly with a small foam roller - I think it was 4 inches wide. I was finishing a large entertainment center and it really went fast. I got bubbles if I moved the roller too fast or tried to get too much poly out of the roller - pressed too hard. Instead I just dunked the little roller in the gallon of poly. I let the excess run off for a few seconds and then rolled it on. I have a HVLP now and will probably use it for the next big project like this but a roller will work with the right technique.

Jim

[KLF]

Thanks for all the input/advice. These doors are in a public area with lots of traffic, to be hung in existing painted metal jambs of an old building. I'm looking for something that is durable, I'm not so concerned with getting the best finish, furniture grade is definitely not necessary. Speed of application and drying is also important, so I'm leaning towards urethane instead of a slow-drying varnish.

I'll investigate the HVLP sprayer idea, but I'll probably just get a good 3-4" wide brush and go with that.

If I were to spray, there is a large shop area right next to the room where they are being hung, with a big parking lot. I was thinking I could set each door outside on sawhorses, spray, they carry inside to dry.

[cabinetman]

"Spar" type urethanes are usually intended for outdoor use as they retain some degree of flexibility, and have a longer "cure" time, even though they feel dry. If you want oil based polyurethane, use one intended for indoor use. Use a natural bristle brush.

I've had great luck with water based polyurethanes. Dries much faster than oil based, try a sample. Use a synthetic bristle brush.

Spraying anything requires some trial and error to get a "pro" type finish. You need good ventilation, lotsa light to get a reflection of how wet the surface is getting, and setup space. I've had to either hang doors or nail a base type board to the bottom to coat both sides at once. Sure beats doing one side at a time.



"I'M NEVER WRONG - BUT I'M NOT ALWAYS RIGHT"

[WayneJ]

My choice would be a wool pad or a bristle brush. Don't shake the can of varnish, stir very slowly if mixing is needed. I would go with a few thined coats rather then a heavy coat. You can rub out any dust with 0000 steel wool after its dry. If you lay the door flat any brush marks tend to flaten out as it dries.
Wayne