Finishing 5 piece Cabinet doors? - Woodworking Talk

cain8885 · 02-08-2010, 07:42 PM

Hi All,
I've made several posts here about building cabinet doors. I have material all dimensioned and am preparing to cut the rails and stiles. I have a question as to how to finish the doors.

The carcasses have oil based poly on them. I would like to stay with oil based poly for consistency. What would be the best way to apply this and how? The other surfaces I have applied poly to are flat. These doors will have a flat panel surrounded by 2 3/8 rails and stiles. I am concerned about how to apply the poly to this uneven surface and avoid pooling up in the corners?

My thought had been to go with a wipe on poly applied with the doors horizontally face up. Then once finished with the front coats flip the door and apply a coat or two on the back.

Does this make sense? Is there some other more optimal way? I've never had the best luck with wipe on poly so I am looking for advice.

Much appreciated
Brian

edp · 02-08-2010, 07:53 PM

spraying on your finish? I used to be afraid of spraying only because I had never done it, but, once I started, I threw all the brushes away. It is hard to beat a sprayed on finish and it's really pretty simple to do. You don't need to spend a lot of money on equipment either. If you have a compressor with sufficient output (rated as CFM which is an abbreviation for "Cubic Feet per Minute") to support a spray gun, one can be had at Lowes for about $40.00. If not, Rockler and several other retailers offer an HVLP setup with it's own turbine for under $120.00. Actually, the Rockler version is the one I started with, and used for about 2 years.

Ed

Tony B · 02-08-2010, 10:04 PM

Quote:

Originally Posted by edp

...... I used to be afraid of spraying only because I had never done it, but, once I started, I threw all the brushes away..... Ed

Amen Ed
You can teach yourself to spray carcases and doors in about 20 minutes by following the directions that come with the gun. Chairs and intricate geometries take practice and thought as to how to handle the peice.
If you lived near me I could teach you in 10 minutes. As a matter of fact, I just did it, 2 days ago.

cain8885 · 02-08-2010, 11:38 PM

Hi Guys,
edp, I had seen your prior posts about the rockler version. I may indeed go with that.

I see all of this tools people use to hang doors for spraying. Would this be possible with spraying oil based poly? I imagine hanging doors to spray is more feasible for something like laquer where it dries really quickly?

I assume for a proper hvlp gun on an air compressor I am going to need something more than my porter cable pancake compressor? How big of a compressor would I actually need to make thsi work?

Brian

jlhaslip · 02-09-2010, 03:02 AM

2 1/2 hp or better

several light coats is better than one heavy one

edp · 02-09-2010, 06:24 AM

Quote:

Originally Posted by cain8885

I see all of this tools people use to hang doors for spraying. Would this be possible with spraying oil based poly? I imagine hanging doors to spray is more feasible for something like laquer where it dries really quickly?

Yes, they don't care what you are spraying. I am really happy with the hooks I purchased from Rockler. They work great if you are using the hinges that require the 35mm counterbore. I only use one per door.

I assume for a proper hvlp gun on an air compressor I am going to need something more than my porter cable pancake compressor? How big of a compressor would I actually need to make thsi work?

The best way I find to answer this is to say, "Look at the CFM required by the gun you are looking at and then find a compressor that can provide that volume of air".

Brian

Don't be afraid to try this. You will be very happy with the results in very short order

Ed

Tony B · 02-09-2010, 08:59 AM

Quote:

Originally Posted by cain8885

Hi Guys,...... How big of a compressor would I actually need to make thsi work? Brian

HVLP guns require A LOT of air. The HV part of HVLP referrs to a High Volume of air. Look at some typical guns and you will see the required CFM. When you size your air compressor, subtract about 20% of what the manufacturer's specs say.
I recently bought a self contained unit with a turbine. My current aircompressor is 60 Gal. and I think about a 4HP motor.......way too small for HVLP. You will probably require an 80 Gal with a 5 to 7 HP motor to get the required CFM to run an HVLP gun.
I would recommend lacquer for lots of reasons. In your case, I would recommend NOT spraying poly. Your whole world will become like fly paper.

cain8885 · 02-09-2010, 10:00 AM

Wow, they arent kidding when they say high volume. I dont have near the power or supply to do that. I guess I will seriously look at one of those self contained hvlp units.

Perhaps my problem understanding how to hang my doors and spray poly is that I am thinking of brushing where my coats were kind of thick. Perhaps the ticket to avoiding runs on vertical doors is just to make sure that the coats of my poly are very very light.

Tony B.
I am planning to use poly because the rest of the parts were finished with poly. I want to maintain consistent so as the parts age and yellow they would age the same and because the oil based poly itself adds a golden hue. Perhaps this is misguided and I can get the same efffect with another product?

And I understand about my world becoming like flypaper. I have an outdoor area under my deck that is covered and I can tarp off with plastic and basically turn into a 8 foot by 15 foot spray area.

Thanks,
Brian

Tony B · 02-09-2010, 11:37 AM

Quote:

Originally Posted by cain8885

........ And I understand about my world becoming like flypaper..... Brian

Not to worry, just keep a cell phone handy. I just dont want to see you listed as missing and your picture turn up on a milk carton.

BTW, I think Rockler sells a turbine unit for under $150 and so does WoodCraft.
Turbines have an advantage that the air gets heated which helps keep the finishing product moisture free as it is sprayed. Portability is also a biggie.

jlord · 02-09-2010, 12:09 PM

Quote:

Originally Posted by Tony B

HVLP guns require A LOT of air. The HV part of HVLP referrs to a High Volume of air. Look at some typical guns and you will see the required CFM. When you size your air compressor, subtract about 20% of what the manufacturer's specs say.
I recently bought a self contained unit with a turbine. My current aircompressor is 60 Gal. and I think about a 4HP motor.......way too small for HVLP. You will probably require an 80 Gal with a 5 to 7 HP motor to get the required CFM to run an HVLP gun.
I would recommend lacquer for lots of reasons. In your case, I would recommend NOT spraying poly. Your whole world will become like fly paper.

I don't quite agree with this. HVLP stands for "High Volume Low Pressure". The air pressure required by an the spray gun is only going to be lower than an air tool would require. An HVLP gun will spray material at a lower pressure which results in less overspray. Many HVLP guns a designed to work with an air compressor under a slightly different principle than the HVLP turbine guns.

I have a 60gal w/5hp motor & have no problems with spraying a HVLP gun. I have even used a 20gl compressor. The compressor does run a little longer on a smaller compressor.

Your compressor just has to have the required cfm. You can see in my photo's, items that have been sprayed as I spray all my finishes with an HVLP gun w/compressor. The only reason you would need a larger air compressor is with multiple users using at same time.

I think Poly is an excellent choice for a finish on a cabinet. I's very durable. I prefer oil base products. If using oil base poly I would thin it with Naptha instead of Mineral Spirits. It will flash quicker which helps with vertical surfaces.

http://www.wisegeek.com/what-is-a-hvlp-spray-gun.htm