Hello everyone. I am new to the forum and would appreciate any advice anyone can for me. My next project is to build a complete set of kitchen cabinets and I would like to apply the finish using a spray gun. I would like to use an oil based polyurethane and need any info on how much it needs to be thinned to adquately flow through a paint gun. Are mineral spirits okay to use as a thinner? What would be the proper ratio between finish and thinner to achieve a durable finish? Any info would be helpful. Thank you.
Discussion Forum
Discussion Forum
Up Next
Video Shorts
Featured Story
The Big Beautiful Bill could do away with much of the Inflation Reduction Act, including the 25C, 25D and 45L tax credits.
Highlights
"I have learned so much thanks to the searchable articles on the FHB website. I can confidently say that I expect to be a life-long subscriber." - M.K.
Fine Homebuilding Magazine
Fine Home Building
Follow
-
Fine Homebuilding
Dig into cutting-edge approaches and decades of proven solutions with total access to our experts and tradespeople.
Start Free Trial Now -
GBA Prime
Get instant access to the latest developments in green building, research, and reports from the field.
Start Free Trial Now
- Home Group
- Antique Trader
- Arts & Crafts Homes
- Bank Note Reporter
- Cabin Life
- Cuisine at Home
- Fine Gardening
- Fine Woodworking
- Green Building Advisor
- Garden Gate
- Horticulture
- Keep Craft Alive
- Log Home Living
- Military Trader/Vehicles
- Numismatic News
- Numismaster
- Old Cars Weekly
- Old House Journal
- Period Homes
- Popular Woodworking
- Script
- ShopNotes
- Sports Collectors Digest
- Threads
- Timber Home Living
- Traditional Building
- Woodsmith
- World Coin News
- Writer's Digest
Replies
Mineral spirits,yes. You can thin up to 50/50, first coat. But I spray thinner to poly at 1 :5. Two coats minimum,three is better. Sand between each coat allowing roughly 24 hr dry time each coat. But most importantly, follow the directions on the can.
ya want a viscosity cup..called a ford no4 I think...it measures the viscosity of your chosen finish to the SIZE of the orifice of your gun and air cap..it varies. HVLP is another option, some of those units will actually add enough heat to the finish that thinning may not be needed..
I stongly suggest you do some reading on wood finishing..Dresdner, Flexner, Minnick, Jewitt..are good authors..check in knots (next door) and they will set ya right up, if not overwhelm you with thier pomposity..lol
Spheramid Enterprises Architectural Woodworks
Repairs, Remodeling, Restorations.
actually it may be a zahn cup..sorry bout that
Spheramid Enterprises Architectural Woodworks
Repairs, Remodeling, Restorations.
Sounds like might be your first venture into the world of spray finishing. ?? Be forewarned that it's apt to be frustrating and perplexing if you go at it alone without an experienced mentor to show you the ropes. A good teacher can have you handling the gun and material pretty well in a days' time at most……..if you're a good student.
There's so much ground to cover as far as techniques, equipment, material of choice and application techniques that one couldn't really cover it all effectively with a keyboard on a forum.
If your choice of finish is oil-based poly, be advised that conventional varnishes can be kinda nasty coming out of a spray gun. They atomize very finely into a sticky cloud that will soon fill the air of your shop and make life miserable unless you have adequate, but controlled ventilation. A cartridge respirator is also a must. If you intend to shoot this with a conventional high-pressure gun, you'll have more of this problem than with an HVLP outfit. Not saying you shouldn't do it, just a forewarning.
If you intend to spray the interior of the cabinets after they're assembled, you'll have problems getting material into the corners with a high-pressure gun and even worse if the backs are on the cabinets also. An HVLP unit would serve you better in this regard.
Here's a pretty good intro to spray finishing. Make sure you see the spray pattern link.
http://www.boomspeed.com/firstfinish/ViscosityAndWetMils.htm
You'll need to know what you have for a tip set on your gun and you'll need that viscosity cup. Here's a link to a viscosity cup conversion chart that should cover whatever you get or have. The Ford 4 and Zahn 2 are pretty popular cups.
http://www.taunton.com/finewoodworking/pages/w00157.asp
If this is your first spraying endeavor, make sure you practice as long as necessary and have everything under control before you approach the cabinets. Again, there's really no substitute for a good teacher, although it is possible to learn on your own.
Bob Flexner's "Understanding Wood Finishing" would be an important read and reference for you if you don't already have it.
Thank you expounding on what I was aiming for..this cold'monia has me wiped out..you were right on the money, I just couldn't type and hack at the same time..
Spheramid Enterprises Architectural Woodworks
Repairs, Remodeling, Restorations.
More than happy to serve as your mouthpiece ...........so long as you keep your distance right now.
And don't be sippin' from my glass when I ain't lookin' neither.
I hates stuff like what you got.
Knowledge is power, but only if applied in a timely fashion.
ummmmm... GH..... That was yur glass he was using...
Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming.... WOW!!! What a Ride!
I sense some ambiquity here.
Are ye implying that I gave it to him........or that I'm about to overcome by the dreaded critter?
(You promised to keep quiet, damn it)
Knowledge is power, but only if applied in a timely fashion.
Go to bed now... Save yurself the crawlling to it latter....
Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming.... WOW!!! What a Ride!
Above posts already very good advise... Spraying oil poly is my LAST choice of finishes... Runs easy... looks too "plastic"...
A better, and somewhat more forgiving choice is a good pre-catalyzed lacquer or even a catalyzed version... I get mine from Sherwin Williams mostly, M/ L. Campbell is another good supplier... I also recommend using a compatible vinyl sealer first... SW or MLC can tell you what to use... This is a pro finishing product... only sold in 5 gal pails... Will cost you about $250. to set up.
If you look at any of the better cabinet & furniture manufacturers... this is what they all use... Although some are now switching to water-borne lacquers because of OSHA rules.
The stuff you get at the big box stores is ALL a big pain in the arse... trust me on this.
PS: They were exactly right about getting Bob Flexner's book... Well worth your time.
Edited 6/26/2004 12:47 am ET by Brick
Edited 6/26/2004 12:54 am ET by Brick
Cat-lacquers are definitely the predominant choice of finish not only for cabs these days, but most furniture as well….and that's been the case for many years already. As you said though, the shift to the water-bornes is taking place even as we speak. And I'll mention that the 5 gallon bucket of cat-lacquer has a shelf life of about a year or so. Of the ML Campbell cat-lacquers, I'd recommend the MagnaMax over the MagnaLac. Good stuff in the right situation.
Gotta play a bit of a contrarian here for a bit though, I guess. I'll start by saying that IME oil-poly finishes don't have to look all that "plastic" really. Depends on the choice of product, method of application, preparation of wood to which it's applied, thickness of build-up and how/if it's rubbed out. But I certainly don't relish spraying the stuff either. Better have some big fans going.
I wouldn't say the cat-lacquer is the primary finish of choice of manufacturers because it's the best or better for the consumer of the goods, but rather because it best meets several important criteria for the manufacturer, speed of dry time being high on that list. Those same virtues make it a favorable candidate for interior house trim when time to occupancy and scheduling of other phases of work take precedence. But I don't personally think there is such a thing as a universal best finish. What's best in any situation is contingent on numerous factors, but for the manufacturer……..less time from the saw to the shipping box and less chance of air-borne contaminants settling and lodging in a fresh finish, less chance of sags and runs………. are all of primary importance. These folks aren't about to put up with long dry and cure times of any finish, let alone oil-based polys.
Cat-lacquers and varnishes definitely have their merits, but they also have their downsides. Limited allowable thickness of the film build-up would one of those and difficulty of direct overcoating and achieving a bond in the future is another. The toughness and chemical resistance of the film itself certainly makes up for some of this, but when the finish begins to wear thin around the cabinet knobs and handles or gets those dreaded scratches, you could well find yourself in for a complete strip, recolor and refinish. (The stuff doesn't strip all that easily either.) How long before this occurs, of course, is going to be dependent on numerous factors, but these days I see alot of furniture and kitchen cabs hitting the showrooms that aren't all they should be as they have really thin applications of cat-lacquer; looks like just one quick coat. It would seem many manufacturers like to push the envelope of what will satisfy the eye and lack of experience of their potential customers. I guess that should be okay with me though as I get to and have made some good money refinishing that stuff when the finish inevitably wears thru or it gets scratched up.
And I shouldn't forget to mention that if one applies the cat-finishes too thickly, you'll likely have problems down the road. The manufacturer's specifications for this should be followed pretty closely. That's one of the big reasons I think everybody needs a wet-mil gauge…….or at least until you get mighty familiar with what you're looking at on the surface as you apply the finish. A person needs to get those application techniques down on scrap material and then they're ready to tackle the true quarry.
So there's some of my "cat-finishes aren't and shouldn't be seen as the only game in town" spiel. I'll show some consideration and won't bore anyone with the rest of it. ;-)
Knowledge is power, but only if applied in a timely fashion.
Thanks GH,
I am past the contageous phase..
As ya might know..I spent considerable time working with Michael Dresdner..we were in the forefront of WB finishes..and it stuck me as too funny your mention of a wet mil gauge..I still carry one in my wallet..credit card size hunk of Al. With the teeth that read the thickness..gee and I thought I was the only one who had one..lol
7 hrs on the roof today..beaautifull weather..I must be gettin better..now a few laps on the mower..like 600.
BTW..the glass is safe..I'm a bottle man.
Spheramid Enterprises Architectural Woodworks
Repairs, Remodeling, Restorations.
No, sir. I didn't know you worked with Mr. Dresdner.
That doesn't mean you didn't mention it before or that I didn't read it.......just that if that happened.....it didn't register.
Registered now though.
I suppose this means I gotta watch more closely what I say. ;-)
Are you familiar with this site? Lotsa tech info.
http://www.ucb-coatings.com/techpapers.html
Edit: PS - That "not to worry I'm past the contagious stage" stuff don't hold alot of water with me. Had a certain girl tell me that late one night and that the antibiotics had everything under control.
Liar!!!
I been skitterish ever since.
Knowledge is power, but only if applied in a timely fashion.
Edited 6/26/2004 9:09 pm ET by GOLDHILLER
Man, you'd have a blast oven Knots..hahha..(coff, coff)
Great link..we had a blast just messin with Hydro-Cote products, which was not doing to well at the time..(probly still isn't)
Michael is one of the most knowledgeable finishers there is..IMO
We were simultaneously building Smith Basses and developing Clearwater Color Co....
I was a woodworker for him, till I had an injury that laid me up from that work ( no, not a woodworking injury)..and then became an outside salesman for CCC and Hydro-cote..
Just a litttle boring history from 1991..
Spheramid Enterprises Architectural Woodworks
Repairs, Remodeling, Restorations.
Knots?
Most days I couldn't curl my pinkie tight enough, starch my shirt collar stiff enough or make my chisels glisten sufficiently to cut the mustard.
I can frequently cut the cheese though.
Knowledge is power, but only if applied in a timely fashion.
I'm sure both you and Sphere could point your pinkies straight enough, iron your shirt collars stiff enough, and shave in the mirror polished back of your chisels if you wanted to.
Meanwhile it's time here for a nice cup of hot milky tea to get the day started--- got to to keep that pinkie of mine practiced in the customary straightness.
Now---- let's see if I can find a shirt with a collar to iron, and later I'll root through my sandpaper box for a bit of 25,000 grit wet and dry paper. Maybe I won't bother with the last two today being as it's Sunday, ha ha-- ha, ha, ha. Slainte.RJFurniture
Seems as though Sgian has met you and Duane.....
Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming.... WOW!!! What a Ride!
notice how Richard pops up at the mere mention of Knots? well, maybe the pomposity part caught his attn. hahah
Spheramid Enterprises Architectural Woodworks
Repairs, Remodeling, Restorations.
Oh, it was nothing to do with the Knots reference, Sphere. It was the topic title duplication that caught my eye in the first place, so I was lurking anyway. No-one really picked up on the topic over in Knots, and there has been plenty of good information dished out here. I was merely tickled by the insulting references and felt like joining in.
Funnily enough, I have to spray some oil polyurethane myself in a few days on a table top repair. Sprays fine, but takes a long time to dry with the attendant risks as has been discussed. I could use a faster drying polish, but poly is what's on the original, so poly it is.
Anyway, why am I wasting my time here? There's tea to be sipped correctly, shirt collars to be ironed and chisels and plane irons to be polished. That should take me most of the week. When's an important person like me to find time in the week to lovingly craft a single M&T with my perfect tools if I'm wasting time on forums? Slainte. RJFurniture
The old cure was Malaria...
Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming.... WOW!!! What a Ride!
Fer the disease or the skitterishness?
Blinders is good for horses with the skitters. Never tried malaria.
Knowledge is power, but only if applied in a timely fashion.
The Malaria is for you.....
Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming.... WOW!!! What a Ride!
Me? Malaria?
I think I'll just behave myself and skip the cure. Thanks just the same. ;-)
I will, however, mention the malaria to those I run into in similar circumstances. I'm sure they'll be open to most any suggestion. But I won't be lending them any money to travel to the tropics. They're on their own on that account.
Knowledge is power, but only if applied in a timely fashion.
No need to go to the tropics....
Farm rasied is available...
Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming.... WOW!!! What a Ride!
GH
Your obviously way over my head regarding finish so try to dumb it down a bit for me, what is the major diff/advantages between catalyzed lac and just plain lac finish. I can do plain lac finish blind folded but I have know experience with catalyzed.
I don't have to do any finish work where I work, we hire it all out. I am going to buy an hvlp and just want to know for my own good. Also which one of the books that you mentioned would be the best for a beginner to start with, remembering that pictures are more important than text.
Thanks
Doug
You shouldn't have any problems shifting to a cat-lacquer if you're already having success with your techniques using nitrocellulose lacquer. It behaves pretty much the same except that you'll notice it gets harder and dust-free in a shorter period of time and is ready to handle and rub out quicker as well. And it builds faster.
The involved solvents are pretty much the same and so you can find yourself fighting with the same orange peel and moisture blush situations under the same circumstances as nitro. In brief, you won't likely notice a diddly of difference in application techniques and potential problem resolutions.
Each coat will burn into the previous, just like with the nitro, provided your subsequent coat falls within the acceptable time window. Consequently, you won't experience any difference concerning witness marks between layers when/if you rub out. But that burn-in window is one of the major differences in application. After the cat has cured to point X, no burn-in will take place. This is one of the issues that makes cat-lacquers pretty much impossible to repair in the future and why attempts at future overcoating is not recommended. While you can overcoat conventional nitro twenty years later and achieve full burn-in, that's not going to happen with a cat-lacquer. After a couple of weeks max, you're really pushing the issue if you try it. You could likely end up with a peeling result even if you scuff the surface to provide toothing for the new coat. Been there, done that. Enough times that I won't frequently attempt such anymore. Strip and start over is the most reliable. The cured and hard surface of cat-lacquer doesn't provide a grip friendly surface to new cat-lacquer…or most other types of finish, either……..even when that surface has been scuffed and abraded.
Even dewaxed shellac (such as Zinnser's SealCoat) isn't recommended under cat-lacquers, but I've done so innumerable times without ever experiencing a problem, that I can recall. Sometimes you're forced to use it because the surface is contaminated with silicone or the like. Or you use it because you suspect the surface is and you don't really care to risk your color job if it truly is. Even sanding sealers aren't really recommended under cat-lacquers, either.
Cat-lacquers are considerably much more resistant to chemical and water spills than straight conventional nitro and exhibit much greater resistance to abrasive wear. For these reasons, cat-lacquer can be a wiser choice than nitro, depending upon what the situation requires in terms of durability, etc. While there are numerous other finishes that will give you that kind of performance or better, the visual appearance won't be exactly the same. But you do sacrifice the future ease of reparability when you go the cat-lacquer route.
And you can't build umpteen coats of cat-lacquer like you can with nitro to achieve a finish with great depth. Apply it too thickly and the finish will crack and craze. Following the manufacturer's guidelines on final mils of thickness is recommended.
I like the MagnaMax more than the MagnaLac (which was the product that proceeded MagnaMax, IIRC) because the MagnaLac readily develops tiny surface scratches when you rub it out and those scratches then pretty much defy removal. Those tiny little scratches look similar to the tiny circular scratches you see on some folks car hoods, particularly when they use a buffer and some compound on them. The MagnaMax doesn't do this. Rubs out easier and beautifully.
I'll still stand on the Flexner recommendation, I guess. And will recommend that if you're getting an HVLP turbine outfit, that you buy a 3-stage (6psi) unit or a 4-stage (8 psi) unit. The 4-stage will have the capability to shoot even heavier materials than the 3 stage, but will also develop a bit more drift. If you're getting a conversion gun, you won't have to make that choice and will have greater flexibility. I like the Accuspray guns, but there are others on the market that are worthy, I'm sure. Jeff Jewitt over at Homestead Finishing can fix you up quite well.
I've seen pics of your work. If you excel at finishing as much as the rest of it, I'll soon enough be coming over for lessons.
(And I see Imerc has avoided commentary on all this. He knows alot more than he's lettin' on, in case you didn't already know that.)
As previously noted, I'm truly not fit for Knots. I couldn't even get the pinkie thing right in my head. You're suppose to keep it extra straight while sippin' on that tea. Alas, there's simply no hope for me.
Knowledge is power, but only if applied in a timely fashion.
Thanks GH
I appreciate your time on the subject. I doubt that you'll ever be coming to me for any advice though, I cant excel at something that I really don't have the desire to!
At the place where I work we do no finish work what-so-ever, don't even have a place for it for that matter. Therefore I have to have the ability to do it on my own, that's why I'm going to buy the machine.
I was going to buy the 4 stage, just haven't picked out a brand yet.
As far as the pinky and the tea thing goes, I only drink ice tea so I doubt that I will ever be invited for a sit down! I only go over the fence to look, I keep my typewriter shut while there.
I'm sure Imerc's commentary is forth-comming though. :)
Again thanks
Doug
I had a similar question a coupla months ago. See this thread: 41312.1
Goldy and VaTom gave great advice on the water borne lacquer.
I've just completed the last of the finishing based upon these geniuses recommendations. I am simply stunned with the ease and quality of the end finish.
Although I'm out of town right now, when I get back in a week, I'll post pictures.
Note I used cherry. It in itself is hard to get a nice stained finished. Accordingly, I used this procedure:
Two coats of fruitwood Danish Oil. Follow the label instructions exactly.
Two coats of 2lb amber shellac applied via cheap utility HD brushes. Scrapped with a utility knife blade after each coat.
Followed by 3 to 4 coats of Target Coating's Oxford acrylic lacquer applied via 4 stage HVLP. Lightly scrapped betwixt coats.
No stink in the house at all. Ended up spraying 3 gallons of the lacquer in total in the basement, venting using the built-in dust collector in the shop.
I mean this finish has class. My first spray job and the cabinet maker himself said it meets or beats what he's seen from the pro's he has worked with.
Make sure you use the viscosity cup SPHERE mentions. It makes a big difference.
Stonefever
Thanks, I'll look into that, always thought a water base product would solve at least the problem of how to vent into the neighbor without him killing over from the fumes!
Doug
... That's what I like about this forum... There is always somebody who knows more than I do... :-)
I also restore fine old antique furniture. I generally use whatever finish that is compatable with the original... Usually high quality dewaxed schellac. There is nothing like a beautiful hand rubbed finish.
--- BRICK
"They say that there is a fine line between genius and insanity. I like to color outside the lines...and then eat the crayons." ~ Me
"My next project is to build a complete set of kitchen cabinets and I would like to apply the finish using a spray gun. I would like to use an oil based polyurethane and need any info on how much it needs to be thinned to adequately flow through a paint gun. Are mineral spirits okay to use as a thinner?"
CM,Why do you want to spray? With the right brush and right reducer if needed, brushing is nearly fool proof.
From the questions you ask, it doesn't sound like you have much spray finishing experience, so if you are taking the time to build a whole set of cabs. why risk ruining them, when going the brush route is a sure thing? There are just too many variables to spraying a quality finish.
Nobody here can answer your question. Best advice, buy Bob Flexner's book http://www.reversephonedirectory.com/products/index.html?item_id=0762101911&search_type=AsinSearch&locale=usabout the topic and practice, practice, practice.
Jon
Edited 6/26/2004 3:32 pm ET by WorkshopJon