Stepping Up to a Cheap Airless Spraygun
Here's an interesting argument for using a $300 home-center airless spraygun setup for cabinet finishing. June 8, 2008
Question
I have always finished my cabinets with spray poly over oil stain, but never could get a really perfect finish. I have been experimenting with sanding sealer, then spray lacquer with an HVLP gun and have had some success, but still have a problem with lots of overspray and little white hairs in the finish. I still have to use steel wool after the last coat. How would you suggest finishing and staining cabinets in a small two-man shop doing about 50 sets of cabinets a year?
Forum Responses
(Cabinetmaking Forum)
From contributor R:
You should not be messing with dangerous chemicals without proper knowledge. Are you using a UL approved explosion-proof spray booth? Lacquer sprayed in an enclosed building can cause an explosion big enough to flatten a metal building.
From contributor O:
My advice is to go down to Home Depot and buy the cheapest airless sprayer they offer (around $300). I have three - one for my vinyl sealer, one for my pre-cat, and one for miscellaneous (stain, pigment coats, etc.). I clean them once a month (or I try to - they actually get done every two months). Just use the 515 tip they come with. I use Sherwin Williams Fast Dry Vinyl Sealer and Pre-Cat Lacquer. One coat of vinyl (dries in 15 minutes), scuff sand with 320 or very fine sanding sponge, spray off the air gun and one coat of pre-cat. It won't compete with some others, but is better than 90% of the finishes out there and your customers will be more than happy and only the most discriminating will be able to tell the difference between theirs and yours. It is the most user-friendly finish that is still durable that I have ever used (and I've used a lot). The airless guns will only last about 1.5 years as I describe their usage (at least in the amount I spray of about 15-20 gallons a month total, or 7.5 of each), but will more than pay for themselves in time not having to clean, refill (just put your 5 gallon pail under it and shoot), and the amount of material they put out compared to an HVLP unit. For what it is worth, I do use SW Sherwood fast dry stains, but find most of my customers actually prefer gel stains. While they are slower to apply, my customers like the effect they have. It leaves stain in corners and profiles.
From contributor M:
If you are trying to spray lacquer with a turbine HVLP, you are wasting your time. The heat from the turbine begins to dry the material before it hits the surface, so you must add retarder. This thins the finish and you have to apply more coats... not the best way to apply lacquer.
If you are using a conversion gun (uses compressed air), then talk to the manufacturer about proper setup. Air cap and needle size are important when shooting through a HVLP gun. The setting must be right with the reduced pressure. As contributor R said, airless is another good choice. Talk to your finish supplier to see what they recommend for tip sizes.
The best advice that I can give is to work with suppliers, equipment and material, who will support their product. Finishing is very complicated and you need someone who can tell you what to do and what you are doing wrong.
From contributor R:
If you switched to an air assisted gun, you would save a minimum of 30% on your material usage with very little drop in production from what you describe. If you use 20 gal a month x 12 = 240 x .3 = 72 gallons a year in savings. 72 gallons x $30 is $2160 per year in material that went up in smoke. It is probably more if you are using the 515 tip. Most people using a fine finish would use a 310 or 208 tip for lacquer. A 515 is for latex paint. Use a higher quality rig and your material savings will pay for it within a year. Not to mention less expenditure on spray booth filter media and cleanup.
From contributor Y:
One coat of sanding sealer, two coats of lacquer light sanding between coats. Use Opticlear and Optisealer with vanilla to help kill the strong odor. And the most important thing - buy a Kremlin pump.
From contributor U:
I like 3 coats of Chemcraft and call it good. I use the Turbinaire 1235GT HVLP with the 2qt pressure cup and it works great.
From contributor B:
Actually, I've been using a factory refurbished Wagner FineCoat HVLP system for about 10 years and the sucker just keeps spraying. You can buy the thing from GleemPaint.com for $75. That's the turbine, hose, and gun. I consistently am praised for my finishes, and I'm spraying SW pre-cat lacquer over their vinyl sealer. It is a cheap way to go, but I can't see spending major bucks on another turbine system when this one works so well. I just clean it when it starts acting up, which isn't very often.
From contributor O:
I understand about the AAA setup and finish material savings. However, if I'm going to spend $2500+ on a setup, I'm going to have to treat it right. I don't like that it takes time. I'd rather abuse my machine and replace it in a year and a half for $300. And I've had folks say that it's almost as fast as an airless. I disagree, and I've tested them and seen them spray many times in different finish rooms. I agree they are very nice rigs, but it just isn't for me. I've also used the suggested tips, but I've found that with the particular finish I mentioned, the 515 works best. I know it goes against reason, but I've tested the others. As far as number of coats, using the HVLP unit, you will definitely need 3 or probably 4 coats to get the same mil thickness. That is why I love this particular finish and application method. I can lay it on pretty thick and be done. I've probably used 10 different finishes from different manufacturers in the last half dozen years with many different spray setups also and although it goes against what many of us have learned for fine finishing, it really works. I've worked in the ultra high end finish shops and this gets you so close only those of us reading this would be able to tell the difference, and it's quick. You sure don't have to give it a whirl, but it really works for me.
From contributor A:
I would say contributor O is right on the money. Go buy a $300 airless with a fine finish lacquer tip. HVLP is not the way to go; I really don't understand the hype around them. I think HVLPs are more for the automotive industry where the viscosity of the material is much lower.
Next, I would go down to the closest Sherwin Williams and get a gallon of the Sherwood pre-cat, or any self-sealing pre-cat lacquer, for that matter. We spray fives of the stuff all the time. One coat to seal, scuff with a sanding sponge and spray again, done. You can spray a third coat if you like a higher build.
I would say the next step would be an AAA air assisted airless sprayer. It combines the technology of the HVLP with an airless; this is what all the hype should be about. I bought the CAT Technology’s Bobcat. It's unbelievable the difference this spray setup did to our finishing production. It’s crazy to say, but no runs, dry spots, or overspray. The gun is especially easy to wave and pull the trigger with an amazing amount of control. Got mine at Tool Paradise online for $1700 - worth every penny.
From contributor Y:
I don't agree with the comment "lay it on thick." That's just a bad idea. Yes, you want buildup, but thin coats with a light sanding between each of them. Thick coats can and probably will crack. I started my shop back in '93 with two pressure pots that I still have and use to this day. I have since changed the guns on each unit to HVLP. I bought an airless in 2000 and it has its advantages, but I still prefer the old pressure pots when spraying vertical or inside cabinets. I bought a turbine system a couple of years ago thinking that it would be great for jobsites, and just hate it - too slow, and yes, you do have to use a retarder.
