Question
I need some straight advice on sprayers. I will be spraying mostly lacquer on cabinets but will need to spray latex when requested. I'm getting conflicting information. Everyone seems high on the Kremlin 10:14 with MVX gun for both finishes. Input on HVLPs says they will spray latex only grudgingly and only if thinned. Ideally I would like one rig for both, which I know the Kremlin will do, but it's a little outside the budget. Thoughts?
Forum Responses
(Finishing Forum)
From contributor M:
I own a small shop and was in the same position as you not long ago. I started out with a Porter Cable PSH1 gravity feed gun, but it was too slow with thicker coatings and the capacity was small. I was in search of a better system and ended up going with a CA Technologies CPR Cat Pack (pressure feed) that came with a gun, three needles/nozzles and a HVLP air cap and a reduced pressure air cap. The three needle/nozzles allow you to spray anything from stain to latex. I have sprayed SW ProClassic acrylic, but I did have to thin it with water. I added Floetrol and cranked the pot pressure up to about 30 psi too. I have the CA Tech Bandit 2 quart pot with a higher range pressure gauge just for that purpose. I have also sprayed SW ProMar 200 waterbased acrylic-alkyd which sprayed a lot easier than the ProClassic. It sprays more like an oil base paint than a latex. I have been very satisfied with the setup other than the 2 quart capacity. I already have the need to go with a bigger pot.
Kremlin is a fine tool for lacquer if you can afford it, but a pressure pot system will do well for about one third the price. Pressure pots are all over eBay - guns - many good choices. Devilbiss is the best bang for your buck, in my opinion. Avoid HVLP, which will often sacrifice speed and finish quality to achieve high transfer efficiency (low overspray). Look at the newer RP (reduced pressure) technology, which delivers good transfer efficiency without as much sacrifice in fine atomization.
Equipment choice depends on many variables - portable or not, spray booth or not, compressor capacity, volume of work, etc. There is no single best. I know it's done, but I would not want to shoot latex paint through the Kremlin I use for solvent coatings. I see nothing but maintenance trouble there.
If speed is not of great importance, which of the systems (HVLP, air-assisted, or pressure pot) will give me, a relatively inexperienced sprayer, the best odds of producing high quality lacquer finishes? And with regard to paint, it sounds like a mid range airless is the way to go, given the same considerations?
Air-assisted airless: For wood coatings that don't require the addition of a catalyst, these are the nuts. Reasons: extremely low overspray, great finish, high material savings, very fast application.
HVLP gravity: Decent, can produce a good finish, a little slow.
Compliant gravity: Choice of car painters (like me). High quality finish, decent transfer efficiency, lower air requirements than HVLP, and significantly faster than HVLP (best gun in this category is the DeVilbiss Plus).
Pressure pot HVLP: Faster than gravity feed, otherwise much the same.
Airless: If you're doing latex paint, this is what you use.
Spray quality is excellent, overspray is minimal. Cleanup is extremely quick with clears and quick with pigmented. If you use pre-cats you can leave the finish in the unit for quite some time. Do a quick flush once a week and you are good to go. Post-cats you need to flush the gun every night.
You won't be sorry you spent the money. If you do any medium scale finishing (10 hours/week) you will have quick payback. You won't need a large compressor; I think it requires 2 CFM.
Call me sentimental, but I still have my pressure feed system (two of them) and strangely enough I still prefer using these for certain types of small piece work, like chairs. Recently I purchased the newer Devilbiss Trans-Tech compact gun (the green one). I bought several HVLP guns in the nineties and they all sucked miserably, but I have to say this Trans-Tech delivers a really nice spray, good speed, and very low overspray. The green Trans-Tech is RP (reduced pressure), not HVLP. I tried the HVLP version of this gun (blue color). It is noticeably slower and the spray not so good.
HVLP conversion guns have been widely misunderstood due primarily to marketing hype which persists even today. I remember when the first HVLP conversion guns were being sold in the early nineties. The reps sold them as the latest cutting edge equipment - implication being the quality of spray was superior. In fact the atomization quality was greatly inferior to standard conventional guns, but they never mentioned that. Being a sucker for new equipment I bought and bought again. Four guns later I finally did my homework and learned the truth about HVLP.
The whole point of HVLP is to improve transfer efficiency, which translates into material savings. It did that, sort of, but it did so at the expense of finish quality and speed. The early HVLPs were dogs. Today's are much better, but RP is ahead on the curve. But I digress. If you're doing cabinets and doing any volume, Kremlin is the tool.
I have been looking into the CAT and Kremlin AAA as well as pressure pot systems primarily to have more finish available to me between refills. The gravity guns I have been using are now slowing me down more than I like. I’m thinking I would still use the gravity guns for spraying dye, stain and toners just because of the small volume needed and the cleaning that would be entailed with the pots and hoses. Is that a legitimate concern? Also, for me, overspray is something that influences my final finish quality, so minimizing this seems a plus. I also spray waterborne products - are there units better suited to spraying them? If they are not atomized properly, there is a lot of orange peel, but it seems if they are over-atomized they develop other issues.
I then bought a Devilbiss HVLP gravity conversion gun. It did a better job atomizing the product with less air pressure, resulting in less overspray. It was still slow, and refilling the cup was a pain.
I then bought a 2qt Devilbiss pressure pot and gun. Much better control of the fluid, wider fan pattern, faster speed, less time mixing and filling the pot, less arm fatigue. All in all, I am very happy with the pressure pot setup.
I still use the gravity guns for spraying stains, and small parts, etc, but the pressure pot is what I use whenever I have to spray more than 1 or 2 small pieces.
Depending on how much time you will spend spraying, an AAA rig such as a Kremlin, Binks, Graco, or CAT may be the ticket. You will go through less material due to reduced overspray, you should theoretically get a better finish due to less overspray, and it will go on very fast.
I spend between 4 and 6 days per month finishing. If I was doing any more than that, I would probably buy an AAA, but can't really justify the expense as I don't see the need based with my limited use.
If I were to do it all over again, I would buy:
- a couple $30 throwaway gravity feed HVLP guns for stains
- a high quality gravity feed HVLP gun for NGRs, small jobs, etc
- Kremlin or Bobcat as my main gun for spraying. The AAA units don't cost a lot more than a quality pressure pot setup and they should pay back that difference in material savings.
I'm not really sure why you would want to spray latex through any of these, but you will struggle trying to spray latex from a conversion gun, and it will be a pain to change from solvent to latex in an AAA if you have to do it frequently.
