Through Thick or Thin, Which is the Right HVLP Sprayer for Me?
Last month I was pleased to tell you about the new ASI-HVLP ECO Series HVLP spray systems that Apollo Sprayers has added to its product range. This has brought back a regularly asked question that I would like to talk about this month.
We are asked “With so many options in HVLP spray systems, can you help me make the right choice.” Let me try to simplify.
The basic concept of all HVLP turbine spray systems is the same, portability, no compressed air, less overspray or mist in the spray environment, less paint consumption, and generally easy to use. For many, it is the opportunity to apply a spray finish where it was impractical or impossible previously. Now the question: What is the right equipment for me?
There are a few things to consider when purchasing an HVLP spray finishing system.
- What are the coatings, paints or finishes you intend to use with the equipment?
- How much will you actually be using the equipment?
- What are you looking for as an end result?
Each turbine system offered provides a maximum atomizing pressure based on the output and size of the motor installed. The lower the maximum pressure of the system the more limited your access to the finishes you can spray or what compromises are necessary to successfully spray them.
Coatings, paints and finishes are manufactured and supplied at a particular viscosity (thickness or thinness of the product). Often a coating, paint or finish needs viscosity to be reduced or thinned in order for it to spray and provide a smooth desirable surface finish. Some products can be thinned with no problem, others cannot or will only withstand minimal reduction. It is important to understand this fact when selecting an HVLP system. You need to determine what coatings, paints and finishes you want to use, what their properties are and how they are best adjusted for desired results.
One of the biggest mistakes made when selecting and purchasing an HVLP spray system is to think that if you are an occasional user then you can look at the smallest and least expensive systems available. This can only lead to disappointment and poor results.
If you are looking to spray conventional finish coatings like stain, lacquer, shellac, polyurethane, enamel paints, etc. then a mid-sized HVLP turbine system (3 stage) should do the job for you quite well and to your satisfaction. These products lend themselves to thinning so you can adjust your viscosity to produce desired results. You will even spray selected waterborne and waterbased finish products (not including latex paints) quite nicely.
If you are looking to expand the viscosity range and products you would like to apply, then considering a four or five stage system would have many advantages. The additional power of these systems will ensure the ability to provide desired results without excessive thinning of the coating, paint or finish. The big question that always comes up is about latex paint. There are many misconceptions about this so I would like to clarify. Yes, you can spray latex paints with an HVLP spray system however, it is generally necessary to reduce or thin the paint to achieve good results. Thinning or reducing latex paint excessively can cause unwanted results..
Lower powered turbine systems will require a fair amount of thinning to spray latex paint appropriately (sometimes up to 50%), oherwise atomization will be coarse, delivery will be slow, and the finished surface could be wavy (orange peel effect) or uneven. Thinning is the only option if there is not enough pressure to break up the paint. Adding a latex conditioner such as Floetrol will help however thinning will still be required. One of the drawbacks to thinning latex paint excessively is loss of sheen (gloss will become flat). Another would be the application of many multiple coats. If you can get past these compromises to get the results you want, there's no problem using a lower powered machine. Caution - don’t be misled into thinking that using a larger nozzle/needle combination will solve the problem of a lower powered HVLP system. If the pressure is not there to atomize the finish, the results will not be there.
If frequently spraying latex paint along with various other products is important, then a higher powered turbine should be considered. Compromises are less or non-existent and finish results meet expectations.
The next question that comes up has to do with cost of equipment. As some manufacturers produce less expensive HVLP systems, the compromises increase. For example, you will see shorter and fatter air hoses which become bulky and clumsy to work with. You will notice that the spray gun has minimal features, often only having an air hose connection at the top of the spray gun rather than into the handle. While this might be OK for some limited applications it can add to operator fatigue and other issues. You will find that connecting to the air hose will be limited to a push in friction fitting. This is fine until it pulls out at a critical point when you are spraying, messing up your finish. I can continue on but I think you get the idea. As in any market you get what you pay for.
I mention all of this as Apollo worked hard to develop and provide the least compromise in a mid-priced HVLP spray system with its new ECO Series. We have delivered power/pressure in each system, in most cases exceeding other units in its class with 12% - 15% more power. In fact the ECO Series 3 stage model is equal in power to most other 4 stages models. The ECO-4 stage is yet more powerful and our ECO-5 is the first five stage system under $900.00. Air hoses are full length, lightweight, smaller diameter with quick disconnect to the spray gun. No issue with the air hose popping off inconveniently. Apollo spray guns are full featured with an appropriate range of nozzles and needles to cover all product applications. Turbines are quieter with new Quiet Technology.
Getting back to choice: Determine your needs when considering an HVLP spray system. If you know you will be using just a few low to medium viscosity products, a 3 stage turbine, especially Apollo with the extra power, is sure to do a fine job for you. If are you looking to spray some higher viscosity products our extra power 4 stage or 5 stage models give you the assurance that when you need it, the power is there, whether it is the new ECO Series models or the POWER, PRECISION or PRODUCTION SERIES HVLP turbine systems. Apollo has not only the products, but answers to all of your finishing questions and needs.
Any question? You can reach us at firstname.lastname@example.org
Sr. Vice President
Apollo Sprayers International, Inc.
Safety and Protection Equipment - Don't Start Work Without Them
What's the number one rule when operating in your workshop, or doing any woodworking task? Always wear safety equipment! It's that simple, and that essential. You value your eyes, always wear safety glasses. We all want to protect our lungs (if you know anyone with COPD or emphysema, you'll know exactly why), so always wear a respirator with fresh filters. There, that's not so hard, is it? This month, we're making it very easy to make your work environment as safe as can be. With special savings on MSA Safety Glasses, Respirators and Filters. Don't spray without them, don't work without them, and keep your workshop and your work smart and safe.
Finishing Feature Article by Charles Neil: Aging and Antiquing Wood
One of the things that I enjoy is experimenting with finishing. One of my favorite things is the antique looking finishes. While I do a lot of formal finishing, particularly on period pieces, I do enjoy playing with the old aged look and I must say they have served me well. Over the years we have sold a lot of what we call "primitive” pieces, where the objective has been to make them look old. The same techniques are used in antique restoration as well. If we had a repair to make or needed to replace a part we had to get it to match. If it was a formal piece that had a nice stained or naturally aged , we could usually achieve the color with a little experimenting with various stains and dyes. When it came to the more "rustic pieces” we had to get a little more creative and this is what I find to be a lot of fun.
Even to this day, one of my favorite "aged finishes" is the all too familiar "crackle" finish that is done to mimic old aged, cracked paint. While I was willing to let go of the bell-bottom pants and tie dyed shirts, I still held on to the "old crackle" finish. READ MORE
Finishing Tip by Bob Flexner: Ghosting
Ghosting occurs when you sand or rub through one layer of finish into the one below, as shown in the accompanying picture. You can recognize ghosting when the problem area you’re trying to remove keeps getting bigger rather than smaller—like sanding through veneer.
The term ghosting is the traditional name for this phenomenon. As it starts to appear, you see the “ghost” of the finish layer underneath. It is also called “layering,” which describes the phenomenon well, and “witness lines,” a relatively new term, which doesn’t. Nevertheless, it seems that witness lines has become the favored term in many recent wood-finishing articles and books.
Ghosting doesn’t occur with shellac and lacquer finishes because each coat dissolves into the previous one so that all coats become one. Dissolving doesn’t happen with varnishes, including polyurethane varnish, or with most water-based and catalyzed finishes. The separate coats form separate layers that are vulnerable to ghosting.
Sometimes you can disguise ghosting by rubbing with an abrasive such as steel wool. The problem is still there, but the scratches hide it.
The better solution is to apply another coat of finish after you have removed all the problems that caused you to sand deep in the first place. Then level and rub out this new coat without going through it.
Finishing Tip by Bob Flexner: Matching Colors
Matching colors is one of the most difficult tasks in wood finishing. Using just a stain rarely works well because the color on the object you’re trying to match is affected by how the wood and finish have aged. The best way to match a color is usually to get the color close, but a little lighter, with a stain, then spray a toner.
A toner is pigment or dye added to a finish and thinned a lot with the proper solvent. Then it is sprayed.
But how do you know what color to make the toner? Here’s the trick. Spray some of the toner you think is right onto a clean glass plate and place it on the wood you’re trying to match.
You’ll know right away how you need to tweak the color to get a match.