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FREQUENTLY ASKED QUESTIONS (FAQ) |
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HVLP sprayguns are easier to use than most sprayguns (especially when compared to high pressure sprayguns). This is because the pressure is low resulting in a softer spray pattern. Turbine sprayguns operate with much less pressure (at the sprayhead) than the compressor HVLP sprayguns. So you can expect even less overspray and bounceback with a turbine spraygun. It takes very little practice to spray and achieve professional results with a turbine spraygun - thanks to the lower velocity. If you can use a paintbrush, you can spray with HVLP. Should the turbine case be hot? Yes, the turbine motor heats up within a very short time and the air becomes hot - especially at the turbine. In fact, if you let the turbine run for 15 minutes or so you had better be careful removing the hose from the turbine. The brass connector will be too hot to touch. The heat is from the copper motor windings and the bearings - remember, these motors are traveling at 19,000 - 21,000 rpm. Where should I place the Turbine? The best place is on the floor at least 20ft away from the spray area. Any 3 or 4-stage turbine should last 10 years or more of normal use (3 - 4 times a week for a few hours at a time). For occasional use it will last much longer. However, there are certain conditions that can cause premature burnout with any turbine.
Size of Turbine Case - Does it matter? The smaller the turbine case, the easier it is to cool. What you need to know is that what HVLP makers call the turbine 'motor' is actually a bypass vacuum motor. This unit has fans (called 'stages') at one end and its own small cooling fan at the other. In between the stages and the cooling fan are the copper windings necessary to power the motor. It is these copper windings that must be constantly cooled. The cooling fan is not much different from the type of fan seen in computers except that this fan is secured to the same shaft (rotor) as the main stages (fans). What this means is that all fans, including this small cooling fan rotate at 19,000-21,000rpm (depending on the motor and certain conditions). So as you know, it's much easier to keep a small room cool with a window air conditioner than it is to keep a larger room cool with the same air conditioner. It is the same situation with turbine case size. The cooling fan size and speed is preset, so a smaller case will be easier to keep cool. The cooling fan air escapes through the vents in the case. Why is there 'Paint' Buildup at the vents? Because the air passing out through the vents is hot, you can expect to see dried paint particles (or whatever you are spraying) on or around these vents. This is normal with any turbine. Although greatly reduced, there is always some overspray in the air and this overspray simply lands on the turbine and at the vents, is instantly dried by the hot air. This buildup is not paint particles passing through the turbine filters and being vented out. Can Brushing be compared to Spraying? In order to spray intelligently, it's helpful to know just how similar spraying is to brushing - in fact, at Fuji, we often say that a spraygun is simply a paint brush with no bristles. Similarities:
How far away should I hold the spraygun? The Spray Pattern is fan-shaped, so for a larger sized fan you do not have much choice - you will be at or close to the maximum 8" distance. It's impossible to produce a large spray pattern if you hold the spraygun close to the object - there is no room for the fan pattern to expand. As you move closer with the gun, the fan will become a smaller size. So for instance, what was 10" at a distance of 8" becomes about 2" fan at 2" distance. When you want to paint something that is, let's say, 2" across and 6ft long - you will find it much easier if you move the gun closer. This will give you the ability to control your pass from side to side properly without wandering all over the place. Plus it will reduce overspray. Imagine spraying 1/2 chair spindles from 8" away with a spraygun when you don't have the bristles to help guide you - it's very difficult. So simply adjust the pattern to be smaller and cleaner and move in close until the fan is the exact same size at the spindles. Once you are close, you will be able to guide the spraygun easily and it will not be as important to have a completely steady hand. Once again, liken it to painting with a brush. You would have no problem with an 8" wide brush painting a swath across a wall even though you were holding the end of the brush handle 8" away from the wall. But now imagine trying to paint a 1" line across the wall holding the end of the brush handle. It would be difficult not to paint wavy lines because each movement of the hand at the end of the handle would be amplified on the wall. But as mentioned previously, we do not have the benefit of bristles to help steady and guide our hand when we are spraying - so stay in nice and close. As an aside - it is usually not possible to bring the sprayhead close to the object with other methods of spraying (high-pressure for instance). Doing so would produce bounceback. The pressure is so much less with turbine HVLP that this is not a problem. Is thinning necessary or important with HVLP? Viscosity of coatings is important. Although we supply a guide, there is often some trial and error involved in arriving at the best viscosity. If a product is thinned too much, there are runs. Too thick and 'orange peel' or rough finish is the result. When thinning, it is essential to use a reducer that is compatible with the product you are using. To be sure, buy a thinner made by the same coatings company - always verify that it is the right product. It is wise to experiment on a practice piece to ensure that the finish is perfect. You may also request information from the coatings manufacturer - don't forget to mention you are spraying with HVLP equipment. Water-based lacquers (acrylics, urethanes and varathanes etc.) can be applied successfully with HVLP. Most of these products require no thinning whatsoever (but some do). Many of these newer coatings contain a high-solids content of 60% or more so the turbine must be powerful enough (at least the 3-stage). Several thin wet coats are preferable to one or two thick coats. Scuff sanding between coats is recommended. Most users report that the preferred Aircap Set for water-based (water-borne) coatings is the #3 Set - this is because these coatings are best applied in thin, wet coats (layers) to prevent orange-peel and bubbles in the finish. Can I spray household trim with Latex Paint? Yes, HVLP is ideal for this application but you must follow a few general rules in order to achieve a good finish. If you intend on spraying Latex Emulsion Paint (House Paint) most of the time, please consider purchasing the more powerful 4-stage turbine systems. To spray Latex paints successfully, some rules must be adhered to. The latex should be 'finish-quality' (the best grade). For best results, a Latex Additive such as Floetrol should be used (Call 1-800-321-3444 for your nearest dealer). Important* Floetrol is not for thinning - it is a product that prevents the paint from drying too quickly - in other words, it is a 'retarder'. So you still must thin with water also. Thin the Latex with water - usually 20% is enough. The #4 needle/nozzle/jet setup is preferred for decent coverage on items like household trim, louver doors, fireplaces, cabinets etc. When spraying Latex, please turn the fluid adjusting screw to limit the paint to a finer spray. This will increase the ratio of air to paint and result in better atomization and a beautiful finish. (Factually speaking, it doesn't increase the ratio of air to paint but does the opposite - it allows the air atomizing power to work on less paint thereby improving the quality of atomization). Spray the paint on 'wet like a lake'. In other words, it must be completely wet in order to flow out nicely and look smooth. If you are only seeing droplets on the surface, open up the fluid knob for more product. HVLP is designed for fine-finishing, this includes... furniture, pianos, cabinets, automobiles, machinery - anywhere a 'Class A' coating is to be applied. If you already own airless equipment, you'll find that an HVLP system will complement it perfectly. Although there is some overlap, every family of spray systems on the market has its special place. For more information about spraying techniques, check out the books listed in the Recommended Reading Section. Can I spray walls & ceilings with HVLP? If your main purpose in buying a system is to paint walls with latex, then we want you to know that you will probably have to thin the paint. Some professionals do not want to do that but really, it shouldn't deter you. If you want to spray latex full strength (absolutely no thinning) onto walls, you would be better off with a Wagner 'Power-Painter' which will do the job without thinning. Although HVLP turbine systems were not designed to spray walls/ceilings, thousands of people have used the Fuji System to paint walls with latex and they are very happy with the result. Just remember to use Floetrol and thin with water (about 20% - sometimes less). For walls you would need the #5 or #6 Aircap Set for greater coverage. The reason a turbine system is not 'ideal' for walls/ceilings is because you have to keep filling up the 1 quart (1000cc) cup. But our opinion is that it is still much faster than rolling because with the roller you constantly have to add paint to the roller - this takes a lot of time and you do it often. At least the cup does hold a full quart of paint and this goes a long way. Because you will be using a larger Aircap size (#6) you can expect some texture (though not as much as with a roller). Texture can be minimized by using Floetrol as well as thinning with water. A little texture on walls is totally acceptable. Can I spray Nitrocellulose Lacquer? It’s the same answer with any coating, yes... just so long as you thin it appropriately. Spraying of lacquer may be prohibited in your location. Also, the amount of thinning may be controlled too. Please check with the local jurisdiction in your area before setting up. Lacquer fumes are toxic and flammable (combustible) so adequate ventilation is absolutely necessary. Explosion-proof light switches, fixture and extraction fan are a must. Lacquers were formulated to dry extremely fast. The very fact that the turbine motors become hot and the air from the turbine heated can be counter-productive with lacquers. If you spray as you would with regular slow-drying paints, you may find that you can only spray a dry coat or you get orange-peel. But as always, there are ways around problems like this.
If all of the above instructions are followed, then a beautiful finish will result. This assumes that the spraygun is held no more than 8" away from the surface being sprayed (closer is ok). We also assume is that the lacquer is thinned enough. In fact, if you have done all of the above and are still getting orange-peel, you will almost definitely have to thin more. Always use lacquer, sanding sealer and thinner from the same company to ensure compatibility.
The fluid nozzle and needle MUST always match exactly. However, the Aircap may be one size up or down from the norm. The sizes No.3 and 4 setups are both ideal for all fine finishing. 3 different setups are available as accessories. Generally speaking, the quality of atomization and finish suffers as you go to the largest size setups (No.5 and 6). Please note that the chart offers you a starting point only as to the setup size to be used. The best way to decide is by experimentation. IF YOU DO NOT INTEND ON SPRAYING WALLS CEILINGS THEN THE ONLY TWO SETUPS YOU WOULD EVER NEED WOULD BE SIZE 3 AND 4. PARTS SHOWN BELOW ONLY FIT NEW XT SPRAYGUN. Aircap Set 3H - 1mm (.039") FINE TO MEDIUM OUTPUT Most fine-finishing. WATER-BASED LACQUERS, SEALERS, CELLULOSE, ACRYLICS, SYNTHETICS, POLYURETHANE, STAINS, VARNISH, GLITTER PAINTS, PRIMERS.
Similar to No. 3H but more coverage. Especially suitable for AUTOMOTIVE ENAMELS, NITROCELLULOSE LACQUERS, CATALYZED LACQUERS and LATEX where finer finish is required such as louver doors, trim, cabinets (see section above about Latex). Also good for VARNISHES and OIL-BASED PAINTS, POLYURETHANES, ETC.
. Where can I obtain a User Manual for my Old Fuji System? Click Adobe Image for PRE-2003 Manual Where can I obtain a User Manual for my New Fuji System? Click Adobe Image for Current Manual 2003+ |
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