You’ve got a paint/finishing project to do and not only is there a lot of it to cover, you also want a smooth, even coating. Let’s be honest, doing it with a brush will take time and probably not leave the best of finishes. Now it’s time to consider using a spray system. There are two main types available; the older more conventional version which uses a spray gun attached to a compressor or the newer HVLP systems which are attached to a low pressure turbine.
What is HVLP?
High volume, low pressure. Nice and simple. It pretty much is exactly as it says on the tin. Where the conventional systems work between 45-60 psi (high pressure) at 8 cfm (low volume), HVLP systems generally produce over 100 cfm (high volume) and all of this has to be under 10 psi (low pressure). So what does this mean to you?
The main reason as to why you should always consider HVLP. At these lower pressures it allows you to lay the paint on instead of blasting it. Although the high pressure is very effective at atomizing the spray, leaving a very good finish, it’s not very efficient. In fact, they’re only around 30% efficient, meaning that only 30% of the spray ends up where it needs to be. The other 70% ends up in the atmosphere which is not good on your pocket or the environment.
With the lower velocity of HVLP, this produces a softer, easier to control spray. This means that much more of the finish ends up on the surface, with figures as high as 85% efficiency for some systems. With some finishing substances being harmful to your health and the environment, HVLP is more and more becoming the industry standard.
Although reduced overspray is a big reason behind selecting these systems, there are other factors to consider…
Something that possibly isn’t spoken about enough but has a big effect on the quality of the finish. HVLP turbines deliver warm dry air. Compressors, on the other hand, produce cooler, damp air that can sometimes foul the spray, not ideal when you’re after that mirror-like finish.
With the largest of turbines weighing in at just under 15kg, they can be carried around wherever they are needed. This makes them great for the tradesman, who may have a number of spraying jobs in a day. You might argue that some small compressors are also around this weight but will they be able to perform as well?
This may be the deciding factor in your purchase if your project has to be absolutely perfect, which could make you lean towards the compressor. But don’t think that the lower pressure of the HVLP will mean a bad finish, in fact the quality of finish of these systems can be identical to the best high pressure spray finishes.
So let’s get down to brass tacks here. The upfront cost of a HVLP system will almost certainly be substantially more than a compressor and spray gun. This of course depends on the size and performance of each of the variants, with high end systems being over £1,000. But what you must consider is the efficiency of the HVLP with the paint savings adding up fast. Over time that initial outlay will be paid for and then some.
HVLP – the future of spraying?
Fast becoming the industry standard in many sectors and with more emphasis on the environment, it’s hard to see it not becoming the only way to spray in the future. If you already own a quality compressor, it may not seem like it’s worth it right now. But if you need lots of jobs doing and the cost of paint is getting too much, these will prove to be a sound investment.