I just bought a siphon-feed spary gun from Campbell Hausfeld on sale. It requires 40 psi but the air flow requirements is 7.0 scfm. I looked at air compressors and the most you can get is 4 scfm at 40 psi even for a model at $300. I was wondering how people get the right air flow and air pressure?
I run a 80 gal 10 horse 2 stage. When painting with a siphon feed gun, a small air compressor just don`t have the volume. On small projects you well still have to wait for air build up.
If your painting planes, try a small detail HVLP gun instead , sprays at a lower pressure, less over spray. I used a Craftsman 6.0 horse 30 gal. with a detailed gun, worked o.k kinda. The small one`s throw a lot of moisture.
With the gun you have you need at lest 45lbs. pressure at a constant 7 cfm.
I was under the impression that the compressor is not the problem but the regulator.
The regulator has to be able to regulate 40PSI at the required flow.
Just buy another regulator for the compressor. Can be an inline one.
Thank you for all you replies. I was planning to use latex, enamel and perhaps automotive paint. I got a very good deal on this spray gun but if the cost of buying a bigger compressor or a new regulator makes this spray gun more expensive than an HVLP or gravity feed, I rather get one of those. What king of spray gun works the best with an entry priced compressor ($70 to $100)?
4CFM is going to limit you to small detail guns for extended spray sessions. Trying to use a larger gun with a higher CFM requirement is going to have a few repercussions. The gun will be starved for air and will not atomize the paint very well. The compressor will constantly run attempting to keep up with the air demand the gun is putting on it. Moisture ( lots of it ) will be the end result.
Detail guns work great for painting planes, they hold the right amount of paint and are easy to manipulate. The only thing I disagree with moondoggie on is to get a standard detail gun, not an HVLP if you will be using a small compressor. The "HV" stands for high volume, as in the air supply, something you don't have. Standard guns atomize with air pressure rather than air volume. You will get more overspray, but the gun will work better with a smaller air supply.
I would recommend you get a Disposable in-line desiccant air dryer to use when you paint. They will have them at your better paint stores, run around 10 bucks or so and keep oil and water out of your paint. They work great.
It takes air that has be vaporized to travel 36 feet before it condenses back to a liquid. If you mount your water trap right off these little compressors you well have a huge water problem.
The way to get around this is to coil a 50ft hose from the air compressor into a 5 gal bucket of cold water, put a little ice in. Attach your water filter to the end of the hose as it comes out of the bucket, then attach your spray line to the water trap. By the time the air gets to the trap, it has condensed back to a liquid and your trap will work very well.
I`ve done custom painting for many years and know this works for sure.