Compressor & Paint Spray Gun.

[weegieavlover]

Hey All,

I have been doing a lot of stripping of the cornice in my livingroom. I have taken the rather drastic step and bought myself a used 24L air compressor to respray the cornice rather than painting it as it will be faster & finished better this way (so I am told!).

However I have never used a compressor or spray gun before!
But you got to learn sometime.

Anyway I have been looking at my compressor stats (collecting it tomorrow) and spray gun stats and I am a bit confused:

The Compressor I have bought has these figures:

Working Pressure = 116psi/8bar
Air Displacement = 7.3cfm/206L/min
Free Air Delivery = 5.4cfm/152L/min

Now I will be honest I do not understand these stats fully and nor do I know if they are that good, considering the money I paid for the compressor I think they are probably extremely average at best.

However when I look at spray guns I am seeing a lot of stats like this:

12cfm
50-70psi / 3.5-5bar
Requires 2.5hp/50Ltr compressor.

That is on screwfix and does not have a massive selection but that looks like it is of no use - would this be a correct conclusion? Or are these normal stats and I just need to understand (with your help) how a spray gun works with a compressor?

I mean will a spray gun always use more air than the compressor can provide?

Could someone in the know help a rather confused novice please.?

Where is a good place to get a spray gun (UK) and how do these figures from the spray gun compare to the compressor?

Thanks in advance for your assistance.

Col

 

[Burnerman]

Col, that spray gun uses more air than your compressor can deliver, I'm afraid....12 cfm sure is a lot of air, which is fairly typical for HVLP (high volume, low pressure) applications.
Most compressors will easily provide the working pressure that you need, but that spray gun will empty the reservoir tank very quickly.
You also need air / oil separators when spraying paint, but to what degree that applies in domestic situations I really don't know.
You could consider an electric sprayer - some are quite reasonable for emulsion paint....
Lets hear what the others say!
John

 

[Deleted member 174758]

A 12 cfm gun will probably require a 3 to 5HP compressor (15 to 20 CFM FAD) with a 150 to 200 litre tank to guarantee it won't end up cycling (cutting in) excessively. Burnerman is right about the other stuff - the compressor will need a regulator, gauge and at least a 20micron coalescing filter to take out the worst of the moisture from the compressed air. At the size of yours you can realluy only run stuff like nailers, pin guns, blow guns, small drills, etc. It will struggle with anything bigger than a medium sized (3/8in) air drill

I like BMs solution - some of the Wagner and Bosch type sprayers are capable of a decent enough finish. If you want to spray extra smooth surfaces (metal, MDF, etc) as well the best low cost approach is LPHV or low pressure high volume where the gun is supplied with a 2-, 3- or even 4-stage compressor/turbine (the more stages, the better the finish quality). They can't drive air tools but they can drive the spray gun. Budget price names to look for there include Earlex (British) who have got quite a good reputation for their hobby outfits.

 

[topper harley]

Hi weegieavlover,

your compressor will be ok for spraying your cornice, however the spray gun requirements mean you will be waiting for your compressor to refill the tank with air often. This is not really a big deal if you are spaying emulsion water based paint with a matt finish. It WILL be fustrating to spray for say 1 minute untill your pressure drops, and then have to wait 3 minutes for the tank to refill again. But if you are only spraying emulsion and are prepared to wait, then this should do the job eventually. If you are spraying emulsion you should not see where you have stopped and then restarted spraying. There are other spray guns available that would do the job better for your application that require much less air (look at the the CFM 's). Personally, as much as i like to spray paint things, I would draw the line at spraying anything indoors. Overspray mist travels a long way, you may be painting the lounge and then cleaning up the overspray in the kitchen and I also hate having to mask up everything you do not want coated in overspray. Of course its up to you.

good luck