What size Compressor?

[nickde-ath]

I spotted an advert in the Sealey Christmas promotions catalogue for a compressor and accessory kit- including spray gun.
I researched Sealey's website and asked them some questions, the short answer was that the compressor listed would need to be 3 times the size to use the spray gun effectively!
Now for the questions.
1. If the spray gun uses 4 to 7 cfm what size compressor would I need to use it for occasional DIY spraying, not full time professional.
2. Compressors seem to come rated by their HP. I will need to run the compressor from a generator from time to time. If 1 HP is 746 watts could I run a 2.5 HP compressor from a 3300 watt generator?

No doubt any answers I get will raise some more questions.

You came up trumps with my questions about MIG welders, I hope you can do the same again.

Many thanks Nick De'Ath

 

[the snooper]

this question all depends on

what you will be spraying ? cars id go for a 14 cfm
i have a 14 cfm compressor and none of my 5kva genny's will touch it due to the massive in rush when the compressor starts up i think the start up draw was something like 40 amps albeit very vreifly the genny just cant supply that sort of power
so the short answer is no the 3300 watt genny wont start the compressor

 

[tigler]

I'll second that, a 3.3KW gen won't start a 2.5 HP puffer.

 

[nickde-ath]

Thanks snooper and tigler, looks as though I will have to do some thinking about what to use/ buy. I will be spraying a car but only in bits and pieces.
I thought I established at some stage that my generator would run a 1.5 hp compressor but then I found out that a 1.5 hp compressor won't produce enough air for a spray gun.
Any other comments/suggestions gratefully received.

Regards Nick

 

[langy]

I use a 14cfm and its fine, anything smaller would be a bit of a struggle