Air compressor for spraying and other activities.
Discussion
Good afternoon guys.
Im after abit of advice regarding air compressors.
I am starting a restoration project on my BMW 2002, and ill be respraying the car with cellulose paint.
Im looking at buying a air compressor, Iv been looking at 50litre ones with around 3HP, giving between 11 and 14 CFM.
would this be the type im after, or would a 50L with 2.5HP that run at 8CFM do? My gun only requires 7.
Any help would be great.
Im after abit of advice regarding air compressors.
I am starting a restoration project on my BMW 2002, and ill be respraying the car with cellulose paint.
Im looking at buying a air compressor, Iv been looking at 50litre ones with around 3HP, giving between 11 and 14 CFM.
would this be the type im after, or would a 50L with 2.5HP that run at 8CFM do? My gun only requires 7.
Any help would be great.
I would suggest you go for a larger receiver if funds permit. once you have air tools like a DA etc which are so useful for the prep work you will quickly get to the point of consuming more air, more quickly.
Once you get to the flatting of the paint stage the DA and fine grade hook and eye pads will become a must to get any likely orange peel out and again a 50 Litre machine will be forever starting and stopping to maintain the PSI that it will consume.
hope that helps
Once you get to the flatting of the paint stage the DA and fine grade hook and eye pads will become a must to get any likely orange peel out and again a 50 Litre machine will be forever starting and stopping to maintain the PSI that it will consume.
hope that helps
As with all 'what compressor' questions the answer is to decide what air tools you want. Factor in that you might want to buy others in the future & look to see what their air consumption is. Then see what size compressor will run them. Things like rattle guns need a LOT of air delivered at sustained high pressure & small compressors won't cut it without frequent stops to let them build up pressure again..
Remember that many compressors are advertised with their output shown as displacement. This is AFAIAC a con. The important figure is Free Air Delivery (FAD) and this is a lot less than the displacement figure often between 50 & 75%.
The figure you give for your gun as 7cfm is a bit misleading as not only does it require 7cfm it requires the air to be maintained at the correct operating pressure whilst spraying, so you need a compressor that can continuously deliver at least 7cfm at that pressure or as I have said above you will keep having to stop to let the pressure build again. Not a good idea if you're painting a large panel.
If the pressure drops too low the gun may start to spit, again not what you want.
If you don't want to buy a big one, consider getting all the parts prepped then hiring a compressor to do all the priming & painting.
Remember that many compressors are advertised with their output shown as displacement. This is AFAIAC a con. The important figure is Free Air Delivery (FAD) and this is a lot less than the displacement figure often between 50 & 75%.
The figure you give for your gun as 7cfm is a bit misleading as not only does it require 7cfm it requires the air to be maintained at the correct operating pressure whilst spraying, so you need a compressor that can continuously deliver at least 7cfm at that pressure or as I have said above you will keep having to stop to let the pressure build again. Not a good idea if you're painting a large panel.
If the pressure drops too low the gun may start to spit, again not what you want.
If you don't want to buy a big one, consider getting all the parts prepped then hiring a compressor to do all the priming & painting.
Edited by paintman on Tuesday 11th August 11:50
paintman said:
As with all 'what compressor' questions the answer is to decide what air tools you want. Factor in that you might want to buy others in the future & look to see what their air consumption is. Then see what size compressor will run them. Things like rattle guns need a LOT of air delivered at sustained high pressure & small compressors won't cut it without frequent stops to let them build up pressure again..
Remember that many compressors are advertised with their output shown as displacement. This is AFAIAC a con. The important figure is Free Air Delivery (FAD) and this is a lot less than the displacement figure often between 50 & 75%.
The figure you give for your gun as 7cfm is a bit misleading as not only does it require 7cfm it requires the air to be maintained at the correct operating pressure whilst spraying, so you need a compressor that can continuously deliver at least 7cfm at that pressure or as I have said above you will keep having to stop to let the pressure build again. Not a good idea if you're painting a large panel.
If the pressure drops too low the gun may start to spit, again not what you want.
If you don't want to buy a big one, consider getting all the parts prepped then hiring a compressor to do all the priming & painting.
And don't forget you'll a need at least one moisture trap to prevent condensation going through the gun (and maybe an oil trap).Remember that many compressors are advertised with their output shown as displacement. This is AFAIAC a con. The important figure is Free Air Delivery (FAD) and this is a lot less than the displacement figure often between 50 & 75%.
The figure you give for your gun as 7cfm is a bit misleading as not only does it require 7cfm it requires the air to be maintained at the correct operating pressure whilst spraying, so you need a compressor that can continuously deliver at least 7cfm at that pressure or as I have said above you will keep having to stop to let the pressure build again. Not a good idea if you're painting a large panel.
If the pressure drops too low the gun may start to spit, again not what you want.
If you don't want to buy a big one, consider getting all the parts prepped then hiring a compressor to do all the priming & painting.
Edited by paintman on Tuesday 11th August 11:50
And whilst spraying you should really use an air-fed mask (with all the correct additional filters) and a small compressor won't be able to cope feeding a gun and a mask.
Iv narrowed the compressors down to these two.
Which seems the best?
http://pages.ebay.com/link/?nav=item.view&alt=...
http://pages.ebay.com/link/?nav=item.view&alt=...
Or does anyone know of any others.
Thanks
Which seems the best?
http://pages.ebay.com/link/?nav=item.view&alt=...
http://pages.ebay.com/link/?nav=item.view&alt=...
Or does anyone know of any others.
Thanks
for what it is worth, both options in your links appear to use the same motor. My most recent compressor used the same unit and it was loud ! after a period of time it failed altogether. I stripped it down to find more metallic bits than it started with !! Now I tend to look after all the things I buy so I suspect I was unlucky, but the noise when it was running was something that would make me look for a belt drive unit next time as my experience of these is the run more quietly.
I don't know by any means all there is to know, but a buzzy motor and it failing suggest to me that it was working at the tope of its game all the time, rather than within its capabilities. And yes I regularly checked its oil level, drained the tank etc.
For the price it looks good value, but for me and my needs going forward I will look at a belt drive machine.
perhaps I am just unrealistic that these machines should last better than the do, but like in all things you get what you pay for.
I don't know by any means all there is to know, but a buzzy motor and it failing suggest to me that it was working at the tope of its game all the time, rather than within its capabilities. And yes I regularly checked its oil level, drained the tank etc.
For the price it looks good value, but for me and my needs going forward I will look at a belt drive machine.
perhaps I am just unrealistic that these machines should last better than the do, but like in all things you get what you pay for.
Direct drives do tend to be noisy. Belt is much quieter - but tends to be more expensive.
I use a direct drive 2hp single cylinder professionally for SMART repairs & - so far in around 14 years - have only had problems with one, which turned out to be a broken strip of metal in the head which acts as a one way valve. Replaced with a new head & that compressor now sits in the garage as a spare.
Either of the two you link should be fine.
As mentioned by squiggs a moisture separator is an essential to deal with any water that gets into the airline - the water is a consequence of compressing the air so you can't prevent it.
I have a small pressure gauge on the bottom of each of my guns so the pressure at the gun is correct. If you set it at the tank gauge there will be a drop in pressure at the gun due to the airline. Get a proper airline. The curlywurly plastics are OK for a tyre inflator but they seriously restrict the air flow due to their small bore which will stop tools working properly.
I use a direct drive 2hp single cylinder professionally for SMART repairs & - so far in around 14 years - have only had problems with one, which turned out to be a broken strip of metal in the head which acts as a one way valve. Replaced with a new head & that compressor now sits in the garage as a spare.
Either of the two you link should be fine.
As mentioned by squiggs a moisture separator is an essential to deal with any water that gets into the airline - the water is a consequence of compressing the air so you can't prevent it.
I have a small pressure gauge on the bottom of each of my guns so the pressure at the gun is correct. If you set it at the tank gauge there will be a drop in pressure at the gun due to the airline. Get a proper airline. The curlywurly plastics are OK for a tyre inflator but they seriously restrict the air flow due to their small bore which will stop tools working properly.
Edited by paintman on Friday 14th August 12:34
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