Thinking of getting an air compressor

Been thinking, for some time, about buying a air compressor. I'm at a loss, have no idea about them. Have been trying to findout about them, reading and looking at different makes and models.
Can anyone give me any advise?
I am now getting towards the end of my 2" model, got about 9 more kits to go.
I'm hoping to build a 4" SCC next.
The 2" I have brush painted it, I will be spraying the 4".
If anyone can help, with what size of tank etc I will need to be sure of getting the right size of compressor.

Thanks Charlie

I found, to my cost, its best to buy the biggest you can afford and store. First start with what spray gun you'll want to use, then look at the CFM of that spray gun and then try to match the CFM of the gun to equal or less than the CFM of the compressor.

I started with a little 4.5cfm with about a 10ltr tank and that very soon ended up running out of puff, then moved to a 50ltr tank @ 9.5cfm and again ended up finding it running far too long, so ended up at the same 9.5cfm but with a 100ltr tank. This gives me decent perfomance for all my air tools and I dont end up with it running to long. If I was to upgrade again then I'd move to belt drive for a quieter life, the direct drive stuff is a bit noisy.

Dunno if the above helps ?

I have found a 50 litre tank fine for spraying however I use a HVLP spray gun at about 18psi. Very little overspray due to the low pressure, doesn't waste paint! I have a separate pressure gauge & adjustment on the gun so I can adjust as I go along with an in-line water trap/filter which needs drying after every use. The air is damp in Cornwall!!

Hi Steve, thanks for replying. I have never used a spray gun before or have any knowledge of them. Can you maybe recommend makes and models for me. All I was thinking, was to use compressor for, was spraying and I have plenty of electric power tools already.
I have been looking at some spray guns, the different types, gravity feed ones etc. Which ones, in your opinion, would be better.

Charlie

Hi Livesteam, thanks for replying. I mainly only want a compressor for spraying, I have, over the years, got electric power tools, enough for my needs.
I have very little space, which is a worry and hoping I will have room for a 4" engine in my garage. I know that space to build and store will be tight. I was thinking, maybe to store compressor in a small purpose built shed/box, out side of garage, but then I have problems with usability. I guess I could get a mobile one and that would solve that problem.
So much to think about and I want to get the right one first off.

Any ideas would be good.

Charlie

chas12154 wrote:
I have very little space, [...]

Any ideas would be good.

A compressor doesn't need to be accessible, as long as you can get air and condensate out of it. Space is not really a problem for me, but I have put my compressor on some sturdy brackets high up on the wall. It's out of the way, but I can still see the gauges and drain the water out of it if I need to. If I ever get a round tuit, I'll hook it up to an air 'system', with multiple air outlets throughout the workshop.

Hope this helps.

Just took delivery of a compressor myself today, still unpacked in the workshop.    
I was thinking down the same line and went for as big as possible inside my budget and ended up with a oil less compressor with 240 l/min air-in rate and a 50 litre tank. I went for a upright compressor instead of a conventional horizontal design as I hope to fit it into the corner of my garage/workshop for the time being. Just remember air-in does not mean delivery rate , mine is claimed to have 240 l/min in and 75 l/min out at 7 bar. Check the need for the largest air tool you want to use and go from there.

If spay painting is what you intend to do, stick with oil-less as oil which is not in the air needs not to be taen out afterwards.

The reply of He who must not be blamed is going also in my direction: as the compressor is said to be quite noisy, I also think about banning it from the Workshop at a later date and run a pipe along the worshop with outlets where I need it. If needed you could hook up an in-line oiler for tools, as they ususally need oil in the air for lubrication.

elwood

Thanks to all that have replied. I have a better idea now of what I need.
A oil-less one seems the better option for me.
From what I can see, most spray guns use about 20psi, now the next question is, which is better and easier to use. Gravity fed or conventional one. I have used neither. Seen car spraying, done in a garage, but as we all know, things look easier than they really are!
Some one here have done some excellent paint jobs, got a mirror finish to the paint. I know good preparation is the key, to a good finish, but still need to be good with a spray gun.

Iv'e got a few months before I will need one, but I thought having a look now would lead me to getting the right one, first time.

Charlie

The other good thing a compressor is good for is running in your engine before you steam it
I have run in all my models in now for the past 25 years on air . It is a lot easer to look over the model when it is running cold and make adjustments to it
You can also have plenty oil in the bearings and just wipe it off as it runs
I have just finished building a A4 loco in 71/4 gauge for a customer and it has been run for about 14 hours so far on air and now ticks over on 8psi and hope to steam it for the first time this month
Mark

Hi Mark, I had that in mind too! Getting to the stage of my build, when I can think about running it on air. With running it on air, do you need oil in the air to lubricate the cylinder and piston?
Its all a bit daunting, if I'm honest, not knowing what to buy. I have sort of made a dissension on size of tank, 50litres I think will be about right. An oil free one too.
Have now to decide on what make and model to buy. I thing a mobile one would be best for me, I'll have to keep it outside of my garage as space is an issue. When spraying, I will have to use one of those pop-up greenhouses, type of thing.
I have decided I will be buying a compressor, thats one thing I guess!!

Hi
You don't need oil in the air just oil in the engine lubricator
I have a 10 cfm 100L compressor mounted high up on my garage wall and I also bought it second hand and I have had it 25 years now but I have replaced the motor once and the air switch once
Have a look at second hand in your local area you might be surprised
Mark

Would a 50 litre one be enough to spray and run the engine on air? What is CFM mean? Been looking at getting one that is 116 psi and 7 or 8 bar.
I have seen a Clarke Ranger 6/500 2hp 50 Litre Oil Free Air Compressor. Its 7 cfm with two outlets, one adjustable and one straight not.
You think one around that size would be ok?

Hi
CFM means cubic feet per minute this is how much air it will deliver most air tools have a sticker telling you how much cfm it takes to run the tool
The advantage a larger compressor has is it does not have to run as long to keep up with air use
My advice (for what it is worth) is to get the biggest you can considering how much you want to spend and space you have
Hope this helps
Mark

Every bit of advise helps Mark. Will have to consider the space I have and go from there. Thanks for your help.