air compressors

[dolphinboy400]

i'm looking at getting an air compressor, and i know some of you guys use them. Would i use it alot?, and would a 25L tank be suffecient? I'm thinking of using 1/2" ratchet drive, sander and for blow cleaning mainly but who knows may do some other bits as well. The ones i looked at were 9.5 CFM and the highest rated tool was the sander at about 7.5 CFM, but in reality how long would it run for with a 25L tank, and would the compressor be running continuosly to maintain the pressure?

Machinemart were not very helpful, just trying to sell me the most expensive one they could and not actually explaining anything.

If anyone has owned or used a 25L compressor i would be interested to hear what they thought about it

[stu e]

Compressors should be listed by KW or HP, giving the size receiver only says the storage capacity. The bigger the tank the longer you can run a tool for without stopping to let the compressor catch up. Pretty much all single phase compressors will struggle to keep up with air tools.
You want to go for a 2.2Kw compressor if you have good voltage and not running it off an extension lead, if the voltage is low or it's on an extension all it will do is blow the fuse/ circuit breaker.
Stu.
Just re read your post you say 9.5 cfm, what pressure is that at or is it free air delivered?

[adricar2]

if you are looking at a compressor . i would go for a 16cfm with a 150 litre tank, the sander will take allot of air, and the reserve in the tank will help allot. Machine mart have some reasonably priced units.



Adrian

[dolphinboy400]

Originally Posted by stu e

Compressors should be listed by KW or HP, giving the size receiver only says the storage capacity. The bigger the tank the longer you can run a tool for without stopping to let the compressor catch up. Pretty much all single phase compressors will struggle to keep up with air tools.
You want to go for a 2.2Kw compressor if you have good voltage and not running it off an extension lead, if the voltage is low or it's on an extension all it will do is blow the fuse/ circuit breaker.
Stu.
Just re read your post you say 9.5 cfm, what pressure is that at or is it free air delivered?

the ones i have been looking at have been 2.5 hp - 3hp but they all have 25L or 50L storage. The write-ups on them all say you can use the tools i listed it's just that i wanted to know from the horses mouth so to speak instead of dealing with 'claimed' performance.

is 'free air delivered' FAD? not many show FAD figures although i did read somewhere that if air displacement is 9, FAD will normally be around 7-7.5 , is that right? the pressures are 8 bar or 115 psi.

If it's not gonna be used alot i would struggle to justify £400 + for a hoby tool as i dont think i'll use it for anything but the cobra. It would be used on a dedicated ring main in my garage so not off the extension lead

[dolphinboy400]

Originally Posted by adricar2

if you are looking at a compressor . i would go for a 16cfm with a 150 litre tank, the sander will take allot of air, and the reserve in the tank will help allot. Machine mart have some reasonably priced units.



Adrian

thanks adrian, i'll keep that in mind. A friend said the sander will be the problem tool, the wife says to me im lazy but i say it could be an essential part of the build and we may just have to get one

[stu e]

Originally Posted by dolphinboy400

the ones i have been looking

If it's not gonna be used alot i would struggle to justify £400 + for a hoby tool as i dont think i'll use it for anything but the cobra. It would be used on a dedicated ring main in my garage so not off the extension lead

As Adrian says, the bigger tank will be better( if you've somewhere to put it) it will allow any air tool to run longer. Any compreesor will run any air tool just not continuosly. A hobby compressor such as the type imported by some tool companies have a design life of 18 hours! They will last longer, but trying to get any spares for them can be a nightmare.
I have a 2.2 Kw Hydrovane on a 100 litre tank, and to be honest I only use it to blow up tyres/ bouncy castles, the last time I used it for a tool was probably over 3 years ago. I got it at the right price, but I don't think i would bother with one otherwise.
If you mainly want it for sanding,why not buy a sander? I have a cabinet full of air tools grinders, impact guns, ratchets, sanders, inflators, grease guns, jigsaws etc, but if I want to grind, sand or saw something I just an electrc tool out, it's less messing about no noisy compressor and no hose to have to drag around.
If you want a compressor then go for it, the biggest you can buy/ fit in the garage the better, there is no end of tools you can get for it( just look at what Robin has collected). One thing to be aware of is most airlines are 8mm, these do not flow as much air as some tools need you should go for a minimum of a 10mm hose. I would also suggest you get an air fuse, people think it's over the top, but it only takes one bad crimp or something splitting the hose and you'll empty the tank with the hose whipping like crazy, which could be scratching you or your expensive paint job.
HTH Stu.

[Andy302]

As has been said, the tank size just really dictates how long you can run a tool without the compressor actually running. I had a 25l Clarke compressor which after using once with a impact wrench I swapped for a 50L unit! Both had the same compressor. Now the gun runs longer without the comp running. Ideally Id like a bigger one still but now that Im past the running gear rebuild stage I hardly use it anyway.

HTH

[oglyoodoo]

I have a small Machine Mart compressor in the garage with a 25 litre tank. I have had it for about 10 years and has had a lot of use. Frankly it's fine for many jobs but the most frustrating thing to use is the Grit blast cabinet. The Compressor just doesn't deliver the amount of air needed to keep it going so you get about a minute, or less, then have to wait a minute or so for the tank to get up to pressure again. Same goes for the Air ratchet which I have to say I have abused by using it as a Right angled drill for holesaws when space has been resricted. If you can accept the time element then a 25litre tank may be OK for you. I keep meaning to replace mine with a bigger tank. Snag is when you get to the larger compressors you need a serious mains supply if you have a heater and a few lights on in the garage. My garage cable is only rated at about 16A. I had intended to buy one of these:-

Clarke - Clarke Air Compressor - Hunter 60 - Clarke DIY & Semi Pro Air Compressors - Machine Mart

I found out Friday that they have now been discontinued. Axminster do have a similar unit though:-

Axminster AW30HP 3hp Direct Driven Compressor : Buy Axminster AW30HP 3hp Direct Driven Compressor at Axminster Power Tool Centre

I wouldn't expect either of them to run the Grit Blast cabinet continuosly but it will save some time.

HTH
Denis

[dolphinboy400]

this was another place i been looking as well as the two you mention

http://www.wolf-online.co.uk/product.asp?id=001721

and this one

Wolf Online - Wolf Sioux 50L Air Compressor Kit

It seems though, i may not use it as much as i thought. I shall have to think some more on this one
As with all tools its after the honeymoon period i am interested in, i dont want to spend the money for an overblown tyre inflator (excuse the pun )

[JonnyBoy147]

My top tip would be buy two cheap 2.5HP (think that is about 1.9kW) compressors with 25L tanks. Then butcher a couple of cheap airlines to make up an airline with a male connector at each end. Plug it into one outlet on each compressor. That your compressors working in paralel. The equivelant of a 5HP compressor with a 50 L tank and 19cfm though i think thats free air delivery.

I have two 2.5HP wolf compressors from aldi. £60 a pop. Had one of them about 2 years and have given it a very good thrashing, had one prolem with it that cost me £30 in parts to repair. Both compressors now nicely support a die grinder that i struggled with with one compressor. I havent tryed it with a large sand blast gun i have yet though.

For £120 quid i dont think you will get a single machine for anything like that money.

Just an idea.

Jon