SLROC Forum

Hi guys,

Looking into getting myself a compressor for running air tools, anyone have some advice on the size/type I should be getting? Also any recommendations for a good value unit?

Thanks,

Robin

Does nobody have an air compressor they'd recommend? 

Hi

There are quite a few to choose from.
I i were you, i'd take my budget to Machine Mart and get the best you can for what you've got to spend.
I think Clarke are good.
Sorry i can't be more specific.
Machine Mart have a good range.

Geoff

I started with a wee 7cfm/25ltr tank compressor..... but it struggled once I got any decent power tools
I then upped to a compressor with a bigger receiver, but still 7cfm, still oil-free...... better - but again, the bigger air-tools just killed it (may have had something to do with getting more tools, mind you!)

Now I'm using a Airmaster Tiger 14/60. It can cope with my tools..... but struggles with the tyre-changer

Its like toolboxes: Whatever you get, you need more capacity down the line

Thanks very much guys, will have a look at machine mart. Just wasn't sure whether a 24 or even 50 ltr (7ish cfm) would be big enough for impact wrench/ spray gun?

I bought one of these - http://www.aldi.co.uk/uk/html/offers/special_buys2_23678.htm - and the associated wrench and spray gun and have found it pretty good for most small jobs.

I have access to a large Machine Mart AC and tools if I really need big stuff but for the money - and the 3 year guarantee - this is a great little machine.

Best reading up on your air tools and what cfm they need to run and buy your compressor acordingly.

Get the biggest and best you can afford.

I know that my paint gun runs 14 cfm. I have a 3.5hp with a 200l tank to keep the pressure up when painting.

Hope this helps.

Gary

I never expected to be offering anyone advice on air compressors, but life is strange and full of mystery...

We bought one last year when we decided to respray our landy. After much research, the bottom line is this: the bigger the reservoir and higher the cfm figure, the more useful (and expensive) it is. Around 14cfm and 100+ litres is probably ideal.

We settled on a 50 litre / 8.3cfm model. It is brilliant for painting with a HVLP spraygun designed for lower output compressors (we used the Devilbiss SLG) but a bit short on puff for running tools such as a sander in more than moderate bursts. Still, overall it did the job beautifully.

I was told that oil-free compressors don't last as long as the oily ones. I don't know if that's entirely true, but it decided us on buying an oiled model. We had no issues with oil getting into the spraygun, but then we did use two filters, the second mounted on the gun itself.

And that pretty much exhausts my knowledge of compressors! Hope it help!

   Well done Kathy!  The filters are more to trap the water than the oil.

    If you are just blowing tyres and doing one panel at a time spraying. the cheap model from Aldi is ok.

  Next up is Kathy's model. The next step up from hers will work air tools as well.

      Belt drive are quiet .......direct drive are as noisy as a TDI in a series 

Thanks very much, a lot of food for thought. Usual story that budget will certainly mean compromise!

2p if you want it....

What do you want to do with it?

If you want to sandblast with it, you need a good airflow and reasonable pressure + you want the right sandblaster (pressure pot).

If all you're after is a few air tools (ratchet + impact wrench + blowing up tires) then anything will really do with a bit of patience because the compressor will eventually keep up with the receiver.

I bought a 14cfm 35L unit from machine mart, paid a small fortune for it a while ago, found that it did not sandblast well (insufficient volume flow rate at required pressure), decided instead of upgrading (+ increased electric supply potentially as it was a 3HP unit) I bought a second slightly cheaper (2.5HP), with a 50L receiver, both plug into the same ring main without issue, in fact you could add a third (just). but they both will now keep up with anything that can be thrown at them.  If I was to do it again, I would buy 2 x 50L 2.5 HP cheap units of ebay, they are all made in China, including machine marts ones.

My advice is manufacturers always overstate the spec's (done in a lab with a good quality unit), you also need to remember that the airflow is free airflow (cfm), you need to allow for your pipeline losses to a degree, small pipeline, bigger losses, but the largest loss you will encounter will be your airline fittings.  If you use Machinemarts quick release couplers, they have a tremendous pressure loss (stick two together and try to blow through them).  I use PCL XF [extra flow], yes they cost a bit more and I bin the machine mart ones, but they have very little resistance so when you are demanding good volume flow rate they provide very little loss.

It's all about airflow rate, pressure is not so much of an issue as you normally use a regulator with airtools to limit the receiver pressure.  Do your research on the fittings you intend to you use, including regulators, air+dirt separators.

If you are going sandblsting you are also better to use an air dryer (lower moisture content), no you don't need to buy one, but can make one from a bucket of water and a length of copper pipe between your compressor and the receiver, or better still a bucket of ice and a bit of water.

air quality is crucial if you are using something expensive such as a plasma cutter and tips cost a lot as the abrasive material will just chew up the tips in no time.