Thread: Advice on Compressor

I just have similar question with Arry , I think I'll just join this thread too.

Thanks .
Mich

https://www.woodworkforums.com/f155/n...s-motor-24290/

This thread covers most of the issues. Lou ended up buying a decent belt-drive electric compressor.

I bought a compressor from Aldi. Its a good unit for my needs, but it has 1 major flaw (aside from being cheap). The tank does not hold more thank 120psi. This is an issue when using a nail gun. It wont drive a framing nail all the way in. For me no big deal i just have a hammer handy. But it is something to consider.

I would look at a minimum of 10 cfm - 12 cfm, separate motor drive (not all in one, direct drive I think they call it) have a look at super cheap auto and talk to the salesman, grab his "best" one and I think you should be right, and it has quite rightfully been said that the lower end models wont drive a first fix nail consistently without being up to absolute full pressure which they lose after the first or second shot, but I dont think that will bother you! if you wish to keep up with the Jones then expect to pay over $2,000 for "contractor" type, dont bother with a motor type if it is not in constant use I.E, everyday then the stale fuel, foul plugs, oil change and filters will give nothing but headaches, go electric

Originally Posted by nickdablack

I bought a compressor from Aldi. Its a good unit for my needs, but it has 1 major flaw (aside from being cheap). The tank does not hold more thank 120psi. This is an issue when using a nail gun. It wont drive a framing nail all the way in. For me no big deal i just have a hammer handy. But it is something to consider.

General purpose comps have the pressure switch set to drop out at around 110PSI, and cut back in around the 85-90PSI point. Therefore the tank should never get to 120PSI.

Most air tools including nail guns are designed to operate at a maximum of about 90PSI, allowing about 20PSI for the regulator, hose and fitting losses from max reservoir pressure.

If your gun won't drive nails fully, there is excess pressure restriction somewhere in the system, probably in the hose and fittings but possibly in the regulator and plumbing as well. First place to look is the hose, you probably are running a curly hose that come with the comp, or an accessory kit offered with it. While convenient for light duty tasks, these are useless for heavy duty stuff. I drop 20psi in a 15ft curly just blowing tyres with a fairly low flow rate, but have no hassle pushing 18guage pins or running small sanders etc with the same hose.

Consider the dynamics of the framing gun. It will have a piston of about 30mm diameter and a stroke longer than the biggest nail length it can handle. It needs to get enough air over about 1 millisecond to push that piston while maintaining at least 80PSI on the piston crown. This would be very difficult with a 5 or 6mm ID curly hose, but a whole lot easier with a 10-12mm ID industrial hose. The larger hose has typically 3 to 4 times the cross section area, and hence only a quarter to a third of the flow resistance of the lighter hose.

Beyond that, minimise the number of fittings in the line, particularly self plugging female units and taps as these place additional flow restriction in the line. Beyond that, the next thing to consider is the regulator and how it is plumbed into the tank. Most regs have reasonable flow rates, but built to a budget units might have an inferior reg or small bore feed tube.

A 20L tank pumped to 110PSI should be able to drive about 10 90mm framing nails before the comp needs to cut in, provided that there is no issues with leaks or undue pressure drop in the plumbing.

Cheers for all the responses.

I dropped into Bunnies on the way home and they have what I presume is their brand TradeAir? compressors for $99 and $150 and a spear and jackson one for $99.

If I buy something I like it to be of reasonable quaility.

Will these be ok for blowing air, spraying poly and occasional nailing or are they complete rubbish.

Any brands etc that anyone can recommend?

They're all pretty similar and nopt much goes wrong with them if you only use them lightly. I usually go for older brands sold at garage sales because parts and attachments are usually made of less plastic.

I find with the smaller compressors the regulators are of an inferior quality and have far more "lag" between cutout at say 110 psi and restart, this "lag" is the trouble time for driving larger nails as found in first fix, I can get a couple shots in then I have to hold the trigger to drain a little air to get the compressor to refire and bring the pressure back up to a decent ammount, it is fine with second fix and brads, staples etc my smaller comp is an ingersoll rand so by no means a cheap brand,

Originally Posted by Arry

Cheers for all the responses.

......................Will these be ok for blowing air, spraying poly and occasional nailing or are they complete rubbish.

Any brands etc that anyone can recommend?

Spraying - no. They will run all the time and get very hot.... Find a gun you think will do the work you gotin mind. Look at its free air demand. It will be 10+cfm. Those very low end ones won't be more than 6 - 7 free air - well, not unless something has changed radically..... So you have to stop and wait for the compressor to catch up. Not good.

"Can anyone recommend a starting point for me"


About $800

I have a cheapie from Auto cheap which I purchased about 3 years ago and its still doing a decent enough job. I only use it for light work, brad/nail gun and blowing out the sawdust from my woodworking machines etc. For the money, the cheap machines are good value.

Harry,

I got a belt drive twin piston 2.2kw Scorpion from Mitre 10 for I think at the time (18 months ago) for around $600.

It delivers 12cfm free air delivery. Runs nail guns and a rattle gun with no probs.

You should be able to pick up a decent belt drive twin piston for under $800.

What does everyone think of this:

2.5HP Hi-Flow Air Compressor + Bonus 30M Hose & 50 Piece Air Tool Kit - Supercheap Auto

Its a direct drive cheapy dont count on it long term use if you are a heavy user, good brands(ie not a Chinese copy)will last 10yrs+ of continual abuse. My Clisby is clocking on 12yrs of service now from painting cars to renovating and furniture of course