Air greese gun

Thanks Ian

I want to be able to grease all points while on extended trips so I won't need a large tank or compressor. I have seen pics of compressed air stored in roll bars etc. I also thought of using my spare type as a tank with 50psi inflated pressure. I might get a few pumps this way. What do you think?
Cheers
Jack

I meant 'spare tyre'

By the way, does anybody know where to buy a smaller fitting for the end of a grease gun? I remember reading something Roothy (4WD Monthly mag) said once, about having a smaller fitting that made it easier to get the nozzle into tight spots (like the uni joints at each end of the tail shafts).

Any ideas?

Roachie

Try you're local CBC branch. They stock Tecalimit stuff. Some grease guns have screw on ends with either flexi or rigid tubes, some are swaged on. If swaged on, you're knackered unless you buy a new tube. From memory they do one that is about 20mm long and the standard diameter. I think there is also a 90 degree version - hole on the side. You can also put remote grease points in certain places (not on your tailshaft though???) We do this regularly on SPM's for the food industry.

The gun i'm looking requires a flow of 5cfm at 40psi min up to 130psi so I guess the question is can my spare tyre our your 3ltr tank provide enough air at these specs to grease one or two nipples at a time before refill. Time is of no consequence as there are only eight or so to do.
Cheers and thanks
Jack

Bushpig, the factors you need to know are;

1. actual FAD of compressor at a given pressure - say for example, 2.3 cfm @ 145 PSIG (10 bar Gauge pressure)
2. Air consumption of the gun at a given pressure (say 60 PSI to pump grease through the grease nipple hole)

Then the following needs to be determined -

1. Utilisation factor of grease gun - duration of usage as a percentage of a minute. i.e. 0.1 minutes per grease nipple = 0.5cfm. Therefore, the actual FAD required is very minimal.

If you put 130 PSI in a receiver and draw off at a regulated lower pressure of say 60 PSI you will get more air out than you put in, so to speak. (ntthat simple, you need to understand the principles of Free Air Delivery, that reciprocating compressors are positive displacement - what goes in comes out, minus efficiency losses,etc, and a few other bits of scientific know how).

So, a small receiver of 3 - 5L it may provide enough air to do a couple of grease points before refilling. Fair chance in fact.

IMPORTANT - make sure you have the correct rated safety valve on the receiver because if you over pressurise it and it blows up it can kill you (or someone you're fond of, like your dog or your mate that brings the beer and crabs). Do not make your own. And your compressor will need a pressure switch if it is to work properly without over-pressurising the receiver or burning the motor out.

While in the compressed air industry I saw some shockers - disasters waiting to happen. Don't take the risk. Same for your spare tyre - not designed to hold 130 PSI.

Sorry about the long winded reply but it's not a simple thing to say yes it will work or no it won't.

Wouldn't it depend on the type of use he's planning, Doug?

I reckon on my Patrol there are only 6 grease nipples (3 on each tail shaft/uni) in all and I'd say that'd be the same on most modern 4bys. With that number to do, and with a small receiver tank like the one I've got, I don't think he'd have any worries at all.

YMMV......

Roachie

Thanks heaps for your input. looks like I will go with the small hand type and leave the Bushman to pump up tyres.I like your thoughts on using the servo's air after buying fuel of course.

Cheers
Jack