Up to the Job?

[Gmwelder]

Hi,

I have a compressor with the following specs

24 Litres

L/Min 270

CFM 9.5

HP 2.5

PSI 115

Bar 8

Has an adjustable air outlet pressure regulator

Would it be up to the job of spraying a mini? (Classic)

I did a dry test (Just blowing air) and noticed that the tank does not last long before the motor kicks in again

Any help appreciated

Thanks

 

[rtbcomp]

Preferably the motor should be kicking in and out, although it can run all the time if a) the compressor has a 100% duty cycle and b) it maintains sufficeint pressure.

I would guess spraying a liquid would take less air and/or maintain highr pressure.than just spraying air alone

 

[Gmwelder]

Hi,

Thanks for the reply,

I will have a check in the manual for the duty cycle, from the specs does it look like it would be able to handle spraying a mini?

Thanks

 

[Gmwelder]

Here is a picture of the compressor

Thanks

 

[bawjaws]

i had the same one (powercraft one), ive had it conttinously running for about half an hour on sevral occasions painting trucks and the like, ideally it shouldent be running that long but it was up to the job and still runs fine, if its a car your spraying make sure you have an air filter and water catch somewhere in the line or it could ruin your job

 

[Chipper]

Make sure you have/get a conventional gun not an HVLP one. Water trap a must, small tank = air beaten about a lot, warm & damp. You can get filters to attach to the gun, as a second trap (not to be relied on - use filter/reg as well)

 

[Gmwelder]

Thanks for the help

Chipper, do you mean a gun like the one in the bottom right of this picture?

Is it a Gravity one I need?

Also would it be up to the job? I need to spray the mini inside and out. I will be using cellulose paint.

People have said to me that the size of the compressor will mean that I will have to stop to let it recharge?

I know someone who has used a 24l air compressor to spray his and the finish was very good.

Also could someone reccomend the type of traps I will need?

Many thanks

 

[Luke]

People have said to me that the size of the compressor will mean that I will have to stop to let it recharge?

You will.

 

[tux]

Chipper, do you mean a gun like the one in the bottom right of this picture?

Is it a Gravity one I need?

The gun in the picture is a gravity feed one. Gravity feed or suction feed doesn't matter, its whether it was built for conventional or HVLP use. HVLP uses a lot more air than conventional.
You state that the compressor is rated at 9.5 cfm, which probably isn't enough to run an HVLP gun, unless its a small touch up gun. Also I would wager that this figure is piston displacement and not free air delivery (FAD) which will be less.
At risk of sounding like a snob, I suspect the gun supplied with the compressor won't give a very good finish either. Maybe OK for primer.

Also would it be up to the job? I need to spray the mini inside and out. I will be using cellulose paint.

It will do the job (eventually) but you will be constantly waiting for the compressor to catch up and build up pressure again. Believe me, its damned frustrating. Ask me how I know!

People have said to me that the size of the compressor will mean that I will have to stop to let it recharge?

Yes, you will. see comment above!

I know someone who has used a 24l air compressor to spray his and the finish was very good.

The size of the air receiver is less important than the air the motor will supply. The quality of finish is dependant on several factors, not just the air supply. Quality of gun, quality of prep work, users skill, quality of materials, ambient temperature, etc.

Also could someone reccomend the type of traps I will need?

I would suggest looking for something like this
http://tinyurl.com/cplo6b
to go on your compressor and then something like this
http://tinyurl.com/c3ydhl
to go on the end of your air line just before your gun.

 

[Gmwelder]

Thanks for the help, really appreciate it

What do you reccomend for the job? Gravity feed or suction feed?

Ive heard about people using this gun from Machine Mart

http://www.machinemart.co.uk/shop/product/details/pro-14c-spray-gun/path/spray-guns-spraying-equipment-air-brushes

http://www.machinemart.co.uk/shop/product/details/pro-18c-spray-gun/path/spray-guns-spraying-equipment-air-brushes

The first one is rated for 2hp or above with a average air consumption of 7cfm

The second 2.5hp or above and 8.5cfm

Which would be better to use? The compressor is 2.5hp but I'm thinking using the second will be working the compressor hard?

Or should I be using a gravity feed?

Many thanks

 

[tux]

Suction or gravity is really a matter of personal taste/comfort, as they both do the same job, just in a slightly different way. Personally I am happy with either. One thing to bear in mind is that a gravity feed gun will cause issues when you try to use it upside down (if you are painting the roof inside for example) as, naturally, the paint will be running away from the gun body.

The two MM offerings are basically the same gun. The 14C has a 1.4mm needle and air cap while the 18c has a 1.8mm set up. The 1.8 would be better for primer as you need to lay down a slightly thicker coat to enable you to block sand, whereas the 1.4 is aimed more at top coats and clears.
What paint are you using? Cellulose? If so, stick with the 1.4.
Again, don't pay too much attention to the HP rating, the air delivery (CFM) is the figure to try to match correctly.

 

[dabrewer]

Make sure you have/get a conventional gun not an HVLP one. Water trap a must, small tank = air beaten about a lot, warm & damp. You can get filters to attach to the gun, as a second trap (not to be relied on - use filter/reg as well)

why not hvlp?

 

[Gmwelder]

Thanks Tux, yes I will be using Cellulose

Would the 1.4mm be okay with the cellulose primer as well? (High build)

Would me using this gun for primer and topcoat be okay with cleaning?

Many thanks for your help

dabrewer, I think you cannot use a Hvlp with a small compressor as they need from what I have seen at least 3hp and a very high cfm to run them.

 

[shenion]

My HVLP gun takes 4 CFM. Was no problem with my 3.5HP compressor (probably 2HP.) Had a 6.2CFM @ 90 PSI rating. 3.5HP is 2.6KW or almost 22A at 120VAC (assuming 100% efficiency.) It ran fine on a 15A outlet with other stuff on the same circuit.

Odd, here motor's HP is stated as peak, not actual output while CFM is rated at FAD not displacement. Wonder if anywhere has real ratings on everything

As the HVLP gun only needs 40PSI adn 4 CFM, the compressor ran about 20% of the time.

 

[Chipper]

HVLP is 'High Volume Low Pressure'. Conventional fullsize guns usually want around 7cfm, where typical HVLP guns want more, like 14cfm or whatever. And thats FAD, not comp displacement. More than the usual single phase compressor can make. Although someone did post up about a 4hp comp with big air delivery, I thought 3-3.5hp was about the usual limit. Mine's 3hp, 14.5 displacement, 9.5 FAD, not enough to properly drive an HVLP gun.

4cfm I'd say is lower than even a conventional gun, except mini-guns. There are guns calling themselves LVLP, with similar req's to that - I have one, a mini-gun and rather nice it is, but it's not a true HVLP gun in any form.

That comps air displacement looks OK, say about 7cfm FAD which is enough for a conventional gun. But the tank is v.small so the comp will be running a lot, and the air will be wetter than with a big tank. But filters/traps are essentials anyways. So it'd work but you'd need to keep an eye on it, let it build enough air etc.

PS as above, the specs things can be a trap, makers like to quote displacement here as it's the more impressive, but tools state their FAD wants (and often seem a bit bloody optimistic at that, esp el cheapo stuff)

 

[tux]

Thanks Tux, yes I will be using Cellulose

Would the 1.4mm be okay with the cellulose primer as well? (High build)

Would me using this gun for primer and topcoat be okay with cleaning?

Many thanks for your help

dabrewer, I think you cannot use a Hvlp with a small compressor as they need from what I have seen at least 3hp and a very high cfm to run them.

1.4mm is perhaps a tad on the small side for high build, but you will probably get away with it. You may have to over-thin the primer slightly and lay down a couple of extra coats to make up the depth.

Using the same gun for primer and topcoat is frowned upon by the pro's but as long as you are extremely thorough with your cleaning it will be OK. I use the same gun for both and have yet (fingers crossed!) to have an issue.

 

[labman88]

spray gun

hi,firstly if your going to use a gun that small,u ideally dont want to be painting the car in one go ,ive got away with using a devilbiss gti gravity gun on single panels such as doors bonnets etc which uses alot of cfm but still got a perfect finish from my 2hp 24litre compressor,the trick is doing small passes waiting for the compressor to build up in between passes(few seconds) ,also use a slow thinner an dont do it in too hot a place as the paint will flash of to fast an u will get dry bits,this gun looks an works just like a devilbiss gti only much cheaper this is y i got 1 for clear coat http://cgi.ebay.co.uk/GX5002-WATER-...66:2|39:1|72:1683|240:1318|301:1|293:1|294:50

the good thing is it only uses 7cfm so will go longer than the gti an give a great finish to and will do you for basecoats solids an clearcoat,although i tend to use 2pack as i get a perfect finish from the gun but celly will polish up nice if you put the work in.
if you need any tips im glad to help