Light Aircraft Association

I'm having bother with my Chinese spraygun again and am looking for an affordable replacement, if there is such a thing. Preferably one that comes with instructions in plain English that a novice like me has some hope of understanding.

All I need is something that will reliably spray a decent coat of primer & finish paint on the internal metal parts. Protection against corrosion is my main concern rather than a showroom finish.

At present, I'm attempting to use some 2 pack etch primer. On the few occasions when I managed to persuade my spraygun to work, it produced excellent results ( by my standards), but recently I have been unable to get the thing to do anything useful. It just will not spray any useful amount of paint, no matter how I fiddle about with it or how thin or thick the paint is. Don't think it is blocked; I can blast paint thinners ( not white spirit of course) through it.

I have the old fashioned variety of air compressor, not the type needed for the more popular HVLP guns, so would need a gun appropriate to this compressor, I assume.

Any advice would be appreciated.

Ian law

It sounds as if you have got some set two pack in the passages. Thinners will go through but thicker paint will not.
Two pack sets in the gun unless you really flush it all out leaving not a trace.
Strip it down to the smallest parts and clear , if you can, all the tiny holes.
If you want a good gun the a devillbis gravity gun might suit you, but they are expensive.
G D

That sounds like a very plausible explanation GD and I'll follow your advice. I have already started dismantling the gun, but haven't had time to set about cleaning it.
There are signs of something nasty around the innards of the plastic "plughole" device that sits in the threaded fitting for the paint cup, but I haven't been able to find a way of removing this without damaging it. I'll have another go tomorrow.

Many thanks.

Ian

Get a Clarke HVLP gravity feed gun - less than £30.

You need about 40psi at the outlet, nicely drained, no oil.

Get a 5ltr can of cheap cellulose thinners and be particularly diligent in cleaning through. It takes no time, however, here is my sequence.

1. Empty excess paint

2. 50cc thinner, swill round, shoot out.

3. Cellulose wetted paper towel, wipe round all parts of gun.

4. 50cc thinner, swill round, then 'burp' the gun. Hold the towel over the nozzle and slowly pull the trigger until it burps and bubbles back through the paint pot.

5. Final clean swill with 50cc thinner, final check for any residue, leave 5cc of thinner in the gun.

Repeat 5 until happy.

My gun is 6 years old, still perfect, a couple of odd colours on the handle but shoots beautifully.

Many thanks Mike and I will follow your excellent advice.

I did manage to clean up my spraygun quite well, using toothpicks to remove some stubborn old paint that had escaped attention before, after watching a helpful video on the web. A few judicious blasts of compressed air also removed quite a few bits of detritus from the otherwise inaccessible innards.
This allowed me to satisfactorily etch prime a batch of steel parts yesterday.

The Clarke HVLP gun sounds like the long term solution for me.

Ian

Ian, before investing in a HVLP gun, check that you compressor is compatible. HVLP required high volume at a lower pressure as the name sez. Many compressors kicking around cannot cope with the volume.

I already have an adequate compressor, but still plan to buy a special HVLP compressor with the large size hoses. Not yet sure which I will buy but it is possible to get gun (not gravity) and turbine compressor for under £200. That is cheaper than a traditional compressor, and a lot smaller.

Many thanks Ian & I'll keep that in mind.

Ian

The Clarke HVLP gun uses a little more volume, however it only requires around 40psi.

I have a 14cfm compressor with a 150ltr receiver - it is on the larger side of some installations but is still a manageable size when we consider how much we rely on air tools when building RV's and similar.

Check the requirements before buying the gun, but if you have a reasonable sized compressor, it should be fine.

Alternatively, invest in a separate receiver as a compensator.

I have a HVLP gun (cannot remember the make) on a conventional compressor - 150lt, 14 cfm.

Probably like the Clarke it hjas a reducer in, well at the handle, so the conventional air hose supplies 40 to 50 psi and the reducer at the gun reduces it. The end results are pretty good and the reduction in overspray and loss of paint to the atmosphere meant the gun paid for itself on the first large piece of spraying....

Many thanks Pete and Mike - I'm becoming more confidant with the benefit of your tips!

Ian