Spray equipment ?

**Soren** · 29th March 2005, 09:51 AM

I have a GMC 40l compressor, and have finished spraying a fence, using a cheap spraygun. I set the pressure to about 100, and managed to spray for about 1 minute, before the compressor kicks in due to low pressure. I then had to wait about 1 - 2 minutes until the pressure built up again. PITA, as it was a trellis fence of about 30 metres long by 3 metres high.

I am not (although this would solve the problem) about to buy a bigger compressor, but I thought that maybe a gravity fed gun using lower pressure (according to the packaging) may eliminate some of the waiting, should I need to repeat such a job.

Any comments would be appreciated :confused:

**Harry72** · 29th March 2005, 05:52 PM

Why are you using such high pressure?
40psi at most even with a cheap gun!
The time it takes for the comp to cut in is more relavent to the size of its tank and the pressure your running 100psi is way to much, its OK for the comp to run conituosly so long as it keeps up enough flow to run the gun properly.

**Soren** · 29th March 2005, 06:29 PM

Unfortunately, at less than 80 odd psi, the gun would just spit out little blotches of paint - sort of pulsating :confused: .
I am VERY green when it comes to spraying, and as the compressor is at best an 8cfm unit, and I believe the gun requires between 6 - 8 cfm to operate, I was hoping that by switching to a gravity fed gun, which according to the box, only requires about 2 - 3 cfm to operate, I would be able to learn to also spray finish on furniture projects as well as the odd repainting of fences

**Harry72** · 29th March 2005, 06:47 PM

You'll find on cheap guns what the box say's and what really is are two very different things, probably written by the sales dept!

Possibly you have some sort of a leak in the gun causing the plusing, thread tape all the joins from the pot to the gun(the path the paint leads ...), also with cheap guns the nozzle doesnt sit in its seat very well(poor machine work or corrosion because of cheap materials)causing the venturi action to break(pluse).
To counter act this an increase in pressure is needed...

What I have done before is to spin the nozzle in a drill and use a fine file on it to get a nice flat seating area.

The nozzle lives under the aircap(the bit with the wings!)

Your 8cfm comp should run your gun, if not theres something wrong with it. If you were to paint a car where a conituous flow is critical too the finish quality the minimum is considered 10-12cfm.

I can only imagine how much overspray your genarating with 100psi!

**Soren** · 29th March 2005, 07:38 PM

Overspray

The 'stuff' I was spraying was Bunnings Walpamur Fence Finish, which in hindsight was probably not the right viscosity (ie too thick).

The gun I have is (again from Bunnings) a Tradeair Model TAR-SSG and the enclosed brochure and stamps on the side of the gun says S770. It supposedly has a 2mm fluid nozzle and has a material output of 345cc. Requires 50psi with an air consumption of 8.8 cfm.

I believe that an HVLP gravity fed gun requires only about 2 - 3 cfm and thus my question.

Will my current gun be any good for applying finishes to woodworking projects, taking into account the use of a GMC compressor ? :confused:

**MajorPanic** · 29th March 2005, 08:05 PM

Originally Posted by Soren

Overspray

The 'stuff' I was spraying was Bunnings Walpamur Fence Finish, which in hindsight was probably not the right viscosity (ie too thick).

The gun I have is (again from Bunnings) a Tradeair Model TAR-SSG and the enclosed brochure and stamps on the side of the gun says S770. It supposedly has a 2mm fluid nozzle and has a material output of 345cc. Requires 50psi with an air consumption of 8.8 cfm.

I believe that an HVLP gravity fed gun requires only about 2 - 3 cfm and thus my question.

Will my current gun be any good for applying finishes to woodworking projects, taking into account the use of a GMC compressor ? :confused:

Hi ya,

S770 would be a Star gun & a 2mm fluid nozzel would be correct for a S770.
I've used a S770 for more than 5 years & it's fine for spraying lacquer.
Does it have a air adjustment knob at the base of the handle? If so this would confirm it as a Star gun.

**Dean** · 29th March 2005, 08:09 PM

I hope the S-770 works ok because i bought one as a backup the other day.
I believe the S770 is quite a good model (for the price anyway).

It should work fine with spray finishes on woodworking projects. I have mine running of a 24L 2HP compressor. It's ok for brief passes at 40-50 psi

**Dean** · 29th March 2005, 08:11 PM

Originally Posted by MajorPanic

Hi ya,

Does it have a air adjustment knob at the base of the handle? If so this would confirm it as a Star gun.

Mine does at least. As long as it performs like a star

I'm thinking of maybe buying one of those $35 touch up guns too with the small capacity container for the occassional bowl finishing spray. Just seems to right size for this task.

**Soren** · 29th March 2005, 09:18 PM

Originally Posted by MajorPanic

Hi ya,

.............. Does it have a air adjustment knob at the base of the handle? If so this would confirm it as a Star gun.

I believe it does, refer attached image

**MajorPanic** · 29th March 2005, 09:31 PM

Originally Posted by Soren

I believe it does, refer attached image

I do beleive it is an early version of the S770
So there should be no problems

**Shane Watson** · 29th March 2005, 09:34 PM

Originally Posted by MajorPanic

Hi ya,

Does it have a air adjustment knob at the base of the handle? If so this would confirm it as a Star gun.

Hmmm I have two different model IWATA guns that have the air adjustment knob at the base of the handle.....Or am I only dreaming...will have to check on that tommorrow

**MajorPanic** · 29th March 2005, 09:39 PM

Originally Posted by Dean

I hope the S-770 works ok because i bought one as a backup the other day.
I believe the S770 is quite a good model (for the price anyway).

It should work fine with spray finishes on woodworking projects. I have mine running of a 24L 2HP compressor. It's ok for brief passes at 40-50 psi

Hey Dean!

I set my regulator to 41PSI for the HVLP nug & the only time I change it is if I use the touch-up nug (6PSI).
For the 770 I wind the air adjustment all the way CLOSED & then pull the trigger while turning the air adjustment knob open. When the nug picks up the lacquer & gives a full spray patten I stop adjustment.
The air adjustment knob is only ⅓ open, if that. I reckon I'm spraying at about 15-18 PSI or so.

**Harry72** · 29th March 2005, 09:40 PM

"It supposedly has a 2mm fluid nozzle"
With that size you should be able to spray thick honey!

MP so the S-770 2mm will spray lacquer OK, I need a cheapy to tie me over until I replace my samson(RIP!)dam cant seem too find the parts to repair it yet.
Might even splashout and grab a binks or devilbiss one day.

**MajorPanic** · 29th March 2005, 09:41 PM

Originally Posted by Shane Watson

Hmmm I have two different model IWATA guns that have the air adjustment knob at the base of the handle.....Or am I only dreaming...will have to check on that tommorrow

But Shaneus,

Is S770 stamped on the handle of your nugs?

**Soren** · 29th March 2005, 09:42 PM

Originally Posted by MajorPanic

I do beleive it is an early version of the S770
So there should be no problems

MajorPanic

What do you mean, the spraygun was only purchased 9 days ago ? :confused:

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