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demuire
10-03-05, 10:55 AM
How do these work? How much are the guns, and can you connect them to a normal air compressor? Or do you have to get a turbine to power them? They appear to be much better than conventional spray guns, less overspray, etc? I've heard the technique to painting is different, in what way? Where can I get one? All the ones I've found appear to be made for painting fences and stuff...

I've got a gravity feed conventional gun at the moment, and have found that I can paint with fairly low pressure too, just with less coverage (compared to my previous gun which was a siphon feed, and a cheap crappy one at that), I would assume that HVLP guns are even more effective?

demuire
10-03-05, 10:58 AM
Also, how do they differ from a conventional gun? From the photos (like one I found at Tradetools: http://www.tradetools.com.au/ProdView.aspx?popup=1&Product=SV870-15S), they look the same as a conventional gun? Is it the valving that's different? How do they atomise the paint at lower pressure?

RESON8
10-03-05, 04:29 PM
I just picked myself up a new HVLP graviy feed gun today.

It is a Devilbiss SGK only been out since christmas and is a cheaper replacemeant to their limited edition Gti gun ($500-600), the SGK set me back $380. I could of got a cheaper one made by STAR ($260) but was told to go for the Devilbiss by some painter friends. I got it from a spray painting crash supply place, i could only find one in SA that stocks this gun it seems as different places are given different products to sell???

Prior to that I was using a standard gravity gun, but was getting alot of overspray/dryspray. I have used a friends Devilbiss Gti gun and found it to be alot better for me to use so that is why I got this one.

They look just like a normal gravity feed gun, and you feed around 25psi, non HVLP around 30-35psi but the difference is that the pressure at the tip of the HVLP is only 10psi whilst he convential gun is still around 30psi. This is what gives you less overspray saving you paint. less dry spray and less orange peel finish.

The technique you use with the HVLP differs as you hold the gun closer to the surface to be painted (6-8inches) and you also have to move the gun faster past the surface.

You don't need a fancy compressor, the info that came with my gun says it only has a air consumption 9.8cfm, so most medium size compressors should be able to keep up.

I hope that answers your questions, I am painting a friends car on sunday i will see how the new gun goes :)

demuire
10-03-05, 04:36 PM
Thanks heaps for that. I'd get a Devilbiss if I could afford one at the moment, but given that I really don't paint much, I think I might end up with a STAR. I've got one of their gravity feed guns now and it's alright. Tradetools here in Qld have a STAR HVLP pot feed for about $130. Most definately not as good as what you've got, but should do the job.

So apart from holding the gun closer, and moving quicker, is there anything else that differs with the HVLP? Someone mentioned to me that you can only go forwards? Didn't really understand what he meant...

bigmuz
10-03-05, 05:07 PM
I have one hundred of these guns.

The new star pressur epot guns are pretty shit. I'm gonna change next time it wears out.

The hvlp from star is pretty good- the needles are not very hard if you use this gun for high solids and epoxies. HVLP just means a more efficient head design- real hvlp uses a big hose and low pressure air from a turbine. For furniture and varnish type jobs.

For bodywork, a good gravity feed gun is all you need. hvlp or not doesn't make that much difference to air consumption. They all lie on the boxes about how little air they use..

Muz

demuire
11-03-05, 07:33 AM
Muz: Ta for that. So the HVLP from Star is alright? I'm not too concerned about air consumption, my compressor runs my conventional gravity feed gun (and my dodgy pot feed I had before) so it shouldn't be a problem - it was more the better transfer rate and less overspray that I was interested in...

bigmuz
11-03-05, 07:49 AM
The old star guns are good- for industrial and enamel type finishes.

For 2pac and good finish, hvlp gravity is the way to go. I have an iwata hvlp gravity feed and it is great. Big wide pattern and very fine finishes. Little bit slow in the (iirc) 1.1mm, next time I would get a 1.3mm setup.

Those star guns are what I use with a pressure pot for spraying protective coatings- like tar or heavy epoxies or high build polyurethanes. Bit coarse for fine finish work, especially with big setups.

Does that make sense? Where will you buy from? What paints will you be applying?

Muz

RESON8
11-03-05, 08:27 AM
I was told you could get just as good results from the HVLP gravity star gun once you had it set up and knew what you were doing. It sells cheaper then the Devilbiss as its threads and machining arn't as good and will wear quicker, but if you dont use it much i dont see the problem.

bigmuz
11-03-05, 08:32 AM
To explain further- the star hvlp gravity feed is good. The new pressure feed guns are not so good.
Sorry, I could have been a bit clearer I suppose...

Muz

demuire
11-03-05, 08:41 AM
Hmm, reading further at other sites, it looks like my compressor (SIP Eagle SCDC2.5/40, 2.5hp direct drive, 155 liters/minute) isn't going to be big enough to run a HVLP conversion gun, since they apparently need more free air than a conventional gun (approx 13cfm?). Bugger. New compressor time? I wonder how much money I can spend... I've been planning on getting a bigger compressor sometime anyway, just not sure when. I've been told the Tradetools Renegade RP13E (2.2hp belt drive, 190 liters/minute) will be adequate.

I'm not sure where I'd buy it yet, if I did. The only place I've found one at is at Tradetools who only have the Star SV-870S which is a pot (pressure?) feed. I'll be applying acrylic automotive paint mostly, so fairly thin stuff. Do you know the model number of the Star HVLP gravity feed? Where can I get one, and how much are they?

hotgemini
11-03-05, 09:06 AM
The tradetools website has the HVLP gravity feed, check again. Oops, just took my own advice and you're right, they don't have it. Try ringing

Why buy the RP13, isn't it the same price as the RP15?

demuire
11-03-05, 09:27 AM
hotgemini: I called just before to find out about the cfm etc required, they only mentioned the pot feed. Maybe they have a gravity feed too. RP15 on the website it says not to run with extensions etc because of risk of damage to motor? I'm guessing it needs high amps to run, could be a problem in a house with not so many power points? Else you're right, it's the same price and a fair bit more powerful.

mopar lover
13-03-05, 07:39 PM
I run the RP15 and the only time I have a problem is if the actual power supply to the house is very poor. This compressor does need a fair wack of amps to restart it with some pressure in the tank.

demuire
17-03-05, 11:15 AM
This is probably a loooong shot, but just flipping through the Bunnings catalog today, came across one of the Wagner HVLP spray systems, it's a small dinky little thing (W640HVLP), 600ml paint pot, 1.8m hose, 80W.

I understand these are designed to paint benches and doors and walls and stuff, and have read you can paint "car parts". It's supposed to be able to paint "automotive finishes" as well (according to the manual). Can these be used to paint a whole car? Or is that kinda asking a bit much?

On one hand, new compressor + conversion gun... approx $800

On the other hand, bodgy Wagner thing, $160. Hmm.

Opinions?

bigmuz
17-03-05, 12:00 PM
Not really good enough mate. They are so slow as to be ridiculous.

I just bought a new gun- Star S870 suction feed HVLP. About $250 retail would be perfect for good quality automotive paint. I got a good price cos it is a run out model now. It is the one with a seperate regulator on the air inlet- rather than a screw. More accurate and consistent.

I am actually going to use it with my pressure pot, so I get a nice fine finishing gun with the convenience of the pressur epot.

Muz

Glenno
23-05-06, 09:30 PM
Do the needle sizes vary much between HVLP gravity feed gind and convential gravity feed gun?

Whats sizes are best for what purpose?

bigmuz
31-05-06, 07:44 AM
Not really Glenno. They generally are 1.1, 1.3 maybe 1.5 mm setups. For general use a 1.3 or 1.5 is fine; then you can use the same gun to apply heavier coatings like high build primer (not really spray putty though) right through to 2 pak clear coats that are really thin. The smaller the setup the finer the paint comes out of the gun. In my experience for amateur use the bigger setups are fine for everything. Just gotta watch that you don't put too much paint on at a time.

The secret with 2 pak is to put on a flat, fine, thin but full coat as a basecoat. Let it tack off for 15 or 30 minutes, then go much heavier and wetter, let that tack off for a good half hour, then put a really wet top coat on. The layers already on the surface will hang on to the heavier coats and you can put much more paint on without runs. Having everything warm helps a lot too.

Glenno
31-05-06, 10:09 AM
bigmuz I think the technique I have been shown is like that but the terminology used was "dust it on then hose it on"

ever heard of or used "dura-block" brand guns?

bigmuz
31-05-06, 04:34 PM
Nah sorry.

I have devilbiss and star. I just bought a star touch up gravity feed and it is my favourite little gun. No overspray- you can almost avoid masking up for a touch up.

SuperNaf
31-05-06, 06:01 PM
Ive never been a fan of HVLP guns, used to love my old SATA Jet90, but cant buy parts so a few years back I bought a SATA NR2000 HVLP 1.4 set up and hated it, prick cost me $700, so I bought a Iwata W400 which was awesome, but my boss made me change to the HVLP W400 and it sucked ass so i went back to the SATA and wouldnt go back to anything else.

The DeVilbiss GTI is an awesome gun, it'll be on my list for another gun, as I can never have too many, just finding cash to buy em hurts. Also have a Star mini gun with a 1mm set up, awesome for touch ups as Muz said.

bigmuz
01-06-06, 07:41 AM
Okay supernaf, now you've blown it. Time for 20 questions :D

What system do you use?

Can you tell us what your priming and topcoating and finishing consists of, that would help me and a lot of other blokes too:

I will put in what I do and could you correct me?

System: Debeers 400 2 pack solid poly.
Panel Prep : 120 grit random orbital.
Prime: High Solids 2k 3 coats- thin the last coat to get it to lay flat
Sand primer- rough work- random orbital 320 grit- hand finish with 320
good work- wet with 300 or 600 wet/dry after 320 random orbital
Topcoat- dust, medium, wet, a little more thinner in the topcoat.
Finishing- my booth isn't set up yet so I wet sand 1200, buff with a foam flat pad and ultra fine compound, then a flat foam pad with polish.

Whattya reckon?

Cheers mate.

browny
01-06-06, 08:43 AM
Which star mini gun are you both using?

bigmuz
01-06-06, 05:13 PM
Star mini S106TG-4 1.2 mm setup gravity feed with a 130ml cup. I payed too much, like $130 but that is a long story :D

edit
http://www.airless.com.au/Star%20Spray%20Guns.htm

Last one on that page. Not from them though.

Madhatr
01-06-06, 05:36 PM
transquip (http://www.transquip.com.au) have some pretty good prices on them too bigmuz. From what i can guess, same sort of model you were talking about earlier with the seperate reg on the air inlet. Range from $213-$219 each.

browny
02-06-06, 01:02 PM
Star mini S106TG-4 1.2 mm setup gravity feed with a 130ml cup.


Ive found a SV106TG-4 (HVLP mini gun 1.2mm) on the Workquip (Star) page but not S106TG-4. But their web page also seems really friggin out of date.

Is it the HVLP or normal gun that you have?

SuperNaf
02-06-06, 04:17 PM
Okay supernaf, now you've blown it. Time for 20 questions :D

What system do you use?

Can you tell us what your priming and topcoating and finishing consists of, that would help me and a lot of other blokes too:

I will put in what I do and could you correct me?

System: Debeers 400 2 pack solid poly.
Panel Prep : 120 grit random orbital.
Prime: High Solids 2k 3 coats- thin the last coat to get it to lay flat
Sand primer- rough work- random orbital 320 grit- hand finish with 320
good work- wet with 300 or 600 wet/dry after 320 random orbital
Topcoat- dust, medium, wet, a little more thinner in the topcoat.
Finishing- my booth isn't set up yet so I wet sand 1200, buff with a foam flat pad and ultra fine compound, then a flat foam pad with polish.

Whattya reckon?

Cheers mate.


Ok, im caught out :rotflol: Your prep sounds good Muz, but like everything we will have different ways.

Firstly I use ChemSpec Metacryl(2k solid) and Metalux II(basecoat), its a South African based company and fucking wicked paint to boot, IMHO it shits all over PPG etc and at 3 times cheaper.

Ok now for my prep work(this is after the bog stage as I have beaters for that shit :P)

1- Sand repaired area with 240 on orbital sander, then use either 3M red scotch pads or 400grit by hand to feather out the rest.

2- Prime with HS 2K primer, 1 set up coat (pissy non covering) then follow with 4/5 decent wet coats allowing 10mins flash off time.

3- Prep for top coat is, apply guide coat, dry sand block with 240 grit, then re guide coat with 3M graphite powder, then I use 400grit on the orbi for 2K solids or 500grit for my basecoat jobs. Then I'll use 3M grey scotch pads for hard to get areas or panels im blending into.

4- Applying paint for 2K, 1 set up coat, once again not wanting coverage, just a nice even coat, wait 10mins flash time then 1 full wet coat. For my basecoat, I will do similar, 1 set up coat, then apply until perfect coverage, usually 3 or 4 coats followed by a cross coat to make sure everything is nice an even. Then its followed by 2 coats of 2K MS clear, 1 set up, 1 full wet coat.

5- Buffing? whats that? Thats why I have a detailer :lol: but seriously, de nib with 1500/2000grit wet and dry, buff with wool pad (i hate foam for cutting), then polish with 3M glaze or Gelson T57 black polish.

Hope this makes sense as this post is currently sponsered by Johnnie Walker :yup: And give Metalux/Metacryl a go, you'll be suprised at how it performs and i gurantee it shits all over DeCrap eeerrr DeBeers.

Also picked myself up a Iwata W71 mini gun today, 1.3mm set up and fucking awesome. The Star will now get passed on to my apprentices to destroy lol.

bigmuz
02-06-06, 04:33 PM
Ive found a SV106TG-4 (HVLP mini gun 1.2mm) on the Workquip (Star) page but not S106TG-4. But their web page also seems really friggin out of date.

Is it the HVLP or normal gun that you have?

Madhatr and browny, my one is not HVLP, but the one on their site is. For the little touch up gun a conventional cup would be best imho anyways. Mine came from the local trade supplies place so I can't put you on to them. We don;t really do the internet in Coffs Harbour :D

I'm just about to read supernaf's reply. Thanks man, I'll post the rest of my questions later :D

Glenno
04-06-06, 11:32 PM
Trade Tools have the Star HVLP gravity feed gun with 1.5mm needle and regulator. $128 I grabbed one on Friday.