5.) Gun strokes too fast. SLOW IT DOWN with each pass... just not so slow you hang curtians [tm]. (RUNS) watch the paint go on. DELIBERATE SLOW STROKES... the slow wack like your watching a porn[tm] Now I know why you are such a good painter....real kustom.....haha... ed...you wetsanded, did you primer it too? i don't know much about painting, but doing it outside is gonna cause you problems.. but yeah i know.. it's practice.. the more time you spend on your truck, the less time you spend on your hotrod..
What size hose do you have hooked up to the gun?I'd just about bet your not getting enough air for the gun.The nozzle size should be adequate for what your doing.
My compressor is an OLD two-stage pump that's driven by a 3/4 HP 110V electric motor. I'd like to go bigger, but the wiring in my (rented) garage can barely handle the small guy. I've flipped the breaker more than a few times. Still, when I pump the tank up to 175 PSI I get about ten minutes before the compressor kicks on at 80 PSI. One should think that I'm getting adequate pressure for at least those ten minutes??? The paint DOES spray a little nicer for those first ten minutes, so I've been trying to keep it in that range, or at least above 44 PSI at the gun. Still, it sprays like shit even in that ten minute window. Also, why do I have to set the regulator at the compressor to ~ 60 PSI to get 44 PSI at the gun? Is all that lost in the hose? As far as my (air compressor) hose size, it's three sections of 3/8" hose with 1/4" fittings. Actually, one section might be 1/4" hose. Kustom52, I think we may have the same problem. Before I repaint, I'm going to borrow a conventional gun and see what happens. Thanks again for the replies. I'll get this figured out yet. Ed
yeah its lost in the hose.... its drag I have HVLP gravity feed guns. 3/8 hose and used to have 1/4 inch fittings... that 1/4 fitting would restrict the VOLUME of air enough so the HVLP gun didnt work properly. By buying the 3/8 inside dia. fittings the gun sprayed like it was intended too. You have to make up for your standard 1/4 inside dia. fittings and the long hose so crank it up to 60 plus... put a guage on the gun, on the handle, the diaphram style and you can tell if you'r getting enough air pressure at the gun. Those guns need at least 50 psi to work right. If your having problems with the compressor keeping up go rent one. Tuck
Thanks for the tip. I'll see if I can't scare up some 3/8" fittings. One of my coworkers is going to bring in a conventional gun for me to play with tomorrow. Thanks, Ed
i dont think you'll need the fittings unless its a hvlp gun, BUT... the dropping air pressure can be fixed by adding another air compressor... address the low pressure problem first.
One of my coworkers brought in a conventional gun for me to play around with. I'm gonna score some 3/8 fittings at Lowes on my lunch break too. Ed
One thing that I have noticed is that moisture will create many problems with paint. If you don't have a pressure regulator/moisture trap you may want to think about getting one. My experience with an air brush has mandated the usage of the regulator/trap and it does make a difference. Not much experience spraying large panels but the process is virtually the same just on a smaller/arger scale. Of course I have been wrong before...
Yep Water is a big problem with Urethanes. A little water in the mix will turn the rubber they make car bumpers out of into something like the rubber they make seat cushions out of
OK, I think I'm getting somewhere with this. I used a conventional gun tonight with the SAME EXACT setup that I used the HVLP with. The conventional gun sprayed great. Nice flat, even coat and I didn't even play with the knobs. So what's this mean? Is my compressor too small? Do I need to upgrade to 3/8 fittings? (BTW, they don't sell them at Lowes) Thanks, Ed
Your compressor may be too small but you can spray a panel, let it catch up, spray a little....you get the picture. I have a true 3/8" line and fittings but I have sprayed it with a 1/4" line and never really noticed a lot of difference.
Higher preasure= finer atomization but also more paint bouncing off the car ....... try using a regulator at the compressor and turn it down to 80psi (not the tank preasure leave that at 125psi) so you have a more consistant preasure for a longer time ....... just an Idea
Any reason why you don't want to continue with the siphon feed gun?...I still prefer that type of gun. Yes, siphons are wasteful, but they WORK. HVLP wasn't invented to do a better paintjob, just a less polluting one.
MarkX just touched on what I was trying to say. Higher pressure at the tank with a regulator set to what you want for pressure with eliminate the "catch up" time of the compressor. Example: 100 psi @ tank with 90 psi @ regulator. It eliminates the pulsation and irregularities. ...Was I talking about hemmoroids????
Link/MarkX - I DO have a regulator at the compressor. It's set to 60 PSI, which is as low as I can go while still maintaining 44 PSI at the gun. Hatch - I want to paint some smaller components in my garage without worrying as much about overspray. Root - Even when my air tank is pressurized to 175 PSI and the compressor ins't running, the HVLP gun still sprays like shit. I have three 15 FT runs of hose tied together. I'm going to try spraying with just one 15 FT run and see if that makes a difference. I'm also eying up a few compressors on the dreaded eBay that I might gang up with my compressor. Thanks for the replies/ideas, Ed
I disagree Hatch. You get what you pay for. I have a Sata that will lay down just as glossy coat as any old siphon feed gun. It's not the guns...it's the painters. Go to the tech-o-matic and look at our resident "superstar" painter (TM) Tuck. He lays it down like glass.
Then it has to be the way you are setting up the gun. Buy a cheap harbor freight HVLP, I guarantee it will paint as many cars as you want. You will desire a better gun before you wear it out.
Couple of things with those HF clunkers. Be sure the air nozzle and tip are the same size, Ive seen a mix of 1.4 & either 1.6 and 1.7 parts. Those Chinese cant read. Those are generic guns and private labled by many, HF buys the floor sweepings. To be HVLP and keep the EPA happy they rate them at 43 psi max. Crank up the regulator a bit and see how it shoots. It wont be pure HVLP but close. Next time around get one of those 2 in 1 guns that are on EPay. They come with 1.4 and 2.0 setups and are one hell of a gun for the $40 they usually sell for. Type in HVLP on the Search window. I dont think anyone mentioned air quality? Do you have both a water seperator and oil filter at the compressor? And also another water filter at the gun? An old 2 stage may very well be misting oil into the line and the lines/adaptors are creating enough friction to add to the moisture hassles. Do you have access to 220V in the garage or close by? If so rewire your 3/4 hp motor; many that size are dual voltage. Good luck.
What's all this talk about the gun? My only advice is make sure that you shake the can real good. Soak them in warm water if its cold outside. Keep your pinky on the "N" of the krylon label and your thumb just above the "K". Make sure that your index finger isn't poking out over the nozzle hole, otherwise paint will get on it and it will drip. If your index finger gets tired or it gets an imprint on it from the x on top of the nozzle, you can switch and push the nozzle tip with your thumb (warning, thumb tip spraying is not for beginners). that purty much sums it up... good luck. HC
hey 286, I got one of those $40 dollar epay guns, my 1st gun, anything I should watch out for? I am actually going to start to mess with it this weekend, got any recommendations, pressure settings, etc. thanks
Root...if you look back at my previous reply I refered to Sata Jet 90(actually, I believe a gravity feed, but not hvlp) as a really great gun. I know I can lay down nice finishes with one, but I can also do the same with my twenty year old devilbiss jga502.....I just thought he was having better success with a siphon and maybe should stick with it due to the cost of wasted gallons of material.
Hatch, Don't worry too much about the cost of wasted material. With reducer, the Duplicolor Super Black is running me $38/gallon. Ed
That's cheap enough to play and learn. I've always tried to get it the first time, due to my lack of energy for excess sanding!!!
[ QUOTE ] I'll prolly catch it from the "real superstar painters" like Tuck, but.....The last coat I thin a LOT and melt it in. [/ QUOTE ] I haven't read through all the replies on this post yet, so this may have already been posted.... Like RootHawg, I too thin it out a little, but I also crank the air pressure up AT THE GUN. I have found that I have less sanding to do and a smoother finish (Two stage or single stage...) My $.02 Bravo
Hey Rey, you will be getting dangerous soon! First thing is to run some lacquer thinner thru it to remove any assembly "lube". When you take it apart for cleaning realize that the brass air diversion ring (#3 on the parts list) is on CCW! As others have mentioned, experiment on some scrap first. There are 3 controls on that gun, learn what they all do. Also experiment with the air at the guns regulator, I like it around 47 or so with a fairly heavy paint. Above all, keep it clean and it will last a long time. If you didnt get that accessory cleaning kit then do it or make up something. Dont spray a lot of straight thinner either, the plastic cup will craze and deterioate. I look at the plastic cups as disposable after a few jobs; I buy by the case and use mainly for primer and Zero Rust. For top coats I use the aluminum ones. I had a pro painter come over one day and showed him the gun (I have several). He used it at his place and called me up cursing that it did as good as his Sata! A good way to tell quality even before you use it is to look carefully at the milling work on all the spray head pieces. If the holes look rough, uneven or not sharp then it wont shoot well. The needle valve should be polished and a perfect fit. Im pretty amazed at the quality progress in the Chinese guns, for a hobbyist or small shop they are now capable of doing a pro job. Heck throw it away after a few years, sure beats a $150 Sata rebuild kit! I suspect that when HF has a sale it is because they have some pretty poor examples and want to dump them fast.
For everyone who was following this thread and offering advice, here's a follow-up. Since the HVLP gun wasn't working out, I borrowed a conventional gun from a coworker. Right away, the conventional gun was spraying better without any of the HVLP gun's orange peel problems. That weekend I drove my truck over to a buddy's garage and sprayed the truck there using the conventional gun. I got a few runs (I think it was too cold for the reducer's temperature range), but overall the paint job came out like glass, especially considering my lack of knowledge and the cheap materials used. I left the truck in the garage for two days before picking it up. I guess that wasn't long enough for the paint to dry, because it has little ringlets in the paint now from getting rained on. Anyone have any tips for removing them? That was about two weeks ago. Since then, I've been putting an engine together, but today I got to a point where I couldn't do anything else with the engine until some new pushrods arrive in the mail. I decided to screw with the HVLP gun some more to see if I couldn't get it working right, and damnit I DID! First, I changed some fittings at the compressor to make sure nothing went below 3/8". No luck. The gun was still spraying like ass. Frustrated, I tore the gun down to clean it up. Wanna know what I found? A piece of plastic lodged in the chamber where the needle meets the nozzle. Thanks for the quality inspection, Harbor Frieght! With the plastic removed, the gun is spraying great. I didn't have any sheetmetal to test spray, so I grabbed one of the landlady's shovels, and painted it up. She is now the proud owner of the shiniest shovel in town. Ed
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