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fugazi885
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Joined: April 12, 2011
Posts: 84
Location: Phoenix
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 Posted: Wed Jul 04, 2012 10:43 am Post subject: hvlp won't atomize under 90 psi @ the gun? |
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| Long story short, after I screwed up my sealer coat and had to resand the entire car I need to figure out why my paint is flowing like a freaking garden sprinkler rather than a proper mist. I have a 60 gallon compressor rated at 11.5 cfm @ 90 psi, my gun is a sharpe fx300 rated at 11.4 cfm. I have eliminated as much air line and fittings as possible to free up as much air flow as possible and bought a cheap can of duplicolor paint shop paint to practice on some messed up panels that I won't be using. Even with a brand new 3/8 air hose mounted directly at the compressor with a disconnect only at the gun end and a single dessicant filter at the gun it seems I'm having to run a minimum 90 psi gun pressure (regulator at gun with trigger pulled) to get nice atomization. At that pressure it does spray beautifully but that's 3 times what the gun calls for. If it's spraying nice sould I just run with it or am I missing something here? WTF |
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skills@eurocarsplus
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Joined: January 01, 2007
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Location: sticksville, ct.
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| Posted: Wed Jul 04, 2012 7:03 pm Post subject: |
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what are you trying to spray? what is your tip size? all of this comes into play...
you can't blast on a fill and sand with a 1.0 tip and you don't want to paint with a 2.5 tip
different guns have different purposes in the process. some guys have paint only, clear only, primer only etc guns
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| VWsArent4Hippies wrote: | | Whenever I click on the baywindow forum I feel like I'm entering a place where most people have no sense of reality |
| schell '59 wrote: | | The honor system works for boy scouts..not in real business |
| modok wrote: | | It was in the instructions back when stuff came with instructions |
| curtis4085 wrote: | | as most your information you give is crap anyway |
| bugger101 wrote: |
skills, you never win with cheap vw people |
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spook
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CanadianBug
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Joined: September 05, 2008
Posts: 162
Location: South Western Ontario
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| Posted: Thu Jul 05, 2012 5:07 pm Post subject: |
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| Or your gun settings are way out of whack... |
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fugazi885
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Joined: April 12, 2011
Posts: 84
Location: Phoenix
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| Posted: Thu Jul 05, 2012 5:08 pm Post subject: |
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| I was shooting my sealer coat with a 1.5 tip, I use a cheap primer gun but decided to use my finex for the sealer just because I thought it would do a better job. I cleaned and inspected the gun before use but just for shits I took it apart after my little disaster and have it soaking in laquer thinner for the last few days. Honestly I think it's an air spply issue, could even one standard coupler choke the air supply enough to cause me to have to run the pressure up so high? Maybe I need high flow couplers or my inline dessicant filter is choking me? If the gun was dirty woudn't that cause a poor spray pattern? I really need to figure this out before a second attempt. Maybe LVLP would be a better coice for my compressor size? I'm just sepeculating at this point, maybe someone else has seen this happen and knows what's up. Thanks for reading. |
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skills@eurocarsplus
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Joined: January 01, 2007
Posts: 3967
Location: sticksville, ct.
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| Posted: Thu Jul 05, 2012 7:27 pm Post subject: |
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it sounds like your gun, not your compressor
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| VWsArent4Hippies wrote: | | Whenever I click on the baywindow forum I feel like I'm entering a place where most people have no sense of reality |
| schell '59 wrote: | | The honor system works for boy scouts..not in real business |
| modok wrote: | | It was in the instructions back when stuff came with instructions |
| curtis4085 wrote: | | as most your information you give is crap anyway |
| bugger101 wrote: |
skills, you never win with cheap vw people |
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tmb077
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Joined: December 28, 2011
Posts: 88
Location: ohio
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| Posted: Fri Jul 06, 2012 7:10 am Post subject: |
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your couplers shouldn't be causing you any issues. Once you are sure everything in your gun is spotless, orifices and all, reassemble it and then play around with each and every adjustment you can. I have a Sharpe that I spray non-metallic base and clear with, and spent a LOT of time making it spray the way I want it to. The Finex is a fairly decent gun (especially for the money)...I'd have to lean towards something with your gun settings or the material is simply to thick for the tip size.
What exactly are you spraying anyway? 'Sealer' includes a lot of different products these days...
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eshan2
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Location: Denver North Carolina
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| Posted: Fri Jul 06, 2012 2:34 pm Post subject: |
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Your compressor is rated at 11.5 cfm and a gun that needs 11.4cfm @ what pressure?Will your regulator flow the same or is it choking the air flow down?Are you using 1/4 inch hose or 3/8 hose? 1/4 inch does not flow as much as 3/8.This may be of some help too.
http://www.sharpe1.com/sharpe/sharpe.nsf/Files/BKFEBKFF/$File/310746F.pdf?OpenElement
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Mike Fisher
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fugazi885
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Joined: April 12, 2011
Posts: 84
Location: Phoenix
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| Posted: Fri Jul 06, 2012 7:51 pm Post subject: |
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| Thanks for all the replies, the sealer I was shooting was Lusid Technoligies sp210 select prime mixed 4:1:1 with very slow reducer per the tech sheet. I am running a 3/8 air hose 25' long, air regulator is rated at 26CFM IIRC and the compressor is rated at 11.5 CFM@ 90 PSI. I cleaned the gun again, tore it all the way down and spent a good hour inspecting and cleaning. Didn't see anything wrong with it. Reassembled and tested again with the same result. I can make it spray really nice, but only with the pressure cranked way up. Is it really an issue to run it at such high pressure as long as the paint is going down nice? Any danger in running an HVLP gun at high pressure? |
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fugazi885
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Location: Phoenix
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fugazi885
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Joined: April 12, 2011
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Location: Phoenix
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| Posted: Mon Jul 09, 2012 4:34 pm Post subject: |
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I finally found the problem and thought it was interesting enough to share. I had a harbor freight inline dessicant dryer/filter (item# 68215) installed at the gun and it was causing a huge air restriction. It was brand new and the dessicant beads were all blue as they should be. I'm not sure if it was a defective item or if they are all restrictive but my gun is now spraying great. Maybe my mishap will be useful to someone else in the future. Thanks again for all the replies.
My project[img] [/img] |
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AZ65CalBug
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Joined: December 08, 2001
Posts: 688
Location: Arizona
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| Posted: Tue Jul 10, 2012 4:39 pm Post subject: |
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OH CRAP! Really? I did a car not too long ago and I have the same gun. I tore that thing so far apart and clean it. It did have crap in it. It still doesn't spray right! Guess what I have on it!??!?!?
You guessed it! The HF inline dry filter!
Damn it!
Let me ask you this...
Did the gun work a few times after pulling the trigger and then stop and act stupid!? THen sometimes work and then not?!?!
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AZ65CalBug
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fugazi885
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Posts: 84
Location: Phoenix
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| Posted: Wed Jul 11, 2012 3:09 pm Post subject: |
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| Quote: | Let me ask you this...
Did the gun work a few times after pulling the trigger and then stop and act stupid!? THen sometimes work and then not?!?! |
Kind of, it seemed like I was constantly fighting it. After I sprayed my sealer coat about half the car had a really bad texture and the other half had less texture (not quite what I would call orangepeel but similar).
If you suspect your inline flter here's how I finally found the problem.
1:Connect gun to air supply and set air pressure (30psi ish)
2:Adjust fluid knob to max flow position (all the way out then back in till you can feel it with trigger deprssed)
Adjust fan control all the way out then back in 1/4ish turn (for wide fan pattern)
3: Put a little water in the cup AIM AWAY FROM FACE and squeeze the trigger.
Look at how the water flows, whether it's atomizing into a fine mist or not. If it's spraying like crap,remove filter and recheck (make sure you check that your air pressure is the same for both tests.
If the problem is your filter it will be very obvious, at 30 psi you should be able to get about a 10" pattern if you have enough air.
hope that makes sense |
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eshan2
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Joined: July 10, 2002
Posts: 247
Location: Denver North Carolina
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| Posted: Wed Jul 11, 2012 5:09 pm Post subject: |
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Those driers suck.Ive never used one that didnt cause more problems than it fixed.I got a devilbiss unit and never looked back.
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I love the smell of nitro in the morning.
1963 Beetle currently under reconstruction.
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