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paint guns

560 views 5 replies 3 participants last post by  Jaffer 
G
#1 ·
Well I decided to finally paint my Jeep, and I bought a pretty good HVLP paint gun. I can't figure out how to get it to work right though. I have sprayed a few coates of primer on the Jeep, but I can't get it smooth. It ends up having a texture to it, similar to what the walls on a house look like that have been painted with a roller. I think it is not set at the right air/paint ratio, but I have adjusted and readjusted everything. Anyone have any ideas/experience with this??
Dan

 
#2 ·
/wwwthreads_images/icons/tongue.gif I'm no painter, but here is what I learned from a Mexican guy out here who can hang more paint in one pass with zero runs than any human I ever saw:**** Shoot a thin "Tack Coat" first, then spray the top coat.....all in one pass....because if you GO BACK and make a pass over the already-setting top coat, the droplets will cause "Orange Peel" texture. This guy paints aluminum truck cabs, and I have to say that he is a Rembrandt with a Binks Paint gun. I had him paint one of my service trucks, and the job was awesome. He claims that if a truck isn't at least three months old, that some finishes will still not be "Overpaintable" like when the companies do their logo designs and so forth. For some reason, all the very best painters that I know are Mexican. We had our classic Karmann Ghia painted by a guy who really laid a show quality job on it. His name is Arturo./wwwthreads_images/icons/smile.gif

CJDave
Quadra-Trac modified by the crack moonguy/wwwthreads_images/icons/wink.gif/wwwthreads_images/icons/smile.gif/wwwthreads_images/icons/tongue.gif transfer case team.
 
G
#3 ·
check the paint viscocity, if this is your first attempt at spraying it needs to be pretty thin, like the thickness of milk. also make sure you have the correct thinner or reducer for the ambient temperature. if it is hot where you are at you may need to add retarder.
is this a gravity gun or a turbine?
good luck jjc

 
G
#4 ·
My brother just borrowed my compressor and the cheap-o gun I just bought. He sprayed the primer on, but didn't thin it at first.......problem. He thinned it 50/50 (not a recomendation for you.....just what he needed for his brand of primer etc.). That made it spray better, but he still had the problem with a textured finish. He called around and found out that for his primer that was normal. It will be sanded again before the top coat goes down so the texture is a non-issue. If you have the same problem with the top coat........well, then you really have a problem. /wwwthreads_images/icons/frown.gif

jo-jo
'77 CJ5 Fozzy Locker
20 degree RTI 1250

'87 Samurai Stock (for now)
 
#5 ·
orange peel is a result of an off mixture of paint and thinner. When spraying primer especially, it takes a lot more thinner than you think! 50/50 is a good start or even 60%thinner, 40% paint. Once you get the mixture that works good for your gun and altitude stick with it. Also, drain the water from your tank regularly and if a drop of water does get though and onto the paint, hold the spary button down only half way to get only air coming out and attempt to "push" the water off.

Here's a cool note on painting somebody told me: If you are painting a metalic paint, ground the vehicle so that the metalic particles don't align themselves in one direction due to static charges. A pro told me that, thought it was pretty interesting.

/wwwthreads_images/icons/cool.gif Big Ed
'88 YJ, 4" susp,3" body,33's,283 Chevy V8,TH350,4.11's,D30,D35c
 
#6 ·
If you still have problems after thinning the primer it is because primer is very "heavy" and it just will not atomize as well as the finish paints.
Especially with the HVLC. You will want to thoroughy sand out the primer coats any way. I am told by my local paint dealer that due to enviromental considerations, that the published thinner ratios in my primer had been drastically reduced to comply with goverment regulations. He suggested upping the thinner ratio. Especially since I noticed that the thinner ratio on a newer can of the same 'fill and sand" primer was much lower than on a can I had bought only a few months previously.
With enough practice - basically what you are doing now - you can learn the paticular characteristics to make your gun work well with all the different coatings you need to a final finish. These include thinning, air volume, needle adjustments and spray patterns.
I can tell you this from experience since I'm doing the final rub out of my first auto painting attempt. It's a(Dupont)metallic base-coat/clear-coat job that has been built up from mostly bare metal which includes etch primer, fill primer, seal primer, base color coat and lastly (3)clear coats.
With this system, you can always back track and re-do a section at any stage if you mess it up.
All with a little DeVillbis touch up gun I originally bought and used to paint the fusalages of RC model airplaines with!
I really like the base coat clear coat system as you can always go back to re-do or touch it up and you can fine sand and rub out the clear coats to a mirror finish.
My finished product isn't perfect but I'm tickled to death by how nice it did turn out. There is a lot of satisfaction in having done the job yourself. Plus, you then now how to fix future dings!
Many get the cheapest high pressure gun they can get their hands on to shoot primer. Primer is a real pain to clean off a gun unless done very quickly after use and you can practically ruin a new hi-tech gun such as your HVLP if you let primer harden up inside of it.
Don't give up. I'll bet it will turn out a lot nicer than you expect given your disappointment of the first coats.

JAF
http://www.monsterslayer.com/jeep
 
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