I need Priming / Painting tips

[firefighter]

Hi guys,
I'm ready to prime and then paint my sheetmetal parts as I get them ready.
I'd just like to toss out some questions and maybe some of you could throw a few pointers my way. Man, I'd really appreciate it.

I know you have to wetsand primer after you spray it, does that mean it's almost expected to have a bit of orangepeel in it as you spray it, cause it's a thicker material?

What size tips do you use for Primer? What size tip do you use for paint? I'm spraying single stage Urethane with an HVLP gun.

What do you have your regulator set at for air pressure to the gun, and is that pressure while you're pulling the trigger, or just standing pressure?

I tried spraying some primer on Saturday (as a test on my old hood) and I was having all kinds of difficulties. I found out I was not getting enough constant flow through the air hose and cheap regulator I was using and I have since corrected that. I'm using an HVLP gun for the first time and am a bit confused by the settings. I have 3 knobs. The one on the bottom is just air flow in. The top one on the back is for fan width control. It seems the important one is how much material you let down into the air stream and how much pressure you have your regulator set at. I know you want to get the atomization correct and have fine droplets of material and not globs or spatters of material coming out.
When I first mixed the primer with reducer, it calls for a 4 to 1 mixture. Right away it seemed a bit on the thicker side but I didn't want to go experimenting. Now that I have my air volume problem fixed, do I try spraying with this recommended mixture first, or do you feel I should try thinning it down just a bit more? I'm spraying with a 1.8 mm tip for the primer.

Are all you painters using high dollar HVLP guns, or just the $100 or less guns. I'm just curious.

Anyway, any replies to my questions or any pointers you care to throw my way, I'd be more than happy to read them.

The good thing about this is that I'm not trying to get a show truck. It's my hunting and wood cutting truck. But.... after all this work of stripping the whole thing down and putting more than a couple thousand dollars into new parts, I'd like to try and make it look the best I can without paying someone else so much money to paint it for me.

Thank you from a nervous primer/painter to be.

[Blazin]

Hunting rig! I wouldn't waste my time wet sanding the primer! Sand it with a DA and 320, or 400 grit paper. If your old paint is in good shape you don't need to prime over it. You should only prime repair areas. When you spray the primer put less on the sanded paint, than the repair. When you sand the primer blend it into the old painted areas. As far as the ratio they have it pretty much dead on, you could play with the reducer a Little bit but any more than 5% your asking for trouble.
I use MAC Tools gravity feed HVLP guns. They are made by Devilbis. They run about $200 plus.

[firefighter]

Thank you Mr. Blazin,

Yeah, I guess I would call it my daily driver.
It will be used for hunting, cutting wood, driving to work, taking the wife to chruch.... I guess a little of everything.
I guess what I'm trying to say is that I want it to look nice since I've put so much time, effort and money into this rebuild, but am going to understand if there is some orangepeel, and if it get scratches in it from parking lots and daily use etc...

[Big Katz]

I'm by no means a seasoned painter, but have painted a handfull of trucks. I have always ended up having orange peel on my primer. I tried to reduce it, but have had little luck making it lay down smooth. The way I do it is sand to bare metal with 80 grit. Do all of my body work. Shoot it with epoxy primer using a 1.8 tip in a cheep conventional gun. Next day shoot it with high build 2k primer. Block sand to get rid of body waves. Wet sand with 400 for nonmetallic paint or 600 for metallic. Shoot the base with a 1.3 Devilbliss Plus HVLP gun. Then shoot the clear coat with a 1.4 tip. I used to use the HVLP for the clear too, but have always had more OP than I like. So I started using the same Cheap conventional gun I shoot the primer with and a 1.4 tip and it has always turned out pretty good. I always end up wet sanding and buffing afterwards. After putting that much work into your truck it is only 1 more day of work and it really makes the truck pop! Looking back I wish I hadn't spent a bunch of money on a fancy gun when I can get as good if not better results with the clear coat using a cheap gun. I also learned a lot from a web site called Auto Body 101 forum. They have a for beginners column. Good luck to you. There is nothing like seeing your reflection in your truck and knowing you did it yourself!

[Big Katz]

Sorry, I just re-read your post and saw that you are using SS paint. I'm not very familiar with that kind of paint.
Here is a link to help you with setting your gun up.
http://www.autobody101.com/content/articles/paint-atomization/

[Kris_77stepside]

I'm no professional either but I did go to school for auto body and paint.  What we did was first started out by sanding all chips and scratches out with 80 grit, then sanded everything else with 320 grit.  Then we would apply a couple coats of primer surfacer.  Then we would block it with 180 by wet sanding or 180 dry on DA sander.  Apply some more primer surfacer then block again with 400 wet or 320 dry on DA.   Then we would make sure the surface was clean and then apply a primer sealer.  Then once it was dry base coat then clear coat or in your case just the single stage paint.  Like I said i'm not a professional and there are other ways to block it out etc. but that is what I was taught.  For guns and tip size I use some cheap $120 gun I got through the napa store at the school and it has a tip size of 2.0.  But for laying down the sealer/base coat/clear coat I use a $700 Sata jet 3000 HVLP gun with a 1.4 tip.  By no means does a at home do it yourselfer need this kind of gun.  You can get good results with cheaper guns.  I got the gun as this is what I want to do for a living and got it cheaper through the school than the $700.  I must say though that it is one nice gun, lays clear down like glass.  Other than that just make sure all your surfaces are clean with wax and grease remover before applying any paint and make sure you wipe all the wax and grease off (I learned the hard way lol.)  Anyways hope that helps a little bit.

[firefighter]

You guys are the best. Thank you very much for taking your time to post the replies.

Ok, here's what happened tonight when I tried spraying my old hood again. I had sanded down the real rough primer I had previously tried spraying, with utter failure because of an air flow problem. That has now been fixed.
I had my 1.8mm tip in the gun, mixed the primer like the can recommended, and then tried spraying. It was an intermittent surging spray and was doing nothing but spattering no matter how I adjusted the air pressure or material feed. In fact, I swore I could hear air bubbles inside the paint cup. Yep, sure enough. I took the cap off the cup and sprayed for a second and there were air bubbles coming up in the cup. I didn't think that was normal.
I was frustrated so I switched over to the 1.4 mm tip. When I installed the new tip I noticed it screwed in way further that what the 1.8 tip had come out. That was the problem. With the new tip in and fully seated, no more bubbles and I could actually starting making sense to the adjustments. I actually finished priming the hood for some practice and felt somewhat comfortable with doing it.
When I first got the gun, I thought the threads in the gun body were a bit screwed up and now I can see the threads are stripping out. That's why the one tip was not seating fully when I thought it was.
Long story short, I'm going to get a new gun before I proceed. I'd like to prime the cab on Friday.
I must admit, I got a pretty cheap gun ($50) when I decided I was going to paint myself. Someone told me it would work good for what I was doing and maybe it would, if the threads weren't stripped.
I'm going to buy a bit better gun now. I'm tired of screwing around with this and I want to get going on the primer and paint.
Now to find a better gun locally within the next few days.

Thanks again guys. I really appreciate the input.

[Blazin]

Check out you local auto parts stores that sell paint. Also if you stop into a local garage, or body shop they could probably give you the numbers to the tool guys that stop there weekly. Give them a call, you could meet one of them somewhere on there route when they are close to you.

[Engineer]

I did my first ever paint job this summer.

I used DuPont paint on my '77 K-30. DuPont has information sheets on their products that suggest surface prep, gun settings, paint mixture formulas, as well as other compatible components. The company that makes your paint should offer likewise.

I have an el-cheapo HVLP gun. It did a fine job. Just keep it clean was the trick.

Here are a couple of pics of mine. Remember, I was a noob at this as well.

[tpull123]

I too just finished my first paint job on my truck.   I used a Devilbliss gun from Summit racing, think it was 150 or so for the kit that included two guns.   All went really well except I seemed to get a decent amount of orange peel in the clear coat and no matter what I seemed to do it was there to some extent.   

Anyone who has tips for that I would be listening.  I was able to wet sand it and get it pretty good, but its still not show quality. 

[firefighter]

I also ended up with the 2 gun kit from Devilbiss. It was the Startingline series.
This kit was within my budget and it was a tremendous improvement over the "cheap" gun I tried using first.

I've heard that spraying clear can be a bit challenging for a lot of people and I'm not sure why. Fortunately I'm shooting with a single stage urethane paint so I won't have to cross that bridge, although I may find it hard to shoot just the color!!

I'm sure there are many painters here who know WAY more than me about painting, but the variables that cause orange peel are:
1 Air pressure
2 The dilution of paint into the airstream
3 How much the paint is thinned down.
4 How far you hold the gun from the surface
5 How fast you're moving the gun
6 The amount of overlap in your passes

Heck, it shouldn't be too hard to get all that correct, right?   NOT !!!
It takes an experienced painter to get all the settings just right.

Have you posted any pictures of your truck tpull123? I'd like to see them.
Congrats on your first paint job.