New painter with ????

[Dwayne1m]

I'm painting my 1st car and I'm learning a lot with lots more to learn. What I am using is a Sprayfine Stage 3 turbine sprayer. I am going with a single stage urethane and a polyester primer-surfacer. My biggest hangup is terminology. I work with a guy who painted cars 30 years ago and he has been "schooling" me but he has been away from it for a long time. I'm asking you guys to get me up to 2015. I am under the assumption that "thinner" and "reducer" are the same thing? Also, there are different kinds of "thinners" like paint thinner, lacquer thinner, mineral spirits, acetone, reducer, etc. What is the difference and are they interchangeable? I was told to use acetone to thin the primer, is that correct? I'm practicing on an old fender. I shot the primer, it came out "rough" because I think I had it to thick, sanded it down to mirror smooth with 400 paper, then shot the top coat. It looked like I painted an orange. I came to the conclusion I need to thin the paint and Sprayfine recommends 50% more thinner then what is normally called for. I didn't add any thinner/reducer. Just the paint and the activator 3-1. For experimentation I added more activator to thin the mixture and it helped greatly.

Final question, I am painting a 74 bug and it is stripped. I was thinking of painting the parts separately(fenders, hood, trunk, doors) and the shell last for ease of painting. Some have told me to put it together and paint it as a whole. Is there a problem with painting the parts separate? I am painting black if that matters any.
Thanks.

[marklee]

as a newbie, just get lots of paint on.Then colour sand and polish.(see the sticky) Thinners must be matched with the paint or primer and not randomly used. Speak with your paint suppliers and follow the instructions on the paint and the equipment....
_________________
CGLI qualified body repair and refinish tech
CGLI qualified motor repair tech
Qualified automotive Glass installer
Motor Insurance Repair and Research Centre,Thatcham, Advanced Vehicle Damage Estimator.
Police qualified vehicle examiner
Police Class 1 High performance, pursuit trained Advanced driver

[buguy]

Poly primer is a bitch to spray. I wouldnt worry about how it goes on though. The problem your having is starting with too fine a grit on the sandpaper. Maybe hit it with some 220 grit first. Really you probably should just spray 2-3 good coats (unthinned if you can so its thick), guide coat it, sand it with 120, then another couple coats (thinned), then 220, guide coat it well, and wet sand with 400.

You also could do your 2-3 coats of poly, guide coat, sand with 120, then spray 2-3 coats of a 2k final primer, then sand with 220 and then 400 wet.

Get tech sheets on all your products, they will tell you if it needs reducer or thinner.....they are not the same nor interchangable.

Black is fine to spray apart.

[Dwayne1m]

Thanks. I thought black might be OK to spray with the pieces apart since black is black. I could see where other colors it might be an issue.

On my practice fender I did go to a 180 grit because I saw the 400 was getting me nowhere fast. Finished with the 400.

Curious though about why so many coats of primer?

Also wondering what guys use to clean their guns. I tried paint thinner and it just didn't work, and I cleaned the gun right after I was done spraying. I ended up using carb spray. That is one of the reasons why I asked what the difference is between lacquer thinner, paint thinner, mineral spirits, & acetone.

Thanks.

[buguy]

I suggested so much primer because you are a novice at this. Even with a few coats of high build primer, you will sand right through it pretty easy. Thats why I recommended 2 sessions of primer. You will be able to get it pretty straight with the first session, then after the second spray there will be enough material left that you wont go through it, and you will have a nice even foundation to paint over. Even with an experienced guy doing it, its pretty hard to get a whole car straight with hammer and dolley work and bondo. Thats why you want to start with an aggressive grit paper at first, its easier to get it straight with courser paper. Then from there you are just spraying again to cover any bare spots you have (and you will have them if you are getting it striaght) and to give yourself some material to fix any imperfections (which you will also have) you missed the first time around. It should also be enough material to get the 220 scratches out with the 400 wet without going through.

If you think you have it pretty good with the first round of high build, then just use a 2k primer after you have the poly sanded to fill the course paper scratches. You can then go right to 400 wet after spraying the 2k primer.

[jspbtown]

And try some guide coat. It improved the look of my paint jobs tremendously.

I clean my gun with acetone. Cheap enough at your big box home improvement stores.

I have mixed my Evercoat G2 high build poly primer with up to 10% acetone. It helps with my 1.8mm nozzle. I don't notice much difference in the build thickness. You can lay it on pretty thick (within reason).

[buguy]

Guide coat is a must! And if your spraying poly with a 1.8 tip you will definately need to reduce it. But there is a big difference with build. Easy enough to put an extra coat on if you need more build though. I reduce my poly with laquer thinner. I also clean the gun with laquer thinner. Dont let poly stay in the gun long, it has a pretty quick flash time. In fact many times in the summer here its ready to sand in a couple hours. In fact the sooner you get to it, the easier it is to sand. I always try to spray one day and sand the next if I can. Never had a problem with it shrinking or anything ever.

[Dwayne1m]

I'm using a 2.0 tip and it seems to work pretty good. The can says to use acetone to thin it, and you're right in that it dries fast. It is a bugger to clean the gun. I've tried mineral spirits, paint thinner and acetone, but nothing comes close to carb cleaner. I had no luck with the other products and I clean the gun as soon as I am done spraying.

[buguy]

Thats wierd. Ive probably sprayed more poly than anyone on the planet and Ive always used laquer thinner. Works great unless it drys.
Ive never used a airless sprayer, but with compressed air, I usually spray at real low pressures and a bit further from the panel than normal to get the best layout. I can really lay it on that way and its fairly smooth (for poly).

[Dwayne1m]

Here is what I am using. Calls for 5-10% acetone.

http://www.eastwood.com/images/pdf/13523zp_instructions.pdf