Any Auto Painters among us?

[Muddy Creek Sam]

I am going to use 2 stage paint for the first time and need to get an Idea of how much to mix so as not to waste it. Anyone have a general rule? I need to do the roof of a mini van. Paint has sure gotten expensive.

Thanks,

Sam :D

[crabo]

What brand and line of paint are you using? The easy way to do it is to first figure out your mixing ratio. It should be on the can or you may need to look it up on the mfg's website.

I teach my students to mix only what they need because once you mix some of them, you can't save the leftovers. One of the big factors about "how much paint will it take" depends on your spray gun. The Binks #7 which was the cadillac of siphon spray guns only had about a 27% transfer rate. The rest went up in the air and all over everything. A good gravity fed spray gun can run about 85% efficency.

I have them use 3 oz Dixie paper drinking cups for measuring. You can use a mixing stick or a mixing cup, but the dixie cups work really well. If it is a 2-1 ratio, you put 2 cups of paint, and one cup of hardner, or reducer, into your mixing cup. I would recommend mixing a 6-3 portion and spray that out. That will give you a good idea of how far that amount goes. If you need less than that to finish out the coat, adjust the ratio, to fit your needs.

A couple of things to remember:

1. Air pressure is very important. Your gun type determines the amount of air pressure you need. Too much air pressure and you will be spraying dry and have excess overspray.

2. Over lap about 1/3 of your pattern, like mowing the lawn.

3. Temperature is a big deal. It takes longer between coats at 70 degress than it does at 90 degrees. Most reducers are temperature specific.

4. Make sure you wear a good respirator. The new paints have a lot of bad things in them. Some people are much more sensitive than others.

There is a lot more, but not knowing specifics, this will get you going.

[Muddy Creek Sam]

Crabo,

Right at the Moment I am getting ready to prime the roof with MarHyde Ultimamum 2 Will be the first time I have used a Primer with a hardener. Then a Base coat Clear coat Paint, not sure of Brand.

Thanks for the insight,

Sam :D

[tomme boy]

Make sure to not use too much hardener. It will crystallize under the paint. What will happen is the paint can flake off. Look at all the cars an trucks that are around that have sheets of primer showing. That was what happened to them.

The factory tried to speed production up and added too much hardener to make it dry faster.

You should be able to get mixing cups at the paint store. Also make sure to get some strainers.

[Muddy Creek Sam]

My Mom had the van painted at MAACO and the Paint blew off in Sheets. Trying to fix it. Wire Wheel on Angle Grinder does wonders to get it to metal.

Sam :D

[koehn,jim]

Where you have gone to metal you need a self etching primer to prep the surface. Crabo sounds correct in what he is advising. Most of the info you need should come from the maker of the paint. Eastwood in Penn sells auto paint and materials for hot rods.

[94Doug]

I sold another brand for many years, so I can't recommend anything. Our basecoat was mixed 50/50 with a reducer/base, they also offered mixing sticks with imprints on them to "add to" levels. Clear was 2 pts hardener to one gallon clear, small amt of reducer to assist flow. Most of the problems I encountered both factory and other shops problems were primer issues leading to peel offs.

Doug

[crabo]

In time, you will probably have pealing issues if your clear is not thick enough. It all goes back to equipment and application.

Make sure you sand the primer well before you paint. I use a light fog coat of flat contrasting paint on my primer to make sure everything is sanded well. ( a guide coat) When your guide coat is gone, you have sanded everything. It will also show you low spots and scratches that need attention. Also run your hand over all the primer to make sure it is smooth.

No matter how well you spray the paint, if you do a crappy prep job, you'll just end up with shiney carp.