TheSamba.com :: View topic - Question on sanding down orange peel on single stage paint

Mon Jan 21, 2019 2:18 pm

I am thinking of painting my own bus. However, every time I spray something whether it be primer or color or clearcoat it has some orange peel. With single stage paint can I sand that orange peel out with 500 (or higher)+ grit and then buff it out?

I painted a two stage color on a 1965 Chevy nova last year and it turned out pretty good except for the orange peel. I traded it for a work truck before I ever had the chance to sand the clearcoat and buff it out. This got me to thinking about the single stage paint. I realize this will take forever but I have a lot of time.

Mon Jan 21, 2019 3:18 pm

Simple answer ….yes you can.

More complicated answer....Work to reduce your orange peel. Single stage metallics might be problematic. Be sure you have enough coats

Mon Jan 21, 2019 5:29 pm

I won’t be doing metaling. I’ll be doing Sierra yellow color.

What causes orange peel? If I remember correctly when I did my nova, I actually didn’t get orange peel in the color coat. I only got orange peel in the high build primer (which I sanded out) and then my color was fine then my clear coat had orange peel. Perhaps the thinner paint orange peels less easy?

Mon Jan 21, 2019 9:18 pm

Well, generally speaking, orange peel is typically the result of improper painting technique, and is caused by the quick evaporation of thinner, incorrect spray gun setup (e.g., low air pressure or incorrect nozzle), spraying the paint at an angle other than perpendicular, or applying excessive paint.

So:

1. Make sure your reducer (activator) is correct for the tempo & humidity you are spraying in.

2. You should be spraying with a 1.4 tip or so. What style gun and air pressure are you using? And how are you testing your pressure?

3. Angle is pretty self explanatory

4. Medium wet coats are best. Don't try todo it all at one. Allow extra flash times to minimize runs

Thu Jan 24, 2019 8:29 am

On my nova I just used a harbor freight gun. I’ll be upgrading for this project. I live in a DRY climate (Colorado) so do I use more of less reducer?

Thu Jan 24, 2019 12:49 pm

Every reducer will list the temp & humidity it functions well at. As an example...I have used Kirker paints. As you can see here there are 3 reducers you can use:

https://docs.wixstatic.com/ugd/f1e4a4_7fe36d8e990a4017a1945023476203a9.pdf

Fri Jan 25, 2019 9:59 am

All paint will have some orange peel, but using the correct hardener and reducer will help. Slower reducer/hardener will let the paint flow better for less orange peel, but will be easier to run.

If you want to sand it out then spray two extra coats so you'll have enough material to work with. Start with 1000 grit and work up to at least 2500, then buff out the sanding marks with a wool pad.

Fri Feb 08, 2019 9:19 am

If you're a DIY type and you don't have access to a booth, you may have to change your approach from what a shop would do.

A shop with a booth with generally do the bodywork, shoot a sealer then go directly to paint. The problem with doing that in a less than clean environment is that dust and orange peel will occur in the sealer coat. I like to let the sealer coat (thinned epoxy) gas out and do a final wet sand until the base is as smooth as the finish coat, then paint.

The reason is that if the substrate isn't perfect, any dust or imperfections you sand out of the color leave a chance of the primer surfacing. Sometimes you just have to paint, sand, then paint again... Not profitable for a shop but you can do show quality work with the right techniques adapted to your environment.

Good luck!