On Tuesday, February 16, 2016 at 6:12:51 AM UTC-8, wrote:
On Monday, February 15, 2016 at 10:30:50 PM UTC-5, wrote:
Is there any reason that PPG concept can't be sanded dry? I need to knock down some bad orange peel (because I'm still learning how to paint). I was thinking about using some 500 to knock down most of the orange peel, and then move to finer grits (wet) take out the sanding scratches before polishing. It seems like everyone is sanding wet, but why? It's much harder to see what you've done because everything gets covered with white goo. If I sand dry, I can blow the dust away and see what I've got immediately. I do know about guide coat and all of that, but I'm wondering what can go wrong if I make the first pass with 500 dry, and then switch to a finer grit wet?

Thanks,

John

Slow down.
Put guide coat on and start with 1000 or finer.
When you scratch it with rough paper you ensure you will need to do a lot more sanding with finer grits to get the scratches out.
You are also much more likely to sand through.
Sand very wet and use a squeegee to clear the gunk off.
Take your time Grasshopper.
UH

Also use a block that's on the harder side. A soft sponge type block with fine grit sand paper will just shine up the undulations.

Cheers,
7Q