I have been reading past posts and searching the web regarding powdercoating the S4 intake. Also getting nervous regarding the horror stories of sand left in there after media blasting.
So the question is, what seems to be the most preferred procedure regarding the INSIDE of the intake manifold?
- blast the inside and leave as bare metal
- blast the inside and powdercoat the inside
- leave the factory coating "as is" on the inside

Thanks
John

 

My guy tried very hard to blast only the outside. Some of the coating on the inside was gone, and I chipped away anything loose. I thought about spraying it with something to bind up any loose coating, but didn't think it would hold for long, or that it might make things worse.

Some sand got in anyway. He spent a lot of time cleaning, then I did. I'm sure it's good.

 

Blast the inside and leave it bare. Have them use sand at low pressure....not beads.

If you powdercoat the inside after blasting, the media that is left will be temporitly stuck in the corners until the manifold gets hot and cold a few times....then it potentially comes loose and ruins your engine.

The problem with not touching it is that if any of the coating is loose on the inside, the media can get trapped under the loose areas....and come out later.

 

Thanks

 

I also had a cylindrical brush made to fit the space and scoured VIGOROUSLY to ensure there was NOTHING left in there.