I pulled the head off my car to replace the head gasket. Took the head to the machine shop where they milled the gasket surface of the head. Do I need to wipe down that fresh surface on the head with alcohol or acetone or anything else? What about the surface of the block?

 

has to be clean from old material and oils. if its brand new from the machine shop slap it on

 

Oh okay, wasn't sure seems like there might be a little residue from the machining process left on the head.

 

How do I clean this stuff off the top of the piston walls? Razor scraper got some but not all of it.

 

i would use a bristle disc/pad on that. dont use a razor blade though it will gouge that aluminum. ive used razor on d-series motors that use the composite gaskets since they seal pretty good but the steel ones need a clean and smooth surface. subaru guys use a big sanding block but ive never done it that way.

obviously best way is let a machine shop touch it up slightly so it matches nicely with the freshly surfaced head

 

i've had success starting with carb/TB cleaner or similar and letting it remove what it can chemically. give it a few rounds of that followed by shop rag wipe down. if there are any stubborn areas left i hit them by hand with some scotch-brite.

wiping with a clean rag soaked in brake pars cleaner is a good final prep for mating surfaces before assembly.

 

I was very careful with the razor scraper to not gouge anything, but since the possibility is there for damage I guess I won't use it anymore.

Cool I have both carb and brake cleaners in the garage. When you say Scotch-Brite you're referring to those scrubber sponge pads right?

 

right, kind of. kitchen spounges come with a scotch-brite pad glued to one side for scrubbing. S-B pads without the spounge are what i was refering to. . a box like that lasts a very long time in my garage.

 

lol dang I swear Amazon has freakin' everything