Underbody cleaning/painting

When I did my aerocoupe I used probably 5 cans of brake parts cleaner. I sprayed and sprayed and sprayed until everything was clean and dry. No residue and it will take off any loose paint as well. I will do it again with my next project.

Make sure you use it in a well ventilated place. It was winter and I had the garage door closed. I had to sit on the ground outside for about 30 minutes before I could get back up. Very scary.

Pressure wash with warm water and soap. Then carb or brake cleaner and paint.

I like to leave caked on grease as a cheap rust inhibitor.

Every time that I need to work on my car I curse the previous owner that greased,oiled and undersprayed everything(including the inside of the aluminum rims because my hands end up black. .
Then I stand back and marvel at the 99%+ rust free SS I found a year ago.

Agree with rented steam cleaner. Then you could use Acetone cleaner. Evaps quickly and cuts through most stuff like grease, undercoating, brain cells. Use a mask with whatever you come up with. I do. I can't afford to lose even 1 piece of grey matter

They sell small hand held steamers that are pretty cool for like $40. My cutty has 16 years of ziebart undercoating. It's a b*tch sometimes, but I'll take solid floors and frame rails any day over rust. If you don't want to use anything caustic I've had good luck removing grease by letting wd40 soak in an loosen it up.

Carb cleaner works good also but be careful with it. It will take the paint off.

Easy Off works great at removing grease and grime....I would spray it with Easy Off and head to you closest u-do-it car wash place, spray the underside to get as much off as you can and finish up the job at home