My question today concerns the removal of heavy rust buildup and various other coatings, to prepare for welding, painting, and/or undercoating. The surfaces I need to clean fall into four general categories:
1. Heavy rust only, such as the control arms (which were probably coated at one time)
2. Undercoated areas, such as underneath the body.
3. Wheel arch areas, which contain what looks like a layer of silicone rubber in addition to undercoat on top
4. Paint only
What I need is an effective way to clean these areas in sometimes hard-to-reach places, without damaging the good metal underneath. I can't afford anything expensive like sand-blasting equipment either.
Thanks for any advice.

My question today concerns the removal of heavy rust buildup and various other coatings, to prepare for welding, painting, and/or undercoating. The surfaces I need to clean fall into four general categories:
1. Heavy rust only, such as the control arms (which were probably coated at one time)
2. Undercoated areas, such as underneath the body.
3. Wheel arch areas, which contain what looks like a layer of silicone rubber in addition to undercoat on top
4. Paint only
What I need is an effective way to clean these areas in sometimes hard-to-reach places, without damaging the good metal underneath. I can't afford anything expensive like sand-blasting equipment either.
Thanks for any advice.

1. A wire wheel on an angle grinder to get the heavy stuff off. From there, you can buy bottles of rust disolver, or I hear lemon juice works too (but I've never tried it myself)
2. Brake cleaner/gasoline on a rag will disolve the undercoating.
3. ??? torch...? never done that. Maybe a scraper? Rubber is hard to get off.
4. Paint stripper/brake fluid or a paint remover pad for a drill/die grinder