Does anyone have any experience with doing dry ice blasting or glass blasting to remove rust from the undercarriage?

 

how bad is the rust....? pics?

 

 

get yourself a decent weighted hammer with a pointed end on it and go around the frame striking the metal. if some light surface rust comes off...that is to be expected. if the sound is more of a deadened
thud vs a metal ping (ie: solid metal) that'll tell you the rust has permeated thru the frame (that's bad). obviously if the hammer makes a hole...run away.

the rear quarter portion of the frames are notorious for rusting badly in salty environments. inspect that area well. also around the 2 catalytic converters.

make sure the metal holding the outriggers to the frame are not rusted thru as well.

 

the positive thing about your frame is it has not been covered with any sort of material that baddies use to mask problems. (ie: rubberized undercoating, etc.). you can see the level of rust directly.

I went over my frame from front to back with a angle grinder with a cup wheel to bring the metal back to good shape, then applied a rust converter to it to neutralize any surface rust that had formed.

then applied a good chassis paint.

 

If you want show quality, dry ice is the way.

If you want to preserve and protect, a good hi-pressure wash, apply a rust converter and then something to protect it. I like fluid film or wool wax. Doing my son's 93 bronco with fluid film this weekend.

I use a lot of glass on smaller projects that are stainless steel and make big noises, but I can't imagine trying to blast under a car with them. Not saying it can't be done with the right set up, but I can't fathom the set-up in a DIY situation.

 

What do you all think of this…

 

you are referring to the drop arms being rusty/crusty? if you give them a light brushing with a wire wheel and use corroseal or something similar...this will turn all the rust to a black color and neutralize it. then cover seal it
with a product that will prevent oxygen from repeating this in the future.

 

Dry ice blasting isn’t any good for significant rust -- light surface rust, yes, but more than that, no. Try something else / a different media. Dry ice blasting is better at cleaning. (I’ve done it to multiple cars of mine...)