Treating surface rust

[musekmkr]

The entire undercarriage of my 70 RR has a bit of surface rust... It's most certainly not rot but I'd like to try and keep it from getting that way. Would it be an incredibly bad idea to knock off the loose stuff and coat everything with a rust converter? Would I have to treat it afterwards or could I leave the rust converter as is? Would the rust converter make it more difficult when it comes time to perhaps blasting it all and painting everything?

The car has factory undercoating as well so I'm hoping it's well preserved underneath the coating but, for those areas that were not coated, I'd like to do what I can to preserve it without getting too crazy. At some point I hope to strip the car down and do it properly but for now I just want to do what I can with it. Thanks for the help!

 

[VitaMeVas]

Not sure how much help I’ll be, but I’ll get the ball rolling. I just scraped all the grease/dirt/gunk from behind my control arms and sent them out for sandblasting/powdercoating. I’m rebuilding the front end/suspension/disc brake conversion. After degreasing what I could u used this ‘rust converter’ I bought off amazon for $50/gal. Had good reviews. It left the painted metal alone and turned the surface rust black after 2 coats (goes on like thick milk and dries). Didn’t give off hardly any odor. So far so good. I’m hoping to redo the frame years down the road, but this is stage one. Maybe someone else will chime in who has used it. Good luck!

The entire undercarriage of my 70 RR has a bit of surface rust... It's most certainly not rot but I'd like to try and keep it from getting that way. Would it be an incredibly bad idea to knock off the loose stuff and coat everything with a rust converter? Would I have to treat it afterwards or could I leave the rust converter as is? Would the rust converter make it more difficult when it comes time to perhaps blasting it all and painting everything?

The car has factory undercoating as well so I'm hoping it's well preserved underneath the coating but, for those areas that were not coated, I'd like to do what I can to preserve it without getting too crazy. At some point I hope to strip the car down and do it properly but for now I just want to do what I can with it. Thanks for the help!

 

[musekmkr]

Thanks! That product has come up quite often in my research so far. I heard that and Rustmort as well as some Rustoleum and Loctite branded stuff. I was hoping whatever I choose I can spray on but would probably want it to be available in quart size or larger versus an aerosol.

 

[Canadian1968]

kinda hard to say what your looking at . You said it's just surface rust? But then you said should I just knock off the loose stuff ?

If you have any sort of flaking rust , this is beyond "surface" rust . Just because you dont have a hole doesn't doesn't mean it's not in a bad shape. What I would do is take a wire wheel and remove as much as you can. Be amazed what a wire wheel and a bit of time can do. Not as good as blasting but it does a good job ! Chances are you all have some pitting . Once you have the metal as clean as you can I would put a 2k epoxy on it . You can brush it on, it does not have to be sprayed . Epoxy is the best way to slow down rust once you have cleaned up the area IMO. As far are rust converters can't offer any advice simply don't hve the experience with them .

 

[musekmkr]

Maybe surface rust was a bit too conservative of a term. I am sure there is some pitting as well but it's not to the point where it's completely deteriorated. There is still some good material under there that can be saved, lets just put it that way. Even with the areas that are actually and truly surface rust, I am sure there is some prep work that I would want/need to do before applying whatever product I end up using, whether it be some sort of epoxy or rust converter. I just want to make sure when it comes time to blasting and doing this properly, whatever I do now is not going to make it impossible to do it right later. Although I suppose there is not much that can stand up to blasting...

 

[musekmkr]

Here are some pics

 

[Builderguy]

So you are just looking to stop any additional rust damage for the short term, but plan on sanding it down and fixing it the correct way sometime down the road. Sound right?

 

[musekmkr]

precisely

 

[Builderguy]

Most, if not all, of the rust converters need you to knock off the loose rust before treatment. Your rust is no problem, the undercoating (on the other hand) is going to be fun. Use some 80 grit on a grinder or air tool and just clean up the rust right up to the undercoat. The 80 grit will tend to just smear the undercoating. No problem just clean up the rusted area. I use like Rust-Oleum Rust Reformer. It works well for a short term fix, just spray the snot out of it. Several light coats. I also use it for a longer term fix, but there are more preparation and application steps for this to work.

 

[eldubb440]

I would hit it with wd40 every now and then, cheap, easy, and effective ...... if and when you restore, just degrease everything before blasting, you would have to do it anyway

plus it keeps the original look for now

I just WD'd the bottom of my durango the other day.....I spray it in the bottom of my doors and liftgate too

 

[440 4 speed]

Don’t know your temperatures, but a good old scraper sure works .

 

[musekmkr]

Most, if not all, of the rust converters need you to knock off the loose rust before treatment. Your rust is no problem, the undercoating (on the other hand) is going to be fun. Use some 80 grit on a grinder or air tool and just clean up the rust right up to the undercoat. The 80 grit will tend to just smear the undercoating. No problem just clean up the rusted area. I use like Rust-Oleum Rust Reformer. It works well for a short term fix, just spray the snot out of it. Several light coats. I also use it for a longer term fix, but there are more preparation and application steps for this to work.

I like the idea of not messing with the undercoating. That just sounds like it will open a can of worms that I don't want to get into right now. That will be down the road. Hopefully the the undercoating has kept the metal in pretty good condition and will help to preserve those areas until I'm ready to do it the right way.

 

[Ranger16]

What about Chassis Saver?