You can just sand it and use a filler primer (make sure it is zinc based). Unfortunately the stuff I used the labels wore off. If you are talking everything off the frame here is how I would do it. Sand/Wire Wheel, rust reformer (EastWood is really good), Primer (depending on what you did in step one you may need a filler primer to smooth everything out) that has zinc in it (they may be labeled as a "heavy duty" primer or "frame" primer) the reason you use zinc is one it protects the metal and two if it does start to rust it will way up the zinc before the actual metal you sprayed, and finally your "Protector" of your choice (I don't remember what brand I used)

 

I have a pressure sand blaster and a large blast cabinet. I don't like pressure blasting, even though its faster and you can do any size piece - because I've got the media all over me by the time I'm done. If you're doing a restoration, complete disassembly followed by thorough sandblasting and prime/paint is hard to beat. You want to be VERY careful with those axles, its easy to get sandblasting media on the inside. Use duct tape over all seal areas on those axles; use a wire brush to get the metal clear where it gets close to seals.

However, if you want to just daily drive it - there are alternatives.

If you want to just clean up the underside of a vehicle, you might try a needle scaler. I use those on my used DD when they're crusty, then I coat with Fluid Film (FF). I'd pressure wash it, go over the spots with the scaler, then pressure wash again... put it somewhere it doesn't get rained on and give it a couple days to dry out - then spray fluid film over it. I tried a couple different spraying equipment I had to apply FF, but eventually bought the kellsport gun for FF. Works pretty good.

Alternatives... por15, chassis saver, or corroseal as a primer with topcoat of your choice. I like the FF because its faster and no drying necessary, you can easily use it in cavities. The drawback, if you rub up against what you covered with FF, you will transfer FF to you. Not a big deal, but something to keep in mind when you're deciding. FF is pretty good to use to combat road salt.

https://www.harborfreight.com/compac...ler-96997.html
https://www.fluid-film.com/
http://www.kellsportproducts.com/
https://www.por15.com/
http://www.magnetpaints.com/underbody.asp
http://www.corroseal.com/

 

Install them in what????

 

Same here but I've also tried a pressure washer with a sand blast attachment on it. Works fairly well as long as you have enough pressure out of the pw. Wear a tyvek paint suit and face shield as the sand does ricochet back at you.

Sand blaster is show at 1:07

 

Thanks guys! It's going to be a driver. I know Fluid Film works but can't handle everything being greasy. I want a fairly smooth finish, but not a show quality painted gloss. I don't care for a rough texture like bed liner either. I would consider a bed liner type product if it would flow out and be smooth. A finish like the semi frame would be nice. Fairly smooth and some shine to it. I know it would take sanding to get it that smooth, so I'll save that for if I ever get a hot rod that won't be driven in the winter. I'm leaning toward pulling the cab and box so I can blast it. I haven't ruled out rust converter, the encapsulator, and then chassis coating/paint.

 

Those are for this. Not a Dodge, but if I can get some sort of chassis coating to hold up on this, it's going on the Dodge too! Kinda funny, the axles in it now have 3:55s just like the Dodges. The newer ones are 3:36. If I can get the KBS when I get home I'm going to try it. I'd like to try the Eastwood stuff but It probably would show up after I leave again. I also need to fix our Excursion before I tear the Dodge apart. That needs the underside coated also. I don't know if I should try a 3rd product on it and then see which of the 3 holds up best? Before I left last time, one of the spring shackles broke in the Dodge, so that has to get fixed first.

 

[QUOTE=Moparite;3399430]Same here but I've also tried a pressure washer with a sand blast attachment on it. Works fairly well as long as you have enough pressure out of the pw. Wear a tyvek paint suit and face shield as the sand does ricochet back at you.

I kind of like that Idea, I'd like a pressure washer anyway. I was going to ask a couple places what it would cost to blast the frame and under body. One has dry blaster and the other, a water blaster. The water keeps the metal cool so it won't warp also.

 

I always wonder if the Zero-Rust, Chassis Saver, KBS Coating are made by one company and repackaged with different names. They sure seem similar.

 

So here is an alternative to blasting small parts. I imagine you could brush it on larger parts.

 

Could use electrolysis also, Depends on how large a scale you want to go. Seen this done on other forums but never tried it. This guy rambles a bit but you can see the final result at 12:30 if you get board.