Possible to deal with chassis rust without taking the body off the frame?

[DR650]

I want to address the rust on my chassis so that my truck lasts a long time. I think getting the chassis sandblasted and painting it with por 15 would be a good way to do that and not too much time and money except that acessing it to do so doesn't seem possible without taking the body off and thats a lot of work from what I've heard. (Is there a way to pull the body off the chassis without pulling the fenders, seats, dash, etc. etc.?)

Is it possible to do a decent job addressing the rust without taking the body off the frame? I was thinking of putting the truck on a lift and having the chassis and underside of the body media blasted while still on frame and then painting everything I can reach with por15. Maybe not the prettiest method but seems like it could be effective. Do you guys think there's any reason not to go that route? What would I want to cover up/protect during the blasting if I did?

My chassis look like this:

 

[Pops68]

Is it possible to clean & treat the top side of the frame without removing the body???

 

[Rbuddy98]

It can be done it’s just time consuming. I did mine that way and I was happy with the results. I used several different size wire wheels and wire brushes. My frame only had mild surface rust.

 

[DR650]

Is it possible to clean & treat the top side of the frame without removing the body???

Fair point, no not really. How do I ensure the structural integrity of my frame long term then? Is the surface rust on it superficial from a materiel strength standpoint and if so for how long I wonder.

 

[thegreatjustino]

How do I ensure the structural integrity of my frame long term then?

You mean longer than the 50+ years it's already lasted without any kind of coating?

 

[Steve83]

Possible to deal with chassis rust without taking the body off the frame?

It's possible to change disk brake pads without removing the wheels, but that doesn't mean it's a good idea, or less work, or that you'll get as good a result.

I think getting the chassis sandblasted and painting it with por 15 would be a good way to do that...

Why do you think it would be good? Have you done it before? Have you seen it done before?

The letters "POR" in POR15 mean "paint over rust". So if you're gonna use POR15, you don't remove all the rust. If you're gonna remove all the rust, buying POR15 is a gigantic waste of money.
And no matter what prep you do; paint (of any brand or type) is the wrong material to use on the frame. Paint CAUSES rust, when it gets scratched & chipped, and then holds water/salt against the steel. That's true even of brand new frames with paint or powdercoat professionally/industrially applied before assembly. The correct material is rubberized undercoating, which can't crack or chip. It's also cheaper, quicker, & easier to touch up if it ever needs it.

...not too much time and money...

That depends on your definition of "too much". If I do ANY work (time) or spend any money, and it has no benefit, I consider that "too much", even if it was less (time or money) than doing an effective job. And since partially fixing the frame will NOT make it last longer (and will probably accelerate its decomposition), I'd say it's too much - you should do MORE work so that you're doing it right. But you don't have to spend more money - you can spend less & get a far-better result.

...taking the body off and thats a lot of work...

So is sandblasting the underside of a vehicle - a LOT of work. So is painting around all the things you didn't remove. Do you want to do this job fast? Or do you want to do it slow? Or just half-fast? Because what you're describing won't achieve the goal you've set.

Is there a way to pull the body off the chassis without pulling the fenders, seats, dash, etc. etc.?

Of course - remove the body bolts, steering shaft, shifters, wiring, fuel fillers, etc., etc., and lift it off.

...putting the truck on a lift and having the chassis and underside of the body media blasted while still on frame and then painting everything I can reach...

Whose lift? Where? Inside a building? Because sandblasting a whole vehicle indoors is pretty messy. So is hand-painting a bunch of hard-to-reach nooks & crannies. Or do you know of an outdoor lift you can use for all this work?

...seems like it could be effective.

So did the Bronco2, but it wasn't.

Do you guys think there's any reason not to go that route?

Many.

 

[Madgyver]

ospho should be used to treat it. loosen body bolts or cut them off. with a rusty chassis, you sure would want new body bolts. get body up a little use 2x4 to prop it up and get the ospho in there after a good cleaning.

 

[DR650]

The letters "POR" in POR15 mean "paint over rust". So if you're gonna use POR15, you don't remove all the rust. If you're gonna remove all the rust, buying POR15 is a gigantic waste of money.
And no matter what prep you do; paint (of any brand or type) is the wrong material to use on the frame. Paint CAUSES rust, when it gets scratched & chipped, and then holds water/salt against the steel. That's true even of brand new frames with paint or powdercoat professionally/industrially applied before assembly. The correct material is rubberized undercoating, which can't crack or chip. It's also cheaper, quicker, & easier to touch up if it ever needs it.

I thought I read somewhere that they por 15 makes rust preventatives as well. That's an interesting take. Where can I read more about this rubberized undercoating? Seems like what I might want to go with.

That depends on your definition of "too much". If I do ANY work (time) or spend any money, and it has no benefit, I consider that "too much", even if it was less (time or money) than doing an effective job. And since partially fixing the frame will NOT make it last longer (and will probably accelerate its decomposition), I'd say it's too much - you should do MORE work so that you're doing it right. But you don't have to spend more money - you can spend less & get a far-better result.

So is sandblasting the underside of a vehicle - a LOT of work. So is painting around all the things you didn't remove. Do you want to do this job fast? Or do you want to do it slow? Or just half-fast? Because what you're describing won't achieve the goal you've set.

Of course - remove the body bolts, steering shaft, shifters, wiring, fuel fillers, etc., etc., and lift it off.

I appreciate you the insight. Looks like a frame off is the way to go, I'll hold off until I have time to do it right.

Whose lift? Where? Inside a building? Because sandblasting a whole vehicle indoors is pretty messy. So is hand-painting a bunch of hard-to-reach nooks & crannies. Or do you know of an outdoor lift you can use for all this work?

My friend is a mechanic and he has an out door one but it's a moot point in light of what you said earlier.

 

[Speedrdr]

ospho should be used to treat it. loosen body bolts or cut them off. with a rusty chassis, you sure would want new body bolts. get body up a little use 2x4 to prop it up and get the ospho in there after a good cleaning.

Out of curiosity, will a 2X4 “shim” fit without having to break the steering column loose? I’ve got to replace the body mounts, hopefully with a minimum of issues. Is that a contradiction??

Randy

 

[66Uncut]

I've seen before/after videos of dry ice cleaning but I doubt it's cheap and it probably can't reach the top side of the frame. The results look pretty good for the surfaces it does reach.

 

[Steve83]

Where can I read more about this rubberized undercoating?

On the can. Or maybe on the mfr.'s or retailer's website.

https://www.rustoleum.com/product-catalog/consumer-brands/auto/truck-bed-and-undercoating/rubberized-undercoating

They even have the label, but you have to zoom in a lot:

https://www.rustoleum.com/-/media/F688E8C6023342EB9BB37B5E564CB119.ashx