How bad is this frame rust, and what's the best way to treat it?

Picked up last week a '96 4x4 Tacoma for $3200 US, with around 255,000 miles. The front half of the frame looks pretty decent but the rear half has pitted rust.

No holes, and still seems solid. I haven't tapped it with a hammer yet.

What's the best way to deal with somewhat advanced rust like this, to preserve the frame?

 

Ima say the whole frame is shot and you gotta find a donor, you can weld a new piece in but i wouldnt take that gamble the frame is probably rusting inside out

 

Can't tell from the photo. Rust is like a tooth cavity. If you take care of it early, it's simple but if you wait, youll eventually need a root canal followed by a prosthetic tooth.

How deep is the rest?

 

Coroseal rust converter inside frame
(Frames rust from inside)
Coroseal outside top coated with Rust-Oleum black farm paint.
Coat the undercarriage in Fluid Film in Spring and Fall.

 

The one photo is inconclusive, but at first look it seems salvageable. I’ve been down this road with a ‘97. You need to first get as much of the rust off as possible, down to bare metal is ideal. Your options are wire wheel, needle gun, or find someone to sand blast the frame with body on. In the end I found a brave soul to sand blast. Treating means completely encapsulating the steel as rust needs oxygen. Use epoxy based Eastwood products, 2-3 base coats and 1 topcoat. It sticks to your skin for 2 weeks, so you know it’s good…

 

It's pretty smooth up to just past the front of the box, where the leaf springs attach then it gradually gets heavier.

 

I say you leave no doubt and smash away

 

Hmmm... I think I'll start contacting the body shops in my area, Vancouver Island, BC.

 

Your going to need a Fabricator you might get lucky with a body shop but most will not do this type of job.

If it needs any sort of welding or a frame splice.

 

Lol, kinda like great stuff expanding foam…it probably sticks to your skin forever, but the top layer of skin eventually stops sticking to itself.

 

Need better pics but that doesn't look bad.

 

Sorry about the singe bad pic... I can't seem to get decent light. Really dark days up here in the PNW this month.

 

Personally the pic looks like surface rust to me. I would treat with a spray bottle of muriatic acid and a wire brush. Spray , scrub and let it sit for 15 -20 min . The rinse thoroughly let dry then treat the frame with whatever rust preventative coating you prefer. Even though it's acid it's not as bad as it sounds lol it's commonly an industrial cleaner you can find at home depot but it kills rust. Make sure to wear goggles and gloves though

 

You asked for "best" way........... replace the rusty metal.

 

This is gonna sound silly, but I think looking at the condition of the gas tank skid, driveshafts and rear axle is a good visual clue as to what's going on with your frame.

If your gas tank skid is rotted through the the driveshafts/axle are covered in rust, then I expect your frame isn't in too hot of shape. Ball peen hammer along length of frame is the best test; Toyota will do it for you if you ask.

Hard to tell from your photo what is going on.

I'd probably invest some time into making sure the frame is sound before converting rust and coating, it is a big job, especially if you don't have room or time to take the bed off.

 

I’d say nothing bad there. Tap with a hammer, if it rings it’s solid. Get it Rust Checked or Krown or well sprayed with Fluid Film.

Mine had spent its life in Nova Scotia, the rustiest place in North America, it was Krowned since new. Frame is like new. Lots of salt on winter roads. We like to buy used vehicles from Vancouver Island. Don’t worry, be happy. You are getting scary advice from warm climate people?

No need to clean and paint, unless you like the look. If you use an acid, you need to use a large amount of water to rinse the acid, it will burn through the coating on wire, maybe paint too if left on it. Google the uses of muriatic acid- used to remove stains off fireplace brick etc, I wouldn’t use it on anything but a bare frame with body removed.
NS rust.