Slowing Rust (1 Viewer)

[Rimmeh]

I have a spot of rust bubbling the original paint rear passenger side roof. It's the only real rust on the 87 FJ60 having been in Texas since new. I've tried slowing the process daubing heavy paste wax over it on the outside thinking it might repel water but it seems now the moisture issue must be coming from the inside. I can live with the small blemish but want to avoid or delay a complete rust through because with my lack of body work skills with any such repair I'm certain it will look far worse. Is there a known weak point in the roof rails where leakage is common? What is the least invasive method to just slow the rot? Rust converter or Linseed oil on the inside surface once the water issue is addressed?
Thanks-
Jeff

 

[Output Shaft]

The rust isn't coming from the inside of the roof, it's growing under the paint. The busted paint is trapping moisture and feeding the rust. Dig it out with a tiny screwdriver till you get to shiny metal. Dig, dig, dig. Anything orange dig out.

Then apply a little OSPHO with a tiny artists paint brush to the spots to dissolve the rest of the rust in the pores of the metal, let it sit a few minutes, then wipe off completely.

Then apply prep cleaner, then primer, then color, then clear coat according to the instructions found on the bottles you can find at

automotivetouchup.com

This was my my roof. 86. Same color as yours.


Dig out all the rust spots & mark with tape arrows.

Primer applied after OSPHO and prep spray cleaned.

Final coats of primer/paint/clearcoat. Blue tape arrows point to spots. Impossible to find locations after first color coat.

Final roof. Red line marks end of touch up.
End result looks ok for a roof. Definitely will not rust in those spots again. Kind of looks like a seagull (or flock of seagulls) unloaded on it during a flyover. But it's fine for the roof.

Ideally the roof should be repainted as a whole (re sprayed) All the little rust spots are indications that entire roof paint is on its way out.

 

[SteveH]

If in digging out the rust, you go through the roof metal, then, yes - it's coming from the inside. How good is the caulk/seam sealer inside the gutter? (look inside the bottom of the gutter). If it has failed (crackly and peeled up), then rainwater is seeping into the roof through the gutter. Do you garage the truck? If so, this will cut down on the condensate that collects in the rain gutters. More pix and closeups would help us figure this out.

 

[60 toy ota]

Nobody ever mentions this, but you might want to install a sacraficial anode, like they have on boats. I believe you can get them from jt outfitters for an automobile. We've had one on the 60 for decades, and while it's not rust free, you'd be hard pressed to find another unrestored 60 that's lived in Utah it's whole life that's as clean as ours, and it hasn't had any body work done to it.

 

[Rimmeh]

Thanks guys an awful lot. It's promising that it is not necessarily from an internal leak. Unfortunately its an outside car as it has always been in Texas. It is surprisingly resilient to TX hail. Not a pockmark, though it does have a few teeth scrapes from a history sharing a field with some bored horses at the previous (original) owner's place for about 7 years.

The gutters look in great shape and to have an internal problem higher than the possible water source didn't really make much sense. Great suggestion on the anode also. I happen to have an extra aluminum hot water tank anode that can sacrifice a couple inches for this application, maybe grounded to an area around the filler neck. Here is a closeup image of the corrosion area:

Thanks again-
Jeff

 

[slomoe]

what is this anode process you talk about?? i'm in the northeast and clueless.