Cause of Typical Fender Rust Hole

[Big Sexy]

Gentlemen,

I presently have both fenders off and under the knife. When I removed the fenders I saw a weather strip that ran down vertically on the backside of the fender to meet the infamous 55 fender rust hole. Aside from the obvious discharge of road water, mud, etc from the front tires, I suspect the aforementioned weather strip is acting as a conduit for water runoff from the top to collect at the bottom of the fender. Evidence of this theory was removing the weather







strip and finding the backside of it was very rusty. My question / concern is do any of you see this as part of problem because at this point, I do not plan to put the strip back on the fender.

 

[bobm]

Jeff, its not the weatherstrip. Its because the bracket on the back of fender is closed at the bottom. It traps dirt and mud and eventually rots the bottom out.

Thanks Bob.

 

[Big Sexy]

OK, I can see that... Being that I will be putting in a good deal of time, effort and cash into restoring the fenders this winter, I will make a plan to 'open' the bottom part of the bracket before remounting fenders.

Any good stories, advice or recommendations from the group on Bob's insight?

Thanks,

 

[scrapdaddy]

I'd say Bob is right and make sure you coat everything in there with some kind of anti-rust product. Anything will be than raw steel, like Toyota left it.

 

[bobm]

Jeff, I do have patches with inner brackets. If interested.

Thanks Bob.

 

[tyama]

hiya, I just finished fixing the same holes on mine. I cut out all the rusted parts, replaced the holes with new metal, welded in a new bracket and cut holes in them so I could por-15 the inners. I did the por-14 app last night so I think I'm good to go for a few years. I also left a gap at the bottom of the supports so water can drain out of them and put fiberglass on the very bottoms instead of metal so they would not rust out as easily. I'll post up pics in the next few days to what it looks like now.

Regards, ty

 

[Big Sexy]

Already have the fender patches - got them quite some time ago from someone off this site. They don't have the integrated support brackets however, so I have (had) a couple of donor fender with good brackets but otherwise wasted...

 

[greentruck]

In addition to the drainage, the way the reinforcement sits acts to facilitate condensation. Any water in the bottom has a nice long rise and temp gradient over the rise to cause it to both vaporize then condense over the course of daily temp changes.

I can tell you that even when new, they lasted about 4 years before rust out here in the Midwest. Vehicles showing this now have likely seen far drier/less salty environments. The sold-new to to the Midwest Pigs have mostly crumbled away by now. After I spent about $2000 in 1980 dollars have it fixed on my '76, it was already starting to pinhole through again when sold in 1984. Truck was never garaged, drove hard and put away wet, because I worked the night shift and had to get home through the country most of that time. The truck never failed to do that, but the body work has design issues, let's just say.

Yeah, probably should have been more proactive the second time around with doing some drainage and coating inside and out with undercoating. I suspect that merely slows things down.

 

[henry morgan]

Jeff, its not the weatherstrip. Its because the bracket on the back of fender is closed at the bottom. It traps dirt and mud and eventually rots the bottom out.

Thanks Bob.

So your saying its not dealer installed option, I was going to bump up my sale price