Anybody repaired a BAD cab corner?

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79dentside

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Adding projects to my list... I’m not looking for perfection, BUT my passenger cab corner is GONE like yesterday. At one time, someone repaired and bondo’d over this, so what is left is litterally 1/8” bondo and/or scaled rust.

The rust underneath goes higher than the paint transition line I can almost guarantee. What have some of you done on rust repairs that the patch panel does not fully cover?? I have already written off the idea of a restoration on the truck, it pretty much needs every panel replaced/redone (hence the name 79dentside...) so I am just wanting to stop the rust, then do some type of blend in or faux patina or faux rust to blend in with the look of the truck. The look of rust doesn’t scare me, but holes in my truck do haha.

I am clear-coating the whole truck, so before I do the passenger side, I kind of want to address this.
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Thankfully, the drivers side cab corner is as solid as the bondo underneath . So I will just be doing the passenger cab corner. I have cleared this side, the goal is to do the same on the other side once that corner is fixed...
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...and yes, the doors are rusty, but that is another day, another project. The cab corner is what is really bad in it and my concern is how high it goes and what options I have from there.

Thanks!
 

RecklessWOT

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Oh, when you put BAD in capital letters like that I thought you meant it was really bad.

No rust is good I understand, but that's nothing really. What's the question? Cut out the rust, replace with new metal. If you have one of those patch panels and it doesn't go up far enough, just buy a flat piece of sheet metal and make your own patches. Or, if you cut the whole corner out for the the new cab corner, it doesn't look like the whole thing is rusty, just salvage some good sections from what you cut out and re-purpose them.

Is is swiss cheese all the way up? Can you put your finger through it? Surface rust isn't an issue, just the areas that are heavily pitted or rusted through need to be cut out. Any surface rust/light pitting can just be sanded/ground/wire wheeled back down to bare metal and hit with some rust converter or naval jelly.
 

79dentside

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Most definitely needs metal, let me go take some pictures :) It is pretty bad.

I like the idea of using metal to make my own patches. Probably what I have to do...
 

79dentside

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I have coated it with clear POR 15 to slow the rust progression which is why it’s glossy... look at this goodness!!!
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Any rust on the truck has all received a hefty marination POR 15. That’s why I’m not so worried about the doors, I don’t mind the look of rust. But when the cab is rotting from the inside out, I definitely need to stop it.
 
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This may have originated from an accident repair. Most cab corners rot lower than what you have, i.e. below door edge. Yours is rotted above door edge. The rot could have creeped up from the bottom though rot loves to meander, is the lower corner all sculpted bondo?
 

79dentside

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This may have originated from an accident repair. Most cab corners rot lower than what you have, i.e. below door edge. Yours is rotted above door edge. The rot could have creeped up from the bottom though rot loves to meander, is the lower corner all sculpted bondo?

You might be right. I know the roof was re-skinned, they may have painted the whole cab at the same time? Maybe it had surface rust that they bondo’d over??

the truck has a 350 with 23,000 on it and a rebuilt rear end so I am not going to worry about it’s past too much. The frame is straight as an arrow and super clean.
 
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bucket

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There's a couple different cab corner manufacturers. One is shorter than the other. Even the short one should go up high enough.
 

79dentside

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There's a couple different cab corner manufacturers. One is shorter than the other. Even the short one should go up high enough.

Good to know. I found a little bit of cracked bondo right next to the passenger side side mirror so it looks like they spread the love to the doors too. New doors it is..... Not messing with someone else’s work.
 

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easy enough fix, but I'd be wondering if those inner cab corners have rot. They are not bad either. I picked up a set of inners and outers from rock auto for like 50 shipped I think it was, maybe less.

Thing is can you weld them back in? or have someone to do it?

If not it's ghetto fab or redneck but rivets work or something else like maybe panel bonding stuff but those guns aint cheap.
 

bucket

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easy enough fix, but I'd be wondering if those inner cab corners have rot. They are not bad either. I picked up a set of inners and outers from rock auto for like 50 shipped I think it was, maybe less.

Thing is can you weld them back in? or have someone to do it?

If not it's ghetto fab or redneck but rivets work or something else like maybe panel bonding stuff but those guns aint cheap.

I recently saw a much cheaper applicator gun for the 3M panel bond adhesive. I think it was in the Summit tools catalog.

Edit
It's cheaper than the old composite one, but still $72.99 (TES-08571)
 
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legopnuematic

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This is how high the ones I got for my 79 go. Got them and the inners from Rock Auto.

Although I'll be using as much of that orange and white cab section as I am grafting the whole back of it for my 79.
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legopnuematic

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I would personally take a scraper and a hammer and chisel out as much of the Bondo in the cab corner to find out what you really are working with. It is not uncommon for these trucks to rot where the b pillar meets the rocker flange, most of the time happening from the inside and then eventually breaking through to the outside.

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Definitely looks like you need outers and inners. Not too big of a job with the bed off, although I had the luxury of also having the entire cab off. If you get the large outers you will have more than enough metal. You can see the weld lines on mine. I got these from NPD because they are nearby and I can skip the shipping cost. I expect most if not all of the major vendors get their metal from the same Taiwan supplier.

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79dentside

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Wow, you all are wonderful! Thank you so much. I was thinking that the patches were way smaller than my area.

I have actually broken off bondo already that was flaring like a wing away from the cab. I would really like to just cut it out and weld it in/or 3m panel cement it in all at once. I do not have a welder, but have many people that do thankfully.

I even considered buying a little welder from Harbor freight. Might be a fun project to learn on.

Yeah this is an odd case of rot, my guess is that the bondo on the bottom of the cab corner is the only thing left and worked it’s way up. Maybe the seat belt was hanging out the door and broke the bondo exposing the rotted cab corner?? That’s litterally all I can think of.

I will look into new metal!!! Again, thank you all so much!
 

RecklessWOT

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I do not have a welder, but have many people that do thankfully.

I even considered buying a little welder from Harbor freight. Might be a fun project to learn on.

I have a harbor freight MIG welder, you can hook up an argon tank OR use flux core wire in a pinch if you reverse the polarity (I would recommend staying away from the flux core only welder, the MIG was only like $40 more IIRC and well worth it, they go on sale a lot). It was pretty cheap and it still works surprisingly well. It doesn't have a lot of voltage settings (there are two switches with a min/max, so 4 different combinations possible, the wire feed is a regular knob though) so it's not great for real delicate finish work, but it's really not that bad either. You could definitely weld sheet metal with it though there will be some grinding, hell I even welded new pivot pin tubes onto my snow plow and it's held up like a champ.
 

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