Rust holes on my roof, how to fix?

[cgalloni]

I just don’t have the money now to weld the roof and I’m concerned the previous owner did a really bad job with the roof I have a friend who has a body shop that says he can fix it without welding but I want to keep the truck for a long run. At this point I don’t know what to do since I just purchased the truck and put the money into it and don’t have anything left now. If the roof was bondo before and those bubbles came out how can bondofix it again? Was this a bad prep ?
Also to the previous comment; you mean the Bubbles formed because of the bad bondo and not rust ? How do you distinguish if the bubbles are cause by the bad bondo or rust ?

 

[Jubsz]

I have limited experience with body work but I'll take a stab. I scrapped a 92 Civic when I was younger because of bondo'd over rust. When metal rusts, it will bubble slightly and the paint will usually flake, showing rust and some flaking metal. Those types of bubbles and waviness usually happen when someone sands the rusted metal, bondos over it and paints it. I've never been sure if there is an amount of prep work that you can do to make that not happen over the longer term. I think it is one of those "it depends things". If it's a very small amount of rust and non-structural, you may be able to sand/bondo/paint. If your metal is flaking and expanding, you're probably at the point that you need to weld metal in. I'm pretty sure that once new metal is welded, they still use body filler (bondo) and sand it down to create the correct shape and ready it for paint.

In your case, it looks like it was probably a fairly significant amount of rust that was sanded, bondo'd, and painted over. There was insufficient prep work and in your case, there may have not been any amount of prep work that would have made it right. It likely required new metal to be welded in first. The only way for anyone to know is to cut/chisel it all out and see what metal is underneath there. After that you'll have a hole to deal with. Body work sucks... I scrapped my civic once I cut out the quarters and knew how much work/money it would take to make it right. I found a new chassis. That is how I learned my lesson about dealing with used vehicles that have rust. Painful but worthwhile lesson.

 

[brillo_76]

Yes you are correct. The only way to know is grind in there and look. See what's going on. Everyone is just guessing until.

The only issue with this is you never know what you will find.



Sent from my SM-J337V using Tapatalk

 

[cgalloni]

Yes you are correct. The only way to know is grind in there and look. See what's going on. Everyone is just guessing until.

The only issue with this is you never know what you will find.



Sent from my SM-J337V using Tapatalk

Well, I took the truck to the shop to be fixed and it was in really bad shape. The only thing i can tell you is to check that your roof rack is not leaking anywhere. The harm is done and I am paying top dollars to fix this mess. I am starting to regret purchasing the truck!
P.S not putting any roof rack or rails back into it. Also. Please check your spoiler in the rear lift gate. It was also leaking in there

 

[stalone]

I have the same problem as you. My uncle just gave me a 2000 SR5 that he no longer drives. I found that the roof had 4 spots that was cracked (most likely due to a bad bondo job) and water was leaking inside near the rear passenger and rear driver side windows. I was planning to take it to a shop to get those areas patched up but I'm worried that there's rust inside the roof that I'm not aware of. Have you taken off the headliner to look for other rust spots?

 

[Groven]

I've been nursing this issue for a few years. Original owner of a '98, but repaint in 2005 created issues that much later caused rust along the roof rack rails, including a couple of pretty good sized holes. The worst of which is in a terrible location surrounding the back roof rack attachment point - very difficult to repair properly without cutting into the support rail which backs the whole length of the roof rack rail along the underside of the roof. I used vinyl wrap to keep water out for a couple of years, but it degraded in the elements and I am past the point where that is practical now. I don't have welding skills and am not willing to make the investment in what is now our "beach, boat and bike" truck to have a pro tackle it. Experience with the limits of Bondo in my youth will keep me from going that route.

So, my current strategy is to lay-up two full length fiberglass pads for each roof rail to extend well past the current corrosion. I'll use the roof itself as the mould and then mount the pads between the rail and the roof. I'm inclined to make them removable in case I want access later, possibly sealing them with silicone. I may, however, decide to bond them in "permanently" with something like Panel Bond or 5200.

I think removing the racks during the repair process, like the OP is doing, is smart long term, but I happen to need the roof racks on this vehicle - as you can see from my profile pic

 

[Groven]

Made a pattern (scrap Tyvek) from which to pre-cut fiberglass mat. Prefer it extend a bit further from the outside edge of the rust spot on the front driver's side, but don't want to end up much closer than an inch from the door sill; it should be adequate.

For the record, the roof rack track mounting holes are close to matching in position - driver vs. passenger side - but definitely not identical.

 

[chapolito]

I have this same issue, and I do want to learn to weld to fix this properly, but could use some advice on how best to tackle reattaching the roof racks.

Last summer I fixed with fiberglass, which has not held up well. Two of the 4 holes on the passenger side are completely rusted out along with part of the rail support underneath:

I'll be pulling the headliner and re-enforcing the roof rail support while welding in patches. However, I want to minimize the chance of rusting in the future. I'm considering the following options:

1. Don't use those holes to reattach the rails. This means 4 bolts on driver side, but only 2 on passenger. I've been running this for over a year without issue, but seems less secure.
2. Drill 2 holes in the patches for reattaching the rail. This seems very likely to rust again.
3. Weld over all holes on roof and weld on tabs/feet. This would allow a full length roof rack to bolt on easily and most importantly, feels the least likely to rust again and have the most airflow.
   

Thanks for the help!

 

[brillo_76]

I would weld in patches then grind them smooth. Apply fiberglass over the patches. Water can't go through fiberglass so it will seal off the steel and stop rusting from the top side anyway. Then decide how you want to attach your rack. If you drill holes just use silicone to create a gasket to keep the water out.

Sent from my SM-A536V using Tapatalk

 

[aontkos]

I'm tagging along on this one. I noticed the same issue on my truck this summer. I can say with confidence that it's from hauling around a canoe on my roof rack after fishing in saltwater. I always rinsed the roof well when I got home, but sometimes I'd drive for three hours before that, which must have allowed the saltwater to penetrate the roof. I still haven't seen any signs of water intrusion in the interior though.

I've delayed getting in repaired because I'm in the process of building a house and I don't have a functional garage at the moment. I'm not willing to pay someone to remove my trim, headliner, etc. but I am willing to pay for the actual body work.

I've been curious to know if the 'easiest' solution is to cut a panel out of a donor truck. If I can cut a section out of a good donor roof, can that just be welded in place fairly easily?

 

[chapolito]

I would weld in patches then grind them smooth. Apply fiberglass over the patches. Water can't go through fiberglass so it will seal off the steel and stop rusting from the top side anyway.

Interesting idea, I hadn't considered fiberglass over steel. I'm worried the fiberglass will be too stiff and crack as there is deflection of the roof. That was partially how my first fix failed—the steel depressed when I put my hand on it and the fiberglass did not, and they separated.

Wondering if perhaps a layer of cosmoline + paint would provide better protection?

 

[chapolito]

I've been curious to know if the 'easiest' solution is to cut a panel out of a donor truck. If I can cut a section out of a good donor roof, can that just be welded in place fairly easily?

I've been playing with this idea too since it would be nice to have the rain channel already there. I don't have a battery powered grinder to take to a junkyard, but maybe I can find a local 3rd gen being parted out. There probably will be some warping when cutting it out, but getting that aligned again will be far easier than manufacturing a new patch.

 

[brillo_76]

Interesting idea, I hadn't considered fiberglass over steel. I'm worried the fiberglass will be too stiff and crack as there is deflection of the roof. That was partially how my first fix failed—the steel depressed when I put my hand on it and the fiberglass did not, and they separated.

Wondering if perhaps a layer of cosmoline + paint would provide better protection?

You have a valid point. I forgot about the roof flexing. Being that the welded plate would flex with it. I was thinking the steel then glass then paint.

Its a very common place to put a layer of fiberglass over the steel in repairs in the rust belt. So if you want to paint then cosmoline, that would work. as Cosomoline would be the top layer..