So the guy before me did a raptor liner spray job on the roof on my jeep. I dunno if he did a bad job or if raptor line just isn’t that good. I knew it was needing some attention but I didn’t expect this after a little wire wheel. What are my options? (The tape was just to keep the rubber gasket out of the way)

 

The guy before you owned a vehicle with major rust in the roof metal. He covered it up to hide it, seal it, or both. The quality of the product is not a concern here

All of that metal needs replaced to actually be fixed properly. the vehicle may not be worth that kind of effort and money. That is a choice you are going to have to make

 

My roof at the rain gutter rails had same issue. I filled all the holes with the expandable window foam, and then cut off and smoothed the excess when dry. I painted over with the tv rubber in a can stuff because you cant really see it. If i were you i would cover with a layer of fiberglass and then spray can paint it. It will look ok.

 

Now I just have more questions

Does fiberglass bond that well to old metal long term? Better than the bed liner?

Does the expanding foam seal out water or trap water? I am working on my rear quarter panels and considered the expanding foam but don’t want to make it worse. Seems like a good idea to provide backing but is it ok if water somehow still gets in?

second question though is I suspect there are other spots on the roof like this. Is it practical to glass the entire roof?

Thanks.

 

Sorry don't have the answers to that..fiberglass is waterproof but can't guarantee how well it bonds. Im sure there is water and more rust in there that you cant see. The jeep is almost 25 years old...if you get 30 consider it a win

 

The only long term solution is to cut and weld new metal in. I've cut out many old fibre glass repairs where the rot just keeps expanding.
Expanding foam traps water around it, not necessarily between it and the metal but right on the edges. Many manufacturers use some expanding foam in places but later down the line, it's that area which goes first.

The question is, what do you consider long term? If you want to get a few more years out of it, a bodge may hold up. If you want it still going in 10 years time, you'll be dealing with much worse than you are now.

 

that is beyond belief.

I have no idea how it would rust like that, maybe snow sitting on it ?

I would check the rest of the vehicle very closely before proceeding, if there is major rust in floor or unirails, I would cut your losses

You need to strip of the rest of the roof covering an evaluate

Many years ago, I did have a Daihatsu F20 that rusted like that and we did fibreglass the roof, and it lasted quite a few more years, but rust keeps going unless you cut out all the corrosion

 

If the rest of its not rotten find a junkyard that will sell you a partial or let you cut one up. Brace the old one, remove the glass, weld the donor piece in, new glass, you're set. Hardest part is getting the headliner out and back in.

 

Ok, I feel there is a lack of progress pics on this site in general so here is where I am at:
I started with the ole wire wheel. I think the previous owner was a little light in the application of the bed liner cause the entire roof has rust spots and yet much of the bed liner was still really well bonded. After giving up with the wheel of power I went for heat. I just put my electric garage heater directly on the roof, waited for a few mins, hit it with a scraper and it came right off. Sure there might be issues on the other side, but nothing caught on fire. Sure it warped the roof but it just made it a bit worse then it already was. My next plan is to get it shiny and use fiberglass filler for the holes at the front and haven’t figured out the rest yet.



Toasted please. (Just wait for a little smoke)


Just right.




Off it comes to reveal a lovely rust surprise (not surprised at this point)

 

A little advice from rust country up in Canada…if you live in areas where rust is common never use thick coatings like bedliner, rubberized undercoating, gravel guard! If any moisture gets behind it causes rust like in your pictures as it’s trapped between the coating and metal. Some of the worst rust buckets up here were at some point “protected” with those coatings. Many dump trailers and other utility trailers up here come with a factory powder coat or those thick bedliner type coatings - in 4 years it starts flaking off in sheets to reveal a complete pile of rust.

 

I am also up in Canadia. In fact, my city uses a liquid salt brine on the roads that is even better at melting snow and rusting cars. And as someone said, the rust is likely from snow sitting on the roof. So just a good job of sanding, patch and paint if I’m not cutting and welding?

 

Get it as clean as you can, use a rust converter to try and neutralize the rust as much as possible. Canadian tire sells one by rust check that’s decent. Follow the directions closely. Be sure to clean/degrease before priming and use a self etching primer over bare metal. Then a couple coats of regular primer, then your colour coats. If the rest of the jeep is bedliner you could probably just use the spray cans of trem clad over the primer, it’s pretty durable stuff. No matter what you do the rust will come back eventually in some areas, at least if u use regular paint you can notice it before it eats holes through the metal and the repair will be much easier.

 

I have done a few roof rust repairs. Its essential to remove all corrosion that is FeO4 that physically expands with water and air

I use an angle grinder with a wire wheel then rough stripping pad, this leaves bare metal, sometimes needs a couple of goes, I will dremel pits

then rust convertor, and its much better if you can use 2 pac products to paint, as they dry by chemical catalyzing, not evaporation of thinners, which leaves pores

Using porous single pac products allow the air and moisture to react with any remaining rust, and it bubbles back up

2 pac has some pores, but its a tiny fraction. You need a compressor and spray gun

 

That's terrible. This is exactly what Im trying to avoid. The roof on my 2000 XJ has gotten surface rust and Im pretty sure I know how it happened. The paint had become ever so slightly cracked throughout the roof and must have allowed water to seep through the paint cracks and "BAM!" instant rust. Not just surface rust but some decent pitting as well. I had to replace metal where the factory roof rack rails mount and the rain gutter between the A and B pillar. Now I need to remove the windshield and cargo hatch to replace metal around there. Im definitely not looking forward to the work but I'll be happy once the rust is gone and has fresh paint and clear to protect it once again. Hopefully for longer than 20 years. Chrysler has some of the s***tiest clear coat IMO.

I love my XJ so Im doing what I think is best and replacing metal for metal. Sorry to say, but if my roof was as bad as yours looks in the photo (particularly at the front near the windshield) Id probably be looking for a donor roof. It seems like the simplest thing if you want to fix it correctly.

 

This got me thinking. I really really like my xj, so I don’t think I am gonna go for the “best”.