Roof Rust

[toddtomorrow]

Only a couple years ago I had no rust issues whatsoever, now I have bubbling paint with lifting chips ALL OVER the roof. Whats up with that?

[nxski]

Only a couple years ago I had no rust issues whatsoever, now I have bubbling paint with lifting chips ALL OVER the roof. Whats up with that?

I assume you have an l300 with crystal lite roof!? This is a common problem that is caused by condensation forming between the headliner and the roof. The rust has been there for a while but has only just made it's way through the metal so you can see it. There are 2 options, one is to pay about $2000 to have your roof professionally re-done. The other is to do it yourself. If you're a DIY person shoot me a pm and I'll go through in detail what needs to be done...

[psilosin]

Why not just post the details on the site right here instead of in a PM. That way the info is here and searchable for the next guy.

[nxski]

I believe it actually is posted on the site (with pictures from when I did the repair)... I'm at work on my iPhone so I can't search for it at the moment. I think "Hermione's makeover" has information in it. I've helped out a couple people already with links etc but it helps to pm if there are specific questions on what to do.

[nxski]

Just got onto a computer and found the link...

http://www.delica.ca/forum/removal-of-i ... 10537.html

[Drive-By]

I'm glad this came up as there are some patches of filler on the top of my L300's roof from a previous owner

Armed with this info and the very helpful link at least I have a fighting chance to stop it in its tracks or at least slow the damage and repair what's already broken through.

Thanks

[toddtomorrow]

Thanks for all the info, I too will start on this project when we get a few days of sunshine. One thought though: how did the moisture get in there in the first place? My sunroofs weren't leaking as far as I know. And is there a way to keep the condensation out after the repair? Maybe a couple of ventilation holes in the liner...?

[nxski]

What I've been told is that the lights create heat so condensation forms under the headliner and rust starts to occur at the weld points.

[White Mule]

The light theory is good, but I'm of the thinking that it might be caused more from sleeping. Imagine two adults on vacation in summer or winter, waking in the morning with no condensation on the blankets/sleeping bags or their faces. It probably stays dry because of that nice layer up in the ceiling. Much like an attic in a house. Ventilation and possibly insulation would serve well.

Now on the other hand if our "non-crystal-lite" brothers and sisters were to chime in, perhaps this theory could have legs. Have you woken to moisture everywhere?

[nxski]

I was thinking about that too, there are probably many reasons for it. Considering that some people don't sleep in their vans, some don't use their lights, etc and yet most vehicles get this rust forming around the same time.
I'd definitely be interested to hear from those who don't have the cl roof.

[speshul_deli~very]

i have the seemingly ubiquitous rust spot on my roof, right above the front window and over where the r/v mirror mounts. L400, no c/l roof. gotta find some time to deal with it this winter, but I'm doubtful of my ability to do a professional job.

[thedjjack]

My 1989 low roof (non CL) had zero rust in it when I cut it out. Lots of sleeping inside the low roof...

My roof is now Fibreglass and is lined with closed cell foam so rust is not in my future....

[shealy]

My deli has Crystal Lite cancer as well. I'm in the process of attacking the issue from the outside first - sanding down the roof (but most importantly those rust bubbles). Using rust paint to hit the rust at the source and smoothing the whole thing out with body filler where needed. Then I'm going to re-paint the entire thing with rhino guard (truck bedliner paint essentially). That at least hits it from the outside. Figured I'd do this first to at least stop the rain (which is unfortunately coming soon in Vancouver) from getting in rust cracks and stuff I had forming up there. Later, I'm going to repair from the inside (minus the bedliner paint), and it should make the whole thing a bit stronger and last longer. I'll make a post with pictures once I get more completed with it all!

[vixentd]

I believe the rust bubbles you see are actually pin holes with moisture coming through from the underside of the roof. This can occur as the warm air trapped inside the roof between the liner and the metal roof cools and the moisture condenses out, similar to water drops on the outside of a cold glass on a warm day.

The underside of the roof does not have the same protection and moisture on the underside of the roof forms iron oxide or rust.

If you are sanding down the rust bubbles my advice would be to make sure that you use a waterproof bondo, like everglass otherwise the moisture will still come through underneath the paint and form bubbles. It is a little more money but well worth it. You will finish with a topping coat or icing in the trade of a very good quality self leveling 2 part glazing putty.

To fully treat it, remove headliner, grind off all the rust or sandblast, then treat with a rust prohibitor ( Rust killer) that will turn any rust black, prime, fill and paint.

If it is impossible or not practical to remove the headliner and you have a really bad area of rust coming through you can cut the area out with a cutting wheel on the grinder, and attach a fiberglass patch over the area removed and using short strand fiberglass bond over. Tap down the area around the cut, so that when the fiberglass patch is applied it will sit flush. Cut a piece of fiberglass cloth and apply about 1/4 inch of water proof short strand fiberglass to one side of the cloth byt spreading it over the cloth when it is on a piece of paper. Lift the cloth up carefully and place over the hole with the 1/4 inch short strand facing down. Using you fingers make sure the patch is pulled tight over the hole as it will dry in a few minutes. Sand and apply a skin coat of water proof bondo, dry, sand and top with glazing putty and paint. If done properly you will never be able to detect and it will never rust out again.

[toddtomorrow]

My 1989 low roof (non CL) had zero rust in it when I cut it out. Lots of sleeping inside the low roof...

My roof is now Fibreglass and is lined with closed cell foam so rust is not in my future....

What is this closed cell foam you speak of? Should I use it on my CL roof when I'm done sanding?