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Diesel
09-04-2013, 03:40 AM
Hi Y'all,

I will add a link to dropbox which shows pictures of the Rust on the Top of my roof. It is mainly on the seams where the sheet metal joins.
What's the best way to deal with this?
I was told to take a wire brush and get the rust out and then to apply a product called Rust-Mort on there. Is this the best product to use? It also was recommended to me to put perhaps a sealant like Silicone on the seams. What do you all think?
Here is a link to the pictures.

Notice that there are rust stains in the cabinetry on the inside. What is everybody's opinion on this? Should I be concerned about this indicating a problem on the inside of my vehicle?

https://www.dropbox.com/s/iylbw8ural5xia4/Rust%20%28Rear%20on%20Driver%27s%20Side%29.jpg
https://www.dropbox.com/sh/93odan3c6nc1lsv/bjweSbG1iu

tblume
09-04-2013, 03:58 AM
My friend from upstate NY has kept some rust at bay for a little while- dental syringe with ATF- it'll displace water and wick into tiny joints.

Sealing the rust and damp in with silicone sounds like a bad idea.

Bottom line- it's cancer. Same friend has put three FJ60 land cruiser bodies on his super rare turbo-diesel manual trans frame. That he powdercoated. And zinc plated all the hardware. And removed many seams and voids where damp and salt linger. And....

There were parts of the last body where you could easily push a screwdriver through. On top of the C and D pillars- so up about 7' above ground level, forget the lower panels.

Aqua Puttana
09-04-2013, 12:42 PM
First, I would not choose silicone seal for any of your repairs. Silicone seal has a nasty habit of leaching silicone to the surronding areas which keeps paint or other products from sticking unless it is THOROUGHLY cleaned. Another downside is that nothing I know of sticks to cured silicone seal, not even more silicone so if you need to touch up it needs to be THOROUGHLY cleaned.

How much do you want to spend?
How much effort do you want to invest?
How old is the Sprinter?
How many more years do you think it will be in service?
Do you care what the top of the Sprinter, which people can't see, looks like?

The answers to those questions can help determine what repairs are selected.

In my opinion, just grnding out the rust, repairing the damage, and then repaint will be a fairly short term solution. As has already been indicated the rust always seems to return.

My response to some rust on the seams of my 2004 was to sand it a bit, prime and paint, and then cover with a generous coating of sealant. Not pretty, but it has held up so far because the sealant keeps the moisture out. No more moisture means less future deterioration.

I feel that a complete cover seal can buy many years of service. Some basic surface repairs followed by a sealant and fairly wide cover strip will work. Membrane roof material comes in black and white colors. It can be cut into strips and glued down over the repairs.

Eternabond tape is well known for RV roof repairs. It comes in widths up to at least 6". Using that is my plan for any future problems.

http://www.amazon.com/s/?ie=UTF8&keywords=eternabond&tag=googhydr-20&index=aps&hvadid=4652379969&hvpos=1t1&hvexid=&hvnetw=g&hvrand=1720911617983316926&hvpone=&hvptwo=&hvqmt=e&hvdev=c&ref=pd_sl_94cp7yb6gw_e

My thought is that if it is a roof repair, then nobody sees it so effectiveness trumps beauty. Not everyone feels that way. Good luck. vic

Petalumasprint
09-04-2013, 03:04 PM
These trucks have horrible factory paint and rust prep. My 2006 had the roof seam rust and, fortunately, I don't have interior panels. I used spot sanding and a Dremel wire brush to take the surface rust to shiny metal, treated the steel with rust converter, then primed and spot painted the surface. For the seams, I diligently injected rust converter into the seams letting it dry between applications. After letting everything dry thoroughly I applied Eternabond tape over the seams. (I also used it around my Fantastic Vent fan). Three years later and still no leaks and no rust at the seams. I still, however, have to routinely go over my van's exterior and spot treat small surface rust spots that appear. Total crap factory paint.

I second the silicone warning. That's what failed with the Sportsmobile install of the Fantastic Vent fan. They used silicone to seal the opening and it didn't last one year. It took wire brushes and some really nasty silicone cleaning solution to clean the opening before I could repaint and apply the proper putty sealant and reinstall the vent, using Eternabond to finish the top seal. Dry as toast now.

seans
09-04-2013, 03:33 PM
Some, but not all silicone sealant releases acetic acid which is corrosive (http://yarchive.net/electr/silicone_sealant_corrosiveness.html).

In my case, I used clear silicone sealant to fix a leak a few years ago. I saw some rust had developed beneath the sealant, in the seam, a few days after I applied it, but the seal has held and the rust has not gotten worse.

In hindsight, I would have sought a non-corrosive version, and looked for UV resistance. The linked post makes some suggestions, but it is over 15 years old.

I would agree with you and the others that you need to treat it properly, and the Rust-Mort is probably as good as anything. I found that touch-up paint alone was not sufficient so next time I put POR-15 on my crop of rust. That was worked on most spots, but after several years I'm seeing evidence of rust resurfacing under one or two previously treated spots (not necessarily the fault of the treatment, but perhaps impingement from the edge of the treatment area.)

I'd pull the cabinets, too, and see what's going on inside.

seans
09-04-2013, 03:55 PM
(some error led to a duplicate post - moderator, feel free to delete)

icarus
09-04-2013, 05:03 PM
Don't use silicone!

As I understnd it, silicone promotes rust, I believe due to it's acidity! Use proper automotive sealants!

Icarus

mean_in_green
09-04-2013, 10:32 PM
Moral of the story: urethane sealant to the insides of your roof seams, on a dry warm day or - even better - when it's been in a paint oven.

For some time I've put forward the suggestion that the roof seam rot begins inside, where joints are not sealed and condensation collects. Next stop Rustville, population: most Sprinters.

bankodave
09-05-2013, 12:20 AM
Check out Eastwood online. I have purchased a lot of auto restoration tools from them in the past. They have a section on Rust treatment that may have something that will work for you.

Here is the link:
http://www.eastwood.com/paints/rust-solutions/treatment.html

Dave

Diesel
09-05-2013, 03:21 AM
My friend from upstate NY has kept some rust at bay for a little while- dental syringe with ATF- it'll displace water and wick into tiny joints.


Bottom line- it's cancer.

Is it really Cancer....or does it just act like Cancer?

Here is an interesting link. It is saying that Rust may Cure Cancer.

http://onlineathens.com/uga/2012-04-03/uga-scientists-kill-cancers-iron-oxide

InnoVAN
09-05-2013, 01:18 PM
I just stripped the wrap from my van and there are a few areas I need to address, but really, I'm pretty impressed with the strength of the horribly thin paint... I have a spot under the rubber trim of a rear seat window that is about the size of half a dime, that shouldn't be too bad. There are a couple areas where a trim knife for the wrap penetrated past the paint, then the solvent I was using to remove the rubber cement ate away at the paint a little. Those should be easy. I also have some slight rusting discoloration on the roof seams, but not too bad.

Is there a preferred white for Sprinters?

Aqua Puttana
09-05-2013, 01:24 PM
...

Is there a preferred white for Sprinters?
For color match or specific brand with better performance over another? To the best of my knowledge all white Sprinters are Arctic White(wash). There are touch-up kits and many cans of Sprinter paint listed on Amazon. vic

Boater
09-05-2013, 01:49 PM
MB arctic white is slightly on the grey side of white, I think the paint code is 147. Perfect match is never going to happen but it should be good enough to only be visible close up when the light falls a certain way. Mine has a variety of different shades, I think a PO must have had the whole van painted and might not even have used Arctic white for that, but at a glance it all looks OK, except where I have primer that I didn't get round to putting a top coat on (that needs stripping again because there is some rust poking through).

Even if you buy paint from Mercedes different batches may dry to a different shade and fresh paint never quite matches old (it will be closer if you t-cut the whole van - eek!)

ohlsonmh
09-05-2013, 07:40 PM
These trucks have horrible factory paint and rust prep. My 2006 had the roof seam rust and, fortunately, I don't have interior panels. I used spot sanding and a Dremel wire brush to take the surface rust to shiny metal, treated the steel with rust converter, then primed and spot painted the surface. For the seams, I diligently injected rust converter into the seams letting it dry between applications. After letting everything dry thoroughly I applied Eternabond tape over the seams. (I also used it around my Fantastic Vent fan). Three years later and still no leaks and no rust at the seams. I still, however, have to routinely go over my van's exterior and spot treat small surface rust spots that appear. Total crap factory paint.

I second the silicone warning. That's what failed with the Sportsmobile install of the Fantastic Vent fan. They used silicone to seal the opening and it didn't last one year. It took wire brushes and some really nasty silicone cleaning solution to clean the opening before I could repaint and apply the proper putty sealant and reinstall the vent, using Eternabond to finish the top seal. Dry as toast now.

I did basically the same - standing on the bed of my daughter's pickup I cleaned it as best I could, painted several times with Rust Converter, then covered the seams with a marine sealant, and then covered the whole works with aluminum, metallic, tape to keep UV & Oxygen from deteriorating the sealant.

So far [one year] the "Sideways Racing Stripes" [bright, shiny aluminum on dark green!] have been perfect.

It still galls me that Mercedes can't even provide a metal roof that doesn't LEAK!

-Oly

uglied
09-05-2013, 10:00 PM
HAD SAME PROBLEM ON 2 OF THE 3 SEAMS. Sanded as best I could. Applied rust converter, cleaned up and applied etching primer than sanded and applied Etrana Bond tape. Had to Cut tape where it overlaps the ridges in roof in order to be sure of good adhesion. Inside sanded, applied rust converter, Than primed with etching primer, sanded than applied spray enamel. No more leaks. Can not tell if rust will continue to form under all this. Truck is an 03 with 200K miles and adding 1 k per week so I am sure the repairs will out last the truck. Etrna bond tape is the way to go as it will flex with the truck flexing and not leak.

oregonjim
09-07-2013, 09:06 PM
I too have rust on my roof.
no doubt there are different choices to deal with the rust issue.

I am aware that the rust process is a chemical reaction in which the ferrous metal is trying to revert back to its original form.
I have fought rust for many years including auto restorations. Typically I use OSPHO (available at hardware stores, not home depot, real hardware stores for about $9 a quart. Apply OSPHO direct to the rust . Ospho can stop the chemical reaction. The rust will turn black once it has been neutralized . It is still necessary to use a good primer and finish coat. It is not perfect but often works.

Twelve years ago I installed electronic cathodic protection equipment on 2 vehicles. I met a guy who was in charge of a fleet in Wisconsin and had experience with cathodic protection . He retired to Fl.and was looking for somebody to install it on a car. He acquired 2 kits. I installed one on his vehicle and one on my '94 Pleasureway. (we both lived near salt water.) It sets up a low voltage charge between the steel and the anode. The anodes are sacrificed to save the steel.
I can't testify how well it worked, Marq moved away and i sold the '94 Pleasureway, but somebody here might be interested in checking it out,

I am familiar with electronic cathodic protection. Have a system installed on my balcony to control rebar rusting for 10 yeara. Of course cathodic has been around for ages and is used on every water heater.

Hopefully somebody can solve this problem.

Boater
09-08-2013, 12:32 AM
Jim, that's basically an impressed current CP system, used quite a lot on marine structures. Since the body is already negative it shouldn't be too hard to arrange some anodes, the science part is knowing how many you need to effectively cover the surface area, and how much current you need to pass through the system. Unfortunately it's one aspect I have never calculated myself, the suppliers are the experts, we just give them enough info to do the calcs!

SoCalSprinter
10-15-2013, 04:47 AM
I have rust on my seams that have gone unchecked until now. The result is complete rot thru the length of the seam and it leaks water.😫
I have disassembled the interior to get access and must begin to grind/cut out the rust. I think I'll be left with a gap up to 1" wide in some places. Will the above mentioned methods work (RV-roof tape) with such a large gap?
Or should I find a fabricator and get some welding done?

I don't have any experience in body work and welcome any replies.

Nuke
11-25-2013, 05:46 AM
I hate to revive an old thread :bash:
actually I realized I had chosen the wrong one
so deleated it and came to this one instead :doh:

I'm talking a minor case here
Back seam leaks, small little area where it can be seen
rust has started and allowing water to get in.

So on another thread they said Captain Trolley's creeping Crack cure is an
acrylic copolymer, emulsion-based product :thinking:
with exceptional penetrating properties

So what is an acrylic copolymer, emulsion-based? :wtf:
I'm sure it can probably cure the leak
but does it do anything to cure or prevent future rust which would cause future seam expansion and more leaks?
Hoping one of the professors can enlighten me :professor:

POR 15 says DON'T us a rust converter
Says to thin no more than 5%
But if it was thinned enough to have
Capillary action to get to any rust and prevent its growth
Would that be a viable alternative?
The thinner eventually evaporates right?
We're talking trying to get between the seams without tearing them apart.

So then what about rust converter?
Can that be thinned enough to get capillary action to seek and convert the slight amount of rust that seems to be developing in the Roof seams?

Obviously we want to treat the outside and inside before we install an interior.
Probably need a syringe to pump into the inner seams.

Once I get in the roof vents, fridge vent and whatever other hole I might plan on poking through the roof, I intend to coat the whole thing with white elastomeric roof paint, so there are no seams up there to let anything in. Just want to get the very slight rust treated first so it doesn’t rust and cancer out under my elastomeric.

mean_in_green
11-25-2013, 06:19 AM
Once it gets into the seams it's difficult to fully eradicate. I found POR-15 ok on bare metal, less so if over existing paint. Other two pack systems work better I reckon.

If ordering a new van make part of the "pre-use preparation" application of urethane sealant to all internal roof seams. There are a couple you can't get to because of roof ribs. For these I injected a creeping cavity wax and hoped for the best.