roof seam rust repair

Aqua Puttana

Poly - Thread Finder
Another piggy back on this thread...figured keeping them together makes more sense that not.


...
Any tips would be greatly appreciated.
Does to me too. :thumbup:

You seem a bit picky as to how the roof looks, but are you completely committed?

Back in my building maintenance days and aluminum framed window walls I recall that the contractors used good quality sealants which would likely match your metallic silver color (at least for the roof). You might explore window sealants in silver colors.

:cheers: vic
 

kkanuck

LUV my T1N
Does to me too. :thumbup:

You seem a bit picky as to how the roof looks, but are you completely committed?

Back in my building maintenance days and aluminum framed window walls I recall that the contractors used good quality sealants which would likely match your metallic silver color (at least for the roof). You might explore window sealants in silver colors.

:cheers: vic
I want to use the sealer that was the factory sealer Sikaflex-252 is meant to be the stuff, however, only in black and white.

I figured I clean the seam, put the sealer in the small crack, yet leave the roof flush, so not raised bead of sealer, just filling the crack, and use touchup on top pf that.

Does this sound like a poor strategy? I prefer not to have an ugly seem if at all possible...
 

Aqua Puttana

Poly - Thread Finder
...

Does this sound like a poor strategy? I prefer not to have an ugly seem if at all possible...
You should poll real body paint people.

My experience with automotive body paint over sealants is that it doesn't adhere/last well. The two materials are different in bonding, expansion, contraction, etc.

There are probably newer technology paints and sealants that I'm not aware of.

:2cents: vic
 

skippytdi

Member
I want to use the sealer that was the factory sealer Sikaflex-252 is meant to be the stuff, however, only in black and white.

I figured I clean the seam, put the sealer in the small crack, yet leave the roof flush, so not raised bead of sealer, just filling the crack, and use touchup on top pf that.

Does this sound like a poor strategy? I prefer not to have an ugly seem if at all possible...
If thats your concern then masking tape both sides of the seam and worst case scenaro if someone looks at your roof all they see is what looks like a horizontal pinstripe made of chaulk.
And also if it hasn't been mentioned the best way IMO to get rid of rust is to use pure phosporic acid (home depot and lowes sell it in the paint section its called prep and etch) just remember to wash it off. I've got an 04 and i live in ct. and its practically rust free up and down.

NOTE: test on paint first though i own a black van that went through a period of leapord spotting and i touch up with black matte carc replacement so i could give a flip what my van looks like as long as its close enough and rust free.
 
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skippytdi

Member
I too have leaking rusty seams (see pics below).

My plan is wire brush, then OSPHO (or generic equivalent), Rustoleum rust primer, 3M Marine 5200 Adhesive Sealant, and then Rustoleum Topside paint tinted to match.
About the entire bottom of my van is primered in army jeep parts iron primer they sell it in cans and gallons i haven't had a leapord spot appear in the few years since i went through the trouble. i'm not a fan of rustoleum primer. its not a very good sealer and for a primer to be both a good sealer and a good primer is very doable but imo rustoleum doesn't play that game.
 

kkanuck

LUV my T1N
Another piggy back on this thread...figured keeping them together makes more sense that not.


I have an 04 Sprinter, in metallic silver, which likely, for it's age, has held up well in comparison many other's on this site. The van has lived out of the rust zone all of it's life in Atlanta, with the odd short trip north here and there.

My roof seems are still decent, but am to the point I think I should be proactive.

If you look at my pictures, you will see there is no surface rust to be seen.

The sealer between the seem panels look like it may need to be reapplied to keep the roof from deteriorating.

I just bought some Sikaflex-252 in white which I have read here is the closest to OEM as fart as seem sealer.

My question is, If I do not want to butcher the rook with an ugly coat of tape on this seem, could I clean this as best as possible, apply the Sikaflex-252 in this few millimeter wide seam, and then paint over that with an OEM touchup paint in a small bottle with the brush on end of cap, and they put "clear" on top of that also in the same OEM touchup paint kit?

Would this be a viable fix? Currently, I have no sign of any interior leak. I have not removed the interior panel either at this point to see if there is any interior rust not visible form the exterior.

The main point here, is the paint is metallic, which has been quite decent for longevity, so perhaps repair or fix to a seem may be different technique compared to the white non metallic paint.

Any tips would be greatly appreciated.


I wonder what the best method or tool would be to clean my old seem seeing as I do not have rust (from the top anyways, I have the wagon with interior roof panels that I have never removed) without messing up the metal, or removing paint that would be counter productive, or so it would seem. Pic is in my original post..
 

skippytdi

Member
I too have leaking rusty seams (see pics below).

My plan is wire brush, then OSPHO (or generic equivalent), Rustoleum rust primer, 3M Marine 5200 Adhesive Sealant, and then Rustoleum Topside paint tinted to match.
Please note i just read up on ospho directions and they do not say to rinse and that is not how phosphoric acid is used on metal it is applied then washed off with water before it dries and as the rust gets converted you keep doing the same thing until the rust is gone. if you leave it on until it dries it gets sticky and disgusting. also the sun is ur friend the hotter the metal before you apply the faster it converts just remember that is dries quicker also.
 
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skippytdi

Member
i forgot where i read it but back in the fifties and sixties a custom painter would have a bare steel shell of a car and he would douse it in prep and etch then wash it with water before he dried it and painted it. it sounded like insanity the first time i heard it but its true the steel will get a slight shade of rusty orange after it dries but its nothing to worry about. the corner of my sprinter passenger door had a rust issue so i ground it down to steel, a small triangle section about 3 inches and i treated it with prep and etch and i haven't painted it in five months and its still barely starting to rust.
 

skippytdi

Member
I too have leaking rusty seams (see pics below).

My plan is wire brush, then OSPHO (or generic equivalent), Rustoleum rust primer, 3M Marine 5200 Adhesive Sealant, and then Rustoleum Topside paint tinted to match.
I wonder what the best method or tool would be to clean my old seem seeing as I do not have rust (from the top anyways, I have the wagon with interior roof panels that I have never removed) without messing up the metal, or removing paint that would be counter productive, or so it would seem. Pic is in my original post..
i would use a small scraping tool and however much "damage" you do cleaning the joint is at least how wide your chaulking pinstripe will be. i would NOT * advise working in the sun especially when working with masking tape but you can control the depth of your chaulking pinstripe with multiple layers of tape, that way when you squeegee the chaulk off the joint you ride two tape rails and when its done it looks pretty good. take off tape when chaulk is wet is how i would do it and its funner that way you get to see the fruits of your labor sooner.
 
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skippytdi

Member
Does to me too. :thumbup:

You seem a bit picky as to how the roof looks, but are you completely committed?

Back in my building maintenance days and aluminum framed window walls I recall that the contractors used good quality sealants which would likely match your metallic silver color (at least for the roof). You might explore window sealants in silver colors.

:cheers: vic
:bash:
army jeep parts does not sell a stencilling military white otherwise i was going to say it would be an easy fix for your white leapard. their black matches my sprinter perfectly that sounds like a joke i am half joking. is that the factory white paint job or was that a custom white color? i always wanted the green one the brochure had the picture of the van in the woods. i'm a huge opponent of progress if mercedes would have kept the tin can on the production line by now that van would have a profit margin that would have kept it (*) within a price point of under what it originally sold for and that would have benefited everyone and mercedes would have owned the light medium work van genre. i can't stand the new can the brains on the original are already screwy enough and how the duck do you wash out the sand and salt from the plastic bumper side panels on the new ducks? i threw away my rear fender flares a long time ago i like the look but they are fender suicide unless you remove them every year.
 
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mean_in_green

>2,000,000m in MB vans
I appreciate that this is not a solution to the examples above however if you read this early on during ownership of a Sprinter it is not a bad idea at all to go around the roof's internal lap joints with a few tubes of quality urethane sealant. There's a couple that you can't get to because the ribs coincide, just hit those hidden seams with a creeping body wax down a lance from an aerosol. I've always thought the main cause for these examples of corrosion is likely due to moisture being easily able to enter the joint on the inside of the body rather than from the outside. Force sealant into the seams, put plenty on and you won't have to deal with this down the road (which is good because it will free you up for dealing with corrosion in other areas...).
 
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C3Auto

New member
I appreciate that this is not a solution to the examples above however if you read this early on during ownership of a Sprinter it is not a bad idea at all to go around the roof's internal lap joints with a few tubes of quality urethane sealant. There a few that you can't get to because the ribs coincide, just hit those hidden seams with a creeping body wax down a lance from an aerosol. I've always thought the main cause for these examples of corrosion is likely due to moisture being easily able to enter the joint on the inside of the body rather than from the outside. Force sealant into the seams, put plenty on and you won't have to deal with this down the road (which is good because it will free you up for dealing with corrosion in other areas...).
Thanks
Should I paint over it or spray any rust converter acid over it first or do I just put the urethane sealant on which hopefully encapsulates the light surface rust?
 

mean_in_green

>2,000,000m in MB vans
It was more a suggestion with regards to preventative maintenance really.

If it helps, my own routine for dealing with rust is first to do whatever is necessary to get back to bright clean metal, then application of any of the proprietary rust treatments (e.g. Bilt Hamber), light key, etch prime, light key, fill/shape, light key, glaze, light key, 2k Lechler direct gloss.

For a lap joint such as the roof seam it’s more about getting the rust out. Judicious use of a wire wheel might help, a bodyshop type Roloc or Mule Skinner wheel (wire in resin). Then treat, prime, paint and seal as best you can.

I did see some pretty bad cases of roof joint rot on YouTube involving slit wheel grinders and fibreglass, but they were well advanced examples.

Also the theory that it starts from the inside is just my own thought, based on the observation that rust was first visible inside the roof of my old T1N when the external joints appeared sound. I think 906s (NCV3s) have superior external sealing, but the internal joints are just as exposed as the 903s / T1Ns.
 

Axiom

Mike from Florida Van Man

My girlfriend's Sprinter was pretty bad. We peeled and removed all the old sealant and found plenty of rust underneath. Grinding it out did create more holes, but we patched them with Bondo Fiberglass. It's ugly but it works. We used POR-15 underneath the fiberglass though we have heard conflicting things about it. Mostly that it needs to be applied in THE perfect situations otherwise it will crack later. It also requires a topcoat. We have plans to paint this van so just decided to spray white over everywhere that was bare POR-15. Planning to Raptor line it, so stay tuned for that next part of her conversion!

After a few months in the Florida sun/rain/sun/rain, it's still holding up. It's not pretty but if you're planning to paint anyway, it's not a big deal.

OH and we applied the Fiberglass across each seam from beginning to end instead of just covering holes with it. My thought behind that was that we're removing the old sealant, let's fiberglass it up now.

Cheers.
 

Aqua Puttana

Poly - Thread Finder
Nice video.

Fiberglass can be a good solution. I prefer epoxy to polyester resin. Epoxy is more expensive, but it bonds better for repairs.

A link from a quick search.

Thanks for the info.

:cheers: vic
 

mean_in_green

>2,000,000m in MB vans
I’ve used POR-15 a few times, one good result / several poor so if nothing else the name appears apt. Hopefully yours will be ok. I have to say that I threw the unused tins away.

Some epoxy primer and 2k solvent paint (direct gloss) are far superior in terms of quality, strength and durability. For a repair like this no problem to brush or mini roller on.
 

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