Discussion regarding T6 ONLY roof corrosion

[burnercan]

I haven't read through the 200+ pages on this T5-T6 subject but I'll offer this:

A couple of products in use in aviation to slow and/or prevent galvanic corrosion (corrosion between dissimilar metals, steel and aluminium in this case): CorrosionX and ACF-50. Both are slightly oily liquids, like highly glorified WD-40, and as such need to be reapplied when washed off. Aircraft skins are almost always a mid-grade aluminum and most anchor nuts and many other fittings made of steel often riveted directly onto the skin. Typically this doesn't pose a big problem because the joints are, for the most part, dry unless it rains. Fresh water isn't a superb electrolyte but when salt is added it suddenly is. So seawater, in the case of aircraft I have maintained, or salty grime in the case of a Cali pop top seal on a wintery road, can make the problem nearly uncontrollable. Low coastal areas may also have high salt content in the air, making the rain equally destructive as is rinses salty deposits off of surfaces concentrating them in areas where the run-off collects. Such as, you guessed it, in the roof seal. I've tested/used both of these products with good results on areas where this type of corrosion was problematic. And no, I don't work for either of these guys...

On the old Westys, the pop top seal was held in place with a metal grip. Over time, the grips would rot out and the seal would fall off. This wasn't a galvanic reaction since there was only one metal, but that one metal was cheap, untreated carbon steel so as soon as it gots wet it would just rot. Since the top was fibreglass all that needed doing was to replace the seal and she looked just like new. Retro-fit seals for a T3 Westy are certainly available without the metal and work just fine. As has been suggested/asked here, the profile for the T5-T6 top is probably available as well. The good news is, once you remove the the electrical potential by removing one of the dissimilar metals, the corrosion will pretty much stop. So if the damage isn't too bad, at least it won't get any worse.

When I get my spanky new Beach (in approximately the time it takes for a baby to arrive from conception) the first thing I will do is remove the seal and apply one of the above mentioned products. Then I'll set about finding a non metallic replacement seal. Since it will be inside the seal, it shouldn't wash out easily so may only need to be applied once every year or so.

Can't wait!!!!

 

[Jabberwocky]

I haven't read through the 200+ pages on this T5-T6 subject but I'll offer this:

A couple of products in use in aviation to slow and/or prevent galvanic corrosion (corrosion between dissimilar metals, steel and aluminium in this case): CorrosionX and ACF-50. Both are slightly oily liquids, like highly glorified WD-40, and as such need to be reapplied when washed off. Aircraft skins are almost always a mid-grade aluminum and most anchor nuts and many other fittings made of steel often riveted directly onto the skin. Typically this doesn't pose a big problem because the joints are, for the most part, dry unless it rains. Fresh water isn't a superb electrolyte but when salt is added it suddenly is. So seawater, in the case of aircraft I have maintained, or salty grime in the case of a Cali pop top seal on a wintery road, can make the problem nearly uncontrollable. Low coastal areas may also have high salt content in the air, making the rain equally destructive as is rinses salty deposits off of surfaces concentrating them in areas where the run-off collects. Such as, you guessed it, in the roof seal. I've tested/used both of these products with good results on areas where this type of corrosion was problematic. And no, I don't work for either of these guys...

On the old Westys, the pop top seal was held in place with a metal grip. Over time, the grips would rot out and the seal would fall off. This wasn't a galvanic reaction since there was only one metal, but that one metal was cheap, untreated carbon steel so as soon as it gots wet it would just rot. Since the top was fibreglass all that needed doing was to replace the seal and she looked just like new. Retro-fit seals for a T3 Westy are certainly available without the metal and work just fine. As has been suggested/asked here, the profile for the T5-T6 top is probably available as well. The good news is, once you remove the the electrical potential by removing one of the dissimilar metals, the corrosion will pretty much stop. So if the damage isn't too bad, at least it won't get any worse.

When I get my spanky new Beach (in approximately the time it takes for a baby to arrive from conception) the first thing I will do is remove the seal and apply one of the above mentioned products. Then I'll set about finding a non metallic replacement seal. Since it will be inside the seal, it shouldn't wash out easily so may only need to be applied once every year or so.

Can't wait!!!!

Welcome, especially with good information about anti corrosion methods!

 

[sbmcd]

I haven't read through the 200+ pages on this T5-T6 subject but I'll offer this:

A couple of products in use in aviation to slow and/or prevent galvanic corrosion (corrosion between dissimilar metals, steel and aluminium in this case): CorrosionX and ACF-50. Both are slightly oily liquids, like highly glorified WD-40, and as such need to be reapplied when washed off. Aircraft skins are almost always a mid-grade aluminum and most anchor nuts and many other fittings made of steel often riveted directly onto the skin. Typically this doesn't pose a big problem because the joints are, for the most part, dry unless it rains. Fresh water isn't a superb electrolyte but when salt is added it suddenly is. So seawater, in the case of aircraft I have maintained, or salty grime in the case of a Cali pop top seal on a wintery road, can make the problem nearly uncontrollable. Low coastal areas may also have high salt content in the air, making the rain equally destructive as is rinses salty deposits off of surfaces concentrating them in areas where the run-off collects. Such as, you guessed it, in the roof seal. I've tested/used both of these products with good results on areas where this type of corrosion was problematic. And no, I don't work for either of these guys...

On the old Westys, the pop top seal was held in place with a metal grip. Over time, the grips would rot out and the seal would fall off. This wasn't a galvanic reaction since there was only one metal, but that one metal was cheap, untreated carbon steel so as soon as it gots wet it would just rot. Since the top was fibreglass all that needed doing was to replace the seal and she looked just like new. Retro-fit seals for a T3 Westy are certainly available without the metal and work just fine. As has been suggested/asked here, the profile for the T5-T6 top is probably available as well. The good news is, once you remove the the electrical potential by removing one of the dissimilar metals, the corrosion will pretty much stop. So if the damage isn't too bad, at least it won't get any worse.

When I get my spanky new Beach (in approximately the time it takes for a baby to arrive from conception) the first thing I will do is remove the seal and apply one of the above mentioned products. Then I'll set about finding a non metallic replacement seal. Since it will be inside the seal, it shouldn't wash out easily so may only need to be applied once every year or so.

Can't wait!!!!

Very interesting thank you.

Had a look at the AFC 50 website, they also do a grease compound which I think may be better suited to our roof corrosion issue as if you fill the seal before fitting it would also exclude the water / electrolyte.

My roof gets done this month, I shall let the paint cure for a couple of weeks before I apply anything, at the moment the choices are, silicon grease, AFC grease or a barrier tape as used by VW on the latest pop up roofs since end 2016.

Not certain of the long term effect of the grease compounds on the paint so currently think tape may be the best route?

A non metallic seal would be the best option but it will have to grip well enough, I would hate to pop the roof in winter and find the seal still frozen to the van. Note the seal section is different at the front and sides/rear, the VW one is bonded at the join on the front corners. Do keep us posted if you find something suitable.

Despite continued requests VW have still not got back to me with details of the protective tape the are now using.

 

[sbmcd]

Just had an email from VW, the dealer now has a part number so tape can now be ordered from VW, I have asked for a price.

 

[gazmungo]

Hi folks,
I'm a newbie here thinking of buying a California. I've read the thread and many others on the forum and think, but am not sure, of two things. Could anyone confirm/disconfirm?

1. The roof corrosion issue is a VW SE/Ocean/Beach/etc. issue, not a T5/T6 issue (e.g., not a known problem with T5s/T6s converted elsewhere)?

2. The corrosion is cosmetic, but wouldn't be visible unless one where (i) standing up high somehow and looking at the roof (which is normally too high to be seen unless you're super tall), and possibly even (ii) doing that, while lifting a rubber seal or piece of trim?

Apologies if these questions have been answered. I have tried to find the answers via reading and the search function.

thanks!

Nick

 

[Jabberwocky]

Just had an email from VW, the dealer now has a part number so tape can now be ordered from VW, I have asked for a price.

Long time no speak! Trust you are well and still exploring. Can you share the part number and cost when you have it? Cheers, Sp soon.

 

[sbmcd]

Long time no speak! Trust you are well and still exploring. Can you share the part number and cost when you have it? Cheers, Sp soon.

Still enjoying my adventures in my California, will share the info when I get it.

 

[burnercan]

Just had an email from VW, the dealer now has a part number so tape can now be ordered from VW, I have asked for a price.

Does anyone know if this means that new builds will already have the 'tape' installed, or has anyone seen what kind of material it is?

In any case, experience with how VW handles niggles like these says to me that this quite literal band-aid to a design flaw probably won't solve the problem consistently. Imagine some sort of presumably thin plastic or pvc tape applied between a friction fit of two metal components: The possibility for the tape to be cut or otherwise compromised by the installation sounds pretty high to me. Now the metals would be back in contact and you'd also have the tape in there to make sure that it is harder for any accumulated moisture to evaporate.

I will still have a look at mine when I receive it to see for myself what's up.

 

[B J G]

I was going to do a check on mine when I spotted some tape showing on the rear nearside corner. Therefore I'd suggest having a good look around to see if any showing.
March 2017 T6.

 

[sbmcd]

I was going to do a check on mine when I spotted some tape showing on the rear nearside corner. Therefore I'd suggest having a good look around to see if any showing.
March 2017 T6.

View attachment 26431

Tape should be fitted to all elevating roofs after end 2016.

Just found out the tape VW supply for this as a spare part is only 15 mm wide, that suggests that it is only the outer edge of the roof that is covered. My roof has corrosion / blistering paint on inner and outer edges below the seal.

I am nterested to know from anyone that has a 2017 California can see any evidence of tape on the inside edge of the roof.

 

[Bearreds]

Could they be driving the special Editions? They have a blacked out roof panel on the top but the canvas is still the same.

Ah right! didn't realise that !
You are possibly right as they are black up to the rail bar grooves , as I hadn't seen this before and there were so many new Californias with this black roof , I thought they might of done something about the corrosion issue !
If only !!!

 

[Jabberwocky]

Tape should be fitted to all elevating roofs after end 2016.

Just found out the tape VW supply for this as a spare part is only 15 mm wide, that suggests that it is only the outer edge of the roof that is covered. My roof has corrosion / blistering paint on inner and outer edges below the seal.

I am nterested to know from anyone that has a 2017 California can see any evidence of tape on the inside edge of the roof.

Tape on inside?
This is on inside rear. How far it stretches round or how wide it is I am not sure. I will see if I can find a section where there is evidence of tape on both sides. I have this other photo where the tape is visible on the outside. What I noticed on BJG's photo is it looks as if the tape has a step in it or is at a joining point.

 

[sbmcd]

Tape on inside?
This is on inside rear. How far it stretches round or how wide it is I am not sure. I will see if I can find a section where there is evidence of tape on both sides. I have this other photo where the tape is visible on the outside. What I noticed on BJG's photo is it looks as if the tape has a step in it or is at a joining point.View attachment 26488
View attachment 26487

Thanks, it looks like tape inside as well from your photos, that suggests there is a join, overlap or gap on the roof edge assuming factory also fits the 15mm wide tape. This would certainly make it easier to fit but risks an ingress point at the join.

I am in correspondence with ACF 50 re their grease product to determine if it could have any detrimental effect on the paint. I am now thinking apply the tape inside and out as VW do then fill the roof seal with ACF 50 grease before fitting to fill any voids, that should prevent any water accumulation in the seal and provide anti corrosion properties inherent in the product. Will keep all posted on developments.

My van is booked in for 12 Oct.

 

[Hotel California]

All who are wondering if-why-what tape is under the roofseal on the T6.
Just pull the seal off about 30cm do it on the long side when the roof is up you will see the tape . And push the seal back on , you will not damage nothing , you will not loose your warrenty ...don't panic to much.
I pull the whole rubber seal away afther a clean my Cali (T5 ) to see how my corrosion evolves without tape on and never had a issue with the seal itself .

The tape should be there on ALL T6 models from about the begin of this year .
It is transparant tape the they put on with a special tool , a roller witch bends the tape in 1/2 as so it goes as wel on the outside and the inside (underside) of the roof .
Those who where with my group during the factory visit witnessed the tape beeing put on as example .
https://vwcaliforniaclub.com/thread...tour-hannover-important-updates.15758/page-19
VW told us it is to prevent the corrosion on the roofs edge . Meaning less risk of dirt/sand scratching thru the paintlayer causing the corrosion between the alu roof and the metal structure in the roofseal.

If the tape now can be orderd as part from VW spare parts i am not aware until posted here above , but....
I read on here not many even dare to look under the seal so wonder how many will get the tape and put it on themselves....? Witch also is not an easy job to do propperly and in a even line...
Just let VW deal with the problem under warrenty or live with it is my point of view.

 

[leightonjthomas]

All who are wondering if-why-what tape is under the roofseal on the T6.
Just pull the seal off about 30cm do it on the long side when the roof is up you will see the tape . And push the seal back on , you will not damage nothing , you will not loose your warrenty ...don't panic to much.
I pull the whole rubber seal away afther a clean my Cali (T5 ) to see how my corrosion evolves without tape on and never had a issue with the seal itself .

The tape should be there on ALL T6 models from about the begin of this year .
It is transparant tape the they put on with a special tool , a roller witch bends the tape in 1/2 as so it goes as wel on the outside and the inside (underside) of the roof .
Those who where with my group during the factory visit witnessed the tape beeing put on as example .
https://vwcaliforniaclub.com/thread...tour-hannover-important-updates.15758/page-19
VW told us it is to prevent the corrosion on the roofs edge . Meaning less risk of dirt/sand scratching thru the paintlayer causing the corrosion between the alu roof and the metal structure in the roofseal.

If the tape now can be orderd as part from VW spare parts i am not aware until posted here above , but....
I read on here not many even dare to look under the seal so wonder how many will get the tape and put it on themselves....? Witch also is not an easy job to do propperly and in a even line...
Just let VW deal with the problem under warrenty or live with it is my point of view.

The problem is that they will not use the tape as part of the warranty repair. My T5 was repaired in August but I found evidence of bubbling under the seal before I had even driven it away from the dealer. It's going back in on 13 November.

 

[leightonjthomas]

Thanks, it looks like tape inside as well from your photos, that suggests there is a join, overlap or gap on the roof edge assuming factory also fits the 15mm wide tape. This would certainly make it easier to fit but risks an ingress point at the join.

I am in correspondence with ACF 50 re their grease product to determine if it could have any detrimental effect on the paint. I am now thinking apply the tape inside and out as VW do then fill the roof seal with ACF 50 grease before fitting to fill any voids, that should prevent any water accumulation in the seal and provide anti corrosion properties inherent in the product. Will keep all posted on developments.

My van is booked in for 12 Oct.

 

[leightonjthomas]

Thanks and good luck with the repair.

 

[sbmcd]

All who are wondering if-why-what tape is under the roofseal on the T6.
Just pull the seal off about 30cm do it on the long side when the roof is up you will see the tape . And push the seal back on , you will not damage nothing , you will not loose your warrenty ...don't panic to much.
I pull the whole rubber seal away afther a clean my Cali (T5 ) to see how my corrosion evolves without tape on and never had a issue with the seal itself .

The tape should be there on ALL T6 models from about the begin of this year .
It is transparant tape the they put on with a special tool , a roller witch bends the tape in 1/2 as so it goes as wel on the outside and the inside (underside) of the roof .
Those who where with my group during the factory visit witnessed the tape beeing put on as example .
https://vwcaliforniaclub.com/thread...tour-hannover-important-updates.15758/page-19
VW told us it is to prevent the corrosion on the roofs edge . Meaning less risk of dirt/sand scratching thru the paintlayer causing the corrosion between the alu roof and the metal structure in the roofseal.

If the tape now can be orderd as part from VW spare parts i am not aware until posted here above , but....
I read on here not many even dare to look under the seal so wonder how many will get the tape and put it on themselves....? Witch also is not an easy job to do propperly and in a even line...
Just let VW deal with the problem under warrenty or live with it is my point of view.

Thank you for that information on the seal fitting at the factory. Interesting that the tape now being supplied as a roof part is 15 mm wide, the seal itself is 9 mm deep on the sides and rear, to cover inner and outer edges you would require a minimum of 20mm wide tape.

The roof warranty will not last for ever, while I appreciate your point of view, I would prefer to try and fix this problem to prevent re occurrence. The materials required are low cost and the job is relatively easy.

 

[Digger]

With all their knowhow it is beyond belief that VW have not found a solution to this issue. I still think the load area protector paint is the best solution as a permanent impervious barrier which can be overpainted just covering the seal area.

 

[WelshGas]

With all their knowhow it is beyond belief that VW have not found a solution to this issue. I still think the load area protector paint is the best solution as a permanent impervious barrier which can be overpainted just covering the seal area.

JLR and its predecessors never found a solution for the same problem on the Land Rover Defender from the Series 1 to the Puma, same problem and same cause.

 

[Digger]

JLR and its predecessors never found a solution for the same problem on the Land Rover Defender from the Series 1 to the Puma, same problem and same cause.

True and I owned 3 Defenders over the years but that was different. The only contact area on the Cali now is between the seal and the roof itself. That is the only area requiring to be isolated. The other point is other vehicles today have aluminium panels or bodies apparently without this problem.

 

[WelshGas]

True and I owned 3 Defenders over the years but that was different. The only contact area on the Cali now is between the seal and the roof itself. That is the only area requiring to be isolated. The other point is other vehicles today have aluminium panels or bodies apparently without this problem.

True, but normally they are fixed panels that don't require an edge seal that is bound to move when the the roof is opened and closed. The seal has to be firmly fixed as, in my experience, the seal can often be stuck to the roof due to dirt/tree sap etc: and when closed a fair amount of force is applied to the seal. Just try closing the roof with a sheet of paper under the seal. Difficult to pull out when closed.
A different type of seal fixing, maybe glue, rather than a steel insert, or a Non-Aluminium roof panel is the only way I can see a permanent solution being found.

 

[Digger]

I think that between us, WG and the rest of the forum members, we could probably fix the roof problem a lot quicker and cheaper than VW seem to be doing.

 

[Jabberwocky]

It’s a curious thing but I guess VW won’t repair your roof to a better condition from when it was new. i.e. put the tape on.

 

[sbmcd]

Long time no speak! Trust you are well and still exploring. Can you share the part number and cost when you have it? Cheers, Sp soon.

No part number but cost is £19.00 for an 8 m by 15 mm wide roll, available on back order only.

I think I will go for a wider tape to cover inside and out without any joint.

https://www.vikingtapes.co.uk/colle...ape-short-rolls-25mm-x-3m?variant=34688318791