Painting over seams

[stormforge]

I've read the several good threads on dealing with seam rust but I'm still a little perplexed...

My understanding is that the separate body panels are designed to move slightly with respect to each other and are bonded with a fairly wide (as far as these things go) bead of flexible sealant. An archaeological dig into my van's seams appears to show that VW sealed the bare-metal seam and then painted over the whole thing. Isn't it inevitable that the paint is less flexible than the seam sealer and that it is bound to crack and admit water?

To me it seems like the right thing to do would be to get a great paint job on both panels and then seal them on top of the paint (ideally with the same color of sealant!). Or paint, seal, and then some more paint on top -- so that when the top paint cracks there is still a coating to protect the metal.

It seems like most of the Samba seam discussions recommend clean metal, flexible sealant, and then paint. Has this really worked well for people over 5-10 years?

Thanks!
-Bill
'89 Syncro

[ftp2leta]

Hi Bill, panel are spot welded behind that flex (not so flexible after 20 years) seam.

there is no cure! You asked the right question, will it hold foe 3-5 years, yes, no more. It's not a bad idea to apply flex seam sealer over the paint but there is no way to match the color.

The Vanagon where built with many welded panels, they did a good job overall but our vans are now 20+ yo and they where not design to live that long.

That said, broken/light rust seam can be easily maintain with some light/sharp (thin edge) sanding and hand painting.

You can also weld the seam but it's a painful and time consuming job.

Remember that: when doing a body job you work the most rusty/damage area but sometime other seam/part of the van don't show rust now but will in 6 months or a year. That painful because when you did the van all was fine in those area.

I hate bodywork:

After 20 van done or so i ca tell you that there no easy way to fix those, I have tried several solutions and none will fix those at 100%
_________________
Working with rust, grease, dirt and dust is a sad truth.
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[danfromsyr]

one problem that VW should have and never did address is that the INSIDE lip of the seams are jsut 2 pieces of metal and aren't sealed at all.
this wicks moisture into the seam from the rear..

just another area to worry about.
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[insyncro]

Battling rust is in the details.
The more details the better the chance of keeping it from consuming your vehicle.
I have only done complete panel replacement with ust encapsualting paints as the first coat and built up from there.
I have had good success with Wurth Panel, Protective and Undercoatings waxes once the van is repainted.

dylan

[stormforge]

Thanks Ben -- those pics of the seams (and the rust!) are very enlightening! If the seams don't move a whole lot then maybe there is a better way to address them than with a flexible sealer? How about a very careful prep (grit blast & metal-ready) and then fill them with high-quality epoxy strengthened with milled glass fiber?

I'm tempted to go this route and to use the same epoxy as a primer around the seam, then wet-sand, then paint over everything.

Stupid idea?

Thanks!
-Bill
'89 Syncro

[j_dirge]

Curious...

If the seam is not that bad.. and does not need to be cut open or needle blasted.. and it is left intact..
Do you seal/encapsulate from outside and waxoyl (needletip) from inside where accessible?

Or seal/encapsulate from both sides?
_________________
-89 GL Westy, SVX.. finally.

-57 pan f/g buggy with a 67 pancake Type 3 "S"
"Jimi Hendrix owned one. Richard Nixon did not"
-Grand Tour, Season 1, episodes 4 and 5

[insyncro]

True encapsulation is from all sides and must be airtight.
I have purchased a system that uses pressurized wands to gain access to all the "hard to reach" areas.

I only use POR15 products under bodywork and spray a tie coat primer to be able to layer up and over it.
Eastwood and Marget Paint products for suspension and the underside.
Wurth waxes for all interior and underside treatments.

[stormforge]

Yeah -- I'm definitely a big believer in the various wax products. I sprayed both sides of my seams with LPS-3 (probably not even as good as waxoyl for that application) and it pretty much stopped the rust in its tracks for a couple of years...

Here are some pics -- it seems pretty obvious that the water/rust snuck through from behind...

Time to start digging out all that old sealer.

Cheers,
-Bill
'89 Syncro

[ftp2leta]

Hi again, look under the seam (your picture), it's already pitted (little cavity), THIS is the real problem. You need to get rid of that and there is no easy way. It need to be grinded deeper and you may make a lot of holes. The holes can be fix from the inside, you need to weld some metal plate (small strip) so you can reinforce and grind deeper. Sand blast in the way to go but it's messy. I'm not talking about a 50$ sand blast machine.


Ben
_________________
Working with rust, grease, dirt and dust is a sad truth.
------------------------------------------------------
FI part for sale: http://www.benplace.com/parts_sale1.htm
My site: http://www.benplace.com/vw2.htm
Subi conversion: http://www.benplace.com/vanaru_eng.htm
Youtube http://www.youtube.com/user/ftp2leta

[Corwyn]

I'm going to disassemble my Westy and POWDERCOAT all the body panels (NOT); but it would look nice . . .
_________________
'90 White Westy ("The Longship")
FAS Gen V 2.0
The Annual Baja Rally
https://www.thesamba.com/vw/forum/viewtopic.php?t=604813&highlight=baja

"If anything's" gonna happen, it's gonna happen out there"
~ Captain Ron ~

[stormforge]

OK -- I have some more time to dig into these seams. I'm a little mystified by the internal geometry of these panels. Here's a view inside the wheel well. Where does the inner edge of the piece of metal that forms the outer wheel arch end? A, B, or C? When it ends is it also tack welded and glued?

Does this piece and the internal metal under the bed form a little hidden cavity? With a portion of the seam cleaned out I can slide a little blade about 3.5 inches into the seam and then I hit something. The blade comes out all covered in powdered rust. How do I get to this hidden area to take care of it? Should I drill a little access port from above and fill it with waxoyl?

A side question -- does the filler I've exposed indicate some previous body work, or is that possibly from the factory?

Thanks!
-Bill
'89 Syncro

[Worms]

[FNGRUVN]

Here's why we'll never get rid of seam rust.

The rust goes all the way across where two panels overlap. Fixing it on the outside and on the inside won't do anything to get rid of what's sandwiched between. Rust never sleeps.
_________________
"Democracy is two wolves and a lamb voting on what to have for lunch. Liberty is a well-armed lamb contesting the vote." - Benjamin Franklin

[240Gordy]

[toomanyveedubs]

[stormforge]

My van is a non-westy and the main side seams are solid. Everything looks clean and good when I take off the inside trim panels. My problem is the wheel arch seam and I don't think there's any way to get to the back of that one...

I have a nice little spot blaster that does a great job on flat metal. It's hard going on the flexible seam sealer though and the grit blasts out sideways through the seam so it makes a pretty huge mess. Plus, if you succeed in blasting through the sealer you'll be filling the void in the wheel arch with grit -- not so great. I've had best luck with a #7 exacto blade and a little razor saw. Slow work though. The total seam width between the spot welds is only about 1/32" so there's not much room to get more serious tools in there. Plus the spot welds are about every 2-3" so you can't simply run down the length of the seam.

FNGRUVN -- your picture is great! I think that shows the exact place I'm working? So in my picture above it looks like the inner edge of that void is about at position "B"? That means it's a pretty small, triangular-shaped void? Right now I'm thinking the best approach might be to finish cleaning this seam out, hit it with phosphoric acid, seam-seal, and paint. Then I might drill an access hole from inside the van to get to that void and fill it up with waxoyl. Has anyone else tried this?

Cheers,
-Bill
'89 Syncro

[ftp2leta]

[FNGRUVN]

[stormforge]

YES! Pics would be VERY helpful.

Thanks!
-Bill

[VanMan2009]

Hey guys, not to hijack but I have a related question. Ben, I know you've done some amazing work on these vans and your opinion is highly regarded. It sounds like you guys think you can never really repair seam rust, without welding in new metal? I have a westy that has the beginning of some seam rust in the usual spots. It's not bad yet, you can just barely see the rust coming through. I've been told this is 'repairable' but I'm not looking for a 3-5 year solution. Is that the best you can hope for with products like POR15 and the like? If you do a thorough job and attack it from inside and out can you address rust "permanently" in this way? I've seen a lot of posts from people that have done this, and I'd think it wouldn't be a popular method if it didn't work. But it seems like from this thread you guys don't think there's any way to fix it permanently. I don't like to think my van is destined to a slow death unless new metal is cut in.