Rusty sunroof pan.

[tjk68]

Hello, I have a 1971 bay, with sunroof, it has rusted out at the rear of the pan where it drains and connects to the drain pipes, just wondering about ideas of best way to repair this?

[SGKent]

it you want it done right the top has to come off after drilling spot welds, then the sunroof pan, and the reinforcement area. Then make the replacement steel. Because three pieces of untreated steel come together, and because the area sweats from condensation, almost every sunroof bus made will have some rust in this area after 40 - 50 years. This is one reason I don't recommend sunroof buses to folks unless it has already been restored. I had the damaged areas on mine filled in with a zinc process.
_________________
“Most people don’t know what they’re doing, and a lot of them are really good at it.” - George Carlin

[Jack_O_Trades]

I have the same issue with my 69. The passenger side rear corner is rotted out. I'm look at tackling this from below without removing the roof.

I think I can replace the section that is rotten from below but then my concern is with getting the remaining rust stabilized and sealed up.

SGKent,

what are your thoughts on trying to do this from the access you have through the sunroof channel? I was thinking of using the POR15 system to treat the remainder of the rust.

[SGKent]

there are layers. The rust forms in between and eats away all the layers from within. I have no idea how someone can fix it properly without disassembling it and reassembling the pieces after they are individually repaired. The rust can be slowed significantly with a zinc repair after digging the rust out.

roof
pan
support pan
supports

https://www.thesamba.com/vw/forum/viewtopic.php?t=...t=roof+pan



.
_________________
“Most people don’t know what they’re doing, and a lot of them are really good at it.” - George Carlin

[Jack_O_Trades]

[SGKent]

the rust is also there between the layers - it just hasn't broken thru yet. The problem is condensation gets in there on the untreated metal and forms rust between layers, especially near the spot welds.
_________________
“Most people don’t know what they’re doing, and a lot of them are really good at it.” - George Carlin

[lil-jinx]

Depending on what level of restoration you're doing,you could just spray it with fluid film or other rust protection spray to prevent further rust,then add a respray to your yearly maintenance routine.
_________________
https://www.thesamba.com/vw/forum/viewtopic.php?t=620186
https://www.thesamba.com/vw/forum/viewtopic.php?t=668799
1974 Bay Westfalia. she likes to be called Ethel.
1968 Dune Buggy
1974 parts bus
A smart man learns from his mistakes,a very smart man learns from other's mistakes.

[Abscate]

I think thats a major Fuster Cluck to get that rust out of there - a serious piece of body work. It doesn't make a lot of sense to POR one side of rusty metal.
_________________
.ssS!

[Jack_O_Trades]

I started digging into this problem and think I might have an action plan.

I started drilling out the spot welds on the passenger side starting from the rear and working my way forward. There are two rows of spot welds on each side that you have to get to.

Initially I just wanted to peel back the supports to assess the damage. Upon further inspection on both sides the damage is more extensive than I originally thought (this is where you can say I told you so).

I'm actually more concerned with the driver side rust. From the opening of the sliding sunroof to the rear of the vehicle the pan is attached to the roof panel with the supports and some kind of foam sealant. It looks like on the driver side, the foam let go or was never attached. It doesn't look compressed. This allowed any water that would have pooled in the pan to evaporate and condense on the unprotected portions of the roof panel.

From a cursory visual inspection, it looks like all of the rust is isolated to the rear of the vehicle (behind the sunroof opening). Just playing around with drilling out the spot welds of the supports to the lower pan, and tugging on the pan it looks like the rear half of the pan could be removed if you decouple if from the supports. It seems evident that the it's not that well attached to the roof. My thoughts are that if you cut the pan, just before the spot welds of the pan to the roof (on both sides), then drill out all the support spot welds and bend down the supports; you could drop the sunroof pan.

With the pan down, it makes addressing the rust and rot a lot more realistic.

Is this a crazy, dumb, half-assed attempt at the repair?

[Jack_O_Trades]

Today, I butchered my bus. There was more cutting and drilling than I initially thought. In general, I started from the rear and worked my way forward. I first cut through the rear supports. I then drilled out all the spot welds on both sides of the pan. I then pulled back the supports so that I would be able to drop the pan.

On each side fo the pan there are two cross member that need to be cut back. I originally cut them free of the pan but realized that they still captured the pan because of the lip around the pan. So they had to be cut back. With the rear two member cut, The pan is free to drop/sag.

I then moved to the middle of the pan or the rear of the sunroof opening where I would make my two cuts in the pan dropping only the section I was interested in. I wanted to take the middle drain ports with the pan so that I could work on some rust damage on these. This was trickier than expected. The cutting wasn't too bad but unexpectedly, the pan was spot welded to the hidden third layer of material. This is a piece of metal that reinforces/stiffens the sunroof opening (as shown in this photo).

The spot welds are hidden by the under pan support. So, I had to cut and bend pack the support. I was hoping to avoid cutting the support but there was no way around it.

With all the cuts made, and the spot welds drilled out, the pan was free and clear to come out.

And here are the fruits of this PITA. And now it should be easier to stabilize and repair this rust.

[Jack_O_Trades]

I've did some shopping this weekend and ordered some replacement weather stripping between the pan and the roof.

Here is the original

And the new stuff. I am replacing the old stuff with 3/8" EPDM Foam stripping from McMaster. The new stuff looks and feels the same and is weather resistant, rated for outdoor use.

I've also started to tackle the rust. I am trying to get the crusting out of the nooks and crannies and start welding in the voids.

[Jack_O_Trades]

I have been busy with this little project. I got all the rust repaired, stabilized any existing surface rust, and painted the parts. I'm giving the paint a couple of days to get hard and will then glue on the foam weather stripping and weld the pan back in.

This was the biggest hole of many that I patched

The donner piece

tacked in place

All welded up

From the inside with all the major holes plugged up.

The surface rust on the other corner of the pan.

On the opposite side of the pan, I scrapped off the old batting. I want to put a fresh coat of paint after it's installed and I also want to lay up some sound deadening.

I started by scrapping off the batting with a plastic putty knife. For the most part they came off in one piece. Then I hit the glue with some 3M 08987 adhesive remover.

On the roof, I went ahead and stripped the paint and treated any rust. Truth be told there wasn't really any rust on the roof but there was plenty along the support ribbon.

Here is the pan again getting some Ospho treatment. I went back later and stripped the remainder of the paint and did another Ospho treatment. If you can't afford the time to do it right the first time you certainly can't afford the time to do it a second time. I saw that quote recently and thought how true it was. Me, I've got gobs of time so I do things over and over again.

With the Ospho dry, I went ahead and primed and painted the roof and pan. I brushed on a coat of primer and two coats of paint. Hopefully that will fend off any rust for awhile. I also sprayed the areas that I would be welding with weld through primer.

[Jack_O_Trades]

On a side note: Now that I have access to the roof, I'm %90 certain that I want to throw up some sound deadener while access is available. The only caveat that I see is if the deadener were to fall off sometime in it's life, I might make a gooey mess. From my experience with Dynamat as a professional installer, I have never seen it fall off if applied properly.

Thoughts?

[busdaddy]

WoW!, you aren't messing around!, nice work!

The sound deadener wouldn't hurt as long as you are confident it'll stay in place, the goo wouldn't concern me as much as a section sagging and interfering with the sunroof.
_________________
Rust NEVER sleeps and stock never goes out of style.

Please don't PM technical questions, ask your problem in public so everyone can play along. If you think it's too stupid post it here
Stop dead photo links! Post your photos to The Samba Gallery!

Слава Україні!

[dasdachshund]

Wow, all the pics are great. Keep up the good work.

-dasdachshund

[Wasted youth]

That's a serious piece of work, thank you very much for contributing this thread with all your pictures and notes. I can't say that I've read or seen any thread where somebody actually did this much work.

[Jack_O_Trades]

Thanks for the nice words guys. With as much as I have gotten out of this forum. I certainly have no problem trying to share my experiences, albeit from a casual weekend warrior.

With the paint good and dry, it was time to glue on the weather stripping.

I used 3M 08008 Black Super Weatherstrip and Gasket Adhesive. This is sort of a contact cement/adhesive

The instruction say to spread it out in a thin layer and let dry until tacky. I rolled out about a 3/16" bead and spread it out with an acid brush. You want to apply this thicker than you think. I tried it thin, where you could kind of see through it but it either became too dry or there just wasn't enough goop to bond to the weather stripping.

Once it becomes tacky, it's fairly straight forward to apply the weather stripping. The only advice I would give is to not stretch it out otherwise you run the risk of it shrinking on you. I basically laid it out and then went back and pinched it down.

While I was waiting for the weather stripping adhesive to become tacky, I took the time to install the sound dampening material. This is some stuff that I picked up off e-bay. It's about 1mm thick, and similar to Dynamat.

It has a nice feature of a diamond pattern. You are supposed to roll the pattern out. That's how you know you have applied it properly. In this photo, the one on the left has been rolled out and the one on the right has yet to be rolled out.

I decided to not completely cover to roof. I tried to do a pattern that would look somewhat stock.

Now it's time to slide the pan back in.

The drains want to get hung up on stuff as you slide the pan back in. However, with a little bit of finagling, it goes back in.

With the fresh weather stripping, There is some resistance to getting the pan back in place. So I let the rear sag and get the front cuts lined up.

I then put down a couple of tack welds

Now I go back to the rear and jack up the pan getting it pushed nice and tight against the roof.

I go back to the front and look through the opening and make sure I can see no light between the pan and the roof. Everything looks good here.

The next step is the keep jacking up the pan and weld in the four side support struts that were cut out and the rear support straps. At this point I'm beginning to not like welding overhead.

There is still a lot of welding ahead of me. After the supports are welded up I will need to go back and bend back the support strips and re-weld all the spot welds. I will also need to repair the paint as it well get destroyed from the heat of welding.

[Jack_O_Trades]

I have been on a seven-month hiatus with my bus but I am back into it. I figured I should close out my work on this portion of the project.

After initially getting the drip pan back in, I now had to weld back all those spot welds that I drilled out and bend the support strips back into place. This was tedious which is why I have avoided the work. Pretty much everything about it sucks. Your welding overhead, dealing with weldthrough primer, dealing with thin metal, etc.... The first day, I wasn't wearing enough protection and ended up with some pretty good splatter burns. By the end of the week I had, it figured out.

It took another week to grind down the bulbous welds. I suppose I didn't really have to do this since it will be hidden by the headliner but what the hell.

Everything is welded up and ground flush.

You can imagine, after welding the drip pan in, I was going to now have to deal with the damage to the paint on the inside of the pan. My plan was to scrape the dead paint out, primer, and repaint. I would do this with all my tools duct tapped to rods so that I could reach all the way to the back of the cavity.

By the end of the today, I had everything in a coat of primer

The final step is to paint the inside and the underside of the drip pan to the final color. I'll give the primer a couple of days to dry since it went on heavy.

[ivwshane]

Damn! Impressive!
_________________
77 westy 2.0 FI
69 ghia coup 1600dp
70 single cab

[SGKent]

before you are completely done and make your final paint, be sure that the drip tubes in the B pillar are open and not rusted thru.
_________________
“Most people don’t know what they’re doing, and a lot of them are really good at it.” - George Carlin