Preplanning tintop to poptop conversion

[msewalson]

So like the title says, I’m preplanning a tintop to poptop conversion. I currently have the whole roof section of an 81 Westy and plan to transfer the roof skin in addition to the fiberglass poptop. I’ve been considering copying FNGRUVN http://www.thesamba.com/vw/forum/viewtopic.php?t=502828 but hesitant since I have no welding skills. I do have a few friends that are competent welders and I’m sure I could get them to give me a hand with the project. But I hate relying on others and like to challenge myself. So I’m considering a whole new approach and thinking about using a panel adhesive to secure the metal roof section. I should note that Mike @ RMW got me going in this direction when we discussed it briefly at Syncro Solstice.

Tentatively my plan is this:
First cut the donor section at the body style line that is directly above the drip rail. I would probably traverse the roof just in front of the B pillar cross member and an inch back from the hatch opening. On the van I will cut an inch up from the body style line and basically make it so the donor section over laps the van section by 1 inch. The goal of cut placements is that they only be visible when the top is up. The reason for the over lapping section is to create an area to use Fusor panel adhesive to bond the two metal sections together http://www.lord.com/products-and-solutions/adhesives/automotive-repair-adhesives/product.xml/289 . Prior to bonding I would dry fit the section and once satisfied with fit, pre drill holes to use as a guide for glue up. Holes will also be used for sheet metal screws which serve the purpose as clamps for curing. I’m considering once the adhesive is cured I would pull the screws and add rivets, still up in the air on that one. I would then paint any bare metal using a quality primer and rattle can paint, which would be temporary until a full professional paint job can be performed.

Some pros to this method would be no welding which avoids any potential damage to the van and sheet metal. Also prevents any corrosion from forming between to two pieces of metal. Minimal tools would be required to pull it off.

Some cons to this method would be non factory look. Also potential fit problems since the section would be sitting up higher, the thickness of the metal.

So with all of that being said I’m seeking feed back from anyone with body work experience, especially experience using panel adhesive.

Photo of cut location on donor roof just above rain gutter.

Photo of cut location at B-Pillar cross member.

Photo of cut location at rear of van near hatch. Still not sure on this one though.

Photo of cut location on van roof, above drip rail.

Thanks,
Matt
_________________
87 Syncro w/EJ22

[Syncro Jael]

From what I remember helping my son do his conversion is that you will need to replace the cross beam that supports the upper bunk.

Drilling out the spot welds and tacking them was time consuming but easy work. My son drilled them all out, I showed him how to tack a few to position the new top and let him have at it. He did a great job.

He has a blog that show much of what was done.

http://wandrerwesty.blogspot.com/2012/09/putting-it-all-back-together.html

Maybe this will give you some ideas.

It is was fun doing this with my son.
_________________
1987 Syncro Westfalia Hightop - NAHT
Subaru EJ25 Forged Frankenmotor, Triple Knob.
Jael = (Mountain Goat)

[msewalson]

Syncro Jael,
You're right about the cross beam and that is something I would need to figure out prior to bonding the donor roof to the van.

I'm sure I could pick up welding fairly easily but I'm really not wanting to invest any money in additional tools. I also don't think it would be any more solid than going the panel adhesion route. I've also heard some horror stories of corrosion when welding two panels together especially when they are situated in a way to trap moisture. Granted they pulled it off in a factory but that's a controlled environment and a process we are unable to replicate in our garage.

Thanks for the link, a lot of pics available to study. I like your guys approach, drilled out the rain gutter spot welds and traverse cuts at front and back, something I haven't seen yet. It's a combo between Ricks install and this one, http://www.thesamba.com/vw/forum/viewtopic.php?t=364878 . Kinda like the saying goes, more than one way to skin a cat.

Matt
_________________
87 Syncro w/EJ22

[16CVs]

I did this just about a year ago. I did the full job front glass pinchweld to back and to the rain gutters ,as well as the inside supports. I think it is less of a job then you think , Over lapping it and gluing it you'd hate your self later. The only thing I would do differently is I would cut the back like you are doing and step the metal on the receiving van and just weld across the back. Getting through the back part where all those panels come together is dicey ,they have brazed a lot of it because they could not get in there to weld it .
Setting up the roof top hinge plates is critical and have to be welded before the roof goes on. There are locations for it but be diligent when removing these because use you need all the metal you can get .
Drilling out the spot welds on both roofs is about a weekends job ,buy your self a "Rotobroach" and learn to use it . Most of this job is drilling ,cutting and fitting ,you could do most of the work yourself and pay a pro to weld it all up for you if screw it all in place . I would think it would be 3-5 hrs of welding ,you can clean and dress the welds yourself . Buy some Weld through primer and use it liberally when assembling your roofs.
Think about any wiring mods that need to be dropped down the pillars before the roof goes back on . Wiring such as Lighting ,PDL's or whatever now is the time to do .
I have photos of mine ,but this has been documented enough my photos look like everyone else's.
Beside the cost of a "Rotobroach" (not a Harbor Freight Chinese copy)I spent about a $100.00 in supplies and primer.
A buddy of mine ( a sheet metal guy with a welder) pushed me along and we had it done in 3 weekends working mostly Saturday's with both of us, and me doing clean up and prep when he was gone.
Good luck ,take it in bite sized chunks and don't burn out in the middle ,that is a good way to turn a usable van to a worthless hulk .



Stacy
_________________
1987 Syncro Westfalia Triple knob (bastard)
1989 Syncro Tristar Triple knob "Swedish"
2013 Jetta Hybrid a true "Zwitter"
Samba member # 14980
Call anytime number 650 722 4914 .
Keep Your van running and upkept tastefully for the love of the hobby.
Don't let your van end up in an "abortions" thread.

[DLJ]

I have just finished my ninth westy top install. It is a lot of work but certainly doable by yourself. (except lifting pop top on to receiving van). I do the conversion pretty much like your planning.
I use the aluminum moulding that holds canvas as a cutting guide. Screw it down on the donor van and cut along the outside. You should end up with ONE piece to include "C" pillar crossmember. You should have about a one inch overlap with the receiving van.
Cut the roof off the receiving van using the inside body frame as a guide. Cut behind the "B" pillar, using it a s your guide. Do the same at the rear hatch area. You picture of where you plan on cutting this area is good. But I like my way of following the aluminum strip better. I have done it both ways, its personal preference.
I have some pictures, PM me for further details

[jberger]

I have done the swap to several vans and have cleaned up someone's botched attempt. It takes me two days to do it alone...(cut donor section, cut and prep recipient, weld in new section ready for new canvas)

Formed and welded sheet metal does crazy things.... when you cut your roof off, some areas will pop up and others will pull down. Trying to tweak the roof back into shape with epoxy and sheet metal screws will not work in my opinion. Clamping, tacking, hammering.... Proper fitting of the Westy section around the perimeter of the van will require drilling all the spot welds on the inside (you can feel the line around the roof where the fresh air vent tubing is)... swapping the cross member, which should be attached to the donor section when you cut it out. I would also cut around the outside of the hinge locations to allow you to cut the reinforcement out of the donor and weld it into your roof prior to setting the section.

You will find that no two roofs are created quite equally either. take some measurements\templates and you will see that all is not perfect from the factory and panel dimensions to vary a bit, making overlay practically impossible.

[Howesight]

I did my Westy to tin-top swap using the overlap method. I trimmed the cut-down Westy donor roof so that it overlapped the recipient van roof at exactly the location where the aluminum strips that hold the canvas down are located. There was between 3/4" and 1" of overlap of the donor portion over top of the recipient roof. This allowed the overlap donor part to be glued in place with 3M permanent bonding epoxy. The sheet metal has to have the screw holes for the aluminum strips drilled anyway. You then use the aluminum strips and the sheet metal screws to act as gluing clamps at the time of panel bonding.

The cross-beam does need to be welded in place. Screws or rivets will not cut it here. You use the existing pillar double-skinned metal to make up a flange to receive the Westy cross-beam.

In my case, I used the entire inner flange of the donor roof cut and jammed it inside the existing matching flange and welded it in place. This did require me to section the donor piece by 1/8" front to back and did require me to pry the sides of the van apart by about 1/4" (since the donor flange is 1/8" thick). This was done with welding tacks about the same size as a spot weld, not a continuous line of welding, to prevent the heat from affecting painted sections adjacent to the tacks. I would go from side to side to keep the welding heat down. The beauty of this approach is that all the welded portions are hidden behind the interior trim pieces in the Westy interior. The exterior portions are hidden by the aluminum tent strip.

I, for one, did not want to risk rust intrusion from welding parts to which there would be no future access for painting or otherwise protecting the weld-affected areas from moisture. The approach I took is also faster and easier. I do think, however, that many purists would consider my approach to be inferior since the conversion is detectable - - if you go
looking for it.

One critical tip: Measure the precise distance between the sides of the roof BEFORE you cut out the tin top's centre beam - - you need to ensure the donor top is installed maintaining this distance. In my case, after cutting out the centre beam, I checked for movement. The sides had moved over 3/16" closer to each other with the centre beam removed.
_________________
'86 Syncro Westy SVX

[msewalson]

Thanks a lot fellas, this is all great info. Definitely has me thinking a bit more.

Howesight, do you have any pics from your build?

Thanks again to all that has provide insight,
Matt
_________________
87 Syncro w/EJ22

[MarkWard]

To the two of you that are bonding the donor roof to the tin top, I understand you are using the outer edge of the aluminum strip as a cutting guide. I also get that you are using the canvas strip screws to hold it together while is cures. Good thinking.

A few questions. Doing it this way, I assume you end up with an exposed painted sheet metal edge along the strip? Are you doing anything to disguise it? How are you prepping the overlapping metal for the sealer? Are you using bare metal or something else?

I will be embarking on a similar project when time permits. I am able to weld and fabricate, but am also concerned with how the welded seams would hold up over time. Welding puts a lot of heat into the surrounding metal and even using weldable primer, some areas will not be perfectly sealed. I expect it would be hard to prevent rust forming over time in humid climates like Florida.

If either of you has some photos of this process, I'd like to see them too. Thank you. I have book marked this thread along with the others.

[msewalson]

rsxsr,
I have found that both 3M and Lord Fusor require both pieces to be bare metal. After application with a caulk gun you tool it out to cover all of the bare metal. One thing I like about the Fusor brand is that it contains glass which prevent over clamping and over squeeze out. You can also weld through it but need to use a specific spot welder tool.

Matt
_________________
87 Syncro w/EJ22

[msewalson]

I found another method to doing the conversion while searching. I forgot to bookmark the thread but did snag the pics. The pics are from North Westy and show how they do the tin top to pop top conversion.

I like how they dealt with the C post cross member.

Matt
_________________
87 Syncro w/EJ22

[MarkWard]

It is hard to tell from the pictures you posted, it appears they are using the overlap method, but rather than using sealer to glue the shell around the perimeter, it is seam welded. If you look at the pictures you can see how welding is really hard on the sheet metal. You could address and seal the outer weld, but I am not sure how to deal with the burned metal on the inner sides. It also looks like they are not using the entire lip from the donor section looking at the first photo. If you find the thread again, if you could post it up. The north westy website gives you enough info to get yourself in trouble.

Jael, I read your son's blog and the idea of using the majority of the cap makes sense too. Using the Mig to weld you'd be able to address the heat damage on the under side of the lip. Other than weldable primer, how are you keeping the moisture out of the two seams?

Has anyone done this using an actual spot welder? There are decent ones for the hobbiest. I just don't know if the the jaws would fit the underside of the lip.