Belly Pans/ Frame Work/Ragtops and 21-23 Windows

[SolarPoweredPickles]

Hey everyone!

I’m feeling like diving into a chat about frame strengthening. Specifically, I want to talk about 21-23 window buses, double doors, ragtops, and belly pans. It’s pretty clear that most of the 21-23 window buses and double doors, whether they’re stock or modified, have those belly pans.

That said, I’ve worked on my fair share of Chevelles, C10s, and other Chevy rides. Usually, I just do a good frame cleanup and box the frame, and honestly, it’s a pretty straightforward project that makes a huge difference in performance and safety.

Now, when it comes to our buses (mine’s a 1961 previously chopped up panel with a double door conversion in progress, some previous owners doing and some mine) I really want to keep this conversation focused on safe, interesting, and creative frame work, chassis boxing and stock belly pans. Has anyone tried something different from the usual belly pans, or is that the "BEST ROUTE"?

I’m focusing on a few things, like cost, shipping, and how buying new belly pans stacks up against various frame strengthening options similar to the muscle and classic car scene. Is buying/using on-hand steel and going a custom route a path any of you have gone, if so, experiences and advice, sharing tips? Keep it stock stupid "KISS" applies to many avenues, and tried and true techniques are rock solid, that said, I am just a curious cat.

[BarryL]

Those vehicles you mention all have much thicker steel for the frames as well as cross beams and stuff. Boxing those makes an enormous strengthening. Buses frames are like tin compared to those. The whole bus is part of the flex-strength. The pans are engineered to hook onto and spread and grasp the flex.
I have one bus with belly pans and one bus without. The belly pan bus flexes and the straight frame one flexes. I've always been on the lookout for cracks and tweaks as I've done major long and grueling off-road things and have yet to find any damage. Someone else will have to answer the boxing the VW frame scenario.

[SolarPoweredPickles]

[pondoras box]

Belly pans are just flat steel with pressings to strengthen them up. You could fabricate your own and be fine. You would need a bead roller and a break but you could get them pretty stock looking to the untrained eye. Or if you had some tubing lying around do a Nuespeed style brace for it.
_________________
Looking for anything from Hal Casey Motors out of Hamburg New York, from license plate surrounds to matchbooks.

1961 23 Window (Bobo)
1965 11 Window (Zelda). https://www.thesamba.com/vw/forum/viewtopic.php?t=563183
1965 13 Window (Lucas)
1957 Oval ragtop
1960 hardtop
1964 hardtop
1965 hardtop
1973 standard bug
https://www.thesamba.com/vw/forum/viewtopic.php?t=804912
1988 Cabriolet VR6 conversion
Plus a lot of other rusty junk

[SolarPoweredPickles]

[pyrOman]

FWIW...

After cutting a YUGE chunk off the top of my bus to install a Dormobile top, I knew I'd need belly pans. Didn't have the $$$ to buy originals, if they were even available then, or the time to wait for them. So I made my own! This was done back in '09 and is still going strong!

One important thing I overlooked was the possibility of eventually having to replace the wiring loom. Factory belly panned buses have a tube/pipe to run the wiring through. So before doing the pans I suggest you provide for that too!
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Some people are so busy being clever they don't have time enough to be wise.

[djfordmanjack]

Hot Rodder here, A, Deuce and 34 rails boxed.
You always need to think like in space frame. US iron mostly had ladder type or X frame and body bolted on top. later on unibody design ( from ca 1960s like Falcon, Mustang etc.). it is not the thickness of plate, but the distance of spaced elements. the belly pans in Vw buses are a terrific design and adding a lot of strength, but they are spaced only so much from the main rails and below the floorboards.
Boxing the main rails will hardly add any strength to a bus.
If your floor structure is rusted, you may think about replacing the I beams or open T hat crossbeams with square tubing. tying it all in with bracing and tubing like in a tube type sports car chassis. all of this sounds stupid and it is.
A set of belly pans will give your bus all the strength it needs. much like Barry told you in his first reply.
I am building a crazy space frame barndoor chassis, but in reality it isn't needed at all. after all, it's just a bus.
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Hotrods, Fords, Veedubs and Triumph Twins !
52 Barndoor DLX Coachbuild project
54 Oval project
55 Wolfsburg panel project, og paint Taubenblau L31
62 Dickholmer, Seeblau L360
63 1500 Notch, og paint Rubin Rot L456
67 1500 Käfer, og paint Lotus weiß L282 w/red interior

[BarryL]

[Clara]

I had a SC that was off-road raced. They boxed in the frame rails, added a roll cage, and did some other mods to do things like this:

The current owner tidied it up under there:

That said, if you add a sunroof , or DD both sides, the generally idea is to add the belly pans
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The Obsolete Air-Cooled Documentation Project http://oacdp.org/

[djfordmanjack]

even with added boxing plates to the main rails. imho the effect will be minimal. The whole design is made to allow for flexing. a Sc truck is something else, because it has a second floor structure and pan ( bed), which actually acts exactly like a space frame. a SC or DC is a better design from the start !

when you box the main rails, you also need to tie them together with huge tubular crossmembers, or a z shaped structure, much like a crane would look like.
Single structural elements will only add minimal strength. it is the space frame construction, with widely spaced reinforcements, that makes it rigid. It is mechanical engineering, not adding a lot of steel plating, which makes it solid.
_________________
Hotrods, Fords, Veedubs and Triumph Twins !
52 Barndoor DLX Coachbuild project
54 Oval project
55 Wolfsburg panel project, og paint Taubenblau L31
62 Dickholmer, Seeblau L360
63 1500 Notch, og paint Rubin Rot L456
67 1500 Käfer, og paint Lotus weiß L282 w/red interior

[SolarPoweredPickles]

[Malokin Martin]

[SolarPoweredPickles]

[livnlow]

I made mine bolt in so I could still have access at a later date. I was installing a Dormobile top and didn’t have time to go into a full restoration but felt like I should have the pans. I noticed a difference in stiffness based off my cargo door alignment.

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1963 356B Coupe
1965 sundial

[thom]

Nice work. I would use heavy-duty washers, as that green metal is very soft. Or even better, a bolt-down strap for each side, but at that point you may as well just weld it.

[thom]

I put a sunroof clip in a bus years ago, without any underside support, and you could feel the twist when going over bumps. The cargo door area would also distort enough that you could see marks at the top and bottom of the opening.
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-Thom
1956 Single Cab
1957 Porsche 356A Sunroof
1957 23-Window Deluxe
1957 Mercedes Westfalia single cab
1963 Unimog 404
1965 E-Type

[Alan Brase]

I've a little perspective on torsional stiffness on type 2's: For many years I drove bay window buses in my contracting business. They are so great going into rather rough terrain and I would often put a wheel over the curb and just go from there. My 69 double cab had some pretty serious rocker rust and it would bend so much that it would often emit a loud TWANG! Pretty sure it was the center partition "oil-canning" so to speak. It had a solid partition and a 1 + 2 front seat with spare tire storage.
Also, at that time I had a rusty 1971 Dormobile. A full euro spec Dormie NOT a Westy with a Dormobile top. It was evil to work on replacing brake lines and I did cut some access holes.
I often figured if I were to properly restore one I would get new proper Gerson belly panels and attach them with PANEL ADHESIVE and self drilling pan head screws. If I ever had to service under the panels, it would be a simple matter to heat the adhered areas with a heat gun and remove them. Pretty sure this would work and only about $50-100 to find out. One could always weld them on later if it proved to not be strong enough.
_________________
Al Brase
Projects: 67 sunroof bug, 67 Porsche 912 Targa, 70 Westy
Dec 1955 Single Cab pickup WANT 15" BUS RIMS dated 8/55, thru 12/55
To New owners: 1969 doublecab, 1971 Dormobile
Vanagons:
80 P27 Westy JUL 1979, 3rd oldest known US
83 1.6TD Vanagon, 87 Wolfie Westy daily driver, swap meet home

[Alan Brase]

[iamdonquixote]

why not weld outside pans and bolt middle ?