We have a 1939 Budd diner, ex ACL, that we're considering putting back into service. There appears to be a possible roof leak in the area above the air conditioning blowers. I know that back in the day, car cement was applied to leaky roofs to seal them - not a route I'd want to go.

Does anyone have any recommendations for sealing the roof?

Thanks.

We use a standard silicone caulking for cracks. Then the roof gets a coat of grey spray on roof sealant paint. If you want to know more, I can find out the exact brand name.

Eric

If you think of it, please find out what it is so I can research it and whatever anyone else suggests. I’m working on a cost estimate to get this car firstly watertight and secondly in operable and presentable condition inside and out. We’ll hopefully get started on it in earnest sometime this winter.

Thanks.

This permanent rust sealer will seal all your seems. Seal the area with this first especially if is a rusted area and apply your silicone caulk this car is being painted at IRM the product being used is Mastercoat primer/ sealer/ servicer. Rust bullet is a similar product. This particular type of coating will seal gas tanks that are pinholed inside and out. It's also good is a bonding agent for metal patches

Budds leak, especially the truss cars. We have used Polyurethane "Roof and Flashing Sealer" and much prefer it to silicone of any description. It comes in tubes and applies using a caulk gun. We have a couple applications where it was used 15+ years ago and it's still not giving it up. Silicone on the other hand simply does not "grab and hold" as well. To that end we're careful NOT to use it where we may want something back apart in the future, lest you wind up with a fight. It's available at Lowes and Home Cheapo here locally.

https://www.homedepot.com/p/Loctite-PL- ... /203163733

ETA

A old Passenger Carman I knew who always claimed the Budd's were designed to leak.

He told the story of a Budd car that apparently had a "little" leak, it turned out the car was just about full to the bottom of the windows, they dragged the car out of the shop and started drilling drain holes. He claimed "It pee-ed for a couple of days".

My my own experience Budd's with their Stainless sides and Aluminum interior trim separated by Masonite, mixed with water made a perfect battery.

The problem with silicon caulks is that they cease to seal if the the adhesion is broken after curing, we used a butyl caulk that never really cured and would re-flow if moved, we got it from a place that did auto windows.

And then there was a Budd Dome that had a couple of windows that made very nice turn and bank indicators.

-Hudson

Hy-Tech Thermal Solutions:

Roof Guard - Insulating Ceramic Roof Coating

Has anyone ever sealed a fluted roof as shown in the image I include with this inquiry (which is very unlike the smooth roof pictured earlier in this thread) ?

My issue is a 1947 stainless Budd coach (ex-NYC). I need to spend more time on the roof, but I think my issue includes all the joints around that air vent.... the restroom under the vent is a mess w/ water damage while the rest of the car is not so bad except for issues around/due to the 'school bus windows' that previous owners installed.

Has anyone had to seal the seams on the fluted Budd roof?

Same ideas for sealants as noted earlier in this thread ?

Has anyone sealed seams and then sprayed an overall sealer on the whole fluted roof (as was noted for roof example earlier in this thread) ?

Has anyone ever had success applying a rubber roof over top of a fluted roof?
(I'm not trying to play dumb, just need to fix the problem with an eye towards 'really long term' if possible.).

Thank you very much!!

RayG.

Ray - Your car's roof is the same as ours, a typical Budd roof. So far, these are the options I'm considering pending research on suggestions by others:

1. Chasing individual leaks and sealing with Dow 1200 OS primer and 791 silicone (not your usual big box store stuff).

2. Going over the general leaking areas with an elastomeric paint-on rubber membrane, either tinted or paintable. Using compatible caulk or sealing tape at any gaps 1/8"+ prior to coating.

3. Coating the entire roof with #2 above and get any/all leaks at once.

Cleanliness is most important, i.e. remove all old caulk as best as possible to avoid dissimilar material degradation, and cleaning off any loose paint, dirt, oil/grease, etc.

You have to be careful with silicone sealants. Nothing else will really bond with it other than maybe silicone if you're lucky. And it's not compatible with most other types of sealants and gaskets. MEK is a good cleaner prior to using silicone. Acetone works almost as well. Use appropriate safety precautions.

Cost is a big factor in this project (isn't it always) and we'll have to make a determination of which way to go after a much closer inspection to get the best bang for the buck and considering the amount of long term maintenance for each system. The less you walk on the roof, even with tennis shoes, the less leaks you'll have to chase.

Ray G.

Yes, we seal our Budd corrugated roofs with the spray on sealant I identified in a previous message. We have to add something to mix the appropriate color, but it works very well.

I wanted to post a picture of a finished project, but could not get the file size small enough to upload on this forum.

Eric