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Canvas roof over wood?
https://www.rypn.org/forums/viewtopic.php?f=1&t=29892		 Page 1 of 1
Author:  robertmacdowell [ Thu Aug 05, 2010 2:15 pm ]
Post subject:  Canvas roof over wood?
I'm looking at roof repair to a steel car with a wood roof. It looks like that delicate little "mini tongue and groove" like you often see on circa-1910 streetcars.

What would be the correct roof coating here? It looks like canvas to me - but what goes under the canvas - and what goes on top of it?

If "white lead paint", what's the modern alternative?

And how often should a roof of that type need maintenance? It's parked outdoors.

Attachments:
File comment: Not our roof, this is a car of the same class. This is what we presume to be under our roof. We won't peel the roof to find out!
SouthShoreCarRoofDetail.JPG
SouthShoreCarRoofDetail.JPG [ 85.03 KiB | Viewed 3383 times ]
Author:  S. Weaver [ Thu Aug 05, 2010 4:12 pm ]
Post subject:  Re: Canvas roof over wood?
Robert:

if the car is going to be a static display, boat canvas can go back on it, soaked with a heavy alkyd oil paint, thinned with linseed oil. Underneath you would need to prime until the wood is satisfied using a good alkyd oil primer with some raw linseed oil. You just need to keep paint on the roof with re-coats and address any weather penetration immediately.

We used canvas roofs for years but they didn't hold up long with the twisting and action of the car. We now use a thin rubber roofing, edge nailed as is done with canvas. After a couple of seasons it fades to a nice gray and is virtually indistinguishable from a canvas roof except experts (marine and railway) might notice.
Author:  Frank Hicks [ Thu Aug 05, 2010 4:50 pm ]
Post subject:  Re: Canvas roof over wood?
For a South Shore car, the roof would definitely have been canvas over wood. I don't think there was anything between the canvas and wood though I'm not certain on that point. I assume it would have been painted with several coats of canvas paint.
Author:  Dave [ Thu Aug 05, 2010 5:39 pm ]
Post subject:  Re: Canvas roof over wood?
There's a white, heavy, gloppy, Elastomeric Roof Coating available in 5 gallon buckets at home depot that makes an excellent modern bed coat, patching compound, and cover coat for canvas railcar roofs. being a latex/acrylic based product, it can be tinted with the addition of latex/acrylic paints if color change is desired.

I second the recommendation of seamless rubber roofing for very durable in-service applications.

dave
Author:  colfaxstation [ Fri Aug 06, 2010 1:47 am ]
Post subject:  Re: Canvas roof over wood?
We're in the process of stripping an 1884 mail car's secondary roof that was added when the car was converted to a house. The original (1920 era rebuild roof) was mostly intact. The upper roof was canvas with a tar coat, over a thin oilskin type paper. The lower roofs were a rubberized canvas over the same paper. We are going back with red rosin paper as the under coat over the tarred upper roof with a rubber roofing material, and simply the rubber roofing over the rubberized canvas below. We had to replace only two boards on the lower roof. Everything else was intact, except the last 6" of the ends had been cut off to accommodate supports. (Don't ask why, it didn't make sense from what we could see). I'll be posting photos after this weekend.

Herb Sakalaucks
Colfax Railroad Museum
Author:  Dennis Storzek [ Thu Aug 12, 2010 3:00 pm ]
Post subject:  Re: Canvas roof over wood?
I'm kinda' surprised that discussion just died on this. Anyway, while looking for something else, I came across this FAQ page that documents a lot of IRM's experience with the subject.

http://hickscarworks.blogspot.com/2008/10/faq-on-canvas-roofs.html
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