I searched but could not find any info, what would be the best thing to waterproof the canvas top on my 1923 canopy express? Thanks
Get some Canvak
I used the rubberized stuff that you can put on plier handles. I bought a gallon of it from an outfit in Minnesota. If you need info I can get it early next week when I go back to the shop
Mix mineral spirits and silicone 3:1 ratio and paint it on your material. May take 2 coats. Be sure you use odorless mineral spirits. Don't ask me how I know.
Ed, it would help if we knew how you top was constructed. Canvas is naturally waterproof due to its tightly woven structure. That is not to say it doesn't get wet to touch. A properly constructed top needs no waterproofing, but it does need to be made with the correct materials.
US western red cedar is the best material for wooden windows and doors because it is not adversely affected by moisture. If the slats under a canvas roof are of cedar, then you have a good base for the top. Wool felt used to be used over the slats to give support to the canvas and to take out the imprint of the slats. The gaps between the slats allowed the felt to dry out after any wetting, and wool can take repeated wettings as long as it is allowed to dry out in between. Today I use dacron batts for the same purpose, as it is not affected by moisture at all.
Heavy cotton canvas today usually comes with a certain % of polyester woven in. This helps reduce shrinkage and makes for better waterproofing.
With such construction there is no need to treat the canvas.
Allan from down under.
If you want to fill in the weave and have a smooth, paintable, waterproof surface, use a canvas filler like they do on wood and canvas canoes.
Old Town Canoes sells it by the gallon or you can haunt the wooden canoe restoring discussion boards to get a myriad of traditional or "secret" recipes so you can make your own goop.
Heres a link to a guy using Robsons RT-10 latex based filler on a canoe restoration. Scroll down the list of videos and turn off the sound unless you like Enya!
The canvas I used is cotton duck material from a fabric store. I tried spraying it with 3M scotch guard last year, but it did not work. I will try the silicone and mineral spirits mix and let you know how it comes out. Thanks for all the great suggestions.