Waterproofing Canvas after mold treatment

It is probably a good idea to check with the trailer manufacturer as to what sort of treatment the canvas has had in the first place.

I have found that some of the pre-treated brands of canvas such as 'Wax-Converters' brand have such a good initial coating that it is hard to wet it with anything other than a solvent-based waterproofing such as 'Re-proof' or 'Wapro' brand canvas proofing. These work well but stink of strong solvent for a while and you need to test (on a small bit of canvas or an inconspicuous part of the trailer) that it doesn't make the colour run.

I prefer to use a water-based 'Nikwax' canvas proofing because I can apply it when I am travelling and use the trailer without the solvent smell. These water based waxes are harder to "wet" the canvas with. So you might have to wash it with a sponge then apply the proofing and work it in. They do also work well as I have tested my trailer through Victoria and Tassie in the wet.

good luck
Geordie

Bouncer
Don't know the answer tp your question but just checked our manual under "canvas care" and it clearly says not to use detergents or soap products as this will remove the waterproofing. From what you describe you have used a strong oxidising agent (sod hypo) and you can bet you have cleaned off your water proofing compound.
The wet/dry method only works to activate the water proofing stuff applied so I understand. You will need to reapply water proofing and I reckon I would be contacting the maker or a canvas shop for recommendations. I am sure you can buy commercial products from Rays etc but maybe you will need the real thing.
Rusty

I recently waterproofed a 25 year old canvas tent, with 'Joseph Luddy' brand waterproofer. As mentioned in a previous post it is very chemically based, and stinks, but it did the job beautifully. Tent didn't leak in torrential rain. Be warned that you would need a lot of it and it isn't cheap! Hope this helps - Jo