Waterproofing Canvas Question

[Soinkuhndog]

I'm getting ready to waterproof some canvas for a tent I'm making. I know it's not PC, but I'm using a commercial water-seal liquid. As I understand it, this doesn't really water-proof the material as much as help with mildew. Question: Do I paint just the side that is facing out or both? Or, does it matter?

 

[Holley]

It is better to soak the whole thing....but you can paint or spray it on the top surface for a farely good job. Get in all the seams and corners too. And there is a commercial waterproofer called MILDEX that has a mildew prohibitive in it.
Canvak is the better of the water proofers out today...but more expensive than BHAER.

 

[ladysmithtrading]

Easiest and most thorough way to apply that is with a garden pump sprayer like you would use for insecticides, and as sated above, saturate the seams and corners.