RE: Homemade waterproofing
I'm a systems engineer, not a chemical engineer. I don't know the answer, but homemade stuff like this rarely works out the way we would like. If you really want to carry through with it then common sense tells me to test it with a similar piece of scrap cloth (e.g. from an old winch cover) to see what happens. If you don't happen to have an appropriate scrap of cloth, I'll bet a neighbor does. Offer to share the recipe if it actually works.
Has anyone at all experience with the home-made remedy
I came across; mixing soy bean oil with 50% turpentine and spraying on? 2 parts oil to 1 part turpentine... There seems to be a general understanding to avoid silicone-based waterproofing with Sunbrella and this would, at least, qualify in that department...
In these recessionary times I am happy to save quite a few $$ by making something, but not entirely sure how destructive this mix may be. I am asking a chemist friend and hope to figure out the science behind the mix and would love to hear if anyone have tried it before.