How do I make fabric superhydrophobic/waterproof?

I am looking for a solution to make a fabric waterproof. (including cotton and polycotton blends/synthetics) I am looking to do something cheaper than buying a store-bought solution, such as making it from scratch. I have looked into purchasing octadecyltrichlorosilane, but it is both expensive and hazardous to ship ($25 hazmat fee) If possible I am also looking into finding a solution that is non-toxic and is safe for use on people.

rickharris5 years ago
Your question has too many variables

Does the fabric need to be flexible after waterproofing?

How flexible

Does the waterproofing have to leave the fabric looking like it did before

How long does it have to last

How much are you willing to spend?

I doubt you will beat the price of commercial tent/ fabric waterproofing agents.
foobear5 years ago
Well, you could mix up some oogoo (https://www.instructables.com/id/How-To-Make-Your-Own-Sugru-Substitute/) and thin it with Mineral Spirits then paint it onto your fabric and let that cure. That will definitely work. That will give the fabric a rubbery texture/appearance though, which may or may not be acceptable.