Thanks Jeff and Hirilonde
I can fully appreciate the reason why a coating is not wanted, when thinking on the adhesive part. I will surely prefer buying from a seller that sells for this purpose too, but of course check if I can find any European store to start with. The main reason for this is a 25% import tax.
Buying from you at kudzucraft, is a safe and good solution as it assures the correct material, not only uncoated, but also in terms of weight/strength.
My guess is the 6oz, I found so far, is probably not suitable.
I also may require more than usual as I am thinking of creating internal "sacks" and sow onto some hatches. A kind of hybrid kayak i guess.