I know this question/statement has been put out there, I have asked and been given advice, but this is what I got so far from my own life lessons.

Let me also say that I would love for someone to put this together with some more facts or insight.

So I have made 15-20 tarps of various sizes and material. But basically silpoly and silnylons of different brands. No Cuban or the heavy hh tarp material with the thick coating.

I have not seam sealed them all but the vast majority of the ones I make I seal. Not sure what to use originally I asked and purchased permitex flowable silicone. I chose this because unlike other options, I could get it from stores near by. Its sold in most auto stores. I have found this stuff to be easy to use right out of the tube. I have not had a single tarp leak. I will admit its not easy to make it look pretty and I never do. I guess I could push some out and paint it on with a brush, but then I risk wasting what I didn't use and I would need a new brush each time (or clean it somehow).

So the last time I purchased some new fabric I figured I would see what was recommended. Maybe other stuff worked better or looked cleaner. It said to use seal and adhesive from McNulty I think its called. Well I finish a big 144 rl with doors and side pulls. I string it up and get set to use the new stuff. It even came with a screw on brush. I get set to using it and was liking the brush. It looked mostly cleaner. I noticed I was using more of the tube then I usually do but over all if it looked better I was on board. So after 28 hours I give it a once over. Well it didn't stick. It was falling off all over. It looked ok at first but the slightest tug, scratch or pull and it came right off. We'll that's not entirely true. It hung onto the thread and was a pain to remove ALL of it.

So I then went out to the auto zone advance Reilly pep parts place and got permitex. I strung it back up (now using the other side)and sealed the seams and side pulls.

Now to be completely fair there was one difference and although it looks good, its only be about 8 hours since I sealed it. The difference it I was indoors. So I do most of my work out in the garage. Usually I only do it from fall to spring because even though I work for sweat shop wages(i usually don't charge anything more then materials) I don't like to sweat unless I have to. So this year I moved my sewing indoors. I had the tarp strung up inside. In case that was the issue I faced the heat and sealed it out side with the permitex.

I am by no means knowledgeable enough to understand the chemistry. And even though I explore life like its my own experiment I just start with what works and go from there. I tried to look at each product to see what's what, but no such luck. I figured all chemical products like that would have to disclose contents but other then the obvious (silicone) I got nothing.

I have not tried silnet and based on recent science I am not sure I want to. I know its a long way to give a small opinions but I figured it was better then " I like permitex".