Apparently we don't know how to seam seal. Advice needed!

[Trail Runner]

I did it after it was dry. Or mostly dry if memory serves.

[MAD777]

I use 1 part 100% silicone mixed with 4 parts mineral spirits. It takes a good while of continuous stirring to get the two to mix. Then apply with a disposable foam brush. This is important, make sure the seam is under tension, staked out tight when sealing and drying. (So do it on a fair day). After dry, dust with talcum powder. I seal the outside and inside.

[BrianWillan]

The Permatex is manageable without dilution. I've never used the Silnet so hopefully someone who has will chime in.

This is the Permatex in question.

Permatex Flowable Silicone Windshield and Glass Sealer It is available a many auto parts stores. It is rather easy to apply, no diluting needed. Apply to outside of seam on the threads.

Cheers

Brian

[Country Roads]

I use silnet or GE silicon 3 (use the clear, not the kind with coloring added) and I thin it 50/50 with mineral spirits. It is very easy to use one of the sponge paint brushes to actually push the sealer into the threads/seam.
I seal the outside of the seams with a thin layer of sealant, let it dry at least 24 hours; flip the tarp and seal the inside and let this dry; I then finish with another thin coat to the outside. After it cures for a couple of days, I sprinkle powder on it to take away the stickiness. You should only need to seal the side panel pulls on the superfly.

[Drybones]

Do all of these cure with some tackiness? I did notice the material sticking to the silicone on the last trip. I wonder if some pulled off due to that sticking.

Mix 100% silicone you can get at the hardware store with oderless mineral spirits, I mix as much silicone as the mineral spirits will dissolve and apply to the seams, after you have a applied to a section wipe any excess off with a rag, there should be no tackiness within a short period of time. I always do both sides, never had a leak on a tarp or tent.

[tundracamper]

That's all great info. Had never thought about wiping it off. I would probably be concerned about wiping off too much. Of course, that would eliminate the tacky problem.

[tundracamper]

I went ahead and removed as much of the old stuff as I could and did a re-seal job. A few things I noted.

When mixing Silcone with Mineral Spirits, the result is a very thin coating. The area is still quite flexible, but I can tell there is a very light coating that appears much more penetrated than before.

I couldn't find any non-medicated talcom powder to keep the silicone from sticking to the other parts of the tarp.. Then it dawned on me that dirt from the back yard should also work - and I'll have access to plenty of that on the trail. Plus, dirt has no scent.

I plan to put the tarp in the bag for a week or so and then pull it out and test it with the hose. Not pretty, but I feel pretty good that it will work. Thanks again for all the advice!!!

[mrjaw14]

I second permatex flow able silicone. Find it at an auto parts store. I took some cheap flux brushes from a hardware store, cut the bristles a bit shorter. I runs small bead along the seam, then use the brush to gently work it in. Use a wet finger to smooth out any thick or raised spots. You can just use a finger on the sil, nylon pullouts, ridges, etc the brush really works well to get the silicone into the thread holes. I seal both sides just to be safe. I do it in a garage or other cover and let it set for about 2 days. You don't have to let it sit that long, I just like it to cure under tension for a while.