Few Questions

I pitch my silnylon tents in order to seam seal them, but that is at least partly so I can get to all the seams easily, and so that the silicone won't stick two layers together by mistake. Works for me.

I try to get the silicone to penetrate the stitching as well as coating them, so I do it under tension. As Roger mentioned it also makes it easier not to get one bit of fabric sticking to another, keeping in mind that even in the sun it takes more than a few hours for the silicone to fully dry. (I tested that….one of my shelters has a small patch in the floor to remind me of that)
Franco

I read somewhere, but now can't find it, about cutting the silicone with white gas. What's up with that? What would be the ratios?

I think it's common to thin the silicone with turpentine, haven't heard of white spirits but that might work too. The ratio is really just enough so the silcone penetrates into the seams rather than just sitting on top. Maybe ~50% solvent?

The ratio of Silicone to thinner is roughly one to three IIRC. You want it thin enough to use a brush and to penetrate the stitching but thick enough to only need one coat. Turpentine will work if available but mineral spirits (AKA paint thinner) is cheaper and if you get the odorless spirits, it leaves no lingering odor.

The thinned silicone is actually more of a slurry than a solution. For small jobs, I just take a dab of un-thinned silicone sealer on my fingertip and apply it directly to the seam.

Yes you can use white gas (naptha) but you should only mix and use the stuff outdoors. White gas is, as I'm sure you all know, volatile and flammable.

When mixing clear silicone from a caulk tube W/ paint thinner (mineral spirits) be SURE to use only ODOR FREE mineral spirits. Regular mineral spirits really have a long-lasting and strong odor.

The 3 (mineral spirits) to 1 (silicone caulk) ratio is a good starting point. Always mix very well, at least a minute, to be sure you have a consistent blend.

Then RE-mix every 3-4 minutes to maintain the silicon in solution. Add more mineral spirits if you want it thinner or as the mineral spirits evaporate in the container while using. Use a narrow (1/2") brush. Wash the brush out in mineral spirits when done because you will very likely need to touch up seams or cover stitched up rips from time to time

Eric

Is this method safe to use for sealing seams on a cuben tarp? I also heard somewhere about using seam sealer around the guy out points to increase strength.. Does this work or just add weight?

Phil

This weekend I tested a cuben seam (on a stuff sack) that I sealed half of (with Seam Grip). Once cured, the sealed seam was dramatically stroner than the unsealed seam, so from now on I will seal all the seams this way.