Maybe you should seam-seal before re-proofing? Anyway, I re-proofed first (see the last post)…

Seam-sealer seems expensive for the amount you will use on a small tent and I read somewhere about making clear silicone brushable by diluting with white spirit, so I thought I would give it a go.

I guess there are no hard and fast rules on diluting silicone – I made it up as I went along and it worked fine. Sue gave me a most useful tip on mixing silicone and white spirit – add a little white spirit to the silicone, not the other way round. Doing this means you don’t get blobs of silicone sloshing around in the white spirit. A shame she told me this after I had chased blobs of silicone in white spirit with my mixing stick! I got it mixed in the end, but Sue’s way (as described below) is definitely easier.

I used a jam jar lid for mixing the sealer, a thin piece of wood (a lolly stick would be ideal) as a mixer and a cheap artist’s paintbrush to apply the sealer. It’s a messy job, so I wore disposable gloves.

Squirt, say, 2 cm long by 6 mm diameter of clear silicone into the jam jar lid and add a small amount (a teaspoon, maybe) of white spirit and mix. Add a little more white spirit and mix. Keep doing this until you get something that is the consistency of thick-ish yoghurt. You want the sealer to be easy to apply with a brush, not something that sticks to the brush in a lump – like the undiluted silicone would.

Seam after sealing

Seam a day after sealing

At this stage you can either use this mix and make more as you go; or add more silicone and white spirit to mix up a more sealer. Depends on how much you need. Now apply the sealer to the seam. Work it in well and apply to both sides of the seam if you can get to it – see the photo. I was sealing a seam on a tent groundsheet that runs the full length of the inner, so I wanted to get a good coverage. The photo shows the seam the day after sealing, it has dried well – not quite invisible, but hard to spot at first glance.

I have no idea how long the mix wil stay useable, depends on all sorts of things, the mix I made was OK for at least 20 to 30 minutes.

The seam was touch-dry after an hour, but I would try to not touch it for as long as possible to give the sealer a good chance to thoroughly dry.

White spirit seems to make the jam jar lid very slippery – I dropped the lid and , of course, it landed upside down on the grass.

Now I just need to mix up some more sealer to do the seams on the fly – using Sue’s method, of course.