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First coating silicone on aluminium mesh

November 20, 2019 — BarryK

I posted recently about the idea of using an inner liner for the basin-type solar still, constructed with aluminium insect-screen mesh and coated with silicone sealant:

The mesh is not raw aluminium, it has some kind of dark coating, I presume that is an anodized surface. Don't know anything about the properties of that surface, but the silicone seems to stick to it OK.

Now for the next step, to coat a large piece of mesh. The intention is that this will be inserted inside the distiller frame, and will completely isolate the frame from moisture. There will also be some insulation injected between the inner liner and the frame. Still planning on using pine for the frame.

Want one large coated surface, which will be folded afterward, so a minimum of cutting -- basically, the only cuts will be for inlet and outlet holes, and to trim the edges where the liner is sandwiched under the glass -- anyway, those details will be clarified as the project progresses.

Here is a photo of the mesh stretched out on a table:


...the g-clamp has two purposes, to prevent the mesh from folding up when I lift it off the table, and to hang it up on a hook. The other end has a length of small-section wood attached with wire.

Underneath the mesh is plastic sheet. That plastic just arrived in my backyard one day, a year or so ago. Thought it might be useful, so put it in the garage -- so, finally it has a use!

Wanted an area about 950x750mm. Used cheap Parfix kitchen-and-bathroom acetic-cure silicone sealant from Bunnings -- this has anti-mold additive, which I don't want, but it shouldn't matter in the final product, as it will be coated inside with black Silastic 732 sealant.

The end result was hung up:


...the white spots and streaks are holes. I have learned from experience not to try and patch the holes. Instead, let it set and tomorrow will give a second coat. Note, that large white area at the bottom is direct sunlight. One more detail: I wiped the plastic with a cloth, to remove silicone bumps, as the plastic will be used again tomorrow.  

Tags: nomad