Internal Alu Mast sealing.

[Robbie.g]

thanks brian, i think your right the multiple holes and the copper tube is the trick. I've been working with the sealant and a plastic tube taped to some alu welding rod, but getting to the back of the wiring tube is always the hard bit, a hole on the opposite side is also the go.

And yes your right on the pull the mast, and insert a slab of foam is the go, i use 2 sheetsof foam cut around the wiring tube, (tight fit), one to just below the finished level, push up a 2nd covered in poo when they meet the poo squirts out to the edges this glues and seal them in place. I then pour in the clear seal, this works about 99% of the time. But with your ideas, the mast in fix with another hole or two to get to the back of the wiring tube with a copper tube is the best solution. .
Thanks for your input brian