Get it done right weld it.  once you start putting shit in there, silicon and so forth, it gets harder to fix.  i have done few dinghys and boats where people have used araldite, silicon, devcon sikaflex etc and you blow more holes trying to burn the other crap out.  wouldnt cost you much i wouldnt think.

Lol, if you're blowing holes in a boat burning out sikaflex and the like, its pretty far gone anyway.

The material used in pressed ali boats, its pretty awful to weld, and in an older boat its like soldering up the holes in a teabag.

Just sikaflex it.

i would first look at getting it welded. if that cant be done there is a product that is like a putty but dries as hard as a rock .i have heard of it being done before on alli boats and worked a treat. it is available from auto shops. also used to fix holes in alli fuel tanks in cars

weld it ... not hard at all in any age boat just got to find a good welder sikaflex or the likes should be a last resort

My father in law found a leak on an old tinny he had bought to do up,found a guy that came out to his house and welded it for him,he also rebuilt the transom for him as well because the previous owner had done hacked it about to fit a shorter shaft motor.

I have used wet area waterproofing (shower recess) stuff painted onto/into fibreglass matting and it is by far the easiest to do yourself. sticks like shit to a blanket. Visit a job site and ask a tiler for a very small amount. My quick repair job has lasted 10yrs no problem.

Buy a bucket and an epirb!

I can weld it for you for you although am away for a couple of weeks. Bottle of Wild Turkey would put a smile on my dial. PM me if you want it done.

Should aim a bit higher sea-kem.  Makers Mark or Rare Breed maybe???

LOL now ya talkin! I think I better give the obligatory Fishwrecked discount.

but i might just go down to local metal fabrication shop an get a quote

Just to let you know I am a fabricator and have a w/shop in Welshpool.

using sika flex it seems like a good choice