I hit a sharp rock docking my aluminum jon boat on a rocky shoreline and ripped a hole about an inch wide and a couple inches long below the waterline. The rip was right where the bottom of the boat goes from flat and starts to to curve up twards the front. There was no way it would sit in the water and not take on water, the bilge pump would always run.
I got it home and pounded the aluminum back to the flat position and applied JB weld to both inside and out. I pre sanded the aluminum so it would remove the paint and primer and any dirt etc. so the metal would be clean and applied the JB weld to both sides and let it harden. I put on the slow hardening and cure type and it took overnight to harden and cure. This was probably 15 years ago and it still doesn’t leak. Silicone in the screw holes (has) to be removed, nothing will stick to pure silicone. Sand the surface on both sides if you can of the screw holes and definately remove the silicone in the holes. If I remember right the only thing that cuts silicone is acetone and it does not do it that well, like completely remove it. Look on the back of a tube of silicone and look at the information on clean up, how to clean it up, I do alot of painting and I don’t know of a good silicone removeimg chemical, if there is one.(This is just for personal information but Silicone is unpaintable and the paint will come off, siliconized acrilic caulk is paintable). After the silicone is sanded off and removed then put on JB weld, the slow cure type is what I use just because I personally think the slower cure type is more durable. JB welds the best I know of and it does work and is paintable. Acrilic and epoxy resins won’t stick as good as JB weld, use that.
Heres a story about how good JB weld is. I heard from a guy who worked in a machine shop that machined raceing motors for guys who raced locally. An engine was brought in that blewup and he had to save and use this engine. The machine shop boiled the parts to get them clean, put the parts back together useing JB weld and remachined them to the tolerances they had to be. The engine was rebuilt and put back into the raceing car, 200 mph. plus track, and it blew up again, they race hard here at a one mile oval asphault track. They brought the engine back to the shop, they tore it down and where it broke this time wasen’t where the jb weld was, it was broken in new places, but this time the engine was beyond repair. So this is how good and strong JB weld is, so don’t be afraid to use it because it sticks and holds well.
. I have repaired gas tanks also with the stuff and all the repairs I have made with it are still holding fine today! 
Bout did the same thing 2 weeks ago OUCH
