Bonding to aluminium hull

[Tintin]

Here's the situation.... Aluminium Hull, bilge has been painted. When I remove the log, or put it in, enough water comes in to be a PITA, seeping through to a fairly inaccessible bilge low point.

I want to build a "dam" around the skin fitting to contain the water, ideally some 1" x 1" batten or some 1" L profile plastic extrusion.

The question is about what to use to bond it to the aluminium hull.

My thinking goes as far as....
abrade the bilge paint until I get to bare metal, degrease, then fairly sharpish afterwards (before surface oxidisation occurs) use some sort of magic glue to stick aforementioned items to hull.

But what to use? Good old sika? No more nails?

Another thought is to get a large tupperware tub, cut a hole the same diameter as the skin fitting, put that on the skin fitting with a second large nut and seal it.

 

[Fr J Hackett]

Most of the usual bonding agents will stick to the paint, I think it's a very bad idea to remove perfectly bonded paint from an aluminium hull.
Aluminium oxidises in milli seconds.

 

[penfold]

What the Father Jack said; a great deal of effort has been gone to to get paint to stick to aluminium(not an easy thing), don't muck that up if you can avoid it.

 

[zoidberg]

Yes. Just clean the paint in way of where you want to secure your cofferdam, then use Power Grab and Bond by those nice CT1 people. It 'goes off' much quicker than CT1, but the final strength is the same - according to their very helpful tech guru. ( see tube/pack for TelNo )

 

[Tintin]

Unfortunately the paint is failing and flaking in many places.