Painting under the capping

What do people recommend for under the cappings of the rear tub. I have removed the very rusty old ones, rubbed down the oxidised aluminium and given a coat of etch primer. Is that going to be enough or do I need to go to the effort of top coating it as well?
Originally it does not look like it was top coated from the factory. And I will be putting a layer of foam tape between the Ali and the galv capping.

I would paint it as primer is porous (well more porus than a topcoat) and damp will get in there. I'd also probably apply a smear of red (rubber) grease on the foam tape too, just to be sure, to be sure.

dag019 said:

What do people recommend for under the cappings of the rear tub. I have removed the very rusty old ones, rubbed down the oxidised aluminium and given a coat of etch primer. Is that going to be enough or do I need to go to the effort of top coating it as well?
Originally it does not look like it was top coated from the factory. And I will be putting a layer of foam tape between the

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dag019 said:

Ali and the galv capping.

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Good timing with this question as I’ll be doing the same very soon. My cappings are in good condition except for the welded join. They are a bit rusty there and I want to get rid of that.

miktdish said:

I would paint it as primer is porous (well more porus than a topcoat) and damp will get in there. I'd also probably apply a smear of red (rubber) grease on the foam tape too, just to be sure, to be sure.

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What’s the rubber grease for ? Just wondering as I have a roll of closed cell foam I use often, but have never used the grease as well as !!

meego said:

What’s the rubber grease for ? Just wondering as I have a roll of closed cell foam I use often, but have never used the grease as well as !!

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That’s exactly what I use. Have spme
Neoprene tape I use for jointing. But also have never greased it.

miktdish said:

I would paint it as primer is porous (well more porus than a topcoat)

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That was my concern but was just trying to avoid top coating as the enamel takes much longer to dry than the primer so means I can’t fit the cappings for a while yet and I need a few good days to actually paint as inside.

dag019 said:

That’s exactly what I use. Have spme
Neoprene tape I use for jointing. But also have never greased it.


That was my concern but was just trying to avoid top coating as the enamel takes much longer to dry than the primer so means I can’t fit the cappings for a while yet and I need a few good days to actually paint as inside.

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Can you use another quick drying top coat then of the same colour. You could strike a line just before it’s seen with the capping refitted and paint it up to that ??

meego said:

What’s the rubber grease for ? Just wondering as I have a roll of closed cell foam I use often, but have never used the grease as well as !!

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It stops the rubber decaying and hardening and will also stop any moisture wicking (capillary).
Red Rubber grease doesn't have a mineral oil/petroleum base (it's made from vegetable oil) so won't decay a rubber/neoprene substrate.

miktdish said:

It stops the rubber decaying and hardening and will also stop any moisture wicking (capillary).
Red Rubber grease doesn't have a mineral oil/petroleum base (it's made from vegetable oil) so won't decay a rubber/neoprene substrate.

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Good stuff mate, cheers