Post by Franklin1 on Sept 15, 2010 9:53:15 GMT 10
G'day brewer,
The big problem with spraying something into the aluminium/steel joint is knowing whether it has penetrated the full joint, or is really only covering the the exterior part that was sprayed upon.
You don't say whereabouts the van resides, because the climate the van resides in will have a big bearing on the success of whatever you do.
For a complete job, I'd be inclined to put rust converter into the joint and hope it penetrates deep down. Then I'd be painting the whole joint so that future moisture can't penetrate. Rust converter based on phosphoric acid shoudn't harm the aluminium. Phosphoric acid is the latest method used for anodizing aluminium. Many redundant aircraft stored in the Arizona desert have been preserved by the phosphorous content of the pigeon poo covering them (along with the low moisture environment).
Corrosion between metals requires some sort of moisture to be present. Eliminate the ability of moisture to get into the joint, and you will significantly delay any corrosion. Even if you did nothing to the existing rust/aluminium corrosion, preventing any further moisture getting into the joint would slow the corrosion rate down considerably...well past your lifetime.
For the "cheap weekend option", think about how you might run a bead of caulking/sealant along the exposed joints where the aluminium overlaps the steel. Use a sealant that you could remove 'easily' in the future if you needed to. Something like the butyl mastics or No More Gap type sealants.
Keep the van dry, or at least be able to dry it thoroughly after it gets wet, and you will slow any further corrosion down quite markedly.
cheers,
Al.
The big problem with spraying something into the aluminium/steel joint is knowing whether it has penetrated the full joint, or is really only covering the the exterior part that was sprayed upon.
You don't say whereabouts the van resides, because the climate the van resides in will have a big bearing on the success of whatever you do.
For a complete job, I'd be inclined to put rust converter into the joint and hope it penetrates deep down. Then I'd be painting the whole joint so that future moisture can't penetrate. Rust converter based on phosphoric acid shoudn't harm the aluminium. Phosphoric acid is the latest method used for anodizing aluminium. Many redundant aircraft stored in the Arizona desert have been preserved by the phosphorous content of the pigeon poo covering them (along with the low moisture environment).
Corrosion between metals requires some sort of moisture to be present. Eliminate the ability of moisture to get into the joint, and you will significantly delay any corrosion. Even if you did nothing to the existing rust/aluminium corrosion, preventing any further moisture getting into the joint would slow the corrosion rate down considerably...well past your lifetime.
For the "cheap weekend option", think about how you might run a bead of caulking/sealant along the exposed joints where the aluminium overlaps the steel. Use a sealant that you could remove 'easily' in the future if you needed to. Something like the butyl mastics or No More Gap type sealants.
Keep the van dry, or at least be able to dry it thoroughly after it gets wet, and you will slow any further corrosion down quite markedly.
cheers,
Al.