Corrosion in aluminium panels
Discussion
Can it be treated successfully such that a panel can be repainted and not fail again in short order? I've spoken to a couple of marque specialist who didn't fill me with hope that any repair would last more than a few years max and maybe only 6 to12 months.
If it makes any difference this a classic Defender with corrosion on the roof and windscreen frame which is very common.
If it makes any difference this a classic Defender with corrosion on the roof and windscreen frame which is very common.
Our tanker semi trailers are all aluminium, tank and chassis.
By year 4 the signs of bubbling are starting particularly where steel bolts go through the chassis, but given the guage of metals involved they can look as scabby as hell and still be ok.
I suspect if the bolts were coated in something (don't ask me what) or a gasket in place where alloy butts up to steel it would help prevent the reaction between the two metals corrosion would be slowed indefinately, but that would increase production costs (and lengthen an already long service life to indefinate).
I look after my own tank, the chassis gets too battered by weathering to keep up with and of course one can't get to the contact point where steel meets alloy, when a stone or other chip appears on the painted tank i touch it in with the correct paint which generally stops corrosion spreading.
Years ago most tipper trailers were unpainted aluminium bodied, these would obviously see dulling of the finish but serious corrosion wasn't an issue until the body was very old and covered millions of miles.
If you were to strip an alloy panel off, repair and repaint any damage before its really starts, then use something as a gasket between the two metals and a swathe over such points in marine grease after repair you could probably delay corrosion indefinately.
By year 4 the signs of bubbling are starting particularly where steel bolts go through the chassis, but given the guage of metals involved they can look as scabby as hell and still be ok.
I suspect if the bolts were coated in something (don't ask me what) or a gasket in place where alloy butts up to steel it would help prevent the reaction between the two metals corrosion would be slowed indefinately, but that would increase production costs (and lengthen an already long service life to indefinate).
I look after my own tank, the chassis gets too battered by weathering to keep up with and of course one can't get to the contact point where steel meets alloy, when a stone or other chip appears on the painted tank i touch it in with the correct paint which generally stops corrosion spreading.
Years ago most tipper trailers were unpainted aluminium bodied, these would obviously see dulling of the finish but serious corrosion wasn't an issue until the body was very old and covered millions of miles.
If you were to strip an alloy panel off, repair and repaint any damage before its really starts, then use something as a gasket between the two metals and a swathe over such points in marine grease after repair you could probably delay corrosion indefinately.
Agree galvanic corrosion is the root of the issue on the Defender too, having such a mix of steel and aluminium panels. There's various things can be done to isolate the metals, foam tape at the contact points, weicon paste on the fasteners, ACF50 applied to joints regularly etc., bit sadly JLR were not very thorough in this regard when my car was built.
What I'm trying to understand is if it is possible to treat existing corrosion such that a panel can be repainted to a good standard and the finish not fail again in very short order. What I've been told is that once a panel has had corrosion it is difficult/impossible to remove or stabilise it effectively. Surely the wonder of modern science can deal with this?
The only alternative is a replacement roof, not ideal and finding one without corrosion would not be easy.
What I'm trying to understand is if it is possible to treat existing corrosion such that a panel can be repainted to a good standard and the finish not fail again in very short order. What I've been told is that once a panel has had corrosion it is difficult/impossible to remove or stabilise it effectively. Surely the wonder of modern science can deal with this?
The only alternative is a replacement roof, not ideal and finding one without corrosion would not be easy.
Gassing Station | Bodywork & Detailing | Top of Page | What's New | My Stuff