I was just wondering if anyone has problems electrolysis between the steel chassis and the aluminium panels?

I know it happend alot on the old Land Rovers

[Edited on 21/4/03 by I love speed :-P]

sounds like what you are refering to is also known as dissimilar metal reaction ie 2 diffrent metals rusting together

if you can powder coat your chassis

now heres a tip, its a stuff called (if i remember rightly) polyurathane sealant. it comes in a piston tube (like bathroom sealent) instead of rivets to hold your panels on, this stuff is strong enough to fix it permanently, so you can use one or two hidden rivets to secure the panels whilst it cures, thus giving it a slightly more professional look

it removes contact between the steel & ally (thus removing the dissimilar reaction)

most modern cars use it in places they want to fully seal to the elements (arround grommets etc)

as a bonus you can paint over it when its cured

and as a bonus it will kill any panel rattles (if they cant move, they cant make noise)

i have even seen wind screens bonded in with this stuff

finally its cheap: £7.50 + p&p from car builder solutions

This is something that will always be a problem where two dissimilar metals are in contact with each other.

The best solution is to not let them get in contact with each other uncoated.
Before fixing ally panels to chassis, make sure the chassis is painted well first. If the chassis is prepared properly before painting there is no reason why the ally panels cannot be bonded ontop of the paint. Ideally ally panels should be uncoated before bonding and preferably etched to remove oxidesed coating that forms almost immediately.
Anyway I diversify!

Wherever untreated metals come in contact with each other there will be corrosion unless covered with something to keep out air or water. Petrolium jelly is good for electrical connections.

I don't know what to suggest if you are riveting your ally panels on!

Wherever ally panels will be used I will be bonding, unless they need to be removable and then I will be using ally fixings.

Terry

We use some stuff called PRC at work to prevent bimetalic corrosion when riveting. Its similar to silicone sealant, but it's a hell of a lot more stickier and remains flexible, thus doesn't crack off. You just squirt some into the hole and onto the rivet before you pop it on. It stop's a sea harrier from falling out of the sky!

If your really stuck, there is also JC5A ( a jointing compound) that will prevent any corrosion. Only snag with it is it remains tacky and can wash off.

As for the rivets rusting, you should be ok if you seal the panel well after riveting. As long as no water come's into contact with the area around the rivet, panel or chassis it's not an issue. bit of a bugger if you leave the panel plain.

I read somewhere on a website about a guys locost (one of the first) and his report on corrosion, he didn't mention anything about rusty rivets, just loads of chassis rails!

I have a couple of spare tubes of it prc if you interested. Their out of date, but that shouldn't be a problem for a locost, the only snag would be the big brown mess it makes, not any good if your not painting the panels.

Hope this helps!
Chris

Hi guys
this is very simple....
have you guys ever wondered how steel boats didn't rust away.
well they use what is called a sacrifical metal that is higher in the scale.
have a look this was you have the brass propeller which is low in the scale and then a steel shaft which is higher in the scale so it will rust away before the brass propeller, then the hull of the ship.
they also use this on out board motors you might find blocks of zink in certain areas.
anywas ally kinda corodes and then to a point the corosion will act as protection.
ally that has been anodised is bascly rust which is is then coloured with die

if ur paranod you could use bitumin based tape or malthoid as a separator or something we call no more nails or you could use fibreglass panels