gal and zincalume -Barry White "question?

[durwood]

Barry can you tell me the likely result for this set up.

Need to get an old box section gutter which is in gal replaced.

Roofer I had doing quote suggested just dropping new zincalume section into the old one. The gal box is bent over and fixed under the edge of the clip lock roof so to take it out would mean removing the roof.

As there is a reaction between the two will the gal just completely disappear in the form of rust or will something else happen. Its rusted out on the bottom but the sides are ok, Its approx 160mm high and 150 wide.

The box gutter is hidden inside a timber supporting box and can't

[echnidna]

water running off the zincalume over the gal will rot the gal out

[Barry_White]

If you ensure the Gal box gutter is completely dry before installing the Zincalume one there really should be no problem. The gal box gutter may continue to corrode but should not effect the Zincalume one. If water was to get in between the two the corrosion would be accelerated and may cause the Zincalume to develop a black coating where it touches the gal gutter and may help to develop corrosion but if you can prevent water from getting between them so much the better.

You may need to take the ends out of the gal gutter but not being able to see what it looks like that is only a guess.

As`what echnidna says is correct.

[Claw Hama]

Durwood, you could paint on a good coat of duraseal/blackjack before putting your zincalume in this would protect it and stop it from comming in contact with the gal.

[Barry_White]

Durwood, you could paint on a good coat of duraseal/blackjack before putting your zincalume in this would protect it and stop it from comming in contact with the gal.

That's probably a pretty good bit of advice also.

A collective group of minds always come up with better solutions to problems.

[durwood]

thanks guys for the advice,

The gal is already full of holes and if it gets eaten away it won't matter as long as the zincalume doesn't get eaten away I'm sweet.

I like the idea of the blackjack, i had thought of just throwing in some plastic sheet or similar.