Galvanizing exhaust collars on my GSX750ES exhaust center

[Guest]

I completely rebuilt the exhaust center of my GSX750ES . I replaced the destroyed pipes with precisely bent SS pipes and now I want to take care of the collars that attach the exhaust pipes to the engine head. These aluminium collars endure very high temperature and I wonder if galvanizing them will last ...

collar.jpg

[londonboards]

I would get them vapour blasted and leave them as is.

[850GT_Rider]

I am unsure you can effectively galvanize aluminum, and further, even galvanized steel doesn't like high temperatures. Galvanizing is an ambient-temperature corrosion barrier.

As stated - just clean them up and use them as is.

[nastyjones]

If they're aluminum you can have them anodized. Not sure how they would hold up to the heat. Ask a metal refinishing shop.

[Nessism]

It's been a while since I worked on one of those ES's but many GS bikes have cast iron/steel exhaust collars. That's why with age and weathering they rust. Are you sure those collars are made from aluminum? You might want to put a magnet on them to test the metal.

[GregT]

It's been a while since I worked on one of those ES's but most GS bikes have cast iron/steel exhaust collars. That's why with age and weathering they rust. Are you sure those collars are made from aluminum? You might want to put a magnet on them to test the metal.

Agreed.
If they are steel, the original finish will need removing then I'd dull chrome. this will survive the temps where zinc won't.
If you actually have alloy clamps, yes they can be anodised - but some colours will fade worse than others with high heat. Talk to an anodising company.

[dpascal]

I'm 100% sure it's Aluminium. It does not stick to a magnet and it is light as a feather.

[Agemax]

you cannot anodize cast aluminium

[GregT]

you cannot anodize cast aluminium

Not universally true. Some Japanese die casting alloys do anodise reasonably well.
In this case, I'd vapour blast and talk to an anodiser about clear anodising as it's less touchy to do.
Alternatively, simply paint with an etch prime of your colour choice.

[dpascal]

After reading all the responses and speaking to some shops in my area I reached the conclusion that I'll thoroughly clean the exhaust collars and install them without any coating.
I guess a thin layer of corrosion-block will do no harm once in a while ...

http://www.opieoils.co.uk/images/VARIANT/small/197961.png

[Nessism]

I think you will be fine to just leave them raw aluminum. A nice bead blasting job to clean the metal wouldn't hurt. That's what I did on similar aluminum exhaust collars before anyway.

[Ghostgs1]

Are there different metals used in these? I just tested mine with a magnet and they are very magnetic. Certainly not made of monel or 400 series stainless as they can rust, so they have a lot of iron. They were probably zinc plated originally, but with the temps being so high, that doesn't hold up forever. Chrome plating would be a good choice, but expensive and hard to find a shop these days. Possibly the silvery colored ceramic coating would be an acceptable substitute.