Stainless steel and masonry/concrete

[Massimilliano]

Hi
I want to put a chimney on my outer arch. I don't want to have an exposed SS flue so am planning to "cover" it somehow.
One idea I have is to enclose it within an outer chimney of, say, vermicrete.
My question is, can I just shape the vermicrete around the SS flue or will that cause the steel to corrode?
If ghe concrete will cause corrosion Is there some way of spacing the concrete off the flue?
Is home brew a better idea than vermicrete?
Cheers
Max

[david s]

Re: Stainless steel and masonry/concrete

Vermicrete is not particularly strong. On its own it will probably crack. Remember the flue pipe will expand slightly when heated. You would need to encase the vermicrete in something. Ferrocement, brick stone etc. Cement actually inhibits corrosion. If it is stainless you should be ok.

[Massimilliano]

Re: Stainless steel and masonry/concrete

Thanks David
I had forgotten how fragile vermicrete is. I was planning to render it like the rest of the oven.
I guess I will shape home brewed fire clay around the flue and plaster that. Although I suspect that may be a bit heavy

[david s]

Re: Stainless steel and masonry/concrete

Yes you can just render over it like the rest of the oven, but give it some strength by using some mesh or chicken wire like a ferrocement boat once you've done that it doesn't matter what happens to the vermicrete because it's trapped inside..

[Massimilliano]

Re: Stainless steel and masonry/concrete

Thanks again David
Do you mean tender straight over the steel or use a layer of home brew first?
Max

[david s]

Re: Stainless steel and masonry/concrete

No, I mean vermicrete then ferrocement.