Joining stainless steel flu sections Design Styles, Chimneys and Finish Discuss Joining stainless steel flu sections in the Pizza Oven Design and Installation forums; Hi. I have two 900mm sections of stainless steel flu I need to join. I can join them by using ...

[pizzahead]

Hi. I have two 900mm sections of stainless steel flu I need to join. I can join them by using self tapping screws but was wondering if there is a product out there that can be used to seal them eg a high temp silicone product?

Thanks
Jase

[nissanneill]

Jase,
each section should have one end that has been rolled/corrugated and the diameter reduced slightly to fit inside another. These sections are normally rolled parallel, ie. they are the same diameter both ends which is unlike most plumbing drain pipes which have one end slightly smaller than the other.
I just sat mine in the other (3 high) and leave it at that, yes unsupported and surprisingly sturdy. It is now supported by the new patio roof where it goes through it but was unsupported for a year without trouble. My chimney is 10" and not a screw in it just a snug fit and no smoke leaks.

Neill

[david s]

Stainless steel pop rivets work well. I've just done some tests on some silicone sealants and found Dow Corning 732 is adequate.

[bimbo]

there is a red silicone that can be bought from auto spare part stores that is designed for high temp like car exhaust etc which i would imagine would be fine to use.

[david s]

Just be careful, a high temp silicon that was recommended to me contained carcinogen, so I bypassed that one. Check what's in it from its MSDS sheet.

[pizzahead]

Thanks all for your advice.

I ended up just slipping the sections into one another and they are holding very well. I did put some self tapping SS screws in just to be sure.

Cheers
Jase