Revolving chimney cowl

[CliffordPope]

We have a Rayburn with a newly-lined flue emerging at a chimney at the back corner of the house. Because of the angles of nearby roofs it is not ideally placed, and although projecting as high as possible it still has a tendency to blow back in particular, but rare, wind conditions.

I fitted a revolving cowl 2 years ago and it brilliantly solved the problem. Even when the so-called self-lubricating bearing seized up, the design of the spiral vents still miraculously managed to prevent blow-back.

However, the cowl mounting block has badly corroded, and yesterday collapsed, partly blocking the flue, the cowl itself narrowly missing my head as I climbed a ladder to investigate.

So although the stainless steel vanes have totally resisted the attack of wood and coal smoke, the cast aluminium base clearly did not.
Can anyone recommend a good lasting product as a replacement?

 

[Penners]

I can't make any personal recommendation, but this looks like an interesting product. The bearings, they say, are located outside the cap and thus, presumably, out of the path of the corrosive fumes.

http://www.fluesystems.com/shop/Dragon_Force_In_Base_200mm.html#a18_2fDRAGON_2fFI200