Solid boat collar

[Jazz]

Looking for a non recessed solid cast boat collar any idea if they still available? Are they hollowed out to save on steel? Surely a flat collar would achieve a better seal? Thanks

[bizzard]

Looking for a non recessed solid cast boat collar any idea if they still available? Are they hollowed out to save on steel? Surely a flat collar would achieve a better seal? Thanks

I don't think clergymen wear cast iron dog collars. Is this a chimney collar your speaking of please Jazz.

Edited March 27, 2016 by bizzard

[bizzard]

I don't think clergymen wear cast iron dog collars. Is this a chimney collar your speaking of please Jazz.

I think I know what you mean. The underside of chimney collars all seem to be hollowed out now with just a rib around the edge to seal on. Bedded down on a thick ring of sealant (to account for any roof curvature) like Sikaflex or Marineflex with another thick ring of the sealant around the hole in the roof where the collar passes through will be fine, once bolted down a finger run around the outside edge to smooth out the sealant that has squashed out before painting will do the job.

[onionbargee]

Seeing as your roof is not flat, a flat underside to the collar would be of no benefit to the seal, probably making it less effective as the two expand and contract at different rates. Steel and cast iron. Use high temp 300deg C silicone. That should last ten years plus.

[Jazz]

Thanks Mr Biz! Will do this if solid collars not available but last one I had was ......

The base of the collar can be bought ready angled to accommodate slope of roof?

[bizzard]

Thanks Mr Biz! Will do this if solid collars not available but last one I had was ......

I wouldn't use any silicon, use Sikaflex, Marineflex or The Works. The collar shouldn't get at all hot if the flue pipe inside it is installed correctly with no metal to metal contact between collar and flue pipe.

[bizzard]

Thanks Mr Biz! Will do this if solid collars not available but last one I had was ......

The base of the collar can be bought ready angled to accommodate slope of roof?

Indeed they can to allow them to stick up straight, but not the curvature.

[Jazz]

Its an awkward job as flue pipe is on an angle and fire welded to the hearth so getting a 4 inch pipe to fit inside a 5 inch collar and seal with pink fire foam

[bizzard]

Its an awkward job as flue pipe is on an angle and fire welded to the hearth so getting a 4 inch pipe to fit inside a 5 inch collar and seal with pink fire foam

If its poking through centrally you should have a half inch gap stuffed with fire proof rope with no flue pipe to collar contact. If the flue pipe is touching the collar ' metal to metal' you'd better use the heat proof silicon.

[Jazz]

Is it the metal to metal that's the problem even just the edge of the pipe? Is fire foam not a good idea to fill the large gap on one side?

[bizzard]

Is it the metal to metal that's the problem even just the edge of the pipe? Is fire foam not a good idea to fill the large gap on one side?

Even an edge contact will transfer quite a bit of heat. I'm not sure how fire resistant fire foam is.

[Ray T]

When we had a stove fitted in 2011, we had a hardwood collar fitted. Hasn't caught fire yet.........

 

 

 

I don't know how it is insulated from the flue.

 

I had the collar fitted as chimney's at an angle are an anathema to me. I like them vertical, sad but hey ho.

 

I have seen a couple of examples made from aluminum but I don't know who made them.

Edited March 27, 2016 by Ray T

[bizzard]

When we had a stove fitted in 2011, we had a hardwood collar fitted. Hasn't caught fire yet.........

 

DSCF4015.jpg

 

I don't know how it is insulated from the flue.

 

I had the collar fitted as chimney's at an angle are an anathema to me. I like them vertical, sad but hey ho.

 

I have seen a couple of examples made from aluminum but I don't know who made them.

Used to be a very common practice, as long as the flue pipe is not in contact with the collar.

[ditchcrawler]

Well I can only find solid ones http://www.midlandchandlers.co.uk/store/product/hc-601.aspx

[Jazz]

Can't see the underneath in that photo

[bizzard]

Unless they've altered them I fitted a couple of them last autumn, one angled and they weren't flat bottomed, they both had the rib.

[bizzard]

Can't see the underneath in that photo

Sounds like your flue pipe needs a few degrees bend in it or cut and re-welded so it fits centrally through the collars hole.

[Ray T]

Chimney fitting from Andy Watson of this parish here: http://walkerstug.blogspot.co.uk/2012/08/saloon-stove-flue-roof-collar-and.html

 

 

"The collar has been shimmed with a custom made tapered spacer to make it absolutely vertical on the sloping roof".

[Jazz]

Many thanks Ray