I've hit a problem with my chimney collar fixing.

[Kendorr]

On my new build, I bought the cast iron collar and got boat builder to cut the hole for it. When the shell is finished and spray foamed, I'm thinking that I've had the hole cut a bit close to the bulkhead. Also, where the hole finishes there is a strengthening beam going across the roof. As such, I'm going to find it very difficult to get the holes in for the bolts. Hope that all makes sense?

 

So, my question is, is there a suitable sealant that could be used the stick the cast iron collar in place without using the bolt holes? or is this suggestion a big negative and I must find a way to get the bolts in position?

 

Thanks, Kevin

[mrsmelly]

1 minute ago, Kev's Halcyon said:

On my new build, I bought the cast iron collar and got boat builder to cut the hole for it. When the shell is finished and spray foamed, I'm thinking that I've had the hole cut a bit close to the bulkhead. Also, where the hole finishes there is a strengthening beam going across the roof. As such, I'm going to find it very difficult to get the holes in for the bolts. Hope that all makes sense?

 

So, my question is, is there a suitable sealant that could be used the stick the cast iron collar in place without using the bolt holes? or is this suggestion a big negative and I must find a way to get the bolts in position?

 

Thanks, Kevin

Hi Kev

I havnt bothered with the bolts. Its sealed down tight with sikaflex and it aint going anywhere. It will be removable though if it rots and needs replacing with a crowbar. I have used this method in the past without fault.

[philjw]

What material will the bulkhead be made from? If the collar is too close to the bulkhead, does that men that the flue will aldo be close to it and be a fire hazard and BSS fail?

[bizzard]

7 minutes ago, Kev's Halcyon said:

On my new build, I bought the cast iron collar and got boat builder to cut the hole for it. When the shell is finished and spray foamed, I'm thinking that I've had the hole cut a bit close to the bulkhead. Also, where the hole finishes there is a strengthening beam going across the roof. As such, I'm going to find it very difficult to get the holes in for the bolts. Hope that all makes sense?

 

So, my question is, is there a suitable sealant that could be used the stick the cast iron collar in place without using the bolt holes? or is this suggestion a big negative and I must find a way to get the bolts in position?

 

Thanks, Kevin

The boat builder should have checked for beams before makiing the hole and advised you.  Stove collars and stoves can't always be installed exactly where you want because of this. If the beam crosses a bolt hole you'll have to hack- grind it flush with the roof and hope it doesn't weaken it. A beam alongside could be added and welded in.

Edited July 20, 2018 by bizzard

[rusty69]

You could always get it welded up, and another hole cut. If well done, the weld may fall beneath the collar. (depends whether internal woodwork is in place). 

Edited July 20, 2018 by rusty69

[bizzard]

The hole could be elongated by a couple of inches away from the beam and still seal fine.  As mrsmelly said sticking it down with either Stikaflex or Marineflex works well too.

[Kendorr]

Thanks folks, food for thought, I have the space, and would prefer to fit it without changing the position of the hole.

 

[Boater Sam]

Weld bolts on top of the roof and nuts to hold the collar.

[rusty69]

Or weld nuts on top of the roof if their is room beneath the collar

[Guest]

2 hours ago, mrsmelly said:

Hi Kev

I havnt bothered with the bolts. Its sealed down tight with sikaflex and it aint going anywhere. It will be removable though if it rots and needs replacing with a crowbar. I have used this method in the past without fault.

Wish I had known that 14 years ago!

4 minutes ago, rusty69 said:

Or weld nuts on top of the roof if their is room beneath the collar

I imagine if some countersunk head bolts were welded down to the roof, then the collar counterbored sufficiently underneath, that it could be bolted flat to the roof. Edit sorry didn't see Boater Sam had already suggested similar.

Edited July 20, 2018 by Guest