Stuart boiler flue

I have this Stuart Turner boiler dating from when they were in Henley. It has never been used! Can anyone tell me how they envisaged fixing the elbow for the chimney into the end of the flue please? The cast iron elbow has a spigot that goes into the end of the flue but it is a poor fit. There is a difference in diameter of about half a millimeter. Does it have to be gas tight? I would like it to be upright and secure without external props or brackets.

Maurice

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On the flue for my cast iron wood burner the gap was more than 2mm. All plugged up with fire clay.

That's what happens full size, may not be considered 'good practice' for models though.

Regards,

Richard.

Thanks Richard, that's what I was considering. I did consider rolling up a thin ring of copper to go in the gap, to make it a wringing fit, then some fire clay as a seal.

Regards

Maurice

If the end of the flue is a single walled piece of copper tubing projecting past the boiler end, could you drill four small holes in the projecting flue from the sides, 2 each side, and drill and tap mating holes in the sides of the elbow, then fit screws through both flue tube end and elbow to hold them together? . As mentioned, any gaps could be closed with fireclay before fitting the screws.

If the end of the flue is double walled with a water space between the walls (doesn't look like in the pics, but just being cautious) you should not drill it, and may need outside brackets to the boiler supports, or the boat frames, to hold the elbow.

Good luck with it. JD

You can use hi temp loctite, good for 200+ degrees, your boiler shell wont get anywhere near that hot provided it has water in it.

Probably ment to be sealed with fire clay, ans asbestos string, the gap is to allow for expansion, and a non metalic joint area reduces the transfer of heat to the chimney.

Ian S C

Thanks for the sugestions; the way ahead is clear!

Maurice