Boiler bush in Smokebox tubeplate not level!

[Geoffrey WrightParticipant @geoffreywright91241]

Hi Gents,

The bush into the smokebox tubeplate in my boiler for the Regulator/Superheater flange was not, for some reason, fitted level when soldered by the boiler maker (a well-known maker, sadly no longer with us). This means that when I screw in the 1 1/4 inch bronze fitting into the vosh it leaves a gap of about 20 thou. on one side, and therefore doesn't filly tighten down on the flange.

My though is to use 2 soft copper washers, either soldered or Loctited together, and then filed down at an angle to produce a wedge-shaped washer that can be used to close the gap. This could be held on the boiler bush flange by Loctite to prevent it moving whilst tightening up the fitting.

Does anyone have any thoughts on this please? Sorry about the quality of the photo.

Thanks

Geoff

[Geoffrey WrightParticipant @geoffreywright91241]

[Paul KempParticipant @paulkemp46892]

Sounds less likely that the bush has been soldered in out of square and more likely the thread in the bush was tapped out of square to the face. I think I would make a threaded guide that is a nice neat fit in the bush with a spigot say 1/2" long which can be used with a home made spot face tool (like a tap seat cutter) and then rotate slowly either by hand or cordless drill / flexi drive to face the bush square to the thread. I think I would be inclined to do it by hand rather than under power given the minimal amount to come off. Better to make it right in the first place than try and bodge it up with a wedged washer.

Paul.

[Martin KyteParticipant @martinkyte99762]

I was just about to suggest the 'spot facing idea' when I read Paul Kemp's post so I concur with him. Maybe you should screw in a long piece of bar suitably threaded on the end just to check where the tread is pointing and if it is within your limits of where you want it. If it is then resurface the face of the bush as has been suggested. If the thread is on the wonk in relation to the boiler and the fitting/regulator tube is supposed to run through the boiler to the firebox end and be in line you may have other issues.

On closer inspection can we assume that the bush is threaded externally? and you have shown the fitting to the bush in place?

regards Martin

[Geoffrey WrightParticipant @geoffreywright91241]

Thank you Paul and Martin.

 

Strange, but as far as I can tell with Mk 1 Eyeball and a square, the pipe filling made by me appears to sit up square and straight, therefore the internal bush thread would appear to be OK. I will see if I can put a little undercut (if that's the right term?) on the threaded fitting. Perhaps it's not quite level and square at the finish of the threaded end, therefore leaving a bit of a tapered spot. Not sure, but no harm in trying. Will look at it tomorrow.

Geoff

 

 

Edited By Geoffrey Wright on 21/03/2021 15:03:05

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