Lateral thinking

RocDoc · Lateral thinking

Hi everyone,

Been a bit quiet recently, sorry ... been busy with various things. The 167 restoration is almost done. I'll post some new photos soon. I wanted to share a couple of brain waves I had when making a new part for the chimney (if you remember, the lower section of the chimney was missing. I made a new part out of 3/4" brass tubing).

First problem was how to shape the bottom part of the new tubing so that it would fit nice and snug on the boiler. What I needed was something with the same curvature as the boiler.

Brain wave number 1: The boiler itself was the right shape!

I carefully wrapped some wet&dry round the underside of the boiler then sanded the brass tubing to the correct shape (see first photo).

Second problem was how to hold the two parts of the chimney together during soldering. I didn't want to solder the parts together when actually on the boiler. In his thread on how to make a Bowman chimney, Steve_S made a jig out of bolts and washers and stuff to hold everything together.

Brain wave number 2: Sand!!

An alternative is to use fine grained clean sand. Align the parts correctly and carefully put sand between the narrow inner part of the original chimney and the new outer section. If the alignment is slightly out, don't worry just move the sand a little. Use a match stick to compact the sand into the space. Add more sand until it feels nice and secure.

I must admit that I've not yet soldered the chimney parts together so don't know how the sand will cope with the heat. In theory, it should work.

Steve_S

Two fine brainwaves. The wet and dry wrapped round the boiler is a great idea. I just did it with a half round file and trial and error. I didn't cut the tube to length until the curvature was right... to allow for more trial and error! Your way is much better.

rangerssteamtoys

Like the boiler use idea. I'm not sure about the sand, sand absorbs ALOT of heat. It my take a while to heat both parts.

RocDoc

Thanks Steve,

The tubing I'm using has thick-ish walls so I have to grind out the walls first to make a snug fit onto the original chimney. The I cut the tubing to about 1 inch length then work on the bottom using the shaping method.

Pete

RocDoc