3½" Tich Boilers
Another couple of jobs for the chap I made the Simplex parts for. He seems to be an avid collector of all things Tich!
He purchased two Tich boilers, both commercially made, and asked if I could make the rest of the parts to finish them e.g. regulator, superheaters, and turrets. Both of the boilers had no bush for the steam turret (the 'Words and Music' show them screwed straight into the copper) and one was missing bushes for the regulator and water gauge top fitting.
The first boiler was made by Morewood Boilers and very nicely made. I made a bush for the turret and had no problem silver soldering it in. There was no sign of any of the original solder melting when I did this. The solder forms a new alloy when heated originally and then requires a much higher temperature to remelt it, so, so long as you are careful, further silver soldering is quite safe to do.
Both boilers were the Large Tich version and this one had a threaded regulator bush in the backhead which is really meant for the small boiler version with the Stroudley type regulator. The large boiler was meant to have a disc in tube type regulator (Yuk!) I decided to make a small screw down type instead and managed to produce one that would still screw into the bush on the backhead.
The superheater is a single tube made from 3/16" diameter thin wall stainless (from Southern Temperature Sensors) and is a full radiant type that extends over the fire. A Tich needs all the help it can get to reduce water and coal consumption!
The blower stay is meant to be made from 5/32" thick wall copper tube but this doesn't seem to be available any more. Instead I used ordinary 5/32" tube but soldered bronze fittings on each end to take the threads.
The turret is per drawings and was a fiddly piece of fabrication!
The top fitting for the water gauge was a bit of a problem. I originally made it straight but it didn't line up with the bottom bush on the backhead when it was screwed in so I had to 'bend it' a bit to get it to line up. The bush in the top of the boiler needed to be higher up really.
The firedoor was a basic type made from stainless steel with brass hinges.
Last item was the snifting valve. I couldn't find any details of this in the 'Words and Music' so had to make it up. The drawing of the smokebox shows the valve poking out through the bottom of the smokebox shell so I turned the body with a short 'pipe' on the bottom to go through a suitable hole.
Unfortunately, I didn't take pics of the individual items as I made them but here's one of the completed job:
All of this now has to be repeated for the second boiler although I did make the turret at the same time as the first one.
Finally got time to finish off the second Tich boiler and associated fittings. This boiler was a very nice job made by well known boilermaker Reg Chambers but was made to the drawings and had no bushes for the regulator and the turret. It's got number 47 on it so is probably one of his earlier boilers.
Bushes were made from gunmetal for the regulator bush and bronze for the turret bush. I also made the top fitting for the watergauge from a slice of gunmetal so that could be fitted at the same time. I only wanted to reheat the boiler once!
The top fitting was fastened to the boiler with a couple of bronze screws, the bushes fitted, and the whole lot silver soldered. This took a lot more heat than for the first boiler where only the turret bush had to be fitted. It all turned out ok though.
Just after soldering
The regulator for this boiler is very similar to the that for the first, the only differences are that the body has a flange to fit to the backhead rather than a threaded boss and the body itself is larger diameter. This enabled me to use a 3/8" BSW thread for the valve whereas the first regulator used 5/16" BSW.
The regulator design is exactly the same as I used for Helen and has proved very reliable and steamtight. The port face is bearing grade PEEK and the steam pipe from the regulator passes through the bush on the tubeplate which has a recess for an O ring to seal the steampipe to the superheater header.This is a far better system than where the steam pipe threads into the bush.
The superheater is exactly the same as for the first boiler and is made from 3/16" thin walled stainless tube.
The firedoor is also the same as for the first boiler but this time the latch comes very close to the bottom water gauge bush so I had to limit the lift on the latch so that it won't foul the water gauge when fitted. The hinge and the latch plate are fastened to the boiler with 8BA bronze screws threaded directly into the backhead.
All that's left to do now is make the snifting valve and finish off the turret. I'll give the boiler a hydraulic test before I send it back just to make sure that there are no leaks caused by the silver soldering of the new bushes etc.
Finished off the turret today. All it needed was the lever for the whistle valve so that was fashioned out of a piece of stainless rod turned, milled, and filed to final shape.
I made the snifting valve a couple of days ago and this was a simple turning job from hex brass bar with a 1/8" stainless ball. As mentioned before, LBSC does not detail the valve so I just made something up that looked like that shown in the drawing of the smokebox.
That's about it now. I've just got to wait for some stainless steel screws and some O rings to arrive to finish everything off. The water gauge and blower valve will be commercial items so I don't need to make those.
The O rings and screws have arrived and the boiler is now complete and boxed up ready to be sent back to it's owner.
I shopped around for the O rings and eventually got them from Polymax Ltd. There is a minimum order of 20 of each size but I took the chance to stock up and bought 280 (20 each of 14 sizes). It worked out much cheaper than buying from the usual ME suppliers.