It’s actually me doing my own Blog Post this time, so please excuse the bad grammer & spelling mistakes.
After years of building up a handy crew, I’ve been a bit lonely for the last few weeks. I’m not complaining because I’m lucky enough to still be employed in this pandemic period, but I think Baz & I are starting to get sick of hearing each other from opposite ends of the Workshop.
I have been able to catch up on a few things whilst there are no trains running, like the long overdue repairs to one of our 4 wheel tankers, some “A” exams on Goods vehicles & finally had time to give a good effort on K160’s new Ashpan. I’ll let our normal Blogger tell you about those jobs, as he writes a much better story than I can.
Last Friday I was able to grab our truck & take the Main Internal Steam Pipe with a brand new Cone Joint, & the J pipe down to Newport for K160. I checked K160’s progress, issued a few instructions, & came home with some old Steam Delivery Pipes to be dropped off at our local foundry, & the Whistle Stop Valve off K160’s boiler which needs to be serviced. Monday was drop off the pipes & some old brake blocks, check out a possible brake issue on the truck & clean up my own mess from last week. The next day, I arrived at work, checked for emails, then thought to myself “Right. It’s Tuesday. What will I do? I know, I’ll service 160’s valve & blog the process.”
First up was clean a work area on the bench & give the whole valve assembly a bit of a clean up with a wire brush to remove years of built up grime. Then start on the outside & disassemble my way in. The handle nut was easy, but the handle was stuck on the square drive of the spindle, so a wedge & hammer were used to gently lift the handle. The stuffing ring barrel union came easily with a 1″ Whitworth ring spanner, but the stuffing ring was stuck by dried Gland Packing that had oozed out between the clearances & it wouldn’t move. Lucky I’d already got that wedge out of the Tool Store.
The valve job was going easy, hard, easy, hard. Great, I thought. I now have to separate the main components & I’m up to easy. Wrong! Maybe even very wrong. The valve assembly had been left untouched for such a long time that is was frozen solid. Time to change to the metal bench & fire up the oxy. 5 minutes later after a thorough warming around the thread, the tap body & valve body separated with a loud crack & a lot of effort. Time for a morning coffee because now I had to let things cool down before I could carry on.
After coffee, all the components were separated so that I could inspect everything & assess what work was needed. I grabbed a tap & die nut to clean up the whistle mounting studs & nuts, with generous amounts of Rocol hand cutting compound. I used a file to clean up where the edges of the nuts had been slightly rounded. A sharp scraper was used to remove the old gasket material. Wood workers are crazy, they keep calling our sharp scraper a chisel, but what would they know. The old gland packing had gone rock hard inside the stuffing box, & put up a good fight till I used a small rotary wire brush in the battery drill.
It was finally time for the important bits, the valve face & seat. When luck is on your side, a light lapping with 500 grit lapping paste will usually suffice, but I had found slight evidence of steam cutting on the seat & 2 small pit holes on the valve face, so machining was required. The valve cutter was used with light pressure to gently scrape the seat & re-create the correct seat angle, but I had to put the spindle in the lathe & take 3 fine cuts to remove the pitting. Whist doing lathe work, I also had to make a lapping guide for the spindle, as we didn’t have a small guide to suit the small spindle. This was a bit time consuming because first I had to cut a thread to screw the guide into the valve body, & the spindle thread was 0.008″ under 5/8″, so I had to drill the hole then use a tiny boring bar to make the hole the right size.
Job done, it was back to the bench, & use the new guide to lap the newly machined faces together. First with 120 grit lapping paste, then finish off with 500 grit. We use Bearing Blue to check our contact faces because it will not hide any faults, & after the first check the Blue told me I still had some lapping to do. 20 minutes & several hand cramps later, the Blue showed me a beautifully consistant & clean sealing surface. That’s a win.
Full assembly was now the last task, so a brisk walk across to the Stores to collect the appropriate gland packing was followed by a trip to our Tool Store fridge to grab the Dixons, nickel anti seize & copper grease. The Valve Spindle thread was coated with the copper grease & screwed into its housing so that I could then cut & fit 3 new rings of gland packing. The spindle housing thread, Valve body thread, Stuffing ring & barrel union & the entire exposed Whistle mounting studs were all coated with the nickel anti seize. The sealing faces of the Valve body & Spindle Housing were then coated in Dixons, & the whole lot was screwed together. The final bit of attention was to clean & paint the valve wheel in the same sparkling Stove Bright paint that we apply to our Smokeboxes.
Done. My father used to tell me to take pride in my work & I was very happy with this job, but I don’t know how long it will be before this Whistle Isolator Valve will be bolted back onto K160’s boiler, so I wrapped the whole job in plastic to keep it clean until it goes back to Melbourne for refitting, and that was pretty much Tuesday.
So next time you are talking to somebody who asks why it takes so long to overhaul a steam engine, just get them to read this.