Barney

I tried to cut some new 3/4'' boiler sight glass tube for my steam loco oil feed but had no success so took it to some gem stone suppliers and cutters at Lenwade, Norfolk and asked them to cut it. They cut five before they made a good job of the two I needed, the glass just broke away around the outside edge and although they would have sealed on the O rings ok the cutter was not happy with his work. The cutter said that cutting glass is more difficult than cutting diamonds because it is so brittle.

I brought some kiln dried 4x2" from a builders merchants, twisted all over the shop after only a few weeks.

What was a British Pound worth in 1930? Value of £1 from 1930 to 2017 £1 in 1930 is equivalent in purchasing power to about £62.13 in 2017, an increase of £61.13 over 87 years. The pound had an average inflation rate of 4.86% per year between 1930 and 2017, producing a cumulative price increase of 6,113.29%.

Very nice Steve but rather OTT for just a breather, me thinks.

Steve, Just a quick thought on making a setting tool. Piece of flat plate with mandrill screwed in, upright on edge of plate with stop screw a 90 degs to mandrill, adjust stop screw and pull bits out until they touch the stop screw and tighten the grub screws. I guess that the tool originally had something like this but it had been lost in its 50 plus's years of life. We used a depth micrometer. John

Hi again Steve, This video shows a similar valve re-cutter and will give you some idea what the tool was like but this one appears to have only one cutting bit but then the seats are smaller. It is a lot more substantial than the one we had and it didn't align with the follower bore. John

Hi Steve, Herewith, a rough, very rough, sketch of the vintage valve re-seating tool that I'm sure you could easily make. I understand it came to us from a closed down garage that specialised in horizontal stationary engine generators, Blackstone and the like, that were in many of the big Lord of the Manor houses in Norfolk; a few were still around on the early 1970's when I joined the garage but I never worked on one. If the valve face is off centre then the more cutting bits the better, so I have shown four but it will be very fiddly to get all four to cut, although even if those that don't cut just act as a guide that will be helpful. I remember that we had to turn up guides and mandrills for some engines. Hope this helps. John

Hi Steve again, Some further thoughts on the three way cutter. The mandrill was held tight in the guide by a nut on the bottom and there was a very fine thread on the top end. The cutter was slid into the mandrill and then a ball thrust washer and knurled nut gave the pressure to cut but only hand turned. It was fiddly to set up so mostly only one bit actually done the cutting. We also had a similar tool, also hand turned, for replacing burnt out inserts and for fitting new steel inserts on seats that were too deep to recut, or were too deep after recutting. This tool only had a single cutter but came with an assortment of different size heads and it was necessary to choose one that didn't leave too much overhang on the cutter. Again, easy to use and cut brilliantly. John

Hi Steve, In the garage we had a three way fly cutter for seats larger than the VibroCentric could do and this was sufficient for the occasional extra large seats we got. The heads were cast iron in those days so cutting a new seat was easy. Easy to make, it just used round HSS bits held in with two grub screws so no need to cut square holes. Lorry looking great now. John

Sorry, duplicated post. John

I feel you are overthinking this, Andy. Singer would have chosen the thread on the basis of material to be used, the duty that the component is to perform, and ability to manufacture. Any comparison with a thread designation decided upon by the Americans nearly twenty years after the Singer components manufacture is can only be pure coincidence.

1" 16-UN - Unified Extra Fine Thread, which is used for special purposes.The flank angle is 60°.

Moving on one from Richard Farrant's post may I suggest that having found the area of the leak by pressurising the tank that you re-slosh the tank and pressurise it again with the slosh in the leak area. Hopefully this will force the slosh into the hole and seal it. John

Sorry, re-thought this post and decided it might cause more problems than it would solve so decided to delete it.

Hi Steve I have always set the ring gaps to those that I was taught during my training and have never had any problems. For bores 2 to 3" - 2 thou per inch of bore pro rata For bores 3 to 4" - 3 thou Ditto For bores 4 to 5" - 4 thou Ditto Sorry but I can't give any info on ring temps. Hope this helps. John