Can it still be saved?

[Michael S.]

Hello everyone,
At an exhibition, this cylinder was in a box with other junk. I bought it because the small valves were interesting to me. The cylinder with the two covers is actually complete junk.

But maybe it's better not to throw it away.

I first sealed all the holes and then smoothed the surfaces.

The bore is 25 mm and I think it belongs to a Stuart 7.

Then I searched through my collection of blueprints and found this blueprint. From France or Switzerland?

I think it might work!?


Michael

[crueby]

Looks like it had been butchered pretty badly, but still saveable!

[Michael S.]

I imagine the glued screws will also hold up under steam.

Michael

[Sanjay F]

You certainly like a challenge Michael and yes, it would be great to see it used rather than scrapped!

[Jo]

To add to this: When you look to save a piece it is important that the "plugs" used to fill any problems are made of the same material as the item being repaired. So when you do any further machining both the plug and the casting material is of the same hardness. So for a Iron casting you should use Cast Iron.

Then we need some means to secure the repair piece in the original piece and it must be suitable for what ever it is going to be subjected to once completed. Some of the Loctites are good for the temperatures that a steam cylinder operates under steam at, but check you have a suitable one.  Brazing Cast Iron needs a bit of practise    but can be done. JB Weld does not have the same strength as some of the loctites but can cover a multitude of sins.


Bronze castings are much easier as you can just silver solder on another bit, but years later you get a dirty black line from the silver 

Jo

[Michael S.]

Yes Jo,
that's actually correct. Ideally, cast iron would be the first choice.
I didn't have any cast iron rods for 3 and 4 millimeters. The screws I use are very soft, and it's possible to drill new holes in both the steel and the cast iron.

Best regards, Michael

[Jo]

Morning Michael,

I have never found any small diameter Cast Iron available commercially, 25mm seems to be the smallest you can get. So I normally keep offcuts from larger bits of cast Iron and turn them down to the diameter required to make repair plugs. One source is the round cast Iron plug you get if you use a hole saw to take the centre out when making piston rings.

As you mentioned if the parent and plug material are of different hardness a drill will want to wander into the softer material 

Jo

[Jasonb]

The other option is not to start by filling the out of position holes with the inherent risk of subsequent drills and taps wandering or worse.

Start by forming oversize holes in the correct position which if they overlap the old ones can be done by plunging with a suitable milling cutter. You can then make some threaded bushes and bond those into the oversize holes for which my choice would be JBWeld which wil also fill any other gaps or bits of old hole.

The advantage of separate bushes is you can use whatever material is to hand such as steel or brass, you can tap right through so your thread will go deeper. And if you do snap a tap you just throw the bush away rather than have to deal with removing it from the casting.

If you do plug with different materials then plunging with a milling cutter is less likely to wander than a drill though a tap may still want to follow the route of least resistance. But OK for clearance holes.

[Zephyrin]

the plan shown comes from Jean-Pierre Duval... a prolific designer of steam engines of all kinds,
too much btr screws to my taste in these drawings, but his Decauville loco is a very popular and renowned drawing.

http://jpduval.free.fr

I remember by the way an old recipe to repair cast iron with a mixture of cast iron fillings and sulfur powder...supposed to give a sealing as hard as cast iron.

[Michael S.]

Thanks for the tip, Jason and Zephyrin.

I also have the blueprint for the locomotive.

I would use the cylinder for a steam engine with 4 columns. A simple design is best. The Reeves Trojan would also be possible. It fits the cylinder bore of 25 mm and a stroke of approximately 30 mm. I have to adjust it.
I like the crosshead guide with two rods.
It could go in that direction.

Michael

[Michael S.]

I was lucky with the new holes in the cylinder. After remaking both cylinder covers, I used them as templates for the new threaded holes.

I'll now add the rest to the engine according to the existing blueprint.

Michael

[Grateful Ted]

Excellent save.

[PaulR]

Great recycling!

I feel sorry for the person who had the problem in the first place, it must have been very disappointing to have it come out like that 

[Michael S.]

Yes, the holes have really drifted.

After cutting the vine, I cut the first threads.


Best, Michael

[gipetto]

do you think if you had used 7 holes instead of six would you have avoided drilling over the old holes. then you wouldn't have had to plug them, but it's good for building pressure of course.