Twin cylinder mill engine, slightly rusty.....

[redhouseluv]

I took a break from the clean up today and thought I'd try making the missing oiler. It's not exact as I made it more by eye and it felt more like a wood turning process! I made the thread 0BA and then opened up the crosshead guide to the same thread size; here's the result

[redhouseluv]

Finally, everything is apart and cleaned as best as I can get it

.........now begins the reconstruction with BA size holes and new bolts to fit, new gaskets cut to size and some shiny new graphite yarn. This is going to take a while, but I took lots of photos as I took it apart, so fingers crossed everything goes back ok 

[redhouseluv]

Hmmm.....I've just noticed one side of the inlet manifold has broken free from its flange and can rotate as well as there being a gap (see pic).

The otherside is in good order and nicely soldered so I'm guessing I'm going to have to resolder this. Given I have only just started soldering having bought the Sievert, would the Tenancity flux and 0.5mm silver solder wire 55% be good for this job?

The flange looks to be copper in colour and the manifold brass

[crueby]

That solder and flux should be fine. Be sure to get the mating surfaces really clean first, sand or file if needed. I'm  assuming no soft solder anywhere on that assembly, if any it will melt off. If any other silver soldered parts on it, try and heat just that end so the others dont move.

[redhouseluv]

The other flange is soldered, so yes, I'll have to make sure the heat is focussed on side which needs repair. I think its going to take a fair amount of cleaning as there is gunk inside and out. I'm expecting some intense smoking when the gunk is heated 

[uuu]

The challenge is that the brass part, being larger than the copper flange, is going to need more heat to get up to temperature.  so you can't just blast away at the end.  As you've previously found out, you need both parts properly hot to get the solder to flow.  But you're saved a bit that copper will take quite a bit of overheating without damage.

It won't hurt to apply flux even where you don't need it.  That will reduce the discolouration of the part as a whole and, if other joints soften up, they'll be protected from oxidation and there's a better chance they re-solidify without damage.

Wilf

[redhouseluv]

I think I may have put the work into the citric whilst it was too hot? It sizzled and the solder on the other end came away - maybe that was just a coincidence rather than thermal shock? Do you have to wait and let the work cool before putting it in the citirc?

I think I need to spend an afternoon getting the flux to the the right consistency, getting the flux to run clear, but most importantly I need to get some idea of how long that takes. It turned crusty but didn't really turn clear like it does on the videos, does that mean clean it off and start again?

The side I meant to fix was ok, not as neat as I would have liked it, but cleaned everything up and I used some flux and some more solder to resolder what was the good end.

Anyway, after the citric bath and a polish with a Dremel, there is a manifold. This will need to be tapped and a a fitting made as there is no discernable thread in the inlet port.......strange

[Dave Otto]

Was it soft soldered of silver soldered originally? If silver soldered I would be surprised that it broke apart. If it was soft soldered and you try to silver solder it you may be in for a challenge, you will need to take it apart and remove every trace of the original solder. You will need to do this for both joints as the other one will certainly fall apart.

Dave

[Dave Otto]

Looks like you are one step ahead of me.

Dave

[redhouseluv]

Hi Dave

Yes, that was exactly what I had to do, it was a mess of solder and grime and soot; I think it was soft solder. Maybe it would explain why it melted so quickly when I made every effort to keep the heat away from it?

[Dave Otto]

 

[uuu]

The more of this you do, the more you'll get a feel for how long things take - and how likely existing joints are to part.  Having some kind of hearth - or a pile of thermal blocks to surround the job - will concentrate the heat and reduce the heating time.

You'll have found, as you did the second end, that the first end you did didn't just fall open.  It takes extra heat to re-melt an existing joint.  So with care you can do a multi-phase assembly using the same solder throughout.

Some people like to put hot parts into the citric, as the thermal shock can loosen some of the crusty flux.  I'm not such a fan - I wait until it's below sizzle point.

Wilf   

[redhouseluv]

Thanks Wilf, yes, I did wonder why the my newly soldered joint didn't melt and thought I'd be going from one end to other repairing and melting at the same time 

I think in future a little drop in temperature may be called for before immersion.

I opened up the inlet manifold and tapped it 5/16" ME and made a small connector so eventually I can pump some air in. There were no gaskets on the flanges, but I think I should make some in order to get a good seal

[redhouseluv]

After a day in the workshop the unknown rusty Victorian Mill Engine has been named 'Esther' after a family vote 

She can be turned over by hand and all the bits and pieces seem to be making the right movements as well as some huffing & puffing noises since I installed gaskets and graphite yarn. I've not looked at the valve timing or anything, I just wanted to see if she'd move after being seized solid for decades.

I've never set the timing on twin cylinder engine like this, but presume the same rules apply with regards to the slide valve having equal movement at each end of travel and ports being exposed at TDC or thereabouts. Once I set timing on one side do I just repeat again for the otherside?

https://youtube.com/shorts/-vvNSCX1cu0?feature=share

[crueby]

Correct on the timing sequence - centering travel first, then adjust the eccentric to open just after TDC (and close before BDC). Each side gets same adjustments, relative to its own ports/crank.  It can be fiddly, tiny adjustments, or sometimes it just falls into place and runs!