'WIDE A WAKE' a steam launch tale

[Jo]

A few years ago we had a fitting failure at Guildford when the  Owner had made his own clack valves on the backhead out of brass: It failed spectacularly thankfully no one was close by or where it was up on the steaming bay they would have had a horrific scalding 

Jo

[Ramon Wilson]

' Morning guys - thanks for all your input.

Sandy - many thanks for these drawings. I had an email from our inspector last night suggesting the end flange was set in the shell making the funnel emerge from a dry back. First thought is that this would mean I could keep that original brass funnel as the flue tube is 2" id. However on thinking about it a bit more my real concern apart from a considerable reduced water volume would be getting enough heat down into the shell when soldering that end plate so deep inside.  My money then is still on your method and yes I very much would appreciate any help you could give on the stresses involved, etc. I will PM you later today - thank you.

Stew - thanks for your concern and thoughts of safety. If you look back I did mention this very thing in the first post of this thread (4th para).

When I made the boiler I had no idea of de-zincification. This would come much later when I made another much smaller boiler similar to a Yarrow type - no pics I'm afraid. I made this from some brass tubing that was given me by the Chief Engineer on board a rig I worked on. The ends I pressed from some brass sheet I had. It made a lovely and fast steaming boiler for two little oscillators made at the same time. After a year or so I soldered in a new bush and gave it another pressure test  Those end plates had become porous the pressure falling off quickly as water seeped through - my first and only experience of what I believe to be this process. I have no idea what quality the brass sheet was - the tubing was superb 'marine' quality but the lesson was learnt.

Derek this is not to decry your input - merely to show that I had experienced first hand what, as said, I believe to be a result of this process.

Going back to the dome in question - I now believe this to be made from gunmetal though my only reason is one of colour. When I stripped it down I rubbed the dome with Scotch-Brite - I'm very confident it isn't 'brass' -  up close it exhibits that pinkish hue of gunmetal/bronze . I have some similar stock under the bench that compares favourably. It's about 2mm thick and has a very substantial solder fillet inside so I would like to keep it as is but it will be the inspector who decides.

I see a couple of posts have just come up but I'll let this stand 

Regards - Ramon

[Ramon Wilson]

Hi Guys - just a quick update.

The cleaning up of the ends went very well virtually all traces of solder gone without any detriment to the parent metal. It was then set up to 'cut' the flue top so that when heated the four parts will just drop off - well that's the theory


Couldn't quite get deep enough with this 4mm FC3 so the lower bit was cut by hand with a hacksaw blade. The safety valve bush and the steam valve bush on the dome - both brass - were taken out at the same time



The weather was fine and dry today so I decided to have a go at flanging those end plates. Now this is the first time I've done this and I was quite surprised just how easy it was so the pics below are for those in a similar situation and not for those 'grannies' out there  . I'm only too aware there are some rather good boiler makers out there - this is definitely not for them. On the other hand, if you've never done it but are hesitating there really isn't anything to be intimidated about.

Each end needed annealing four times to get it round the former - it was also surprising how easy it was to tell the soft state from the point it began to work harden. End result is two nice fitting flanged plates ready for the next phase.

I turned the former from steel with a 3/16 radius and drilled and reamed a 6mm hole in the centre as an aid for setting. This is the plate after the first tapping all round ... I didn't remove the clamps just moving them out of the way and tapping all the way round as you see it clamped to the corner of the bench... I also got to use - for the first time - this lovely little hammer I bought at a TE Rally so many years ago 


Once formed around the rim, the OD's were cleaned up and the edges trued. The work is just pushed against the face-plate with the tail stock - the paper providing more than sufficient grip for driving against the cutting force of 0.1mm cuts.


And so my very first bit of 'coppersmithing'


I'm not sure if this is actually too tight. I know there should be room for the solder to flow but should this actually be loose? These are just a (very) light tap fit at the moment. Any comments on the fit required would be welcome


Well, that's it to date - hope that's not seen as teaching granny but is of interest and use to someone. The next phase is to get the plates machined for the flue and bushes and make some kind of jig for holding the flue and uptake together for soldering. That's on hold for a day or two - it's sailing tomorrow

Regards - Ramon

[Stuart]

10/10 for that flanging work top job

Yes it soon tells you when it's ready for softening dull thump to a ting


Keep up the good work

Stuart

[Jasonb]

I think you will find that when you start heating the barrel will expand more than the dia of the flanged plate so you will have enough gap for the solder to flow.

J

[Jo]

Sounds like you have a nice fit for silver soldering (bigger gaps = more SS = more expense).

Just make sure you get plenty of flux covering the two surfaces that you are joining before you apply any heat and lay bits of silver solder around the joint rather than trying to poke it with a stick, that way as soon as it is up to temperature the solder will flash round whilst the flux is still good.

Jo

[Ramon Wilson]

Thanks Stuart, Jason and Jo,

I have lots of silver solder to choose from Jo this is one time where economic use won't matter 

I was taught to Silver Solder at fifteen when I began on the shipyard. Jack, who I was apprenticed to, is now in his eighties and is still as bright as a button. Of course - I'm still 'his boy'  .

Regards - Ramon

[tel]

I'm not sure if this is actually too tight. I know there should be room for the solder to flow but should this actually be loose? These are just a (very) light tap fit at the moment. Any comments on the fit required would be welcome

File a few shallow notches around the sides of the flange if you have doubts.

[fcheslop]

Hi Ramon, I find a light push fit works well for me I realise a light push fit is a little vague.
As already mentioned a few small rivets just to stop the ends slipping are a very good idea as I once had a flange plate move on a vertical boiler with 36 fire tubes 
When I assemble I flux the parts up as I build her up ready to solder I think Im telling my granny how to suck eggs.
Is this boiler to be a wet back flue??.On the smaller boilers I use those rubber bungs for wine brewing and drill them through the middle
one has a nut and bolt fitted the other has a nut and bolt with a hole right through and a pressure gauge fitting .They are then used to blank the ends of the flue and a leak test can be carried out before its fitted to the boiler.These bungs have been used up to 120psi and surprisingly they have stayed put.Hope that makes sense
cheers

[K.B.C]

Ramon,
Can I suggest that you do as Frazer suggests and fit copper rivets into holes drilled around the perimeter of the shell.
I use 3/32" rivets after drilling the holes, light C/Sinking the holes, this holds every thing in place and prevents slippage due to expansion when heating, the ends of the rivets can be cut of and filled flush when brazed.
There is nothing worse than having an end plate slip while soldering which can render the whole job aborted, especially after all the work that you have put into the re-furb.

George.

[Ramon Wilson]

Thanks again for your input guys. 

I think that I may have this just a little too tight so will ease it a little more when finally assembling up for soldering.

Yes, I had planned to pop in a few rivets firstly to help alignment of the flue to the vertical line of the boiler and secondly to prevent movement after Frazer mentioned it before - I guess that was a real 'Golly Gosh - look what I have done' moment  eh Frazer? I can well imagine how you must have felt so I hope you managed to reclaim it.

Thanks for your tips too George. Re your pic. I see there's no flux on it so it may just be to show the final 'dry run' but as you have the lower plate rivets in place too would you set this up as shown with all those bushes in and both end plates set and solder this all in one heat or would you split that into three of four heats, pickling in between adding the new parts as you go? (Multiple heats is my current plan - one end, flue and bushes first  - then the back end - then the safety valve bush (and the dome if it has to be replaced).

Thanks again
Regards - Ramon

[fcheslop]

Hi Ramon , I managed to save most of the boiler just lost a few tubes and one flanged plate. The air was definitely blue all part of the learning curve.The boiler was for the 2inch Clayton it was my first model steam engine .Talk about being ambitious
The last boiler I did the bushes first in the barrel then the end plates.I tend to use two grades of solder just cannot remember the new codes but think its C4 then easy flow2.
If its a centre flue boiler I build the flue up and pressure test it before fitting it into the boiler .Thats another lesson learned the hard way
Cheers

[K.B.C]

Thanks again for your input guys. 

I think that I may have this just a little too tight so will ease it a little more when finally assembling up for soldering.

Yes, I had planned to pop in a few rivets firstly to help alignment of the flue to the vertical line of the boiler and secondly to prevent movement after Frazer mentioned it before - I guess that was a real 'Golly Gosh - look what I have done' moment  eh Frazer? I can well imagine how you must have felt so I hope you managed to reclaim it.

Thanks for your tips too George. Re your pic. I see there's no flux on it so it may just be to show the final 'dry run' but as you have the lower plate rivets in place too would you set this up as shown with all those bushes in and both end plates set and solder this all in one heat or would you split that into three of four heats, pickling in between adding the new parts as you go? (Multiple heats is my current plan - one end, flue and bushes first  - then the back end - then the safety valve bush (and the dome if it has to be replaced).

Thanks again
Regards - Ramon

Ramon.
Yes the pics are for a dry run to see that every thing is in place, I then flux every joint and the bushes, I make my flux into a paste  and paint all of the joint to be brazed, set the boiler up in my furnace with heat resiting material to stop the heat traveling to the bottom, as you heat the copper up the flux goes into a liquid state and flows thro' the joints, I braze one end, turn it around when still hot, pack it up and do the other end which was already fluxed and then the bushes, all in the one heat.

When you braze the boiler you will see the condition of the other end and you may have to pickle and then do the other end.

Most important is to hydraulic test the center flue before brazing into the boiler.

This boiler was 3.5" dia x 6" long.

Hope this helps.

George.

[Ramon Wilson]

Thanks George, very helpful pics. What is the soft material ?
The actual act of soldering I'm reasonably well versed with but apart from doing this in 1972 with the help of a work colleague I've not done anything of this size or complexity since. I just want to be sure I get all the parameters right beforehand.

Re yours and Frazers advice on pressure testing the centre flue. Rest assured this won't be overlooked this time as it was the last  - just one tiny hole and no ability to get a test pressure. Strangely enough now the flue's out the offending hole appears impossible to locate.

There's quite a bit to do before getting to grips with any soldering but it shouldn't be that long. First though I need to source some 2-1/2" dia x 12 swg tube for the flue. I've tried (web search) all the usual places but all are 16swg. I see Blackgates do 2-1/4 x 10swg firehole ring tube so that may have to be the alternative. If you know any commercial outlet for a short length (12") other than our usual suppliers I would appreciate the contact details.

Regards - Ramon

[Bluechip]

Ramon

M-Metals seem to do 2 1/2" x 10 SWG by the inch.

Not sure if it helps or not . Maybe you've spotted it and discounted ??

Dave