Don Young's Black 5

[britannia]

I have recently had the regulator rod out whilst changing the regulator to a process valve following sealing problems with the original Stroudley design (see Model Eng mag). As 'mbrown' says in this thread, the neck ring is fastened on the regulator rod and the whole lot slides into the flange, keeping the rod in place. I then simply put an O ring on the rod using a little silicone, and pushed it into the flange using the gland, carefully tightening the two 7BA nuts on the gland studs (not shown on dwg). The regulator rod sealed perfectly first time with no problems.

[runner42]

Mar 9, 2021 6:21:59 GMT runner42 said:

Mar 8, 2021 22:54:11 GMT coniston said:

Or maybe if you have made the wet header you could add a 3mm spacer between it and the boiler bush?

Chris D

Chris I have done a bit of a compromise. I have reduced the blower bush thickness to 3/32" (2.38mm), this is a deviation from the AMBSC Code Part 1, but I was forced to take this action, because the spacer I produced to bring the wet header out further could only be 3/32" thick because a greater thickness would not allow sufficient penetration of the regulator bush into the smokebox tubeplate. I couldn't reverse the blower bush because in the reversed position the threaded section would extend beyond the smokebox tubeplate so nothing was gained. Have to see if it passes the pub test. This is an Aussie saying used often to indicate an evaluation, it isn't suggesting that I ply the BI with beer to get the right result LOL.

Brian

blower wet header by Brian Leach, on Flickr

blower wet header1 by Brian Leach, on Flickr 

PS The BI generally conducts a visual inspection at first and if it looks right then it is right, so there is little chance that a thickness measurement would be done.

 

Some twenty five years ago I did a personal improvement course titled Investment in Excellence, which among other things painted a scenario where a mishap occurred and the mishap was swept under the carpet. Being out of sight it was forgotten about so the mishap prevailed. This led to poor quality and the appropriate thing to do was keep the mishap in constant view so it was a constant reminder that it needed to be addressed. The thought was placed in ones mind that the mishap if uncorrected would exist for very much longer than the time it would take correct it. So with this reminder I decided to do the proper thing and remake the regulator bush that was 3 mm longer on the 1 " dia and the blower bush to have a 3 mm flange as required by the AMBSC code Part 1. Also, note that I had depicted these items on the wrong side of the smokebox tubeplate, which was another incentive to have the regulator bush a one piece item without the need for the spacer. 

Brian 

[steamer5]

Good call Brian!
It now won’t keep you awake at night!

Cheers Kerrin

[runner42]

Boiler barrel and outer wrapper together with solid copper cheeks at top side of wrapper silver soldered. The steam dome was the last item on this many heat up exercise. Ready for the BI's inspection tomorrow. I found this to be at the extent of my boiler making capabilities. The many iterations was due to lack of visibility at the hot state to determine whether or not good coverage was achieved. It required the boiler to be cooled and put in the citric acid bath for a couple of hours before an inspection could be made. I don't know if it the flux or the very large propane flame (114 KW) that is masking the ability to see, but it didn't provide the same visibility as I have experienced with more moderate silver soldering operations. 

Brian 

barrel_outer wrapper_silver soldered by Brian Leach, on Flickr

barrel_outer wrapper_silver soldered1 by Brian Leach, on Flickr

[runner42]

The boiler has been put on hold because I needed a piece of copper sheet for the inner wrapper. My initial purchase of copper sheet was more than enough to complete the boiler, however I didn't plan the cutting of two quarter sheets well enough and found that the inner wrapper required a sheet size that was just too big for the remaining material I had. Since my local supplier only sells a minimum of a quarter sheet so I had to find an alternative supplier. This copper sheet should be arriving this coming week, so progress can once again proceed. In the meantime I have made the remaining of the backhead fittings except the whistle valve, DY's drawing has me confused. 


whistle valve by Brian Leach, on Flickr

My assumption is that the body of the whistle valve is round, due to the 5/16 " dia X 40 TPI thread as shown, however this is not the problem for me, it is in the position of the pivot pin which in one view is positioned at the centre of the body and in the other appears to reside at the boundary of the body and therefore cannot operate as a pivot because there is no metal to hold it. I am often confused by DYs drawings and it could be I am failing to understand what is being depicted, so I shall not assume that it is a drawing error. However, I would like some help to understand the body shape.

Brian  

[uuu]

I'd make it from square rod, slice a bit off and solder it on top on the end where the pivot goes.

But I'm left wondering what the other end of the spring rests onto.

Wilf

[runner42]

Apr 11, 2021 7:25:52 GMT uuu said:

I'd make it from square rod, slice a bit off and solder it on top on the end where the pivot goes.

But I'm left wondering what the other end of the spring rests onto.

Wilf

Thanks Wilf,

an interesting point you have raised. The drawings do not contain a backhead layout and the LLAS text shows an example of a first class backhead layout but it is not obvious where the whistle valve resides. Some research of the pictures of Black 5 at Station Road Steam shows the probable placement to be at the RHS of the manifold. Looking at the drawings the RHS of the manifold shows a 5/16 " dia x 40 TPI male thread, the same as the whistle valve so it requires a transition flange to enable the whistle valve to be connected to the manifold. I assume that the assembly was configured this way to ease assembly, but for the moment I can't understand why a simple male-female connection could not be used.


Brian

manifold by Brian Leach, on Flickr  

[uuu]

Here's another approach - from Station Road Steam's archive:



It looks like it's been made from a larger round rod, turned down for most of it's length. Then flatted off at the pivot end.

Wilf

[coniston]

Wilf, that looks like a commercial type valve like the ones sold by Polly etc. fitted to a Model Works B5?

Brian, have a look at Station Road Stem website they have one in their archive stock number 4148. It looks just as you describe for fitting to the manifold.

Chris D

[runner42]

Another wasted day! I made the whistle valve to what I understood to be the general rules for technical drawing but either I had a misunderstanding, or that DY's whistle drawing has another error apart from the pivot point referred to previously. The take off connection is shown to be on the top side because the plan view of the take off connection is not dotted, if it is was the other side it would be shown dotted. The consequence of this is that for the actuating lever to be a pull connection when fitted to the RHS of the manifold the take off is pointing upwards which appears to be counter intuitive since the whistle is mounted under the running boards so requires a take off pointing downwards. I don't know if in full size the whistle is mounted on top of the boiler adjacent to the spectacle plate and DY deliberately required the take off to point upwards to follow full size practice, a convenient routing from whistle valve to whistle, but not for a model where changes are required because you can't scale everything.

Brian   


SRS Black 5 backhead cropped by Brian Leach, on Flickr

PS It maybe that other builders have experienced the same problem and overcome it by using a hard connection that can be operated by pushing instead of the flexible whistle chord referred to on the drawing.

[runner42]

Boiler construction has been slowed due to accessing the BI who has been absent on the occasions that I visit the club, which is only the third Saturday of the month. There are 3 BI's but I prefer to keep with the same one, because others would need to come up to speed with construction history so far. I have completed the firebox but before progressing the addition of the flues and tubes I require the OK from the BI. However, I have trial fitted the flues and tubes and found that the 7/16" dia tubes are a tight fit in the 7/16' drilled hole. The issue is getting the right clearance for silver soldering, so two options are available open up the drilled hole or skim the end(s) of the tubes. Whichever option is selected there lies the problem of getting the clearance right. Feeler gauges come to mind but being such a small diameter hole feeler gauges are not practical. Something like a wire gauge would work, but do they exist?

Brian

firebox tubes by Brian Leach, on Flickr

firebox flues by Brian Leach, on Flickr

firebox door by Brian Leach, on Flickr 

[Gary L]

Apr 27, 2021 7:39:58 GMT runner42 said:

Boiler construction has been slowed due to accessing the BI who has been absent on the occasions that I visit the club, which is only the third Saturday of the month. There are 3 BI's but I prefer to keep with the same one, because others would need to come up to speed with construction history so far. I have completed the firebox but before progressing the addition of the flues and tubes I require the OK from the BI. However, I have trial fitted the flues and tubes and found that the 7/16" dia tubes are a tight fit in the 7/16' drilled hole. The issue is getting the right clearance for silver soldering, so two options are available open up the drilled hole or skim the end(s) of the tubes. Whichever option is selected there lies the problem of getting the clearance right. Feeler gauges come to mind but being such a small diameter hole feeler gauges are not practical. Something like a wire gauge would work, but do they exist?

Brian

Hi Brian

I've never built a boiler and never will, so don't give undue weight to my opinion, but I have done a lot of silver soldering on less critical areas. FWIW, I think all the talk about correct clearances for silver-soldering is just armchair theorising. If you can get your tubes into the holes, the solder will go there too. If you make the gaps too big, it will be harder to persuade it, and it will use a lot of solder. My experience is that the gap can't be too small; the solder will flow even if the joint is lightly clamped, though you wouldn't do that in a boiler. Even if you could measure your joint gaps, they are very unikely to be the same all round the joint. If it were me, I would aim for a close fit without actually binding on the tube. Your BI might want something different, if so you will have to go along with him.

Good luck

Gary

PS. On reflection, this is for my favourite solder, the 455. If you are step-soldering as you probably are, the higher melting point types mostly seem to be less fluid and might need somewhat bigger gaps. I'm sure a real expert will be along soon to comment but my attitude is, if the gap is big enough to measure, it is too big.

[uuu]

From my experience of assisting Steve (springcrocus) with his Britannia boiler, I would agree that the solder flows into the smallest of gaps, even when lightly clamped. Steve did skim the ends of the tubes, but this was more to provide a step to stop them slipping, then to provide a clearance.

We started with a higher melting point solder but, it seemed to need so much extra heat that we might have been better to using one type throughout. Once we had the knack, we weren't really troubled by the re-melting of earlier joints - by laying solder in the crack, or a ring around a tube/stay, we could bring the whole area close to temperature, then a blast on the joint itself and the solder would just flow in.

It's definitely easier with two people, and two torches.

Wilf

[lankyyorky]

Hi Brian,

There is some useful info here:

www.cupalloys.co.uk/best-brazing-practice

Dave

[runner42]

Thanks Gary and Wilf, I am using one type of solder throughout which is 45% silver and contains Cadmium. It is designated blue tip, I don't know if that designation is universal or just Australia. I am told that yellow tip is more of a gap filler, but not allowed by the club. However, the BI and fellow club members have indicated that the silver soldered joint should have a fillet both sides, so effectively it requires silver solder to be applied both sides. I assume that the silver content dictates the melting point, so the lower the silver content means the higher the melting point. The range of silver solders available is either 15% or 45%, 15% is just allowed by the code, but I wouldn't attempt to use it because I am using propane only burner and a 15% silver solder would require a too higher melting point that could readily be achieved. The consequence of using one type of silver solder is the possibility of affecting joints already made during higher levels of construction, but thankfully there is a higher melting point in a joint that is reheated than initially required.

Brian

[Gary L]

May 3, 2021 0:25:39 GMT runner42 said:

Thanks Gary and Wilf, I am using one type of solder throughout which is 45% silver and contains Cadmium. It is designated blue tip, I don't know if that designation is universal or just Australia. I am told that yellow tip is more of a gap filler, but not allowed by the club. However, the BI and fellow club members have indicated that the silver soldered joint should have a fillet both sides, so effectively it requires silver solder to be applied both sides. I assume that the silver content dictates the melting point, so the lower the silver content means the higher the melting point. The range of silver solders available is either 15% or 45%, 15% is just allowed by the code, but I wouldn't attempt to use it because I am using propane only burner and a 15% silver solder would require a too higher melting point that could readily be achieved. The consequence of using one type of silver solder is the possibility of affecting joints already made during higher levels of construction, but thankfully there is a higher melting point in a joint that is reheated than initially required.

Brian

Oooh ouch. We haven’t been able to buy cadmium-bearing solders over here for years and years, and quite right too, cadmium is carcinogenic and lung cancer isn’t nice, so take care. Some old stagers have old stocks and persist with it, saying it flows better. That might be true of the higher-melting point solders, but the Cad-free 455 which is equivalent to the old ‘Easiflo’ brand flows well enough for me, and I think it might correspond to your 45% silver material (the numbers seem similar). You might well be OK using just the one grade, I have often got away with this even when the joints are quite close together, though I’ve never been tempted to do anything as heavy as a boiler. You are right too about Propane, it isn’t quite hot enough for the higher melting point grades of solder, it can be a thankless task trying to get the last few degrees of heat.

Gary

[uuu]

I have tended to find the old cadmium-bearing stuff doesn't flash into joints quite as easily as the new stuff. But it does form nice fillets, where the new stuff either goes into the joint or runs away.

Wilf

[runner42]

After umming and erring on where I put the top feed assembly, I decided to follow DY's position and put it further forward than I wanted to, which was closer to the steam dome. But because it is a comparatively large item it would have dwarfed the steam dome and placed the water inputs closer to the firebox, which is not optimum positioning. Being as far forward is preferred. This required that I move the the chassis mounted terminations 4 1/2" forward. This makes the pipe run from the output of the steam injector quite long some 20", I dont know if this is going affect the performance of the injector.

Brian

top feed assembly plumbed by Brian Leach, on Flickr

[runner42]

This is not progress, but some rework on the firebox. The BI rejected the joints on the firebox due to the flange not sitting down and enable a good fillet joint on both the inside and outside of the end plates. If you refer to the previous firebox photos you can see instances of this. His recommendation was to get a small hammer and knock the flanges down, but this was impractical because one couldn't get a big enough swing and more importantly the silver solder already in the joints prevented this. This required some careful thinking on how to proceed. Firstly, it required more than one pair of hands, so my SASMEE colleague Allan Wallace lent a hand, more to the point he took the lead and I was his assistant. I heated the joints using propane and when molten a compressor air gun blew the silver solder out of the joints. Then judicial placement of an iron bar on the flange and hitting the wrapper to bring the two parts together. This is where two pair of hands was necessary. It took some time to close the gaps, but persistence prevailed. To ensure that the joints didn't respond to gravity and leak out should the gap be too great we decided to use oxy-acetylene to small lengths at a time, providing only local heat. I supported this by applying general heat with a propane torch. 

I can understand the BI's concern, in that the whole flange depth should be in contact with the wrapper and silver solder be continuous between both contact faces and not just providing a seal looking from the outside. If this rework didn't work then it meant scrapping the firebox. Allan was happy to help as it gave him more experience in correcting (other peoples') mistakes.

Brian 

[runner42]

It appears that my decision to complete the firebox before the flues and tubes were in place wasn't the ideal sequence of assembly. In retrospect it would have been better if I had attached the flues and tubes to the firebox tubeplate prior to completing the firebox. This led me into a number of problems, namely providing access to the inside of the firebox to undertake the silver soldering of the flues and tubes, also the weight of the firebox caused some set up issues since the firebox is required to sit vertically on the flues and tubes, so some rigid support was required. The last issue was that the flues and tubes needed to move reasonably freely in the drilled holes in the firebox and smokebox tubeplates, which caused them to become detached if the firebox and or smokebox tubeplate was inadvertently moved too far. I proceeded with a number of options which all failed miserably. I can't remember how many times I assembled the flues and tubes to both tubeplates because they became detached. An important issue is to set the flues and tubes at just the right insertion depth in the firebox tubeplate, too far and the flues and tubes may not be sufficiently long to provide sufficient insertion into the smokebox tubeplate at a later stage of assembly. The solution was to construct a stand which provided the means to support the firebox at the correct height so that the flues and tubes when assembled would sit at the correct insertion depth. This last aspect required some means by which the firebox could be raised or lowered incrementally.

The solution was to have a threaded stem which was silver soldered to a piece of steel plate to form a T section, the steel plate sitting inside the firebox with the threaded stem protruding through the firebox door and through a steel collar which is held by the jig and a nut added to the threaded stem to provide incremental movement up and down. Arriving at this solution was not an Eureka moment it took a number of iterations to get there.

I think that this part of the construction is a difficult one, so after which construction should be relatively straightforward.

Brian

The stand with the firebox and flues and tubes ready for silver soldering.

Flues_tubes jig by Brian Leach, on Flickr 

The incremental adjustment for raising lowering the firebox realtive to the flues and tubes.

Flues_tubes jig1 by Brian Leach, on Flickr  

Setting the insertion depth.

Flues_tubes jig2 by Brian Leach, on Flickr

The smokebox tubeplate with a closing copper plate to prevent flues and tubes dropping out during handling of the assembly to the holding jig.

Flues_tubes jig3 by Brian Leach, on Flickr