Phew - I didn't realise silver soldering can be such an interesting and emotive topic!
I wonder, when TC, Stan Bray, Harold Hall, Elmer, and all the others wrote their so instructive books on engineering methods and practices for the beginner/modeller, if this (modern) type of solder paste were then freely and cheaply available to use, it may have become another recognised method of Silver soldering for the model engineer, next to tried and tested silver rod/wire/flux. As Bogs said -used in the appropriate circumstances?
For small, delicate joints with no real gap filling, I like it. Quick to set the joint up, do not burn my fingers holding thin silver wire too close to red hot items, don't stick the end of it in my flesh when trying to bend the stuff into a little circle to fit round a joint - which always slides sideways when the flame blast gets close, don't get runs or waste too much of it, don't have to flux, and only pay £8 for the stuff - even if it lasts only 2 years in its syringe.
To continue with the project, I have completed the final component fabrication - a simple "Globe" valve (stop-cock) to go on the steam off take from the dome of the boiler. Silver soldering was necessary - see later!
I shall be using 4.7mm copper brake line for the main steam supply pipe (remarkably cheap to buy a coil on flea bay - it comes ready annealed!), so all internal holes are 3mm dia - as large as I can get without looking "over scale" - and trying to minimise internal back pressure in the steam passage from boiler to engine. The valve will be sited next to the dome, control handle sideways/outboard, inlet on the other side/inboard to dome off-take and outlet straight down (at right angles to the main body axis).
The results of my first effort of valve making went on the water tank stop valve - clunky looking plain hex stock body, with a naff control wheel - but its mine and may serve to show a youngster (assuming I get to display this affaire) that not everything you make has to be perfect and shiny when you are learning - fun comes first! (well its my excuse anyway).
A "Globe" valve body does look so much nicer and "fits the scene" well.
This time, I had previously come across a recipe to make a globe form tool (see earlier post and pic on this thread) and a (French I think) design for a simple right angle globe valve with easy to follow dimensions. I altered these a bit to suit the stocks of material I have to hand. The important item was the stainless steel rod for the spindle. All I have at present is some 5/32 rod - which is fine, but the only die I have for that size is a 5/32 X 40 (ME thread) - leaving aside metric variations. Since this is really an "on - off" valve, it shouldn't have such a fine thread - takes more turns to open it. However I have used it since I didn't fancy spending time turning small section stainless rod to a different diameter and then die thread the result.
I have taken too many pics. (probably) but it is my hope this may help any newbies reading this to see how simple the job really is.
My camera work using the "Macro" setting is b****y awful in parts - apologies - I was focusing too low - but hope the results give sufficient info.
The body is 1/2" hex bar. This is used 'cos its easy then to mark and drill the hole for where the soldered fitting will eventually go. The bar was drilled and tapped as appropriate, and the cross hole drilled.
![](http://i336.photobucket.com/albums/n354/klank_photo/Globe-ValveBuild002.jpg)
The corners of the hex around te length to be "Globed" were then knocked off using my home made tipped tool - which will take the punishment of an interrupted cut.
![](http://i336.photobucket.com/albums/n354/klank_photo/Globe-ValveBuild003.jpg)
I then used my globe form tool made from a bit of Austin A40 rear leaf spring - described earlier - in anger for the first time. I am dead chuffed with the result.
Here, the tool has just been withdrawn after forming the shape on the hex bar.
![](http://i336.photobucket.com/albums/n354/klank_photo/Globe-ValveBuild004.jpg)
Then just clean up and chamfer the corners using an HSS form tool.
![](http://i336.photobucket.com/albums/n354/klank_photo/Globe-ValveBuild005.jpg)
Then part off to overall length, reverse in the chuck (I had made a threaded brass fixture to hold the internally threaded end in the chuck), turn down and thread the other end, leaving a small hex next to the globe. The externally threaded end was deeply coned with a (Slocumb - lovely word) centre drill, ready to take the nipple when piping up later.
![](http://i336.photobucket.com/albums/n354/klank_photo/Globe-ValveBuild006.jpg)
The threaded insert for the spindle was made from brass hex, drilled and internally screw threaded 5/32 X 40, turned and externally threaded to suit the body. The spindle had a 90 degree end machined on it by setting over the top slide to 45 degrees and gently using a very sharp fine tool. 90 degrees should give a fast opening action, albeit compromised somewhat by the "fine" thread - but needs must I suppose!
The shank then die threaded 5/32 X 40.
![](http://i336.photobucket.com/albums/n354/klank_photo/Globe-ValveBuild007.jpg)
A gland nut was drilled, internally tapped and parted off from hex.
The side fitting (to be silver soldered in) was similarly made from brass hex, drilled, coned, externally threaded and left with a small thickness of hex to add symetry to the affaire when finished. A short length of brass (4mm dia) was left proud of the hex, as a locating peg in the hole in the body.
Here are the two parts. I had just "kissed" the side of the globe around the hole with an end mill, so as to give a "flat" face for the hex to sit on and more surface area for the solder paste to take to.
Here's the paste in its syringe next to the body sitting atop the side fixture.
![](http://i336.photobucket.com/albums/n354/klank_photo/Globe-ValveBuild010.jpg)
I then simply anointed the mating surfaces and locating peg with the goo. Since the paste contains only 42% solder, and I am not certain as to its gap filling properties, I used quite a lot of the stuff. It's quick and easy to apply from the syringe, but I used a modellers micro spatula to compress it where it was needed (the mix contains Cadmium - nasty stuff to get in your system - don't get it on your fingers!)
![](http://i336.photobucket.com/albums/n354/klank_photo/Globe-ValveBuild012.jpg)
Now if I had been using 0.7mm silver solder wire, the joint would be difficult to get at, fluxing needed, and I would have inevitably had "runs" trying to get into the joint with the wire tip when heating - notwithstanding using Tip-Ex fluid (or some such) as a barrier.
Here's how I set the thing up for just plain heating the paste.
![](http://i336.photobucket.com/albums/n354/klank_photo/Globe-ValveBuild013.jpg)
Apply the torch flame around the joint (using a fine nozzle) for about 30 seconds, and job done with a nice silver collar around the inner joint - and absolutely no runs. Neato!! It took about two minutes to do start to finish. (My only caveat may be to see if the joint has properly "taken" when I steam it - but I am optimistic it shouldn't leak).
Here's the result immediately after taking the torch away.
![](http://i336.photobucket.com/albums/n354/klank_photo/Globe-ValveBuild014.jpg)
Just a question of quick pickle, scrub down in washing up liquid/suds and gently polishing with a soft emery flexi pad and an ink-rubber disc in my mini drill.
I haven't yet decided on what type of control wheel - so many ideas - quite a few on MM. I don't think, though, I shall be filing a square end to the spindle shank. I'll probably turn it down and thread it.
Just the piping up to do now, and making a few threaded fixtures and coned nipples.
The display board will be painted/textured after a trial steam - when I expect every joint and gland nut and gasket on the engine to leak - such fun to look forward to, but thats what its about.
Be a while before I can give the results but I'll be back when I've fired it up for the first time.
In the meantime - best wishes to all who have taken the trouble to read this waffle and reply - much appreciated.
Peter