Soldering/brazing a boiler.

[FMESParticipant @fmes]

Brian,

That looks almost like a compression fitting setup, what size is the spigot diameter?

 

Something like this : http://www.ebay.co.uk/itm/3mm-22mm-1-8-7-8-Equal-Straight-Compression-Coupler-Pipe-Fitting-Double-Ferrule-/321498886959?pt=UK_DIY_Materials_Plumbing_MJ&var=&hash=item4adad3b32f

 

Edited By Lofty76 on 06/11/2014 10:25:17

Edited By Lofty76 on 06/11/2014 10:25:50

[Brian JohnParticipant @brianjohn93961]

The tube in the side of the mainframe is 1/8''.

[Brian JohnParticipant @brianjohn93961]

That fitting in your link will still require soldering though won't it ?

[Neil WyattModerator @neilwyatt]

Hi Brian, high temperature loctite would do the job, in fact at the low pressure involved normal loctite or instant gasket would do.

If you want to be traditional, you can still get Boss White in B&Q which is what would have been used in the old days!

Neil

[Keith LongParticipant @keithlong89920]

The fitting linked to by Lofty is a pure compression fitting, no soldering required at all. There are 2 ferrules, one fits into the rear of the other and under the axial load deforms into the front ferrule and swages on to the pipe. What you need to be sure of with those fittings is that the pipe that you're using is within the size spec for the fitting and is of a suitable material to resist the crimping forces from the ferrule.

[FMESParticipant @fmes]

No soldering Brian, the 3mm fitting will do the 1/8" pipe as listed.

[JasonBModerator @jasonb]

But that still leaves Brian the problem of getting his 3/16" x 40ME pipe onto the other side of the compression fitting.

As Neil says you could loctite a nipple onto the 1/8" pipe and then use the nutted fitting you show in teh photo

[FMESParticipant @fmes]

For me it would have been getting the 1/8" olive from a compression fitting and using that in the fitting shown in the photo, If its a standard steam fitting with a taper nipple then it will fit,

Compression fitting one end, 3/16 x 40 steam fitting 'tother.

Not that difficult surely?

Oh, and if you don't want to use the compression olive you could use a nitrile O ring, if it seals sight glasses at over 100psi it will certainly do the job here.

Edited By Lofty76 on 06/11/2014 18:06:50

[Brian JohnParticipant @brianjohn93961]

Okay, I did not understand how the compression fitting worked but it sounds like it should do the job. I could even try cutting a 3/16-40 thread on one side of the fitting for the nipple but this may not be necessary.

[Brian JohnParticipant @brianjohn93961]

I have found a compression fitting from a local supplier ( 1/8 to 3/16 inch) but it is much larger than I thought. It does not look very elegant !

Does anybody make a similar thing but much smaller in size ?

NOTE : it is just sitting there ie. I have not actually screwed it into place yet.

Is this what I need ?

http://www.minicastings.com/acatalog/PM-TUM34.html

Edited By Brian John on 07/11/2014 08:09:59

Edited By Brian John on 07/11/2014 08:14:50

[Neil WyattModerator @neilwyatt]

Agh!

Personally, a bit of silicone tubing pushed over the end of the tube would look better than that!

I got the wrong end of the stick earlier, I assumed you were joining the pipe into the upright, not joining two pipes.

Neil

[FMESParticipant @fmes]

Hi Brian,

I think you are getting confused with your thread sizes, 1/8" BSP has an outside diameter of 0.383" which is larger than your 3/16 x 40 ME thread (0.187" before cutting).

It looks as though you have gone for a 3/16 BSP rather than the ME thread.

Is it correct to assume that you are trying to connect two 1/8" pipes together? if yes, why do you need the 3/16 x 40 thread end? why not just use an 1/8 th pipe compression fitting for both ends?

Something like this: **LINK**

[Brian JohnParticipant @brianjohn93961]

No, I am not trying to connect the two 1/8'' pipes together. I am just trying to put something on one 1/8'' pipe which is the steam inlet. I want to make it easier to connect this pipe to the boiler. Perhaps I will just stick to the silicone tubing. I was trying to convert it to 3/16-40 because this is what all my fittings and pipes are.

Sorry for the confusion.

Edited By Brian John on 07/11/2014 12:11:35

[Brian JohnParticipant @brianjohn93961]

The simplest solution is always the best : 3/16'' tubing almost fits over the 1/8 tubing so I put some pre threaded 3/16 tubing in a hand drill and held a round file against the inside of the tubing while it was turning in the drill. It is now a perfect fit. I will probably fix it in place with Loctite 222.

[Brian JohnParticipant @brianjohn93961]

I am waiting for the step drill, safety valve and boiler bushing to arrive in the mail. In the mean time I am planning how to solder the parts. The two large ends will be done first and then the chimney as per the instructions. But then I have three fittings to be soldered into the top holes. I am concerned that when I attempt to solder these smaller parts I will undo the solder work on the end and the chimney.

What is I were to wrap rags soaked in cold water around the ends and also stuffed down the chimney : would this act as a heat sink or would I be wasting my time doing that ?

This is also coming in the mail. I will use it to solder the smaller parts :

http://www.ebay.com.au/itm/MICRO-BLOW-TORCH-Butane-Gas-Blowtorch-Kitchen-Cooking-Burner-Refillable-MT07-SL-/301289665939?pt=AU_Kitchen_Units_Sets&hash=item4626437593

Any other suggestions ?

Edited By Brian John on 09/11/2014 21:25:58

[JasonBModerator @jasonb]

Yes the rags will be a waste of time.

I very much doubt that the torch in your link will get things hot enough for silver soldering.

J

[Brian JohnParticipant @brianjohn93961]

Having tried the small torch today for the first time, I would quite agree …it is useless !

This is the torch I now intend to use :

**LINK**

I was worried that it would be too hot for the smaller parts but I will have to try it and see.

[JasonBModerator @jasonb]

That may still give to local a flame, with silver soldering you want to bring the whole job upto heat and then the solder will flow, the risk of using a small flame is that you will just melt solder onto the surface where the heat is and not get a proper joint.

[Brian JohnParticipant @brianjohn93961]

What would you suggest ?

The instructions for this boiler kit warn that this type of torch produces too much heat and recommend caution that the metal is not overheated.

[JasonBModerator @jasonb]

I'd be looking at a torch with interchangable nozzels that runs of a large propane bottle, not sure what you can get down under but something along these lines would do

**LINK**

**LINK**

Or a better quality Sievert one

**LINK**

[Keith HaleParticipant @keithhale68713]

Leave the cookery torches in the kitchen for the creme brulee or skinning tomatoes! We want to braze.

All the above kit is likely to create too much heat and melt the unknown parent metals. Check with the Machinemart  salesman.

It looks like you need a fine, focused, low heat output burner. Suggest a Sievert 3938 burner fitted onto something like the Sievert PMPX or 2197 kit..

All products readily available. For more information. **LINK**

Keith

 

Edited By CuP Alloys 1 on 10/11/2014 16:56:45

[JasonBModerator @jasonb]

Keith (assuming its you) is the advice of the small burner related to the 3" dia boiler at the start of the thread or as you mentioned "unknown parent material)" are you refering to the little oscillators plumbing?

J

[Keith HaleParticipant @keithhale68713]

Hello Jason

In the post I take it up from the "plumbing"

Taking it from the start ….

If the decision is to use soft solders then the 3938 burner should cope. If not put on a slightly larger burner eg 3939.

Use soft solders with different melting ranges if it helps. Alloys available with temperatures between 145 and 305 degC

If the decision is to use silver solder the 3938 will struggle.

As I understand it. the jury is out on the filler metals to be used. One of the considerations of burner selection is the melting point of the materials.

Keith

[JasonBModerator @jasonb]

Posted by Brian John on 31/10/2014 09:34:13:

1. No solder is provided with the kit. I have purchased the correct silver solder and flux from a model engineering firm.

Brian Can you let us know what silversolder & flux you have bought so Keith can suggest a burner size and also what diameter the boiler is, looks about 3" to me.

Keith, Brian finds it hard to get hold of some things where he is, could you also suggest the KW rating of the burner so he can look for alternate makes if needed.

J

[Brian JohnParticipant @brianjohn93961]

The boiler is 2'' in diameter

Flux is EZI-WELD 602 flux.

I purchased two solders : 8338 silver solder 245 grade 1.6mm diameter X 750mm

8339 silver solder 245 grade .8mm diameter X 1 meter

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