How to tin brass.

Hello all..

I need some help and advice if possible on how to tin brass.

I am currently building a 1” Minnie TE, and am working my way through the tender,

In the book I am told to tin the edges using silver solder, I have never done this and so am not sure how to do it.

The main questions I have are, should I use silver solder or would soft solder be ok, and do I use a soldering iron instead of a blow lamp.

I understand that once the edges are riveted I can lightly heat the tender to melt the tinned edges and make the joints.

Thanks for any help.

Brian

I've never heard of tinning with silver solder, it's very difficult to re-melt silver solder. Use lead/tin soft solder and a paste flux. Depending on brass thickness a small gas blowlamp will do the job. Flux before riveting up and the run the torch over the joint , you will see the solder run, it will run towards the hotter side.

Hello Brian,

It's possible you read the use of Silver Solder, which in the book referred to joining the pieces of the brass Water Pocket aperture together (page 115).

The next paragraph refers to the Tender joining faces that form the water tank. These faces (edges) require Soft Soldering in the form of 'Tinning'.

You will need to use a torch of some kind that will produce enough heat to Tin initially and reheat when all the parts are riveted.

It is best to use a Solder Paint (paste) and brush a line on along the joint faces to 'Tin', but if you only have Stick Solder or wire, you will need to wipe the excess off while still molten to leave a thin shiny coat before riveting parts together.

You can then add more Solder to run into the joints (inside) to ensure it's watertight if required.

Regards

My experience would be to use a gel flux, usually comes in a small plastic tub and buy Leaded Solder - Screwfix in UK sell both. Get a decent reel of 2mm solder as you will be surprised how much you will need. Paint on the flux and if possible apply heat to the reverse side. Dab the solder onto the flux until it starts to run. Withdraw heat and you should be able to 'paint' the solder along the joint. When it starts to get 'claggy' apply a little more heat and continue till done. Hope this helps.

Thanks guys for the responses, miss read the book as i did wonder about the silver solder.

If i tin the edges with either normal or solder paste, then rivet things together and reheat.

Should i buy multi core solder to use if i need to add some extra during the reheat or will normal stuff be ok, and if so should i add any flux during the reheat.

Edited By Brian Abbott on 17/11/2016 13:27:26

Multi-core solder is intended for electrical/electronics use. I would follow Fizzy's recommendation - paste or gel flux and plain leaded solder.

Russell

Solder paste is usually the easiest thing to tin surfaces with. A mix of solder and flux so it's easy to get a light coating.

Looks like screwfix etc only sell flux paste. The real thing is available from RS Components and Farnel but is pretty expensive.

If I tin something I usually get my fathers soldering iron out and use multicore. The soldering iron is just a pointed lump of copper about 1/2" square on the end of a rod and handle that's heated on the gas stove or with a torch. The heat will pull the film of solder along with it if done the correct way and the same iron can be used to sweat the parts together. They need cleaning up with a file now and again.

Leaded solder is much easier to use in my opinion. In fact I think some plumbers finish of their joints with it as they can't wipe them any more. The lead free is then just used in the actual joint and is all that can contact the water.

If you use a torch take care it can easily burn some of the alloys out of the solder.

John

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Edited By Ajohnw on 17/11/2016 16:36:02

I "successfully" produced a "tinned" joint with silver solder. I did it as a trial using two postage stamp size pieces of 1/8" thick mild steel, just to see if it could be done. The joint was good but there was no control of the thickness of solder. You can forget the 0.004" you get/need for capillary flow. There is none, the piece on top "floated" on the solder. I considered it interesting but not really a good idea.

JA

Thanks for all the advice, i will get some stuff around me and have a go.

Which ever route i take, after cleaning the area to be tinned should i then "rough" up the surface with emery ?

Wire wool or a Scotchbrite pad would be better.

I also wipe teh tinned surface while it is still hot to remove excess solder, copper rag made up into a pad and either dampen with water or Bakers Fluid. You don't want too much solder that it stops the surfaces comming together.

If using flux pase watch it on any steel as it has quite a corrosive flux, wash very well after use. John W mentioned it was expensive but CuP Alloys sell it in small Humbrol sized pots which go a long way for modest outlay.

And stay well clear of Lead free solder.

Regards Ian.

Jason, whats a "copper rag" or am i being thicker than normal

God knows why I typed that, should have been "cotton" eg don't use man made fibre as it will melt and stick to the work.

Thanks Jason, thanks everyone.

Hi Brian,

I would not bother with tinning the surfaces.

Just rivet it up tight metal to metal then do what most of us do for loco side tanks and tenders...

Get some Bakers Fluid flux (easiest these days to get off ebay),

and some old fashioned plumbers stick solder (I have a large box of it if you want any).

Heat up gently, spoon in a few generous large spoonfools of Bakers Fuild and swish around. I use an old brush though you can make a copper wire brush quite easily. Then add the stick solder. Add more Bakers Fluid as required. The soft solder will quickly wizz though all the joints and seal perfectly in less time it took me to type this.

Wash and scrub the joints thoroughly afterwards with a toothbrush and hot soapy water. You may need to do this a few times a few weeks apart.

Cheers,

Julian

If you ask at a plumbers merchants they may have leaded multicore in something like 10swg. I was told some time ago that they usually keep it under the counter. I suspect my reel came from RS.

John

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Screwfix and toolstation sell plumbers solder.
Screwfix link
Toolstation link
I prefer 60%tin / 40%lead solder as it flows better. It does not have a pastey phase like plumbers solder as it is a eutectic ratio. This is used in electrical and electronic applications.

Les.