General advice on brass kit building

[MarshLane]

Chaps,

I am putting together my first proper kit that involves significant soldering of brass, and looking for some pointers - I have had a search and read various topics, but nothing has really answered these couple of questions.  I appreciate there are many different ways of doing things, and no one way is necessarily the best, I am just looking for some advice to move me forward, so all options welcomed.

 

a) When it comes to building up layers of brass or nickel silver to create a better thickness for small items, how is the best way to do it? As an an example, the brake fret for a wagon I am building has four layers - I have tried with a small mount of liquid flux and tinning both sides of layers 2 and 3, and just one side of layer 1 and 4 ... then aligning all four layers together and sweating them into one.  Its work, but I am not sure its the best way? 

 

b) When soldering items to larger pieces of brass (such as the wagon body sides) I am using a temperature controlled iron running around 450 degrees. I know the brass will act as a heat sink, but it seems to solder ok after holding the iron on for a few seconds - am I right in that approach? The temperature controlled iron I am using was acquired during the sell-off period just before Maplins closed, and I dont know if I can get any different tips for it?  The one I am using has the look of a HB pencil - going to a point, but with a small flat top and bottom of a few millimetres.

 

c) If you are soldering two pieces of brass or nickel silver together, such as the body side and end of a coach or wagon, how is the best way to do it so that you know its an accurate 90 degree joint? I am assuming I need to acquire or make some kind of rig that holds the two pieces correctly - but how does everyone else do it?  Obviously the side of a bogie coach is potentially going to be longer and more flimsy in 0.45mm brass/nickel silver than a two-axle wagon body, but I assume the same principals apply?

 

Apologies if the above seems simple, but as a beginner in this area, I am very much finding my feet!  Thanks in advance to anyone who can offer any thoughts/suggestions.

 

Rich

[Brassey]

You don't appear to be doing anything wrong.  You get a better feel for it with plenty of practice.

 

A jig that holds the angle of sides and ends at 90 degrees would be handy.  I have a large, long piece of MDF with a couple of pieces of hardwood attached at right angles.  Not only do you have to make sure that the corners align, you also have to get the bottoms/tops at the correct heights too.  The good thing with solder is that you can correct it.  Therefore tack solder first and check alignment and adjust if necessary.  This is most crucial on loco chassis that have to be square and true.

[Barclay]

Sounds to me like you are doing it all as it should be done. I have a Maplins 60w soldering station - they are still around on-line so you can get bits etc. My favourite bit looks a little like a slightly chunky electrical screwdriver at the end, which could be the same as yours. You don't mention solder but it's handy to have 2 temps. available - I use 188 and 145 which helps if you want to add something without everything you have already done falling to bits. I keep the iron at 400 degrees most of the time - if I use the lower settings it doesn't work nearly as well for some reason. 

[doilum]

In the land of solder, cleanliness IS godliness.

Lots of jigs. I prefer softwood and ply as they take a drawing pin easily. Lollipop sticks pin and glued to the ply are also useful.

1mm drills. Save the broken ones and use them to peg out your work on the above mentioned ply.

[Brassey]

5 hours ago, doilum said:

I prefer softwood and ply

But they leach sap which sticks to the piece once hot. 
 

I try to build things on flat glass but the iron heat can crack that too. 

[brossard]

As said, Rich isn't doing anything obviously wrong.  My only comment is about the 450C is about the limit of the iron and is VERY hot.  When soldering brass, I usually set my iron to 350C.  I'm not bothered about the wood scorching when using it as a support.  The black stuff can be removed with a fiber pencil (an extremely useful tool for me).

 

It is important to keep the bit shiny and I have found a good way to do that is to use brass wool.  Rub the bit in the the wool frequently to remove any gunge that builds up.

 

It is easy to overdo the solder.  My approach is to slice tiny pieces of solder of the reel and pick them up with iron (if the iron won't pick them up, the bit is dirty).  I still get too much solder on a lot of the time, so a scraper (old curved Xacto blade) and fiber pen are used to clean up. 

 

Tacking is a good way to join things together.  Make a couple of tacks and check the join.  If the join is off, tacks are easier to adjust than full seams.  When the join is good, finish the seam.

 

I learned a lot about soldering from Iain Rice and his book Etched Chassis Construction.  My methods have evolved since then, eg. I use less aggressive flux.

 

I have built a fair number of 7mm brass kits in the last while and also a LSWR 5 carriage rake in 4mm some years ago.

 

John

[MarshLane]

Guys,

Thanks for the feedback and comments, nice to know I am not too far out.  I used to use some old flux that my Dad had ... given the style of the tin it could have originated from his father!!  No idea what it was, but I was introduced to a liquid flux for track building that seems to work really well with the kit as well - it 'pops' as the solder flows.  I have sat and watched Nick Mitchell's playlist on the 2mm Association YouTube channel, where he shows how he builds a chassis for a 2mm Jubilee - fascinating and learnt a lot from that.  It was from that video that I acquired the Garryflex block for cleaning the brass and a small vice.

 

7 hours ago, doilum said:

In the land of solder, cleanliness IS godliness.

Lots of jigs. I prefer softwood and ply as they take a drawing pin easily. Lollipop sticks pin and glued to the ply are also useful.

1mm drills. Save the broken ones and use them to peg out your work on the above mentioned ply.

 

That was the other thing I picked up from Nick's videos - make sure everything is clean as possible. I have a small tin pot with a steel wool thing in that I dip the iron in each time before doing a solder, to hopefully make sure the tip is clean.  I had not thought about using drawing pins to hold things, that's a useful thought.

 

1 hour ago, brossard said:

As said, Rich isn't doing anything obviously wrong.  My only comment is about the 450C is about the limit of the iron and is VERY hot.  When soldering brass, I usually set my iron to 350C.  I'm not bothered about the wood scorching when using it as a support.  The black stuff can be removed with a fiber pencil (an extremely useful tool for me).

 

Hi John, thanks. I must admit, that confused me when I first acquired some 145 degree solder, as I thought that was the temperature that the iron needed to be run at!  Being a beginner I must admit, I have just set the iron to the temperature that seems to work, other than that it was a 'not a clue what I am doing' kind of situation. I can vouch for the fact that 245 degrees is bl**dy hot and hurts when you catch your finger on it!  I'll try running at 350C and see how that performs.

 

1 hour ago, brossard said:

Tacking is a good way to join things together.  Make a couple of tacks and check the join.  If the join is off, tacks are easier to adjust than full seams.  When the join is good, finish the seam.

 

That is an approach I had not thought about, to tack at say 1/3rd and 2/3rds mark and then check before doing a full seam - thank you.

 

One other question, when soldering like a wagon side and end together, obviously the brass has to be heated up to allow the solder to run.  But John's comment about 450C degrees set me thinking. Is it better to run hotter so more heat goes into the brass quicker .. or slightly cooler (at the 350C mark that John suggests) and hold the iron on a bit longer? I presume the kind of time we are talking will not cause any distortion in the brass?

 

Thanks to everyone for your help and support - gratefully appreciated.

 

Rich

[brossard]

Tony Wright, in one of his loco building videos said, IIRC, that the iron should be about twice as hot as the melting point of the solder.  IMO, it's really a matter of empirical determinism, if it works it's right.

 

Heat transfers through brass very quickly.  Anyone who has tried to hold a part while soldering it knows this - ouch!  One's grey cells can get a workout, trying to figure out how to get the really small parts on.  My point is that you needn't heat the brass, the solder will (or should) flow as soon as you touch the iron/solder to the work.

 

I've built 7mm kits with a 25W iron using 145C solder.

 

John

[Mallard60022]

Only things I would add are:

use a Temp Controlled Station;

have a couple of irons with different size Bits;

bits should be tinned and cleaned regularly;

use decent and suitable for the work Fluxes;

if a creamy Flux that 'holds' small parts of the work work in place, ensure work is thoroughly cleaned (including washing);

if a liquid flux, ensure work is thoroughly cleaned (including washing);

if using a Fibre Pencil to clean parts, wear rubber gloves and hoover the damn things up!

 

Think that's about it from me.

[doilum]

My cleaning recipe involves a bathroom cleaner / descaler, washing up liquid and hot water. And a toothbrush. I prefer to clean up after each mini session, especially paying attention to areas that may later become inaccessible.

[Steamport Southport]

2 hours ago, brossard said:

 

I've built 7mm kits with a 25W iron using 145C solder.

 

John

 

Same here. And using a 40 W for the bigger bits that need more oomph!

 

 

 

I just followed the technique described here. Some good advice and even if you are past that stage then there might be something useful.

 

http://www.jimmcgeown.com/Questions.html

 

 

First "proper" etched kit I built was one of Jim's wagons. Previous to that everything was glued together (don't tell Tony Wright ).

 

 

 

Jason

[adriank]

Ceramic tweezers are good for holding small parts when soldering. The reverse type are useful clamps e.g. for brake-shoe sandwiches. They are non-conductive so they don't take heat away from the joint and withstand temperatures of about 1000 C.

 

 

Adrian

[Dave John]

All good advice, another tip. 

 

Acquire a fine kitchen sieve, about 6-8 inch diameter. When washing flux off or cleaning  put them in the sieve then run water or clean over them. If there is a dry joint and a wee bit falls off it gets caught in the sieve rather than vanishing down the plughole. 

 

Don't ask me how I know..... 

 

 

 

 

[Battledown]

I find the best cleaning solution post each soldering session or stage is a 50-50 mix of methylated spirit and water, followed by a good rinse then dry it with an old hair dryer.

[ColinK]

I’m making my first brass kit too. Getting all the flux residue off is proving a challenge. Would putting the wagon in a ultrasonic bath do any good?

[Barclay]

I always scrub my models after soldering, with an old toothbrush and some Jif, then a thorough rinse in warm water. I don't really get residue using liquid flux (Carr's green label), so it's more about washing away any remaining acid to prevent long term effects such as corrosion.  I'm sure an ultrasonic bath would do a good job if you have one but wouldn't consider it essential. 

Edited December 23, 2021 by Barclay

[Siberian Snooper]

17 hours ago, ColinK said:

I’m making my first brass kit too. Getting all the flux residue off is proving a challenge. Would putting the wagon in a ultrasonic bath do any good?

 

I've not experienced any problems with putting locos, coaches or wagons in my ultrasonic bath, except bits coming off, due to not being properly soldered in the first place. When emptying the bath, make sure that you use a filter, old tights etc, to catch the bits.

 

 

[brossard]

19 hours ago, ColinK said:

I’m making my first brass kit too. Getting all the flux residue off is proving a challenge. Would putting the wagon in a ultrasonic bath do any good?

 

I've done a fair few brass kits.  I don't think you get much residue from liquid flux, washing neutralizes any acid or chemical that remains (I did try some water based paste flux and that worked well but does tend to leave a residue).

 

If you have a US bath then use that.  If not, bathroom cleaner works for me.  Don't use the washing up liquid with lanolin.

 

John