Ex GWR Ballast Wagon Kit Build

by John KendallThis is a kit that uses etched brass as the material instead of the traditional plastic.  The kit can be ordered from:  http://www.mousa.biz/fourmm/wagons/gwr_wagons4.html

It will make up into a model of GWR diagram P4 ballast wagon.  I plan to construct mine in BR service.  Pictures can be found here:  http://paulbartlett.zenfolio.com/brstarfish/h545911c#h1935fcc7

I thought I’d start by illustrating some of the tools and equipment I use for this work:

Obviously I have a soldering iron – mine is a Weller (can’t recall the power but about 45W) and not the cheapest.  The tip is still in good shape after several years of abuse from me.  The little pot is a tinning compound.  Solders:  I like Carrs and mostly use 145 degree C (orange packet).  If I need to solder someting to a part that needs two solder joints, I use 188 deg. C (green packet) first and 145 deg for the second join.  There is less chance of the first bond coming adrift.  Flux:  I like Carrs Green label (dilute phosphoric acid) for brass and nickel silver.  There are several sources of soldering supplies, Carrs is available from: http://www.finescale.org.uk/index.php?option=com_virtuemart&Itemid=56.  Also check out: http://www.dccconcepts.com/index_files/DCCsolderfluxes.htm  These are well regarded from what I’ve read but I’ve never used them.

I have never found a good source for brass modelling solder and flux in North America – possibly because brass kit building is pretty rare here (I wouldn’t mind being corrected on this).

The keys to successful soldering:  The right tools and materials, hot iron with clean tip, clean surface, lashings of flux, a drop of solder on the iron tip and then in and out.  There should be a fizz and the solder should flow readily.

Some may disagree but the regular electrical rosin cored solder is not suitable for this job. (On the other hand acid flux should NEVER be used for electrical work).

I also don’t like lead free solder – it doesn’t seem to work well, for me anyway.

I think the thing that puts a lot of folk off soldering is the fear of burnt fingers.  Well, not to worry, you will burn them but not with any kind of severity (so far I haven’t – I’ve done far more damage with knives).  It’s wise to hold parts with something other than your fingers when soldering but sometimes it can’t be helped.  It’s amazing the speed of the heat transfer – just grit your teeth.

Spring loaded pliers are useful for holding parts as are tweezers.  The yellow pack is a set of broaches – invaluable for enlarging etched holes.  The good old Olfa knife is a fine general purpose tool – useful for cutting parts off the etch.  Next  to it is a propelling fiberglass pen – very handy for cleaning and burnishing.

There’s also a steel rule, large file (with a dead edge) and a very fine file (red handle).  I’ll use the scriber to push out half etched rivets.

On to the kit.  Here it is:

As can be seen, it is one sheet of etched brass.  The parts are cunningly and artfully laid out.  The instruction sheet runs to four pages of exploded views with very few words (ideal for us guys).  The kit includes some steel spring wire, steel buffers, and something I’ve never seen before – 3D printed axlebox/spring and buffer shanks.  You will need to source wheels, paint and transfers.  Hornby, Bachmann, Markits, Alan Gibson, Exactoscale (EM or P4 only) and Ultrascale all do wheels (3′ diameter or 12mm on the tyre, 8 spoke ).  I’ve listed the wheels in more or less ascending price and quality.  I am using Markits wheels (at least I think they are – they were in my wheels box).

29 June 2012

I started the kit build today.  First step was to separate the solebars from the etch and gently file down the etch tags:

The first thing to do with these is to push out 8 rivets per side with scribe.  It’s seem better days and is not especially sharp.  There are actually 2 folds to make.

Folds made.  At the base of the solebar is a narrow ledge that is formed making a bend in the etch.  This was surprising difficult to do and I really should have scored the fold line better than I did.  I tried to use the steel rule as a bending bar but it wasn’t  very effective.

To join the two halves of solebar together, I tinned the inside surface with 4 small drops of solder.  I then folded the solebar.  Because of the small ledge I used the steel rule to support the piece.  I applied some flux to the INSIDE of the sole (not the side with all the detail) and ran the soldering along it starting at the center and working out.  The small file is useful for pressing the two halves together.  There should be a hiss and you will see solder just showing itself as it flows.

Lastly, in order to straighten out the ledge I pressed the steel rule against it and used the file to complete the fold.  You can twitch the ledge with pliers here and there if necessary.  I put a small amount of solder under the ledge at each end.  I left the middle – it seems strong enough.
The result is acceptable.

Next, some details:

There are 4 boxes (I don’t even know the technical term) to be added to the solebars.  These start out as flat pieces with two fold lines.  There’s also a rivet to be pushed out.  To cut a long story short I used the file (isn’t it useful!) as a former and folded the sides around it.  Use pliers to straighten things out if required (it was for me).  Then, cut very small pieces of solder.  Apply flux to the location (there’s a raised rib so you can’t get it wrong) and place the box.  Use the file to hold the piece (easier said than done) and pick up a small piece of solder with the iron.  Hopefully the solder will flow and the box will in the right place and straight.  In a couple of cases I botched it.  Simply heat and remove the part.  If there is a lot of solder on the rib, I found desoldering braid useful to remove it.  Try again.