Files

I was chatting with Steve Duckworth a couple of weeks ago at Scalefour North. We were comparing various tools and techniques, and the ways that we can model better. I commented on a little change that I have made, and Steve suggested that it was worth sharing.

How many times have you picked up the wrong file? You know the situation - you're doing some heavy-duty removal of whitemetal from a wagon underframe, you reach into the box or rack and pick up your very best fine-cut needle file, usually only reserved for stroking the olive-skinned thighs of Sicilian virgins, and High Level Kits' hornblocks...

Usually you only notice about five milliseconds after you've used it... There is a cry of "oh dear" and an attempt using file-combs/heat/scalpel tips to remove the shiny stuff that you've just clagged the teeth up with. A waste of modelling time, and never fully successful. I did this several times until I hit on a simple approach that won't prevent it, but will make it much less likely.

This is the box that my needle files live in...

And this is how I tell them apart...

I picked up a bottle of Tippex correction fluid, and now the white-handled files are the ones for WHITEmetal (and solder, lead and other clagging materials)

A Black permanent market pen indicate the file is for Brass, as well as nickel silver, steel and so on.

And the yellow handled one? Not for gold, but my scriber. Because it *looks* like a needle file, I kept picking it up by mistake to file things, and used rats-tail files inadvertently as scribers...

As Aleksandr would say, "Simples!".

Patchy

Over on the Scalefour Society Forum, I have asked about the use of metal black as a preparation for painting, and these are my experiences...

Well, firstly, I started off by giving all of the parts that were going to be treated a good going over with Carr's Acidip to chemically clean the surfaces thoroughly, and to get rid of any traces of flux, dirt and so on. After this, it was into some plain water in my wife's jewellery cleaning ultrasonic tank...

This always does a superb job at making any remaining grime and noxious substances literally fall off the model. You can even see the slightly cloudy water streaming away from the model when you switch the machine on. And she is happy as well if you offer to clean her rings at the same time - although preferably without the application of Acidip!

After this, the parts were popped on some kitchen paper in a box to keep the dust off them and left to dry thoroughly in the sun. Such are the joys of modelling in the summer.

After this, I reached for the Casey's Gunblue, and applied it with the end of a cotton bud. Unfortunately this was the result - distinctly patchy.

I'm not quite sure why. The model wasn't handled at all after cleaning, and was perfectly dry. I can only hypothesize that it was variations in the grades of nickel silver that made the difference.

Either way, I followed it up with a thin coating of etch primer, sprayed on, to ensure that the paint would adhere properly. I'd washed the remains of the gunblue off with plain water so the surface for the primer was clean again.

So quite a disappointing result. I still see the merits of using blackening on the edges of models to ensure that any paint chips won't be so obvious. That makes a lot of sense, and I'll be doing it in limited circumstances. I also suspect that the gunblue will "take" better on brass than on nickel silver, so I haven't given up all hope of this method.

I thought that I'd post the results so that you can all see what the outcome was, and perhaps add your own thoughts or experiences.

Don't try this at home...

...or anywhere else for that matter.

As part of my P4 demonstration track, I've planned to show various different types of trackwork construction.  A rough plan of it shows what I mean:

 

Part of it is to link a P4Track Company B8 kit into the three-way point made from ply & rivet.  I'd made the B8 a couple of weeks ago without problem.  Last night I finished riveting the ply sleepers, a tedious task at the best of times, and started laying them out on the template:

Unfortunately, when I looked at it the difference in height between the plastic sleepers and ply sleepers was more significant than I expected:

I'll just have to work with that, laying the ply onto a thick card trackbase.  Once bitten, twice shy, and I'll not attempt to mix the two types like this in future.  I recommend that you do the same!

Also, the act of laying down the sleepers showed that I'd missed out punching and fitting one rivet.  It's right in the middle of the point, at the end of the wing rail.  I thought momentarily about making another sleeper, but then realised that I could just use one of my spare P4Track Co. plastic chairs to fix the end in place.  

So that's a solution that saves the situation and will produce a good cosmetic effect.  Next stage is to start making the crossing vees.

In the raw

I thought that I would make a final post of the chassis construction for the Pug.  The reason for doing so is that this is the last time that it will be seen in this state of raw metal.

The next instructions ar "break the chassis down into its sub-assemblies [done, as you can see] and paint it".  So I lose all of that lovely shiny nickel silver, and start to gain something that looks like a proper locomotive :-)

In case you were wondering about the slightly mangled looking brake gear, it isn't broken or mis-assembled.  Chris at High Level has used a very ingenious design to make the entire brake gear removable from the completed chassis.

There are "carrying tubes" that run through the chassis frames, and through each of these passes a loose wire.  From this the soldered up brake rigging hangs.  The fact that it is soldered means that it all stays in alignment with the wheels as a single unit.  The seemingly misaligned wire at the far left is actually just one of the loose mounting wires that I hadn't tucked properly back in place.  You are even told to put a slight curve in the length of the mounting wires to ensure that friction holds them in place.

I've yet to see the instructions for final mounting of the brake gear, but I may well put a small blob of black paint on the ends of them to fix them securely, yet in a manner that can be easily detached, for extra security.

In the meantime, it will be off with the wheels, a final clean in the ultrasonic bath, and into the paintshop...

And then there were two

Brakehangers that is.

This was the brakehanger that remained, and I wished to copy.  The scrap nickel silver is a OO spacer from the kit, so the correct thickness and also surplus to requirements.

I used my Resistance Soldering Unit to attach the hanger to the scrap.  Using a RSU was ideal for this, as I could "spot weld" the parts together and no risk the completed brakehanger de-laminating or otherwise losing parts. 

I then took a piercing saw and fretted around the outline of the master and whilst they were still soldered together used the holes for the brake rodding to drill through into the new part to get them properly aligned.  When this was done, I carefully slid a scalpel blade between the old and new components and gently heating them with a conventional iron split them apart.

All that I had to do after that was to drill a small hole in the centre for the piece of wire to represent the brakeshoe  retaining pin, and solder in a small piece of wire.  Unfortunately at this point a no.78 drill was lost in action, but we all get casualties from time to time.

A spot of cleaning up with a file and these are the finished articles.  The re-manufactured one is at the front.  Not quite as neat as the original etching, but the day has been saved :-)

Bother!

I've not done very much on the Pug recently.  However I picked it up again earlier this evening to get started on the brake gear.  This is very cleverly designed as a one piece unit that can be removeable.

To start it, I made up the brakeshoes and put them ready to be fitted to the crossbars.  Here's a picture of all four of them prepared.  The next step would be to mount the wheels to set the shoes to the correct position.

Unfortunately, after I'd mounted the wheels on the axles in the chassis, I went to pick up the brakeshoes (centre of picture) and found only three of them :-(((

I suspect that whilst fitting the wheels, I caught one of them with a sleeve and flicked it into the far corner of the room!  I've spent twenty minutes on my knees on the floor grubbing around and not found it.

So out with the nickel silver scrap and the piercing saw when I next start on this again. Sigh...

Chassis progress

Well, although I haven't posted anything for a couple of weeks, I've been busy with the Pug and a few other things - of which more anon - so I'm not going to go through a blow by blow build of the chassis.  Rather, this will be a picture essay, with a few comments where appropriate.

Where I left it previously, I'd finished the cab fittings and was ready to move on to the frames.  As previously, before doing any construction I gave the etchings as a good going over with the fibreglass burnishing brush to remove any surface oxidation.  That gives the best possible start for soldering to be done.

So to start, this is the basic chassis with the frames and the P4 spacers erected.  I had one minor mishap  where I filed off a locating tag by mistake.  There *is* a warning in the instructions, but it comes after you've removed the part from the fret and (if you're of a fastidious mind) already cleaned the etching up :-/   

Never mind, there are plenty of other location references, and the kit naturally goes together absolutely square.

 

 

One of the next tasks was to laminate the coupling rods.  This was done using solder paint, and a cocktail stick rammed through the holes in each end to keep them together and aligned.

 

 This is the finished item.  The slight banana shape of the rods isn't actually there.  It's a function of the camera lens in taking pictures of some very small objects at very close range.

The next picture shows the sliding bearings and the matching hornblocks being held in place by a coil spring so that they stay in place whilst being aligned using the London Road Models tapered axles.  These allow the centres of the coupling rods to match the bearings exactly.  One axle is fixed in my model, so it only needs one set of moving bearings, and not the two pairs if I was going for a fully sprung model.  A conservative choice on my part, given this is the first loco kit I've built in around 15 years.

 

 This shows where I went away from the instructions slightly.  The suggestion is that to provide a mounting point for the front chassis bolt, it is possible to tap into the body moulding.  I found that there wasn't enough meat in the material for this.  As an alternative, I carved a larger section away, and filled it with a couple of layers of thick plasticard laminated together with PlasticWeld.  I then left it 24 hours to dry thoroughly and harden before drilling through and using the mounting bolt to cut its own thread.

 

 So after readying the body and test fitting it, the original cylinders and slide bars are re-used and mated with the frames.  This was done using a 14BA bolt.  Not too fiddly in isolation, but unfortunately when it needs to be weedled into a gap between two spacers with tweezers it became a job that needed much patience and a few rude words when it came to getting the nut on the end of the bolt.

The next (slightly blurred)  picture also shows the compensation pivot point.  It's a chunky piece of steel rod, so there's no danger of it wearing down.  Fixed in place with a little reaming of the mounting holes, and the use of Carrs Brown Label flux, it was very easy to solder securely.

It does seem as though the spacer and slidebar hangers could be more closely aligned.  I may have made a mistake here, but tightening the mounting nut up tightly does induce a distinct bend in the crosspiece that is the slidebar hangers.  Perhaps a spacing washer should be used to keep things parallel.

 

 This shows a more complete state, with the connecting rods soldered in place.  It remains to be seen how much clearance I have when I come to install the wheels behind them, but there is still meat left in the backs of the bushes that can be filed down.  Also visible is the dummy inside motion, which makes the chassis look nicely prototypically cluttered.

 

 

 The ashpan is fitted next.  I pressed out the half-etched rivets by hand, using a sharp scriber and even hand pressure.  This was done on a slightly soft cutting mat, to give a yielding surface to form them against.

 

And finally, some neat little webs not only represent the strengthening ribs on the prototype but also neatly locate the rear guard irons.  Another piece of really clever design that is a hallmark of the High Level Kits.

 

After all of this, the chassis had a good  rinse with Neutralising Rinse (Carrs again) and a dunk in my wife's ultrasonic cleaning bath.  That really made all the accumulated crud and chemicals drop off it, and it was followed by an overnight dry on the top of a radiator.

Brake gear building next time...