Monday, July 27, 2015

SDS Models Bitumen Tanker - Fixing the Handrails

The SDS Models Bitumen Tanker is a lovely model however it has a small issue with the handrails on the walkway. The handrail posts directly above the ladders on each side do not touch the walkway, they are between 0.5 to 1mm off the walkway. This appears to have been caused by the handrail post mounting holes in the tank not being drilled or moulded deep enough to allow the handrail posts above the ladders to drop down to meet the walkway.

I decided that this needed to be corrected so I used a pair of long nosed pliers and a piece of strip wood as a levering block on the tank to carefully extract the vertical handrail posts from the tank one at a time. The posts do seem to be glued but it is a flexible type possibly an acrylic contact cement and the posts came away easily on my model.

Once all the posts were out I cleaned away any excess glue from the tank and posts ends. I then drilled the mounting holes in the tank deeper using a 0.7mm drill in a pin vice. The tank casting drills easily.

The tricky process of getting all the handrail posts back into the tank mounting holes came next. It isn't to hard, just take your time and dry fit the posts working from one end of the tank to the other. I followed up by applying a small amount of clear drying acrylic contact cement to each post mounting point with a pointed tooth pick.

Unfortunately I didn't take a before photo of the handrail post issue but here is a photo of the finished tanker, still to be weathered.

As can be seen from the photo bitumen tanker is the one with the flues on each end. The flues were there as these tankers had gas burners running through the tank which allowed the bitumen to be reheated if it had cooled enough so that it would not come out of the tank easily. I chose this version of the bitumen tankers as being fitted with the flues and burners it could be left in a goods siding to await the arrival of a Department of Main Roads NSW spray seal truck which could use its own gas tanks to reheat the bitumen if necessary. So this is the version tanker that can be useful on the pickup goods during operation sessions on the layout. The other version bitumen tanker does not have the flues and burners so would be for delivering the bitumen to the several BORAL depots around the state. A spray seal truck is used to spray molten bitumen onto a prepared road surface which is then followed by a specially fitted tip truck that spreads a single stone thick layer of stones onto the bitumen by reversing over the freshly spread stones. This process is then followed up by a roller that embeds the stone into the bitumen . The rolling must be done quickly as while a stone will push into bitumen that has cooled it ultimately come out of the surface by the action of the traffic.

Of course,wanting this particular tanker meant that I had to buy the two pack with the blue AMPOL heavy oil tanker which I didn't particularly want as I never saw them in blue. I am going to heavily weather the blue tanker so that it is virtually black as by 1965 they almost certainly would have been, having been painted blue in the 1950s.

Now, do I need an oil burning D55 or D59 Class and a heavy oil filling point in my Wollar locomotive depot?

Saturday, July 18, 2015

New Air Compressor and Two Dual Action Air Brushes

This morning took a risk and bought a small air compressor that came with two dual action air brushes at ALDI for $99.99.

Here is the product description from the web site:

Product Description
  • Ideal for tattoos, nail art, makeup, artwork and modellers
  • Airflow:20-23L/min
  • With variable pressure gauge
  • Compact and light weight design
Air Brush Kit:
  • 1/6hp compressor
  • Low noise: 47db
  • Speed: 1450/min.
  • Airflow: 20-23L/min.
  • Variable pressure: 3 bar/57psi
  • Standard 1/8" BSP fitting
  • 1.8m braided hose
  • Includes 2 dual action air brushes
  • Oil free pistons
  • Auto start/stop feature
  • Adjustable pressure with gauge (on/off light)
  • Filter and thermal protector

I haven't included the web page address as it will likely disappear shortly.

This air compressor and air brush package became available this morning (Saturday, 18 July 2015) at ALDI stores in NSW, and maybe all stores in Australia.

I have tested them and I am quite happy with both the air compressor and the two dual action air brushes.

The air compressor is very quiet when running and does not pulse the air as it seems to have a small reservoir inside it. It will take the air pressure up to 57 p.s.i. then cut off until the pressure drops to 43.5 p.s.i. then start up again, which is almost straight away once you start to use an air brush. I set the compressor output to 25 p.s.i. and it sprayed well.

The two air brushes are different, one has a bottle attachment and a small cup which are friction fit. I found that the small metal cup was a problem when I tried to spray the sides of some rail as the paint leaked over the top of the cup due to the angle I had to hold the air brush at. The bottle of course would not suffer from this restriction. So the cup will only be useful for spraying with the air brush held horizontal. Also the hole in the metal cup where the paint is drawn into the air brush is not smooth and rough edges can catch small pieces of tissue when cleaning which may go through and block the air brush. I will attempt to use a motor tool with a small stone to smooth this down but I really can't see any real use for this metal cup anyway.

The second air brush has a screw on metal gravity cup that can be set at any angle so that spraying rail is easily done by adjusting the metal cup so that it remains relatively level. The cup has a press fit metal lid with a small hole so even if you do angle the brush too far it won't be too much of a problem.

I have a large compressor with a 50 litre tank but it doesn't easily allow me to move around the layout to spray things such as scenery and track so this little air compressor is just the thing I needed.

If you haven't tried dual action air brushes then this a good opportunity to give them a go without spending very much money.

I have previously bought a dual action air brush from Super Cheap Auto for $48 so this compressor and two dual action air brushes is a very good deal.

Usual disclaimer, no I don't have anything to do with ALDI other than being an occasional customer.

Wednesday, July 1, 2015

Modifying a Southern Rail Signal Box

At the recent Epping Model Railway Club 'Brickpit' Exhibition I picked up a Southern Rail Signal Box as it looked quite nice.

Now, before I got it I knew about the incorrect style of door and had some thoughts about changing that if it was possible. Of course the signal box may have been modelled after one with a different door to the standard one so perhaps it may not actually be incorrect.

I also knew that the barge boards under the gable ends of the roof were incorrect as they should be one the very end of the roof and this was definitely a mistake (see photos below).

Unfortunately, what I discovered once I had a chance to sit down and examine it closely was that the model walls were made up of  16 'concrete' panels but the original concrete signal boxes of this type had only 12 panels. Nothing can be done about this so it will be what it is.

Southern Rail photo - Lamps shown are not the production ones - Red text by RP
Here are three photos from Branchline Modeller No.3 to show what the signal box should look like.

Berrima Signal Box showing door and 12 x 10" panels in wall - R. Taaffe 1981
Mindaribba Signal Box showing door and panels
Coolamon Signal Box with 15" panels and the correct style door.
Overall though, I felt that it can still make up into a nice signal box.

I began by cutting the glue holding the small platform to the signal box to give me access to the door. I did the same to the glue holding the bottom of the platform legs, stairs and handrail posts to the base. I found that the handrail posts at the stair end were too long and were tipping the platform away from level so I trimmed the bottoms of the posts with a pair of transistor nippers.

I then proceeded to cut the barge boards away by scribing at the intersection/corner against the underside of the roof with an XACTO blade but using the back edge of the blade tip, I hope that this makes sense.

Once the barge boards were removed I was able to see that I could use the XACTO blade to carefully slice away the glue holding the roof on. The glue appears to be a water based contact cement type and will come away with a bit of work.

Once I could see inside the building I found that the door was part of the wall moulding. I used a fine circular saw blade in a motor tool running slowly to cut through each side of the door and then finished off the remaining corners scribing with the XACTO blade. It was a very nerve wracking job. It would be possible to do this just by scribing with the XACTO blade but it will be slow.

Signal Box waiting for the correct door, LEDs and paint
Now for the door which has four glass panes in the top section and a bit of panelling below. I did a search of available suitable doors such as those produced by Grandt Line and Tichy Train Group but came up empty.

Nothing for it but to design one and 3D print it so I spent an hour or so and came up with the one in the picture below.

Door with handle and bolt as per photos - The long tab on left side is to locate the door in the wall
I have yet to order the door but it will be printed at Shapeways in Frosted Ultra Detail as the frosted material will go clear if coated with some clear lacquer (window panes).

I intend to repaint the signal box in the stone colours and to add some small SMD LEDs to the lamps and inside the box. The lamps need to have the underside and each edge/corner painted black (see the lamp on the wall of the Mindaribba Signal Box in the photo above).

Well that's where it sits for now, I will report back when it is further down the track.