Atlantic's works: Portable layout - Scenic details next

[mick b]

Yes indeed Graeme I wouldnt try and spray Cellulose within a mile of plastic he has done a fantastic job. I can just imagine the plastic melting in front of my eyes if I tried (evil stuff , however you cant beat if for finish on metals).

[45609]

There seem to be a few questions to answer since lunchtime...

Tom, the motion is brush painted and yes I agree that if you don't ensure that it is degreased there may be problems with paint adhesion/drying. Have you tried giving the motion a going over with a stiff short brush loaded with methylated spirit or isopropyl alcohol? This is pretty effective at removing the muck. I also use this technique for washing off the non corrosive orange (resin) but sticky flux.

I too have heard rumours, and I emphasise rumours, that spraying celly onto plastic might lead you into problems. In practice I haven't had a real problem with it. Thinking about the mechanics of what is going on the only circumstance where I could see a problem arising is if a reasonable quantity of solvent got trapped in a space inside the model. It would also be even more of a problem if the volume was in such a place that the, heavier than air, fumes couldn't get out. It would attack and soften the plastic. Back in my aircraft modelling days I've seen a similar effect when I tried to fill a nose cone of a Me262 with Squadron Green putty. This stuff uses an organic hydrocarbon solvent. I, stupidly, used a load of it to try and weigh down the nose to sit the model on the udercarriage. It looked fine when I'd finished for the night but the scene the next morning was a bit of Daliesque horror story. It went in the bin!

Graeme is quite right about the technique for spraying celly. Quick and bold if you want to get a good finish. I'm sure I've mentioned it before, perhaps not here, but an airbrush is not the best tool for the job. You need an HVLP airgun. Similarly, Mick, I suspect your last experience of spraying celly was from the now defunct Duplicolour spraycans? They were great for big spray jobs but with a preset nozzle designed for 12in/ft scale painting were not really the best tool for the job either.

Wolf of B is looking good Graeme. What's left to do? The only obvious thing to me is that you need to lose the lining on the cylinders.

Please do remind us of Geoff's cold forming method. I can't recall the technique although I'm sure he has shown/described it to me in the past.

Finally you'll be pleased to know that I did make a model of a Me262 after throwing the first one away. In fact I made two....

I'll go back to my modelling/decorating cave now and let Graeme reclaim his thread

Cheers....Morgan

[mick b]

Morgan indeed Duplicolour was used for another interest of mine 1.43rd Formula One and Group C cars built from resin or whitemetal kits. Cans sprayed fine on both. It was good as it shrunk into panel lines etc as it dried.
Coachman who used to be on here still uses it for lining Coaches ,no idea how he manages that as Celloluse in my experience turns into a solid blob in seconds !! he regularly refers to its use on his thread on RM web.

[Atlantic 3279]

Geoff Kent's method for forming curved sheets for roofs, tumblehomes etc was covered in a recent MRJ, and it is amazingly simple. You work on a firm surface, and you need a long, slightly raised ledge on which to rest one edge of the sheet of flat plastikard. A ruler laid flat and prevented from sliding by a couple of suitably positioned drawing pins will do as the ledge, or use something a little thicker if you need to form a really deep curve. Put the edge of the sheet on the ledge, the rest of it resting on the flat firm surface. Use a round-ended tool of lesser radius than the curve you wish to form and stroke it repeteadly along the plastic, close and parallel to the edge/ledge. Watch the plastic begin to take on the curve. Repeat until the desired stable, smooth curvature is achieved. You can spread the curve over a greater part of the sheet by moving it progressively further onto the raised ledge, each time you shuffle it up stroking the form-tool over the flat part of the sheet that has been newly moved towards the ledge. For a varying curve such as the three-centre-round typical for a coach roof you use tools with different sizes of rounded end to form different parts of the curve. Drill shanks, pen casings, round-ended tweezers and all sorts of oddments will do as the curve-forming tool. It is best to form the final item from two or three thin layers, each less than 20 thou thick, laminating these together with "thorough but sparing" use of solvent (okay, I know that's a contradiction in terms in some ways, but you need to stick the whole of the area of the layers together (pressing them together bit by bit to exclude air) without swamping the work with destructive solvent that may get trapped within and then dissolve its way out of the finished laminate! Not only does the laminating method help to fix the curvature into the layers of plastic, but the bonding together of the layers helps to ensure that any slight local discrepancies in the curvature of the individual layers are pulled into line with the "average" as the layers are bonded together.
I found some things to avoid, by trial and error:
1. You cannot substitute a resilient cutting mat or mouse mat for the firm surface and raised edge. You need to be pressing the curve down into fresh air, not against a 3D springy surface. If you use the resilent matt the curvature will try to form in three dimensions around the tool, instead of the two dimensional curve that you want, As you try to draw the tool along, the plastic will bulge and distort instead of forming an even curve.
2. Don't apply much pressure on the first passes of the tool, let the curve work gradually into the plastic before you try to force it to assume the desired final radius. This seems to limit the chances of distorting the plastic too.


As photographed, Wolf needed deletion of lining on the cylinders, a fall plate, a whistle, (those jobs now done), spectacle glazing, weight (done) and coal (to add) in tender, touching in of paint here and there, extra pick-ups either on the tender or on a revised trailing truck arrangement, final varnish, and front coupling. Not a lot, just fiddly bits.

[45609]

Thanks Graeme. I knew I'd been reminded of the technique recently but assumed it was from a conversation with Geoff. I'll have to read the MRJ issue again.

All those fiddly bits make the model and seem to go on and on. When I thought I was nearly done on GN I made a list of small things to do, nearly filling a side of A4 paper, and still forgot the tender lamp irons!

[Atlantic 3279]

Off the current topic, but how I laughed at this:

http://www.ebay.co.uk/itm/Hornby-Spare- ... SS:GB:3160

Must be sister loco to Flying Lancer and Gay Scotsman I suppose.

Plenty of greedily priced A4 bodies also available I see.....

[mick b]

Ebay prices have been going up on Hornby A4 bodies presumably due to lack of complete ones to buy of late.
Bet they still sell as well. One on a 99p start last week went for over £26 plus postage and missing front buffer moulding as well.

[45609]

Of course not forgetting "Call Girl", "Mincin" and "Brown Trout". Ah but as an "Experienced Seller" he must have the right to charge those prices?!

[Atlantic 3279]

Just as well it didn't occur to me earlier that Gay Lancer was a possible combination....

[Saint Johnstoun]

I too recently experienced a strange effect of what I presume was a chemical action. I use clear Acrylic tube to form boilers etc. and built up a receiver for a model of a fireless loco from that medium. The domed end was formed with body filler suitably shaped, no problems, but the end that abuts the cab was of course flat. I 'buried' a piece of lead? in the 'boiler' and closed the end off with more body filler to hold it in place (the motor of this loco is in the cab) and filed the end flat to abut onto the cab front. After a time I noticed that the inside of the tube had a series of horizontal cracks all the way round - fortunately they didn't come right through to the outside - any idea whether the cracks were caused by chemical reaction with the filler or what? I fear had I used 1mm thick tube instead of 2mm the cracks would have come through and spoilt the job!

[mick b]

REaction between lead and filler? Pva and lead dont go well together either as it expands

[Atlantic 3279]

I apologise to those who are waiting to see me get on with batches of parts for Pacifics, the generic Howlden coach, the V2 body, and another A2/3 for a special purpose, and to those who are still waiting to see something GC and possibly a tank engine body or two in resin - it all takes time. I have at last however now finally reached the point at which I can shift Wolf off my workbench for probably the final time.
Overall varnish was sprayed onto the loco today, making my first use of the new member of our family. Meet Bertie the Compressor:

I await availability of my daughter's artistic services as a means of painting his smiley face onto the end of the air tank. Reliable paint spraying is now a relaxing pleasure. I am in danger of running out of things to cause me stress and anger......

I also contrived a means of improving pick-up on Wolf, to suit (amongst other things) the owner's fad for left-handed electricity and the associated devilry within the loco. I didn't fancy having to wire the tender, so I produced a variation on my "skeleton" sprung, steering rear truck. In this example, the front portions of the wires that form the suspension for the truck are soldered to the rivets in the chassis keeper plate - thus they are in contact with the loco's pick-up strips. The tail end of each wire is soldered to a stub of 3/32" bore brass tube which acts as a free-running bearing for the 2mm axle. The wheelset is modified in two ways. Firstly the insulating bushes at the wheel hubs have been shorted out by drilling 0.7mm holes and pushing in stubs of 0.7mm brass wire. Secondly the axle is sawn in half and the two parts glued back together (preserving a centre gap) inside a piece of 2mm bore plastic tube.

[Atlantic 3279]

Wolf as finished:

Revised master for A2/3 cab, as the original mould was getting a bit tired and with my increased knowledge of mould making there were obvious gains to be made from producing a new two-piece mould in lieu of the original one-piece:

New etched ventilator, etched surround to mudhole door access, finer rainstrips on roof, and the two piece mould will make for a much neater and more complete rendition of the necessary empty space inside the rear of the firebox. The dimples for the horizontal handrails have also been moved up as high as they realistically can be, governed by the cab window position which is slightly too low, but the higher positions of the handrails will make it possible to apply a panel of BR lining of the correct proportions. Note that the added shuttering around the rear of the cab has been added ready for sticking the rear edges down onto the base of a moulding box.

[davidwest]

I'll be interested to see how the new cab develops....

[2002EarlMarischal]

Lovely work and fascinating as always.