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Resin casting

A good way to reproduce multiple items is to make a silicone rubber mould and resin cast the mouldings.

Below are the balsa and plasticard patterns with Cambrian (http://www.cambrianmodels.co.uk/index.html) plastic rivets. The patterns can be made of more or less anything including moulding clay (not plasticine as the silicone mould material will stick to it). It does not need to be durable - it only needs to last long enough to allow the silicone to set.

The red moulds in the upper part of the photo are made of silicone. This is a two-part casting rubber which takes the exact shape of the pattern. It reproduces detail very accurately and will pick up the wood grain of the balsa, for example. This means the castings madefrom the moulds will have the appearance of wood grain too.




I obtained my casting and moulding supplies from a reasonable supplier and I would have put a link to his excellent downloadable e-guide but unfortunately he now charges £5.49 plus VAT for that so I can't. Shame, I don't feel I can recommend someone who charges for instructions on how to use his products.

There are other places to buy the supplies and I have had excellent service from Alec Tiranti too. Their web site is at http://www.tiranti.co.uk/index.asp

Is it worth making them? Well to be honest, I started when the Accucraft wagons were just coming onto the market. I now use chopper couplings and metal wheels. If I pay £4 for couplings and £8 plus for metal wheels and the resin is not free. Hartland wagons are £10 to £12. it's a lot of work to make a wagon for more than the cost of a very good Accucraft RTR wagon. So, no it's not really worth it now. I have paid £12 for second-hand Accucraft wagons. Mmm...

Here is a set of castings made from the moulds using a two-part polyurethane resin.


The wagon sides are loosely based on the Lynton and Barnstaple wagons in their original form with a top-hung door. These were replaced with side-hung doors but I decided that as that type was available from Accucraft ready-to-run, I wanted something a little different. Oh, and the straps on my wagons go right onto the corners. On the Accucraft ones, the stop short, so not much use as straps really...

Here is a picture of the prototype wagon. The wood grain effect can be seen. The prototype castings were made with an impact-resistant resin as I was concerned about the durability of the resin wagons in the garden but that concern has proven unfounded. An early prototype has spent two summers and two winters outside and shows no sign of deterioration and has certainly never cracked.

The size is designed to fit onto a Hartland wagon chassis.


To prove they don't mind the cold, the picture below shows one of the resin wagons to the right hand end of the train in the background in the snowy picture below. (Never miss a chance for a gratuitous piccie of a steamie in action...)

 




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