Diecast Legends in their November 2012 magazine published a well written response and rebuttal to an article on Auto Art's website regarding the relative merits of diecast metal versus resin in collectors' model cars. Below we provide our own view...
We have carefully read Auto Art's article on their web site. Our response relates, naturally, to our own products and not to models in general which can vary widely in quality of accuracy, detail and finish.
Auto Art is a manufacturer for whose products we have considerable professional respect. They are clearly enthusiasts and produce many excellent models of interesting cars that we, as collectors in our own right, are very happy to own in our personal collections. But we disagree with various views expressed in their article.
Firstly we would stress that we do not regard either resin or diecast zinc as being inherently superior one to the other. We believe that they each have their place according to the particular model being produced. We ourselves have no universal preference of material. The only issue for us is choosing the right material for any given model. We are constantly on the lookout for new materials and techniques to best reproduce a car and all its components in miniature.
Auto Art are quite right that resin molding allows for a shorter delay between the appearance of a real car and the model. However when Auto Art refer to the comparative costs of tooling and the considerably greater cost of steel versus silicone they are only telling part of the story. A major cost component of any particular model comes from the research necessary to ensure accuracy. We employ a team of specialists with different fields of expertise, whether it be in classic F1, Can Am, Land Speed Record or whatever. These people spend countless hours researching particular cars in our books and photo libraries, on the internet and also visiting manufacturers, car shows, races and museums etc. When they have assembled enough photographs and dimensional data the process of producing a prototype begins. This is time consuming and expensive, particularly for any classic cars which cannot be digitally scanned. Scanning reduces the time to produce a prototype by months. All this very meaningful expense is the same for any well researched model whether produced in resin or injected metal and has to be considered as part of the total set up cost.
So for us, the question of whether to use injection molding or resin casting often boils down to the size of any given production run. Depending on the model, if an initial run of a particular version of a car is a few thousand or more we would tend to use diecasting, as indeed we have frequently done in the past. However it must also be said that some models are, quite simply, better produced in resin even if the production run is in the thousands. This has to do with moulding techniques, parting lines and the complicated shapes of some cars where we are of the opinion that a given model will be more accurate in resin. I strongly suspect that many collectors do not even notice when we switch back and forth between materials.
Auto Art is certainly right to point out that it is generally easier to produce opening doors etc in diecast as resin is fragile.However the problem does not completely go away in diecast as one is still often left with the choice of overscaling the hinges and catches or else making them so delicate they also break easily. Collectors still have to make up their own minds on whether they want opening parts or not . These can be very successful on some cars but not necessarily on all. Shut lines can be an issue if they are too wide.
Perhaps contrary to widespread belief, we use plenty of injection molding for various small parts, such as wheels, which can be used on a variety of different cars. It must be said that apart from the initial mold tooling it is easier and cheaper to produce and assemble injection molded components than comparable models using resin.
For the foreseeable future I cannot see us ever using injection molding for windscreens and windows. The quality, transparency and scale thickness of injection molded windows is, for us, totally unacceptable and can in some cases ruin an otherwise excellent model, rendering it, especially in 1/43 scale, far too "toylike" . The method we use is certainly cumulatively more expensive than injection molding. It is very labour intensive and labour costs in China have exploded over the past few years.
Auto Art's comparison of the relative costs of trimming and polishing resin and diecast parts is simplistic and wrong. Diecast pieces never need filling. Resin often does and this is also very labour intensive.
Auto Art is certainly correct to point out the comparative weakness of resin versus zinc. However collectors know full well that accurate scale models are delicate. It is hardly ever the bodywork of a model that breaks with careless handing but rather the various small attachments such as wing mirrors and spoilers that break off. This can happen just as easily to a diecast model as a resin one. Of course if a spoiler is injection molded and overscaled it might well be stronger but there is, to us, an unacceptable price to pay in reduced accuracy. Where any of our models do arrive broken in shipment to our distributors then it is clearly up to us to repair or replace. We take this very seriously.
We have seen none of the structural deformation in resin models that Auto Art suggest is possible despite the fact that we have some that are forty years old in our personal collections. Their comment strikes us as being biased scare mongering. It also neglects to mention that there have been well documented cases of diecast zinc deterioration commonly known to collectors as "metal fatigue" which can result in blistering, expansion, distortion, cracking and even total collapse of zinc castings. It is only fair to say that this should not occur in well controlled production processes and indeed I have many sixty year old Dinky Toys and Solidos which are as perfect now as the day they left the factory.
Like wise we take issue with Auto art's comments regarding the baking of paints. We do bake paints in our factory on both resin and diecast models - so they are simply talking nonsense here. The glossy appearance that they mention is not inherent to the process of painting on resin but a commercial /aesthetic choice that some manufacturers have made in response to their clients' demand for a glossy finish. As it happens we do not like the glossy finish as we feel it makes the cars look as though they are covered in treacle or honey.
We also take issue with what we would regard as oversimplification of the choice of pad printing or decals. We use both methods and the choice for us depends on the individual application. Pad printing can be unsuitable for surfaces with any great degree of compound curves. They are typically appropriate for the flatter surfaces of a car far, less so on any distinct compound curve. So any given model of ours, whether it be diecast or resin, will have a mixture of pad printing and decals. The issue of the transparent membrane yellowing with age becomes obvious on a white or silver background but is not noticeable on most other colours, even on my old 1960s Solido models.
Lastly we would really like to emphasize again we don't care whether a model is made of resin or diecast zinc. We only care if it is accurate or not. Any good scale model, diecast or resin, is a fragile and delicate object. It is not a toy to be pushed around on the floor.