When did manufacturers start using that classic rubber for tires?
I have had a bit of a realization recently, aren’t rubber tires for models really not the best material compared to plastic and resin?
To me, it feels like excellent detail can be achieved with injection-molded or resin-cast without the drawback of difficult mold lines, deterioration, and the difficulty of applying different products to the rubber.
So, am I missing something? is it just cheaper for them to make it out of rubber or is there some other reason for not using plastic?
I’ve seen rubber tires ever since I looked at models over 50 yrs ago,I would guess we dont see resin because of the cost,but plastic ones would make sense like we see in aircraft.
Rubber/vinyl tires can be more readily removed from their molds because they have some give to them. Plastic tires (good ones anyway) can’t be done in a simple two piece mold because the angles involved would trap the tire. You can make them in styrene using multiple slide molds or multiple pieces.
You only need to look at the tires on 1/32 Snap-Tite kits to see why plastic is generally not the go to medium.
Maybe I’m wrong but I thought the reason manufacturers supplied rubber tyres was as a gesture to authenticity – in theory they didn’t even need painting. But they came with the problem of trying to remove mould-lines, and the same applied to the ersatz-rubber versions, i.e. vinyl.
And the problem with the vinyl tyres has been that they gradually melt the plastic wheel rims they’re on, through some chemical process involving acid content. I recall contributing evidence of my c. 1997 Italeri Opel Blitz truck to a similar thread a few years ago, and others reported similar problems on other kits.
I got ahold of my first kit in 1968, and it had rubber tires, so before that. I believe it was done for “authenticity”. What could be better than modelling rubber tires out of rubber?
It always has been, and continues to be, a pain in the ass, and I have no idea why manufacturers insist on continuing to do it. Rubber tire deterioration and consuming of plastic parts has been well known since at least the 1980’s and still we get rubber tires in modern kits. It’s like putting a pack of cigarettes in each kit. Why, when you know it’s harmful, would you do it?
Slide molding one piece styrene tires is easily possible (Gecko Models) or injection molding tires in parts by the “stackable method” also achieves a highly detailed styrene tire (Dragon, Das Werk). So there has been no reason for the past 20 years for a kit to include a rubber tire. It is just senseless and inexcusable on the part of the manufacturers. They need to wake up and inculde styrene tires.
Economics. Slide molding (which many armor reviewers seem to have thought was a magic bullet several years ago, when it’s actually been around since the fifties) is still more expenive.
I’ve been very lucky though. None of my rubber parts have ever deteriorated on the model, although I’ve had several “in the box” incidents on some of my very old kits. I think painting the wheels protects them from any ill effects of the rubber.
I have not ever had a problem with older model car kits damaging the plastic wheel. Could it be the model car wheels have a different formulation than armor track?
I’m not aware actual rubber tyres causes any problem - I was trying to draw the distinction between those, and what is commonly called vinyl tyres. Rubber is rubber with a typically a flat/matt surface and flexible – more so than vinyl tyres which are fairly stiff and have a shinier surface.
So, it’s maybe 3 years since I last examined the Italeri Blitz. I made it around 25 years ago but the kit was probably a couple of years older - I first noticed the melting problem when it was barely evident maybe 15 years ago…
Not so easy to photograph but that glint of liquefying vinyl tyre mixed with plastic hub goes all the way round all four wheels. The double-rear tyres have almost melted right through their hubs now, pushing them outwards. I’m not sure about the yellow around the back tyre, it isn’t on any of the others…but I don’t recall seeing that 3 years ago…
I think when this came up before someone speculated whether I’d used weird paints, or at least oil based paints, and maybe they were interacting. Well, I used Humbrol Steel enamel on the hubs as a primer, Humbrol flat black on the tyres, and artists’ acrylic paints on the outer hubs so who knows - not an unusual combo.
Throw a little mud on it and you are good for another few years.
Manufacturers are not designing the kits to last 25 years. I think they go on the idea that the kit is a plastic toy and it lasts as long as it lasts.
I agree with you both, and besides this was never a particularly good kit & I didn’t do a particularly good job of it either. (So that yellow stuff must be dry powder paint, I must have been under the influence at the time) Its only hope of salvation is either blowing it up or sinking it up to the mudguards in a water-feature diorama – chucking a little mud around won’t hide the forthcoming total hub failures. Some better views…
I worked for Michelin Tires Germany for a while. I can tell from experience that making tires is a complex procedure. So a real rubber tire in scale could not be paid.
Information on real tires form my old outfit. https://news.michelin.de/articles/wie-entsteht-ein-reifen
If the kit is worth it, you could replace the wheels/rims with resin ones - there’s loads on the market these days. But the problem with both real rubber and vinyl is they decay over time.
Thanks guys but I don’t think it’s worth it, as you can see it would need other repairs too & honestly it’s a bad paint job. Besides it’s loaded up with 2 drums of gasoline and a dozen crates of 88 & 75 shells, regulars will know where my thoughts are going about its destiny…except all that would probably be left would be the wheels
I remember the 1970s Tamiya LRDG Chevy is the first kit I remember that had rubber tires. After some time the tires actually split and cracked. I recently bought that same kit with the LRDG crew and purchased resin wheels / tires for it.
What I have been told is that the chemicals in the vinyl that keep it soft will over time leech out into the styrene where they are in contact, causing the styrene to melt and the vinyl to stiffen and crack.
I will use vinyl only as a last resort if I can’t find an adequate AM replacement.
Yes but the manufacturers including vinyl tires isn’t a novelty; it’s including a dangerous and defective product, like Toccata airbags or cigarettes in the kits. This needs to be called out and stopped now.
