Why haven't the model companies addressed the problem with tire melt ?

[Art Anderson]

You don't have much of a stash

You don't build older kits

40 years ? That;s a long time, 1977 ? 

Only about 3,000 or so kits here.

Gentlemen, in all of this, BEAR in mind that model kit manufacturers don't manufacture the plastics with which they mold model kits--that's WAY out of their league.  They, just like most any producer of molded plastic products (of all types,sizes and genre's) are pretty much limited to whatever materials are out there, readily available.

With the issue here being tires--there are only a handful of plastics that can be used to make "soft"tires for model kits--PVC being the most plentiful (and the subject of this thread)--most others have drawbacks far worse.  I along with others, have given very valid, truly workable techniques for eliminating the tendency of SOME PVC tires to attack the rims--I've done the BMF foil barrier several times, and can attest that it does work; so does a thin wipe of epoxy glue around the circumference of the wheel rim.

Of course, there is an alternative--molded polystyrene tires--ala Italeri in a number of their kits, but there goes the fine tread detail we all love to crave, not to mention having to paint te danged things--but I am pretty sure that from the standpoint of any model car kit manufacturer, that could very well be the only reliable solution to this periodic situation.

Art

 

[Ace-Garageguy]

Gentlemen, in all of this, BEAR in mind that model kit manufacturers don't manufacture the plastics with which they mold model kits--that's WAY out of their league.  They, just like most any producer of molded plastic products (of all types,sizes and genre's) are pretty much limited to whatever materials are out there, readily available.

While that's entirely true, it IS incumbent on any manufacturer to exercise due-diligence in quality control.

Kit manufacturers specify the exact materials their suppliers use...or at least they SHOULD.

Clearly, SOME vinyl or PVC compounds are stable while in contact with polystyrene for prolonged periods, and it really IS the kit manufacturer's responsibility to make sure that the compounds their suppliers are providing for molding tires ARE INDEED THE ONES SPECIFIED and THE ONES KNOWN TO BE STABLE...not some bottom-of-the-barrel cost-cutting potential goo from Joe's (or Chang's) Midnight Chemical and Plastics Supply.

Model kit parts that literally self-destruct (sometimes in a disturbingly SHORT period of time) are simply not acceptable.

[Greg Myers]

Gentlemen, in all of this, BEAR in mind that model kit manufacturers don't manufacture the plastics with which they mold model kits--that's WAY out of their league.  They, just like most any producer of molded plastic products (of all types,sizes and genre's) are pretty much limited to whatever materials are out there, readily available.

There ya go again with them negative vibes, Woof 

[Mr. Metallic]

While that's entirely true, it IS incumbent on any manufacturer to exercise due-diligence in quality control.

Kit manufacturers specify the exact materials their suppliers use...or at least they SHOULD.

Clearly, SOME vinyl or PVC compounds are stable while in contact with polystyrene for prolonged periods, and it really IS the kit manufacturer's responsibility to make sure that the compounds their suppliers are providing for molding tires ARE INDEED THE ONES SPECIFIED and THE ONES KNOWN TO BE STABLE...not some bottom-of-the-barrel cost-cutting potential goo from Joe's (or Chang's) Midnight Chemical and Plastics Supply.

Model kit parts that literally self-destruct (sometimes in a disturbingly SHORT period of time) are simply not acceptable.

I work in quality control for a major manufacturer that deals with plastic and many other materials. I can see both sides of this coin presented by Bill and Art.

I agree with Bill that quality control is paramount to a sustainable good relationship with customers and long term profits. They should be (and probably are) doing checks on their raw materials to make sure they are within specifications

However I also see Art's side. You can do all the testing you want of your raw materials before, during and after the manufacturing process, but you can't always predict long term durability of those raw materials. Even if you do tons of environmental and situational testing on your raw materials and finished product, it's not 100% foolproof. The industry that I am in, we do have safety standards we have to meet regulated by a governing body, while the model kit manufacturers do not live within those constraints. So, it doesn't necessarily make sense for them to invest the capital it would take to do this constant testing. People constantly complain about the rising costs of these kits, so imagine the added cost of the much higher level quality control.

Food for thought.

[John Goschke]

One factor that is always a concern in the production of professional art and craft materials is whether they are "archival" or not. That is, will they remain stable over time and not deteriorate over a period of years, decades, or even centuries.

Obviously this has never been a concern in the scale model arena (serious ship modeling may be the exception), especially with regard to the tire issue, as well as decals, some paints, metal foil, etc. Anyone who collects acetate promos or even-more unstable WW2 identification model planes recognizes that this type of plastic was not meant to stand the test of time. Luckily, styrene does seem to hold up reasonably well in spite of its tendency to discolor (whites turn yellow, etc).

If you've got model cars that are 30, 40, 50 years or even older you'll recognize this issue. Does it concern you?

[Ace-Garageguy]

I just noticed the other day that the tires supplied in the AMT model T phaeton kit have eaten into the rather nice wire wheels, and ruined them.

                                                 

[waynehulsey]

As a former graphic designer/pre-press person and art major, John Goschke  has an important point. You buy a tube of Windsor & Newton cadmium red today, it will match the one that you've had for 20 years and still will in a hundred years with reasonable storage. Thermoplastics are a industrial chemical that needs to last maybe 10 years at the most for most situations and models from a manufacturing view are short term toys. I had Joe Henning tell me at a show years ago, that his card stock models (build with Strathmore Bristol art board) such as the ones he did in Rod and Custom Models back in the 60's had stood up better then his plastic kits.

[Greg Myers]

I remember those builds,

[Art Anderson]

One factor that is always a concern in the production of professional art and craft materials is whether they are "archival" or not. That is, will they remain stable over time and not deteriorate over a period of years, decades, or even centuries.

Obviously this has never been a concern in the scale model arena (serious ship modeling may be the exception), especially with regard to the tire issue, as well as decals, some paints, metal foil, etc. Anyone who collects acetate promos or even-more unstable WW2 identification model planes recognizes that this type of plastic was not meant to stand the test of time. Luckily, styrene does seem to hold up reasonably well in spite of its tendency to discolor (whites turn yellow, etc).

If you've got model cars that are 30, 40, 50 years or even older you'll recognize this issue. Does it concern you?

It's interesting that I used exactly that very same kit to do my '27 T Tudor Sedan--which I did over the winter and spring of 2001--and it has yet to see any tire/wheel deterioration whasoever.   But that aside, regardless of what we wish could happen, a preventive measure that always works:  Wrap a strip of Bare Metal Foil around he rim first, then stretch and mount the PVC tire over that.

[Greg Myers]

all without disturbing the bare metal foil, and of course pending on our experience applying bare metal foil.

[Can-Con]

Humm ,, now I'm wondering how the white walls in the new Pegasus wheels will hold up over time???

[Greg Myers]

Hope they do, that is just too cool

[Tom Geiger]

I haven't seen any modern era tires (lets say 1990 to date) melt plastic.  

 

What I have seen is tire shrinkage.  This is a Monogram 1959 Chevy convertible, built back when the kit was new.  The tire is an old Surbanite snow tire from the 1980s. Note how it has shrunk on the rim.  The tire on the front right has also shrunk so far as to pop off the rim.   The tires on this car were all parts box pieces.

Here's an ancient custom from my Olde Kustom Kollection.  It was probably built in the early 1960s.  See where the tire has caused a reaction with the top of the wheel well where it touches. The other side was worse.  But somehow it didn't affect the rim!

 

[John Goschke]

I haven't seen any modern era tires (lets say 1990 to date) melt plastic.  

 

What I have seen is tire shrinkage.  This is a Monogram 1959 Chevy convertible, built back when the kit was new.  The tire is an old Surbanite snow tire from the 1980s. Note how it has shrunk on the rim.  The tire on the front right has also shrunk so far as to pop off the rim.   The tires on this car were all parts box pieces.

Here's an ancient custom from my Olde Kustom Kollection.  It was probably built in the early 1960s.  See where the tire has caused a reaction with the top of the wheel well where it touches. The other side was worse.  But somehow it didn't affect the rim!

 

Looks like that rim is white metal.

[Casey]

[ZTony8]

That S-W-C Willys looks like it was subject to very warm temperatures for a good while. Perhaps that exacerbated the melting problem?

 

[1930fordpickup]

That is some major tire melt going on on that display base. I wonder if it was sitting in the sun while?

 

[Richard Bartrop]

On 6/5/2017 at 1:18 PM, Ace-Garageguy said:

I just noticed the other day that the tires supplied in the AMT model T phaeton kit have eaten into the rather nice wire wheels, and ruined them.

                                                 

I have the one with XR-6, and the tires missed the wheels, but left a divot in the running board.   However I have an early issue Jo-han Cadillac V-16 that's been sitting in the box with no melt anywhere, so some companies seem to have figured it out even back then.

[Scott Colmer]

I just peeked in a Revell Hot Wheels IMSA Camaro and found the slicks were starting to melt into the hood. That's circa 1992. It repairable, but not good.

Edited February 4, 2018 by Scott Colmer

[Ron Hamilton]

I believe that the manufacturers use of certain material compounds in the '60'smodel kits.

I have restored many a 60's model car, and I had to replace the wheel covers and backs with resin pieces, which surpisingly did not melt, nor the Satco tires I used to replace them. Whenever I bought a vintage kit, I wrapped the tires, as I have found tire burn on various parts of the kits, which I have to repair.

I have yet to write about the tire melt on my storage cases. My 1/25 cars are on wooden shelving with no effect,  while my 1/18 die cast cars tires have left divots in the bases of the cases I stored them in.

[64Comet404]

From my experience, the worst tire burn in more recent kits is from the BF Goodrich Radial TA tires in 1980's MPC kits. There is something in the chemistry that just loves to leave tire imprints right in the middle of the window glass. I have seen imprints from all manufacturers, but the old Revell kits from the 1960's seem to be the worst offenders (just like the S-W-C Willys posted above).

[935k3]

Even some modern kits have this problem. Belkits rally cars do. I covered the rims with foil before painting to protect against it. The kit has a spare tire in the interior so I had to foil all the contact points(roll cage) and area where tire lays. Luckily the tires are in their own bag so there was no kit damage.

 

Edited February 5, 2018 by 935k3

[peteski]

On 2/4/2018 at 11:46 AM, Ron Hamilton said:

I believe that the manufacturers use of certain material compounds in the '60'smodel kits.

I have restored many a 60's model car, and I had to replace the wheel covers and backs with resin pieces, which surpisingly did not melt, nor the Satco tires I used to replace them. Whenever I bought a vintage kit, I wrapped the tires, as I have found tire burn on various parts of the kits, which I have to repair.

I have yet to write about the tire melt on my storage cases. My 1/25 cars are on wooden shelving with no effect,  while my 1/18 die cast cars tires have left divots in the bases of the cases I stored them in.

The tires prone to melting plastic are made from vinyl and it is the plasticizer, which makes the vinyl soft that leaches out and softens the plastic it contacts. Satco (and most Japanese kit manufactures like Tamiya, Fujimi, Hasegawa, Aoshima, etc.) make their model tires from "real" rubber.  It does not have any plasticizer, so it will not attack plastic. But (just like real rubber tires) those tires will get brittle after years of exposure to ambient air. Still, that is better than what happens with vinyl tires.  Then there were theose crappy 2-piece hard-plastic tires.  Those didn't look good and were hard to glue, but at least they didn't melt the wheels.

[Ace-Garageguy]

I'm doing a restoration / upgrade of an early 1/8 scale MPC  '70s Harley motorcycle gluebomb that uses identical tires to a recently reissued Honda.

The original tires have shrunk a full 1/8 inch in diameter, and have badly melted the rims where the original builder had scraped the chrome away.

I wonder if the recent production tires are made from the same stuff...they ARE the same tooling, exactly.

[Ace-Garageguy]

It appears SOME manufacturers MAY have addressed the tire-melt problem.

Regarding the post immediately above...

I just received an OLD PRODUCTION MPC Honda 750 kit, never assembled.

The TIRE tooling is identical to the recent reissues of both the street and racing Honda 750s, and the ancient ('70-'71 issue) Bronson Harley 900 Sportster.

On the SPORTSTER, the tires had melted into the rims and shrunk, as noted above.

The OLD production, never-built Honda 750's tires have also SHRUNK almost 1/4" in outside-diameter.

The recent REISSUES appear to be a different material from the earlier issues...but only time will tell if they shrink or melt the rims.

Interestingly, SOME vintage Revell 1/8 scale motorcycles have very heavy solid rubber tires that don't shrink OR melt the rims, but the kits may also contain HOLLOW vinyl tires that have completely disintegrated.