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

[Greg Myers]

Digging up some old kits, it's bad enough when you find the tires have melted into so many parts ruining them.

Then there's the same problem with older built kits where the same thing has happened to the wheels.

I've received tires from some resin companies that don't have this problem and are made of a material looking more like rubber instead of shinny plastic.

Many companies have used other materials through the years but seem to have problems coming up with something that works.

[Rob Hall]

I don't think I've seen this issue with any kits made in the last 40 years or so.  I've only seen it with old kits.  Is it really a problem with newer kits? 

[Spex84]

I'm pretty sure newer kits don't suffer from tire melt. The newest example I've seen was a 90s issue Deuce 3-window with a divot in the hood and roof from the tires, and I was surprised to find that. Flexible soft rubber tires are cool, but at least in the case of the 90s-early 2000s Revell and Testors tires,I find they attract dust and tend to split and crack as the years go by.

As for the older kits, there's nothing the model companies can do about that.
Maybe part-pack sets of wheels and tires would be a handy solution, people could buy them and replace those old melted pieces.

 

[Mr. Metallic]

I can recall a few Revell kits from 10-15 years ago had an issue, specifically the 59 Chevy Impala 2n1 kit. The tires with the separate whitewalls are known to melt the really sweet 4 bar spinners wheels you put in them, along with anything else. But aside from that I don't think this is much of a problem with kits made in the last 20-30 years at all.

[waynehulsey]

One of the reasons, I've always lobbied for styrene tires. No problem with dissimilar materials, doesn't need separate molds and equipment, and with modern finishing materials and paints easy to detail.

[Jantrix]

Well in most new kits the tires are usually bagged now. 

[afx]

If they offered rubber tires like Fujimi, Tamiya, Hasegawa, et al it wouldn't be a problem.

[Greg Myers]

That's what I was thinking, without all the apologetic  nonsense.

Obviously the manufacturers can't , and no one would expect them to, do any thing about kits from the past. This is just where this problem exist and not knowing how the current kits will fare over time.

 

Edited May 3, 2017 by Greg Myers

[espo]

I have experienced this problem on a few older kits. But I have to blame myself for not storing them correctly. Usually these melting tire problems  go back to some time in the past where a kit was exposed to high temps. Years ago it was more common because of the materials used and the shippers leaving a cargo in a truck sitting out in the sun or an unconditioned warehouse.

[martinfan5]

If they offered rubber tires like Fujimi, Tamiya, Hasegawa, et al it wouldn't be a problem.

And Aoshima , but bingo, I have not once had any tire issues with the rubber tires, or have had any tire issues with tire melting with any new kits from the last long long time.

Edited May 3, 2017 by martinfan5

[martinfan5]

One of the reasons, I've always lobbied for styrene tires. No problem with dissimilar materials, doesn't need separate molds and equipment, and with modern finishing materials and paints easy to detail.

No thanks,   there is nothing wrong with the current system of tires in model kits, if it isnt broke, lets not fix it.

[Spex84]

Bagged tires should be a no-brainer.

I always open new kits to bag the tires if they're not already...and sometimes the glass too, if it's sliding around un-bagged (grrr).

...Craig, thanks for the heads-up on those 59 Impala tires!! I had no idea...I like them more than the Revell-o-gram tires included in newer issues of the kit. But it would be a shame if they melted my wheels.

[ChrisBcritter]

The Lindberg '53 Ford has this issue, at least with the styrene whitewall inserts. Yet I have Monogram (Cord, Duesenberg) and Lindberg (Mercedes SSK) kits my dad built in the mid-1960s that have no tire melt on the plastic whitewalls at all. If they had the right formula for the vinyl back then, why didn't they stay with it?

[Spex84]

Ack, I have a Lindberg '53 too. Will have to be careful with those tires.

The worst tire melt I've seen has been on '60s AMT and Monogram kits--but interestingly, the big classics (31 Chrysler, Cadillac, etc) seem to be OK. I don't know what the difference was.

I know some of the old tires gas out and shrink...I have some Monogram '53 Corvette tires that no longer fit their inserts, having shrunk a few percent. Maybe some of the chemicals that were lost are partially responsible for the tire-melt issue?

IE...if tires have sat around for decades (unbuilt), and I mount them to wheels and use them in a project, will they still react and start melting the wheels?

[ChrisBcritter]

They sure will, at least with AMT - I have a few models like a '62 Continental and a '64 Grand Prix that I built from NOS kits in '81, and the wheels have been affected by the tires.

Edited May 4, 2017 by ChrisBcritter

[Greg Wann]

I purchased a mint sealed kit of the 69 Trans Am convertible and found several spots on the body where the tire burned in upon opening it.  I was not very happy.

[skymnky721]

The 1st thing I do with any kit I get  is seperate  all the parts so they dont make any contact with anything else  w/layers of napkins  or tissue paper  to help eliminate any probs like this.  I did a get a "Monroe Handler" mustang 2  from the late 70's   awhile back  and it had "goodyear"  melted across the front windshield!  man was I bummed,,so I just wet sanded it forever  w/different grits paper,,then polished it out  and it was fine,,but it took forever.

[Ace-Garageguy]

Good advice (above) to open older kits and make sure the tires aren't in contact with anything. 

These days, if i want to know the plastic rims in a built model won't be affected by the plasticizers in the tires leaching out, I'll coat the rim in question with a single layer of epoxy resin and let it cure fully prior to mounting the tire.

Something there's just NO cure for (other than making soft resin copies) is that some fairly recent tires tend to split after having been mounted on rims for a while. The only two I can think of right off hand are the ones in the AlumaCoupe kit, and several sets from Pegasus. Annoying to look on the shelf and notice a model sitting wonky, only to find a tire or two to be split into multiple pieces.

[Ace-Garageguy]

 If they had the right formula for the vinyl back then, why didn't they stay with it?

There are several possible reasons. One is that a different mix that supposedly met the same spec was substituted to save money. This is kinda what we're seeing with the really soft styrene coming in most of our newer models.

Another possible problem is that, in some cases, there's just no way to know how a material will age other than by aging it. While two similar vinyl tire compounds may seem to perform exactly the same way in accelerated "age" testing, one may be entirely stable for 50 years and one may turn to goo in 15.

[Modelbuilder Mark]

With a large Tire drawer,  and not knowing which kit which tires came from,  it is a pain to guess which ones will mess up over tinme,  and which ones will not.  I have heard about coating the rims with paint beside,  but not epoxy.  That may be worth just making a regular practice on projects. 

Edited May 6, 2017 by Modelbuilder Mark
Spelling error

[Spex84]

Thanks for the tip with the epoxy Bill. Would foiling the inside of the wheels work too?

[Art Anderson]

OK, a bit of history and a technical note:   

Ever since AMT, JoHan and Revell started offering "soft" tires in their model car kits (those AMT and SMP 1958-59 3in1 kits had a harder plastic tire), the material of choice has been Vinyl, or PVC.

For years, in order to make a soft variety of PVC, there was a compound used that would attack polystyrene ("tire burn"), rather intermittently--it happened sometimes but not always "back in the day"  (I've been building model cars since 1952--I do have a little bit of experience).

About 1974 or so, the US Government slapped controls on a chemical called "polyvinyl monomer" which was a gas given off in the injection molding of PVC, and I got caught up in all of that, being the HR person in our local Essex Group Wire Assembly Plant (we made all the dashboard harnesses for both Lincoln Continentals and Ford Thunderbirds at the time, plus smaller harnesses for Pinto's and all of the "service replacement wiring harnesses for both Ford and Chrysler older model cars).  All of those wiring harnesses had injection molded polyvinyl plugs at both ends!
 

Almost simultaneously with the "at least temporay" ban on soft PVC plastics in consumer products, and their ultimate return to production (remember those gawd-auful AMT hard plsstic 2pc tires of the middle 70's?), tire "melt" almost magically disappeared.  It did come back though, with the shift of model car kit production to the Far East, but in my considerable experience, that was a good decade or more ago.

Now, how to prevent its unlikely appearance (I've not seen any evidence of it on models I've built in the last 210+ years!), as Bill Engwer suggests, a quick "wipe" of epoxy around the circumference of the rim works, as does a strip of  Bare Metal Fol--no polyvinyl components will penetrate either one in my 65 yrs experience building model cars. But, I must say that I've not had the problem crop up on a model car in perhaps 20 years, and not even in more than 40 years on a US domestic-produced model car kit

Art

[Lovefordgalaxie]

I had this issue on a Monogram 1957 Bel Air, the ones in 1/12 scale, and on a AMT 1957 Ford, the one moldem in blue.

On both cars, one of the tires had done a nice job eating the trunk lid.

I could fix the issue on both kits, but had to remove more plastic  from the damaged area, as the styrene was affected, and had became soft to the point you could get pieces of plastic out with your finger nail.

The only other issue I had was with a set of AMT tires, from the 1934 Ford five window coupe. Used the tires on a '32 Vicky, and the inserts were painted black. I used Tamiya semi gloss black spray paint (lacquer). The paint "turned" from semi gloss to real glossy in about two years. Removed the whitewall inserts, and the plastic was not damaged at all. Stripped the paint, and repeinted them with ModeMaster flat black acrylic. It was about six months ago. Untill now, they are still flat. Let´s see what happens with a little more time.

[Ace-Garageguy]

Thanks for the tip with the epoxy Bill. Would foiling the inside of the wheels work too?

BMF on the rims prior to mounting the tires should work at least as well as an epoxy coating...the BMF is probably better, actually...as long as you can mount the tires without disturbing it.

The aircraft stuff I use (because I always have out-of-date but still fine-for-models in stock) is extremely stable and hard once cured, and goes on very smooth and even. Depending on the type of epoxy you use, and how you apply it, there's always the possibility that you might get a thin area due to brush strokes, or you may have an epoxy that's not highly chemical-resistant. 

BMF would not have those potential problems...as long as its integrity isn't compromised by tears or cuts during tire mounting.

[Art Anderson]

I had this issue on a Monogram 1957 Bel Air, the ones in 1/12 scale, and on a AMT 1957 Ford, the one moldem in blue.

On both cars, one of the tires had done a nice job eating the trunk lid.

I could fix the issue on both kits, but had to remove more plastic  from the damaged area, as the styrene was affected, and had became soft to the point you could get pieces of plastic out with your finger nail.

The only other issue I had was with a set of AMT tires, from the 1934 Ford five window coupe. Used the tires on a '32 Vicky, and the inserts were painted black. I used Tamiya semi gloss black spray paint (lacquer). The paint "turned" from semi gloss to real glossy in about two years. Removed the whitewall inserts, and the plastic was not damaged at all. Stripped the paint, and repeinted them with ModeMaster flat black acrylic. It was about six months ago. Untill now, they are still flat. Let´s see what happens with a little more time.

Hmm, i've not experienced the so-called "tire melt" in perhaps 40 years now!  WTF is going on here?

Art