sticking tires

[gary jackson]

how do you keep tires from welding themselves to the display case bottom

[Ace-Garageguy]

A patch of BMF should do it.

Those same tires will melt into plastic wheels over time if the wheels aren't wrapped with BMF as well.

[atomicholiday]

Does this only apply to older kits?  Meaning, it’s not a problem for newer tires is it?

[gary jackson]

13 hours ago, Ace-Garageguy said:

A patch of BMF should do it.

Those same tires will melt into plastic wheels over time if the wheels aren't wrapped with BMF as well.

thanks buddy  yes i just looked at a cameo pro street i built 30 years ago and was disapointed the tires had acted up on the rims  it was a model i had placed with in a contest  bummer

[gary jackson]

Just now, gary jackson said:

thanks buddy  yes i just looked at a cameo pro street i built 30 years ago and was disapointed the tires had acted up on the rims  it was a model i had placed with in a contest  bummer

so can you put a small strip where the tires land on the display floor

[Ace-Garageguy]

2 hours ago, atomicholiday said:

Does this only apply to older kits?  Meaning, it’s not a problem for newer tires is it?

You never know until it happens.

I've had some fairly recent kits exhibit "plasticiser leaching" from the tires, which is what causes the melting of adjacent plastic.

[Ace-Garageguy]

On 6/23/2023 at 12:03 PM, gary jackson said:

so can you put a small strip where the tires land on the display floor

Yup, that should do it. If you don't have BMF, a square of aluminum foil will work just as well.

The object is simply to keep the tire from direct contact with any plastic.

Edited June 25, 2023 by Ace-Garageguy
TYPO

[BDSchindler]

On 6/23/2023 at 12:30 PM, Ace-Garageguy said:

Tup, that should do it. If you don't have BMF, a square of aluminum foil will work just as well.

The object is simply to keep the tire from direct contact with any plastic.

It appears that's another good reason to use resin/3D printed tires (of which I have become a recent huge fan of!)

[Ace-Garageguy]

12 hours ago, BDSchindler said:

It appears that's another good reason to use resin/3D printed tires (of which I have become a recent huge fan of!)

Of course, nobody expected the tire melt issue to become a problem on down the road. 

Just like nobody expected acetate promos to either warp and shrink, or turn to dust.

Just like nobody knows how long 3D resin-printed parts will last.

Many MANY plastics have a relatively short life span before they begin to break down irreversibly.

So there's that.

Edited June 25, 2023 by Ace-Garageguy

[gary jackson]

sadly i guess photos last longer

[Mothersworry]

This is why I much prefer injection molded plastic tires or resin tires, you can make em look more like real tires than the vinylish mystery plastic tires that have been eaten up the plastic in kits fer decades.

And resin wheels aren't safe either, at least not the finish, here's some pics of my SWC Willys that wuz best of Show at the Detroit Autorama in 2006...the front wheels are resin and the tires are vintage MPC funny car front tires, figured I didn't have to worry about the tire melty thing cuz of the resin wheels...wrong!

The wheels are painted with Testors gloss black enamel and then Alclad  polished aluminum. As you can see, the the finish on the rim edge is "melting" just like a plastic wheel would do.

I suspect that it is the enamel reacting to the tire but I'm not sure, I've done resin wheels this way with vintage or vinyl type tires fer years and never had this happen before. I tried Tamiya Lacquer for a base coat but found that the Alclad doesn't like to stick to Lacquer as well as enamel so that's why I used it.

lesson learned...no more vintage tires.

Fer what it's worth.

Edited June 26, 2023 by Mothersworry
Misspelling

[redscampi]

I had several of my models on a shelf coated with enamel paint. The paint had been on the shelf a long time. Guess what sticks firmly to model car tires?

[89AKurt]

Think I've seen this topic before on the forum, but since this is new and easy, here goes.  The "rubber" tires on old kits are toxic to plastic.  Built this Italeri kit last century, mid 1980s.  As you can see, the wheels are trashed.  But this has not stuck the the glass shelf.  "... display case bottom." - do you mean the bottom of the cabinet, which is either varnished wood, or paint?  I can see these "rubber" tires reacting with that, not glass.

When I read about this problem, had to open a sealed kit, the Revell Aerovette, and found the loose tires sat on the windows and screwed them up.  I don't see what the point is of having "collectible" kits that have these tires, if they wreck the plastic, open them up and put the tires into a paper envelope.

[peteski]

The "melting" tires are made of PVC (vinyl), not rubber.  Rubber is more stable.  It will dry out and get crumbly (like 1:1 tires), but will not get sticky. Most Japanese kits use rubber tires.  But  like it has  been mentioned numerous times on this and other forums, some poor formulations of PVC used for tires start leaching out of the material, and affect other plastics, resin, or painted/varnished surfaces. Just like the material it leached out of, it starts making other plastic materials soft.  Paint or varnishes are types of resin too.   Metal or glass aren't plastics (polymers), so they are not affected.

Plasticizer is a chemical that makes plastics soft.  Normally virgin PVC is a hard plastic (your sewer pipes are likely standard hard PVC).  To make vinyl soft (for many uses, including soft tires for model kits).  I would actually prefer if kit manufacturers made model kit tures out of hard plastic.  Painted appropriate color, it is more realistic looking that the standard PVC tires.  Plus it is easier to apply marking decals (like lettering or white walls) to hard plastic.