Weirdness of the wheels (1 Viewer)

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meatloaf109

1st Lieutenant
6,731
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Jan 1, 2012
north carolina
This is a bit of weirdness that came to my attention.
A casual envious remark resulted in a VERY kind gift of one of Jerry's (Woody) extra AMT F-7-f 3N Tigercat kits.
While researching this kit I came across warnings from just about every build review about the "caustic" tires. It seems that they will attack the styrene and melt it. I was suitably impressed with this information that I immediately and calmly inspected the contents thoroughly.
Yep, the nose tire was "stuck" to the decal sheet in a goo that was formerly a portion of one of the tail codes.
I have built at least 5 kits over the years with "rubber" tires, and never have I seen any thing like this!
I alerted Jerry immediately so he could check his tires, and I have put mine in a ziplock baggie and put them in the 'fridge.
Any thoughts?
Any chemists out there that could shed some light on this?

tiger1.jpg
 
Thanks Paul for the heads up my decals are okay but the tires had a slimy feel to them and seems they didnt touch anything else. sorry about your decals.
 
Can't say I've seen it that bad, but I have seen 'rubber' tyres degrade, go hard, go soft, crumble, all sorts of things. I hate the darned things, and wish manufacturers wouldn't use them in aircraft kits. Even when they 'behave', they rarely look right, and often fit poorly anyway, due to contraction and expansion.
The type used in car kits don't seem to have this problem, strangely.
Better off binning them, if you're able to get some resin wheels and tyres?
 
Thanks Paul for the heads up my decals are okay but the tires had a slimy feel to them and seems they didnt touch anything else. sorry about your decals.
Oh, no problem, I was doing the all black with red tail code anyways, I just wanted to alert you (and anyone else that might have this one on the shelf), to a possible problem.
I am going to look around for some replacements from my spares box, and if nothing shows, add a pilot and R/O, and hang it up with the many others.
 
Now I got to go and check all my stash!! But thanks for the heads-up Paul you're a gem of a chap.
 
They have a caustic chemical in the rubber almost every kit I run into with these rubbers should have a "protective sleave" on them that can be thrown away with this rubber tire, because its sht, I've had plastic wing melt from contact with this rubber in the box kit before assembly. I attribute it to some kit maker of theirs being fired and pulling a He-162 on them, changing the formula and causing the parts to fail, making us all mad :S

Reason #2: The tires might have a "Protective" gel so they don't puncture easily or generate a unwanted hole from contact with the plastic sprue. Try washing the tires in detergent ( similar to the stuff you use to wash the kit in, but not while the kit is being washed or before) if it doesn't take the sting out of the tires, just throw them out, or use them for flat tires that have no contact with anything they could melt in dioramas.
 
Ah, yes... Excelent information! Thanks, that seems a good start. I was going to do an experiment with them; (all hanging on a piece of sprue), one coated with "future", one coated with paint, and one left in the natural state. (It's the Dr. Frankenstein that lives in all us germanic peoples.) I will modifiy the experiment to reflect the idea you have presented.
 
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A side note: As a kid I had some fake fishing worms that I used to play with and made the mistake of storing them with my other toys. Damned if they melted in to any plastic toy they came in contact with!
 
Perhaps they are not Vulcanized!!!!!!!!

When I worked for Kaiser Aluminum in the States we coated electrical stranded aluminum cable with rubber, and it went thru a high temp area to Cure the rubber. I can imagine they wouldn't spend the money or time to cure the rubber! I doubt if there is a way of curing these tires now.

I thing raw rubber sticks to anything, not sure. Will have to look into the process. Something else to look for. Annie loves me tho.....

*Short search found this.
http://uk.answers.yahoo.com/question/index?qid=20120307131123AAnFuTF
 
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I am keeping them in the freezer at the moment, I will start the experiments soon.
I really like the way the Tigercat sits on that long front gear.
So far no replacements have presented themselves out of the spares boxes, but I have more to go!
 
Paul, there's a full set in resin (nose wheel and two main wheels, with tyres) available from True Details, and also a set from Czech master (CMK), although don't know if the latter is a full set, or just the main wheels. Both sets are designed for use with your kit and the Italeri kit, and are around $5.
 
A couple of points: 1. The tires in model kits are not rubber so vulcanization is a moot point. Natural rubber is a very poor compound for tires it is soft during hot weather and brittle during the cold. Vulcanizing means mixing natural rubber with sulfur and cooking. Sulfur molecules form cross-linked bridges between rubber molecules forming a typer of polymer. Sulfur forms the same cross-links between protein molecules. Sulfur is in effect the glue that holds you together.
2. Model tires are VINYL. Actually the vinyl monomer is cross-linked into a polymer by using Chlorine gas (PVC) or Fluorine (PVF) or acetic acid (PVAc). PVAc is the familiar White Glue or School Glue or Wood Glue (Elmer's Glue). PVF is used as a film to reduce flammability (especially in aircraft). PVC forms the familiar white plastic pipes but with the addition of plasticizers becomes rubbery and is used to make tubing, blow-up toys, raincoats, etc.
Thus you have a real chemical soup between the plasticized PVC, degrading releasing the plasticizer, chlorine gas which reacts with water vapor to form hydrochloric acid, and whatever heat stabilizer was added and the polystyrene (cross-linked with the vinyl group) plastic of the kit. Polystyrene plastics can release styrene, when heated, a hazardous chemical toxic to the liver, kidneys, GI-tract, and lungs. It is also reasonably suspected to be a human carcinogen (why you should never heat food in a polystyrene containers. They have a recycle #6 stamped on them
 

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