Message: 9
Date: Sun, 25 Apr 2004 19:48:57 -0000
From: "Himawari" 
Subject: Re: Rubber on Transformers?

question...i have noticed even though i take care of all my g1
tf's, their rubber tires, and shockwave's wire, have started to 
crack...

This is from degradation due to oxidization. basically any exposure 
to the atmosphere, heat, UV, overworking ie stretching or other forms 
of plastic deformation will contribute to this.

can you use any type of silicone gel or what not to keep 
this from happening, or is the rubber made so cheaply that it will 
just break apart if i do this?

I don't think cost is an issue. Basically the rubber is probably a 
thermoset. Once it begins to degrade, there is nothing you can do to 
restore it. There are two types of plastics, thermoplastics (think of 
butter) and thermosets (think of bread). Thermoplastics can be 
remelted and reused, whereas thermosets cannot be remelted or 
reformed, just ground up. Once you make bread, that's it, you can't 
make bread again. This causes the problem with let's say rubber that 
is a thermoset, once the bonds begin to break, there is nothing that 
can be done to join them back together. If you tried to heat a 
thermoset, it would simply further degrade or burn. As for adding 
something on the surface to prevent exposure to the outside 
environment, this may work, but I doubt you'd want your toy wheels or 
shockwave wires covered with goop. And, it would only do good if done 
before any degradation started. Oxidization is plastic's cancer. Once 
it starts, there is no reverse effects that can be done on it 
to "heal it". If the rubber were a thermoplastic, you could try 
heating the cracked area only and used force to get the sides that 
were cracked to stick together, or find a solvent that would "melt" 
the two sides together similar to what acetone would due to styrene.
Sorry I couldn't have been any further help.
thanks -Himawari

+++++++++++++++++++++++++++++++++++

Message: 8
Date: Sun, 25 Apr 2004 19:08:19 -0000
From: "Himawari" 
Subject: Re: Rechroming Transformers?
> 
> Sorry, have to make this brief (no time on my hands currently), there 
> are many types of "chroming" some terms are used very general. The 
> application that is used on plastic items or items which cannot carry 
> a current would be a form of metal deposition. This is what is used 
> for toys and this is the process that I used to chrome some stuff as 
> well while I was living in Japan. There is a company in California 
> that offers a service to take small orders and "chrome" them. Usually 
> this type of service isn't available to the general public because 
> they would require a high volume order. It is not a technique one 
> could perform in their basement or garage either. The machine used 
> would be a large chanber where it could be closed and a very strong 
> vacuum applied. From there, the metal that is to be deposited on the 
> surface of the item to be coated is placed on coil filements where a 
> large DC current passes through to evaporate it under vacuum. The 
> objects in the chamber must be turning since the vapour travels in a 
> straight line. There is also the treating of the parts before they 
> enter the vacuum chamber as well, and would require a proper set up 
> for airbrushing and proper waste control. 
> I must also add, that if a person wanted to get something "re-
> chromed", they would have to totally strip all the crome off of the 
> part. This could be difficult without harming the polystyrene resin, 
> or even ABS resin. A person could use a kitchen cleanser (one that 
> said do not use on aluminum) and prepare a bath. Soak the part in it, 
> and all the deposited aluminum will eventually flake off. the next 
> task would be to strip the "glue" that was used for the aluminum to 
> stick to. I remember a product that worked in Japan, but I'm not sure 
> what it's equivalent would be here. I'd want to check on it before I 
> mention what I "think" it would be since I wouldn't want anyone to 
> try something that would not work.
> As for rechroming, if a person wanted to go about another way to do 
> it, they could try brush plating. This type of material is available 
> on the commercial market and could be bought in some hobby stores if 
> not on the internet. Basically it is a form of electroplating, where 
> the peice being chromed acts as a cathode (negative pole/charge from 
> a battery) and a paintbrush that has a wire embedded in it is 
> connected to the positive pole and acts as an anode. The electrode 
> (paintbrush) is then dipped into the electrolyte (solution) and 
> painted onto the surface. The only set back to this is, you would 
> have to coat the part (since it is non conductive) with a conductive 
> material on the surface to plate it. In the industry this process may 
> be used, but on metals (for obvious reasons) to repair chipped or 
> dammaged plating and for small parts. I know this is how they would 
> plate baby shoes. They would spray paint the shoes with a conductive 
> copper solution, and then plate them. You could probably do the same 
> with toys. I have yet to try it though, and I can bet this is the 
> method Delta would have used. It is quite easy, and little waste 
> cleanup. True chroming, like car bumpers etc, isn't even related to 
> what is done in the toy industry, so I won't even get into that long 
> expensive process.
> Wow, this turned out longer than I thought. Hope it makes sense 
> though.
> Thanks.                             -Himawari
> 
> 

(see also: Plastics Degradation due to UV light)

(see also: plastics used in making testshots and other tf toys)