RC Car Plastics

[ROH73]

Because of my day job, I'm very familiar with dozens of different polymers/plastics (I design plastic parts that are molded, extruded or machined). So, I thought it might be a good idea to start a thread that discusses what types of plastics were typically used in vintage RC car construction. Modern cars also use many of these plastics, but they also use many more exotic polymers and polymer blends that were not available 25 years ago. So for now, let's focus on vintage cars. So here's a list (in no particular order) and where the plastic was used:

-- Nylon: RC10 parts (nylon 6/6), Kyosho parts (glass filled), gears, wheels, etc.
-- ABS: Tamiya black parts such as chassis, suspension arms, early bushings, etc.
-- Delrin (acetal): gears, later plastic bushings, servo savers, shock pistons
-- Polystyrene: Tamiya hard bodies
-- Acrylic: Tamiya windshields, side glass, etc.
-- Lexan (polycarbonate): bodies, wings
-- PVC: flexible parts such as bumpers (for example, Kydex is PVC blended with acrylic)
-- Polyethylene: flexible parts such as bumpers
-- Polypropylene: color impregnated RTR bodies
-- Polyester: bodies and gear covers (as PETG or PET)

When it comes to maintaining and restoring vintage cars, I think that knowledge of how plastics age and how they can be cleaned is important. Some examples:

1. Nylon 6/6 embrittles with age as its moisture content drops (drys out) and it yellows from environmental and UV exposure. As we know, old parts can be boiled to increase their flexibility and treated with a hydrogen peroxide + UV bath to whiten them again.

2. ABS also embrittles with age, but unfortunately there's not much that can be done about it. Boiling ABS will distort it.

3. Sodium hydroxide (i.e. lye, like in oven cleaner, castrol super clean, etc.) can be used to strip paint from polystyrene, but it's not really all that good for nylon.

4. Acetone can be used to clean and remove glue from nylon parts such as wheels.

5. Nitromethane, brake fluid and de-natured alcohol can be used to strip paint from polycarbonate, but it will likely leave a haze.

Please feel free to add to this! Or, post any questions. Myself or someone else may be able to answer it.

[THEYTOOKMYTHUMB]

Great info! So just for additional input, who would you say was the most worried about the quality of their plastic (or variation of) over the years? On top of their game so to speak, in your opinion.

[ROH73]

Thanks!

Well, I'm not familiar with every car manufacture (for example, I don't own any Losi cars), but I've always been impressed with Kyosho's glass filled nylon like on the Optima, Ultima, etc. Those suspension arms are nearly indestructible. I also think Associated did a great job with their nylon 6/6 parts, as they were strong and inexpensive. Their mold tolerances left something to be desired, however .

Tamiya's use of ABS sucked and still sucks; they could have added $5 to the cost of each kit and used a much more durable plastic like nylon for critcal, stressed parts like suspension arms.

[THEYTOOKMYTHUMB]

I kinda had a feeling that I would get an answer close to that. As I posted that I kinda ran thru every brand I could think of and I think the early Losi stuff would be better than Tamiya, but worse than some others. HPI has my favorite plastic these days. It's gummy as hell which may hurt their racing status, but great for bashing which I think is their absolute intention.

[ROH73]

Yeah, some of the newer blends are impressive; very durable and flexible. I'm not familiar witih HPI, but I do know that Traxxas seems to have mastered the use of durable plastics. Of course, as you said, all that flexibily hurts suspension performance, but who cares when you're bashing .

[THEYTOOKMYTHUMB]

Oh man, I swore I wasn’t going to do any “off topic” posting tonight, but I just can’t help it…

Plastic factories are a pretty big part of the economy around here and I worked in all of them. When I turned 18 I went to work for a temp agency called Manpower. It worked out well for me because they’d call you and you could just say yes or no depending on your college schedule at the time.

Anyway, I specifically remember being at the LHS(where I worked) the day of my job interview at Manpower, and at the time (1992-3) B.U.M. was a very popular clothing company. Needless to say, I was wearing a sweatshirt that had B.U.M. across the front. I remember the owner of HobbyWorld, the man, the myth, the LEGEND Steve Rocca asking me “Are you really going to a job interview in a shirt that says bum?”

Anyway, Steve still races occasionally at REO and is still one helluva friend and a great competitor(loud too!). So if you need any extruder (or Intruder ) work done I’m your guy! I did a hell of a lot of roofing too! And yes, I was probably wearing Bugle Boy jeans along with that B.U.M. sweatshirt!

Sorry. Back to your regularly scheduled topic!

[ROH73]

Geez Thumb, you're not right in the head. But, I do enjoy your posts!

[klavy69]

Geez Thumb, you're not right in the head. But, I do enjoy your posts!

[THEYTOOKMYTHUMB]