My Contribution to the 25yrs of the RC10 thread

[vintage AE]

I was given an opportunity to contribute to Slotcarod's 25 YEARS OF THE RC10 thread, so I went for it.

Here is a bit of background...Rod and I both used to live Calgary, Alberta, but I didn't get back into RCs until 2 months before I moved back to my home province of Nova Scotia, which was when I ran into Rod. Now we cross paths several times a year as I still work out of Calgary and fly back and forth to home. I was at his house the other day and he handed me a crusty Worlds Car to work on for his 25 years of the rc10 thread.

For those of you who haven't been to his thread, it's about documenting everything that was factory on each and every version of RC10 up to 2009. I'm not sure if he had revealed all of his plans on his quest to document all the RC10s but I think they involve runners of each one and much more. I will be restoring his Wolds Car runner to his requirements and it will be used in his testing.

The to do list

Disassemble
Clean
Rebuild shocks
Rebuild transmission
Boil hubs, knuckles, mounts, bell cranks, and rear bulkhead
Polish all pins and shock shafts
Replace ball cups and turnbuckles
Replace rear tower, rear hubs, rear arms, nose tubes and chassis screws
Rebuild everything as per the Worlds instruction manual
Probably try and strip the body and wing down too

Rod, if there was anything I had forgotten please let me know

I will try and document as much as I can as the restoration goes on.

[Charlie don't surf]

You can document those RCPS turnbuckles to my door any time

[vintage AE]

sure, no problem reggie, I will just tell rod i lots them

For real though I do have something to send your way. My wife cleaned all my tossed, opened envelops from the last time I got home so I don't have your addy anymore. When I get home I will get your addy off that second package you just sent me.

Maybe you can PM Rod and I can send the turnbuckles too.

[esaresky75]

Boil hubs, knuckles, mounts, bell cranks, and rear bulkhead

What does boil the parts mean? I know you add parts to boiling water with Rite Dye but I know you don't mean that for a factory restore.

[vintage AE]

I was told it the parts stronger once they cool. It was the first time I heard it, but since Rod has ages on me in experience I didn't question it. And it's his buggy

[Lowgear]

Theres a number of myths about what boiling actually does to plastic parts. Some say it makes them stronger, others say weaker, and others yet say nothing happens. I've also read that boiling nylon parts shrinks them slightly.

[vintage AE]

I just let my parts perform au natural, but I do like the sound of polishing my shafts though

I got the buggy stripped down and the chassis can take a bath in Goo Gone over night.

Got some cleaning to do tomorrow. I got some O'Donnell Speed Wash and some Purple Power Super Clean. I hear conflicted things about using Super Clean on white parts....some say that it leaves a purple tint, is that true?????

[vintage AE]

I got some cleaning done today. I used the O'Donnell Racing Speed Wash and it works great

Then I got doing some research on the Purple Power and realized that I could use it to get the stubborn blackish coloured stains off of the white parts. I initially planned on using it to remove the paint from the body, but I'm not sure if I will have enough left now. I have the parts and the old hardware soaking in the Purple Power and will check on the throughout the day.

The chassis was soaked in Goo Gone is still soaking I got everything off but one ultimate decal from Ultimate Hobbies. I took a couple sheets of saturated paper towel and laid it directly on top for better coverage. I hope it helps

[RC10resto]

I like to peel stickers off and then hit the residue with some paint thinner, quick and easy. If the sticker is stuborn hit it with a blow dryer.

[vintage AE]

As the shocks come apart it is revealed that they were built just as the manual shows, well almost...there was the o-ring limiter on the bottom of the rear shocks, but they had the same limiters inside as the manual.

Since I will be polishing the shock shafts and the fact that I'm a geologist "at work" with a microscope, I thought I would snap off a close up of the before shock shaft. The are a lot of striations running length ways due to scraping against the outside of the shock body. And a few perpendicular striations which look like impact marks from the shock body opening and not plier marks.

I will go over them with some 3M 2000 grit wetordry abrasive paper and mother Aluminum polish.

After shot, which looks a lot smoother with the naked eye.

[shirochanwrx]

Theres a number of myths about what boiling actually does to plastic parts. Some say it makes them stronger, others say weaker, and others yet say nothing happens. I've also read that boiling nylon parts shrinks them slightly.

I've been meaning to say something about the "boiling nylon" thing for a little while and I keep forgetting ...

... basically, nylon is made by a process in which water is produced during polymerization; a small amount of water invariably is retained and contributes (somewhat) to the mechanical properties of the final product. The primary mechanical properties are dictated less by water content and more by the number of bonds in the average nylon molecule. In general, short chain nylon polymers are more flexible, long chain polymers are more rigid.

As the nylon ages, the polymerization reaction continues, although at a slower rate. The polymers become longer and longer and therefore can no longer slide past one another as easily, making them theoretically both more rigid and more brittle.

Acid (free H+) is bad for nylon ... it ruptures the bonds within the nylon polymer that join the polyamide subunits together, in effect reversing the original polymerization process. Even neutral pH water has free H+ in it, and every time one is used up, the H20 molecules that remain will dissociate and provide more H+. Heat accelerates this process.

Therefore, my feeling is that the primary rationale behind "boiling" nylon parts is to disrupt a small number of the bonds in the nylon to make the part less brittle, which reverses the slow natural aging of nylon. The process is aided by the fact that nylon is also hygroscopic, which means that it absorbs or adsorbs water molecules. This is a very convenient feature of nylon because it means that water-soluble dyes are highly effective with nylon parts.

However, boiling the item for extended periods of time and/or the addition of acid to the solution (even mild acids like vinegar, as is recommended with some dyeing products), may break too many bonds and result in making the product more fragile.

Peroxide, for anyone who was wondering, does not have an appreciable effect on the strength of nylon. This has been demonstrated in the medical literature because nylon is used for suture material and the body uses the release of peroxide to combat infection ... therefore, peroxide resistance is an important feature of suture materials, and nylon is one of the longer-lasting suture materials available.

So, I think that boiling nylon parts for short periods of time is probably benign, and may result in some improvement in the resiliency of nylon parts at the expense of some rigidity. Boiling for extended period of time may be detrimental to the integrity of the part and may increased breakage, and exposure to acid at any temperature should be minimized.

[vintage AE]

wow, you should work for Mythbusters

That should take care of that topic, good job!

[Lowgear]

That makes sense. I remember reading somewhere that boiling nylon "relaxes" it. I guess that coincides with what you said about reversing the polymerization reaction. Now the question is how long does it take for the polymers to change enough where they can no longer slide past one another as easily? Should we be all running to the kitchen to boil our vintage nylon?


I love the fact that we are so hardcore about vintage R/C that we have discussions regarding the molecular structure of the materials used in their construction.

[RC10resto]

I've been meaning to say something about the "boiling nylon" thing for a little while and I keep forgetting ...

shirochanwrx you took the words right out of my mouth

nice explanation

[shirochanwrx]

I remember reading somewhere that boiling nylon "relaxes" it. I guess that coincides with what you said about reversing the polymerization reaction. Now the question is how long does it take for the polymers to change enough where they can no longer slide past one another as easily? Should we be all running to the kitchen to boil our vintage nylon?


I love the fact that we are so hardcore about vintage R/C that we have discussions regarding the molecular structure of the materials used in their construction.

Re: running to the kitchen to boil parts ... it's complicated.

Depending on how the nylon was made in the first place, and specfically, how long the manufacturer allowed the polymerization to occur, the original nylon part had a variable number of bonds in the average molecule, which is why some manufacturers have super-rigid parts and others have more flexible parts, even though they are all "nylon". So that is one unknown. Secondly, all of the environmental considerations surrounding the parts since it was made are another unknown; has it been run hard, kept in a dark room, cooking in a So Cal garage, being baked in UV light as a shelfer in a family room, etc, etc?

I think that the summary would be: if you are thinking about running your vintage nylon parts, boiling them is something you should consider. If you are a serious racer and are using vintage parts, boiling them may make them a little more flexible and resilient, but that may be a trade-off in terms of handling (if you are that good). The rest of us wouldn't notice the difference.

I think that there are three main groups of people out there with slightly different recommendations for each:

1) If you have lots of vintage spare parts to use (and I know some of you *do*) *and* you are a hard-core racer, I would recommend *not* boiling them unless you notice that you are having breakage problems; that will keep you parts as rigid as possible for racing.

2) If you do *not* have lots of vintage spare parts for your runner/racer, or if having the stiffest possible parts for racing is not a priority, it *may* be worth boiling them for a short period of time (30 min or so) because it probably doesn't do them any harm and it might make them more resistant to breakage. After all, boiling water only gets up to 100 degrees C (at normal atmospheric pressures), which really isn't very hot in the grand scheme of things. I would recommend *against* adding any vinegar (or any other acid) to the water (even if dyeing parts) because it may cause the polymer to degrade in a more rapid and unpredictable manner than desired.

3) If you are just going to stick your car on a shelf, it really doesn't matter one way or the other what you do.