hydrogen peroxide, am I missing something?

[njdriver04]

Where do you get 50% Hydrogen Peroxide; is this controlled or can I just go buy it?

Second, do you guys flip the parts over, if you don't flip the pieces over will there be a notable difference?

Thirdly, has anyone reused the hydrogen peroxide, I know it breaks down exposed but does it breakdown the point it can't be reused?

[THE H.P FREAK]

HI!... Don't waste your time and money looking for 50%. It doesn't work any better than the regular 3%. After every batch I do, I don't save it. Every new batch gets fresh H\P.

[klavy69]

Where do you get 50% Hydrogen Peroxide; is this controlled or can I just go buy it?

Second, do you guys flip the parts over, if you don't flip the pieces over will there be a notable difference?

Thirdly, has anyone reused the hydrogen peroxide, I know it breaks down exposed but does it breakdown the point it can't be reused?

50% is still over the counter stuff but still un needed. Stirring the jar every once in awhile helps get fresh light on different sides of parts. Hydrogen peroxide breaks down and is cheap enuf that it gets a new batch every time like Neal stated. The more it breaks down the slower it works. I've reused it before but only to add to once I took the clean stuff out...and then it was sacrificed to the driveway gods.

Todd

[njdriver04]

Thanks guys, I was just thinking that I would be more cost effective, you can just dilute the higher concentrated stuff .

I was thinking of using a glass baking disk with a mirror below it and suspending it in the air with some cuts 2 by 4s, figured it would allow more room for the beam to reflect.

[EvilJim]

Hello, all...happy to have found this resource.

First off, apologies for digging up the dead, but...it seemed that adding my question (and any response) to this thread, made more sense than starting over. I am yet another person coming back to R/C with a collection of older AE cars to refresh and drive again. I already knew about H2O2 for whitening, from other "old plastic" restoration topics, but had an R/C specific angle I was hoping to have addressed here.

When whitening parts, aside from cleaning and de-greasing, is it absolutely imperative to remove all the ferrous hardware?
(All aluminum will be removed..it's far too volatile to leave in place.)

I'd rather not stress the nylon that much, especially some of the steering parts. But, I'm not sure how reactive the steel may or may not be, in the H2O2 bath. Seems like it should be fine, but there's also the aspect of its age as a variable. As you can (hopefully) see in the pic my situation isn't dire, but there is still some work to be done...may as well get it as fresh as possible.

Thnx for any info!

RC10 nylon by Evil Jim, on Flickr

[Frankentruck]

Remove all metal or you will end up with rusty steel parts and rust stains on the nylon pants.

[TRX-1-3]

I'm with F'n Truck on this one. Extra O molecule means more oxidizing means more rusty probabilities.

[Frankentruck]

F'n Truck

[EvilJim]

I'm with F'n Truck on this one. Extra O molecule means more oxidizing means more rusty probabilities.

Of course! I completely forgot about this basically being an oxidation process. My chem teacher would be so disappointed... [facepalm]

Stuff like the bulkhead I'm not worried about, but...just gotta hope the smaller parts can survive.

Thnx, folks.

[juicedcoupe]

If they crack while removing ballstuds, they were already weak.

After whitening them, be sure to rehydrate them in water. Hot water is best but don't boil them. Cold water works, it just takes longer (much longer).

[JosephS]

If they crack while removing ballstuds, they were already weak.

After whitening them, be sure to rehydrate them in water. Hot water is best but don't boil them. Cold water works, it just takes longer (much longer).

Or you could rehydrate them before removing the hardware and whitening so the nylon is less likely crack. Water is a plasticizer for nylon. It shouldn't do any damage to nylon to boil it, though it doesn't help it any either.

I tend to hydrate my parts before whiting so that the nylon doesn't absorb the hydrogen peroxide.

[RC10th]

And don't over-do the peroxide or you'll end up with chalky nylon parts.

[XLR8]

Also, peroxide whitening isn't permanent. I have parts that were whitened a few years ago and they are beginning to turn yellow again.

I also have NIB vintage parts that are in their original sealed bags that are still very white so perhaps nylon is affected by the quality of the air it is exposed to.

I'm not a chemist and I haven't researched this issue extensively so I'm just reporting what I have observed.

[jwscab]

Yellowing of nylon is from uv exposure, so something in a bag is basically shielded from the bulk of uv rays, like a window in your house or car.

Funny enough the use of uv to whiten along with an oxidizer works.

[EvilJim]

Just to follow up, for those who commented and anyone who comes looking for this same topic/info...here's how it went.

Whitening: Overall not a ton of difference, but I feel it is noticeable. Much more so in person, of course...especially outside. (Though, my parts were pretty damn good to begin with, so there's that.)

Before
RC10 nylon by Evil Jim, on Flickr

After
Fresh nylon parts by Evil Jim, on Flickr

And don't over-do the peroxide or you'll end up with chalky nylon parts.

I used the sous vide* method, so I don't think there's much issue with that. Additionally, from what I had read while researching the "retrobrite" process and various techniques in the first place, if something ended up chalky...it was probably chalky already. If not noticeably so, just yet.

Hydration: I hadn't seen the comments about order of ops, so the parts sat in water overnight, once they were rinsed clean of all H2O2. Again, not a lot of difference, but I think this is something that's on a scale below most human perception. The one thing I did notice was that the parts sound softer, if that makes any sense. They feel a bit nicer when being handled, but when moved around they don't seem as hard...less "clanky" and more "thuddy" to the ear.

Damage: I had mentioned my concerns about the R&R of hardware causing cracks in the nylon, but I think that will be alleviated by the hydration. I didn't notice much at disassembly, but I was more concerned about the subsequent installation, rather than the removal. The next car I do, I'll try the order suggested by JosephS.

Or you could rehydrate them before removing the hardware and whitening so the nylon is less likely crack. Water is a plasticizer for nylon. It shouldn't do any damage to nylon to boil it, though it doesn't help it any either.

I tend to hydrate my parts before whiting so that the nylon doesn't absorb the hydrogen peroxide.

Thnx again for folks' help and comments...on to the build!

*Here's more on my method and why I chose to use a sous vide over other options.

Other than being able to run the entire process indoors, my three biggest reasons were:
1. Less reliant on weather (here in the PNW)
2. I figured NOT introducing more UV...even if only to kick off the peroxide decomposition...would be a good thing.
3. Parameters are much more controllable...IOW, repeatable.

My research showed UV was unnecessary, heat being a sufficient catalyst for decomposition. A lot of the "bright sun outdoors" result seems to come from the heat, as much as any UV exposure. Aside from not wanting to use UV in the process, getting the right bulb/lamp was also not cheap. On top of all the rest, it takes far less H2O2 to fill a few zip bags of parts, compared to pan-type vessels. And I saw lots of struggles from people trying to set up their light and tub and reflective surfaces...thinking the UV needed to hit all surfaces...that I just didn't need to deal with.

Instead, I had two quart Ziplocs (of parts), one sous vide stick, a pot, and some tap water...the whole thing fit easily in my laundry sink. Nothing ever left the pot, so there's no reason you couldn't do this on a counter, or bench as well. I ran the parts at 50°C for 6 hours, checking in about every hour to agitate the bubbles free from the parts and release any built up gases.
And that's one other (IMO, huge) benefit to using this method: there's no need to turn parts, or try to keep them submerged/from floating. Parts go in the bag, fill the bag with H2O2 to cover...only close the top most of the way...and lower them into your pot of water. As they submerge, the water presses any air out of the bag...so you have full coverage of your parts, before you complete the seal. There are specific racks for keeping bags in place, but I simply clipped the bags to the side of the pot, so they wouldn't be moved around by the current of the sous vide action.

The only semi-challenging part I decided to undertake, was to purchase food grade H2O2 at a 12% solution. Food grade means you know it's only peroxide and water, and 12% means you have more peroxide to work with in each batch. I suspect 3% would be enough, but felt this was worth it to ensure a shorter cook would be sufficient. Also, being an aqueous solution means you won't have any streaking problems, from uneven application/coverage of cream-based products on the parts.