Making Dyed parts white(er)

[JosephS]

I bought a project car specifically because I wanted a wreck to work with. It was a white part rc10t that was dyed black and the dye has faded over time.

There is a lot of information here on people who tried it, unfortunately many of the picture links are broken.

There was a time when it was thought to be impossible to whiten parts well and now it's accepted peroxide + UV works

There hasn't been as many threads posted on removing Dye as whitening parts.
It sounds like there was some partial success reported in 2008

Remove Dye
2008
Rit Dye Remover https://www.rc10talk.com/viewtopic.php?f=38&t=7873


Whiten Parts
2007

• Westley's Bleche-Wite https://www.rc10talk.com/viewtopic.php?f=1&t=2570
• For RPM white https://www.rc10talk.com/viewtopic.php?t=1451

2008

• Faking it in pictures https://www.rc10talk.com/viewtopic.php?f=35&t=6120
• Iron Out rust and stain remover https://www.rc10talk.com/viewtopic.php?f=1&t=4322
• oxyclean https://www.rc10talk.com/viewtopic.php?t=6766
• bleach https://www.rc10talk.com/viewtopic.php?t=6766
  (bleach has been reported to NOT work for many but this method may be different)

2010
This is the turning point on the forum where it was generally accepted yellow parts can be whitened. Does not affect dyed parts.

Detailed thread
sunlight and peroxide https://www.rc10talk.com/viewtopic.php?f=40&t=14978
based off of
https://www.tamiyaclub.com/showroom_model.asp?cid=98012&id=22525

[juicedcoupe]

You'll never remove the dye. At best, it'll look dingy.

IMHO, re-dye the parts black.

[JosephS]

I’m going to take a shot at it anyway. It looks like the dye is fading out as well is superficial. I can see some rubbed parts turning white in places.

I do think it may take a LOT of time for the dye remover to penetrate past the first layers. It also make take a few passes.

I plan on doing a wash and clean. The sort the parts by apparent dye fade . Then try to use a long soak of the parts into dye remover. I’ll try that 3 times and see what the results are. I was thinking that I may add acetone on the later passes to allow the remover to penetrate deeper into the material.

But yeah I will likely have to dye the parts black

I’m still reading up on what others tried, so the plan may change.

[Dadio]

Doing it in an ultrasonic cleaner may help penetration, just a guess.

[JosephS]

That’s interesting. I have my wife one as a gift a while back. I’ll have to see if she still has it.

[JosephS]

So this link is a little interesting

https://www.ncbi.nlm.nih.gov/books/NBK385442/

It states that nylon dyes are acid dyes and are attracted to positive charged states. I wonder if using a basic solution or if using an charged electrolyte solution (saltwater and a battery) could create conditions to remove the dye from substrate.

[jwscab]

Anything you use will ultimately damage the underlying material unfortunately.

Good luck though

[JosephS]

I'll have to see which one I got
but there are 2 RIT products to remove dye
Rit Dye remover sodium-hydrosulfite

or
sodium dithionite plus sodium carbonate

Either way it looks like the result may be light grey. https://www.onlinefabricstore.com/makersmill/how-to-use-rit-color-remover/

I don't think at the concentrations I will be using it will damage Nylon much since this is designed for fabric with is much thinner and fragile. That may change if I decide to soak a part all night. Especially if it the sulfite formulation. I'll have to find a sacrificial part and start there.

Adding Acetone won't do anything good or bad to the process.

[JosephS]

Now that it’s not 105+ in my ‘workshop’ I got back to this.

The results are mixed but positive.
This is where I am in the process

04758FC7-6D7A-419D-9428-7B48FFD2429A.jpeg (30.19 KiB) Viewed 747 times

04758FC7-6D7A-419D-9428-7B48FFD2429A.jpeg (30.19 KiB) Viewed 747 times

This is where I started.

A0C7C896-8406-47FE-A13B-63461F4A69BF.jpeg (29.68 KiB) Viewed 747 times

A0C7C896-8406-47FE-A13B-63461F4A69BF.jpeg (29.68 KiB) Viewed 747 times

The pictures have mixed brightness. The shock tower is the same in both pictures.The before picture is much brighter. In person the before was very dark and saturated.

The rit dye remover works well as long as the part was not black.

I think that I have been using a much too small pot for this process. I think the more water in the pot, the more dye is removed. Each time the water came out tinted.


The part looks very improved, but it feels ‘chalky’

I this process won’t get the part oem white but it looks better and could be dyed a lighter color.

[JosephS]

I learned a bit but was surprised by how good the results came out for the most recent try.

I used a whole 3 quarts of water and half a box of dye remover for just these two parts. I boiled for about an hour. This is the first try on this and it’s better than I had expected.

Right now I took the water from boiling and the parts and added it to 5 gallons of water for a soak. I am hoping that with some more time and lots of water to diffuse into the dye will fade more

[threesheds]

I always think white looks more "plastic" than other colours? Reminiscent of nylon. How much water!!! for two steering horns. We've got a drought and hose pipe ban here (UK)
But if that's your pref ga

[JosephS]

I always think white looks more "plastic" than other colours? Reminiscent of nylon. How much water!!! for two steering horns. We've got a drought and hose pipe ban here (UK)
But if that's your pref ga

These actually look the correct nylon white for associated . This batch came out much more correct than the other 2 from the same car.
The water came from runoff capture and doesn't go away when I'm done. It's going to go on the garden.

[1911Colt]

I don't know if it works to remove dye, but if anyone has ABS plastic bits that have "yellowed" or "browned" with age, the hair salon bath/ultraviolet light trick works very well.

[JosephS]

I don't know if it works to remove dye, but if anyone has ABS plastic bits that have "yellowed" or "browned" with age, the hair salon bath/ultraviolet light trick works very well.

Using peroxide and UV doesn't work for reducing dye. it does make lightly dyed parts look whiter, but they are still tinted. The gear box was whitened but still retains a bit of light blue dye.