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Removing Yellowing from Plastics - Part 3
- Thread starter Merlin
- Start date
tezza
Veteran Member
Well in my experience real UV lamps are a flourescent tube or a "coil". The latter plugs into a standard light fitting and is essentialy a small tube coiled around and around to give it a smaller physical dimension.
The low-output (fake) ones look just like your normal roundish incandecent lightbulb (which they are) simply painted on the inside with a purple dye. This stops all other wavelengths produced by the filament from passing through except the UV. The UV output of these bulbs are very low and I would not expect them to work for deyellowing.
Tez
tezza
Veteran Member
Yes, that is surprising, particulary considering the concentration of peroxide!
Arrowroot does require the mixture to be heated for use. If overheating does indeed affect the peroxide, it will be good to be aware of it and let others know.
My initial thoughts are;
Anyone else got any thoughts?
Tez
Arrowroot does require the mixture to be heated for use. If overheating does indeed affect the peroxide, it will be good to be aware of it and let others know.
My initial thoughts are;
- The heating did affect the peroxide (in which case Xantan gum, which doesn't require heating, may be the way to go). A chemist (Merlin?) should be able to give an answer on this.
- The lamp was too far away from the case to provide the necessary UV. How close was it to the case? I have read that UV lamps provide far less UV than sunlight. Maybe a single "coil" bulb just doesn't radiate enough UV?
Anyone else got any thoughts?
Tez
The light was mabye 30 to 40 cm from the case, just like in some of the pictures in the wiki-gallery. The thing that bothered me was that i could'nd get the gel thick enough so i heated it some more, and some more, and some more.. I also added more arrowroot and finally got it thick enough but by then i may have overheated the mixture..
/P
/P
tezza
Veteran Member
Yes, material I've now read on the web does say heat accelerates decomposition.
Arrowroot does need some heating to make it "set" into a thick paste. However, if you don't use enough of it, it doesn't set, as you discovered. It can be a tricky balancing act and you probably did overheat it.
I first used Arrowroot, to try out a cheap and readily available substitute to Xanthan gum. It worked for me, but if you can locate a source of the gum it is a better option. It's a little more expensive but it does form a clearer gel and you don't need to heat it (you do need a mixer though). I've found a local source of Xantan gum and I'll now be using that myself.
I'd be loath to heat any concentrated mixture of peroxide. Mine was only 6% and I got a bit of foaming when I added the Oxy after the peroxide/arrowroot mixture formed a gel after heating. However, if it's a high concentration, the foaming after adding oxy to a hot arrowroot/peroxide mix can be quite spectacular (as others have found). It could be even *dangerous* if it was hot enough. Did you get a lot of foaming after you added the Oxy? Given that the mixture would have been hot and you were using quite a high concentration of peroxide (20%) you should have got A LOT of foaming. If you didn't, that in itself would indicate something was amiss.
Tez
Lorne
Veteran Member
This all sounds weird.
Is Pavel storing his H2O2 in a clear container, or a light proof container?
How old is the H2O2?
It almost makes me think bad (ie: spent) H2O2.
Is Pavel storing his H2O2 in a clear container, or a light proof container?
How old is the H2O2?
It almost makes me think bad (ie: spent) H2O2.
tezza
Veteran Member
Yes. Even if (over-)heating does degrade some of the H2O2 I would have expected there to be more than enough left if 20% conc was used. I got good results with 6% and heating the H2O2 before use.
That's why I asked about the foaming. Arrowroot aside, very hot H2O2 at 20% plus the addition of Oxy should have caused a fairly vigourous reaction (foaming). If not, then there was some problem with the raw ingredients.
Tez
The peroxide was used, i opened the bottle 12 hours before i made the gel and used it on some keys but i figured that 12 hours is'nt that much and i could most likely re-use it.
when adding the Oxy it foamed like crazy! i had to remove the foam from the container (i still had some gel left after applying to the case) every 15 mins. Finally it stoped foaming.
I noticed that the only place the gel did'nt foam was on the case. There just was'nt any reaction whatsoever. The gel just sat on the case without drying, foaming or anything else for that matter.
I'm going to do the liquid version of Retr0Bright this weekend. My only worry is if the hydro-peroxide will be to weak concidering i'm going to use a lot of water to fill up a container big enough for a A500 case..
I have 5 x 1 litre bottle of 35,5% peroxide and need probably another 20 litres of water..... will it be to weak??
when adding the Oxy it foamed like crazy! i had to remove the foam from the container (i still had some gel left after applying to the case) every 15 mins. Finally it stoped foaming.
I noticed that the only place the gel did'nt foam was on the case. There just was'nt any reaction whatsoever. The gel just sat on the case without drying, foaming or anything else for that matter.
I'm going to do the liquid version of Retr0Bright this weekend. My only worry is if the hydro-peroxide will be to weak concidering i'm going to use a lot of water to fill up a container big enough for a A500 case..
I have 5 x 1 litre bottle of 35,5% peroxide and need probably another 20 litres of water..... will it be to weak??
tezza
Veteran Member
Ok, well if you got lots of foam it sounds like there was plenty of peroxide there. None of my treatments with 6% H2O2 foamed "on the case", but they still worked.
I haven't tried the immersive technique myself, so I'll let others comment on that. That's a 1 in 20 dilution though which by my calculations will give you only a 1.75% concentration. That's very weak.
Tez
I haven't tried the immersive technique myself, so I'll let others comment on that. That's a 1 in 20 dilution though which by my calculations will give you only a 1.75% concentration. That's very weak.
Tez
I've just done a few plastics that I had sitting around, and it seemed to work okay without any blooming or splotchiness, even if I had a misadventure caused by not realizing exactly how quick xantham gum would bond together. I put xantham gum in the container, poured in my h2o2. Then I realized I forgot something and went to get it. I came back and had a nice mass of xantham gum sitting at the bottom.
I saw that earlier in the thread someone had picked up the 40 vol (12%) Sally h2o2 cream, I had considered using that but decided to go with the XG+Glycerin+h2o2 mixture instead. It would be certainly more convenient but I don't know if what they are using to stabilize it would have any sort of detrimental effects on the process. I also wondered if it was clear or white, because 'cream' products always make me think that they'll be white, if so, I suspect that I'd have to rely more on Oxy catalyzing and less on the UV from the light source if it had things in it that were busy reflecting all the light.
The ingredients in the creme developer (h2o2 cream) are Water (aqua) Hydrogen Peroxide, Cetyl Alcohol, Stearyl Alcohol, Isopropyl Palmitate, Lauramide DEA, Laureth-23, Laureth-4, Nonoxymol-4, Phosphoric Acid, and Trisodium Phospahte. They all seem to be surfactants or emulsifiers except for Phosphoric acid and trisodium phosphate, and neither of those look like they'd cause many problems.
I might go pick up a bottle today and see what happens unless someone notices something in the ingredients that is a big red flag.
(I finally made it through all 3 threads about this)
I saw that earlier in the thread someone had picked up the 40 vol (12%) Sally h2o2 cream, I had considered using that but decided to go with the XG+Glycerin+h2o2 mixture instead. It would be certainly more convenient but I don't know if what they are using to stabilize it would have any sort of detrimental effects on the process. I also wondered if it was clear or white, because 'cream' products always make me think that they'll be white, if so, I suspect that I'd have to rely more on Oxy catalyzing and less on the UV from the light source if it had things in it that were busy reflecting all the light.
The ingredients in the creme developer (h2o2 cream) are Water (aqua) Hydrogen Peroxide, Cetyl Alcohol, Stearyl Alcohol, Isopropyl Palmitate, Lauramide DEA, Laureth-23, Laureth-4, Nonoxymol-4, Phosphoric Acid, and Trisodium Phospahte. They all seem to be surfactants or emulsifiers except for Phosphoric acid and trisodium phosphate, and neither of those look like they'd cause many problems.
I might go pick up a bottle today and see what happens unless someone notices something in the ingredients that is a big red flag.
(I finally made it through all 3 threads about this)
Lorne
Veteran Member
Congratulations, that's quite a feat!
Good thing too, because I have to delete some of the photos I attached previously before I can post any more. Seems I've reached my maximum on the attachment limits. I'll probably start the deletions in part one, but I haven't decided which ones to delete yet - eenie, meenie, miney, moe?
If your reference to Sally H2O2 cream was the stuff I used (ie: hair bleaching/coloring products), don't do it ! It messes with blue and black plastic, to the point of it not being blue or black anymore. Its use was an experiment gone wrong. We now know better because of it, and the Xanthan gum mixture is the preferred route.
Merlin
Experienced Member
@ midway
If you check the Retr0bright Wiki, you can see pictures of Lorne's experience of the plastic and the Sally H2O2 cream version in the Problems and Pitfalls section.
There's something in it that denatures and affects the plastic surface and my best guess is a type of solvent that they added to it. You will have read about it in one of the epic threads.
Blimey! I just realised that this thread is long enough as it is; is it time for Part 4...???
If you check the Retr0bright Wiki, you can see pictures of Lorne's experience of the plastic and the Sally H2O2 cream version in the Problems and Pitfalls section.
There's something in it that denatures and affects the plastic surface and my best guess is a type of solvent that they added to it. You will have read about it in one of the epic threads.
Blimey! I just realised that this thread is long enough as it is; is it time for Part 4...???
Yeah that's the stuff I was referring to. Somehow I didn't catch that that was the product which caused the blue/black problems Lorne was having.
Today I encountered a different issue though, I was trying it on a piece of equipment which apparently has two different types of plastic, as most of it came out perfect, exactly the color I wanted, but one section came out almost completely bleached WHITE, but splotchy and streaky. I can't tell if either it was mixed poorly and there was an overadundance of TEAD(sp?) in the mixture that I put on that part of the machine or if it is different plastic reacting differently.
Today I encountered a different issue though, I was trying it on a piece of equipment which apparently has two different types of plastic, as most of it came out perfect, exactly the color I wanted, but one section came out almost completely bleached WHITE, but splotchy and streaky. I can't tell if either it was mixed poorly and there was an overadundance of TEAD(sp?) in the mixture that I put on that part of the machine or if it is different plastic reacting differently.
Lorne
Veteran Member
If it's the hair bleach product you used, I can tell you that is one of the pitfalls. It works fast, but too fast. I had some light grey parts come out almost white. If I were you, I'd stop using it (and like right now).
I did.
The A500 project
The A500 project
So i went out and bought another 5 litres of peroxide with 35% (totally 10 litres) strenght. I added that together with 5 litres of watet in a container and placed the top casing of my A500 in the liquid.
After 18hours the result was amazing!:D However, i do feel that the case has become brighter then original(?). I'm currently treating the lower part of the case. as soon as all parts have been treated i will post pics.
The only trouble i had was getting the parts to not float to the surface. I had to use some random weights i found in my toolbox.
I have only the keys left to be treated. these keep floating up to the surface and i have no idea on how to get them to stay at the bottom... please let me know if you have any suggestions... Thank's!
Cheers,
Pavel
The A500 project
So i went out and bought another 5 litres of peroxide with 35% (totally 10 litres) strenght. I added that together with 5 litres of watet in a container and placed the top casing of my A500 in the liquid.
After 18hours the result was amazing!:D However, i do feel that the case has become brighter then original(?). I'm currently treating the lower part of the case. as soon as all parts have been treated i will post pics.
The only trouble i had was getting the parts to not float to the surface. I had to use some random weights i found in my toolbox.
I have only the keys left to be treated. these keep floating up to the surface and i have no idea on how to get them to stay at the bottom... please let me know if you have any suggestions... Thank's!
Cheers,
Pavel
Merlin
Experienced Member
Yup; Blu-Tak or Plastercine works for weighting the keys down.
Merlin
Experienced Member
Time for Part 4 I reckon; could a Moderator please close this thread and I'll open a new one for continuing discussions?
Thanks.
Thanks.
Last edited:
Remove magic marker from computer surfaces
Remove magic marker from computer surfaces
Hi. Brand new here, just signed up, looking for something to clean up a yellowed bezel. Found some good info, will give it a try.
Also saw some of you are trying to remove magic marker. I work for an electronics remarketer and we get a ton of equipment with magic marker on it. Good ol' car brake fluid works wonders!
Be careful on some surfaces though. Depending on what you're taking the marker off of, you might leave a discoloration, especially on a dark surface. Works really well on beige bezels... simply put a couple drops onto a paper towel, dab onto the affected area. Wait about 30 seconds and start to lightly rub. Apply a little more, rub a little more. Keep doing light circles until all gone. Clean off with a little 409. Doesn't take any real effort and comes off in minutes. OH, and some plastic hard drive labels may be affected, lettering could come off.... rub LIGHTLY!!! You don't even have to put any pressure on it, just roll up a paper towel to a point, put a couple drops on the tip and "brush" the affected area until marker is removed. Again, clean up after with 409 or even glass cleaner.
Good idea to do some "test" surfaces first. And of course, use goggles and rubber gloves for safety. Brake fluid isn't caustic or noxious, but it can't be good long term.
Remove magic marker from computer surfaces
Hi. Brand new here, just signed up, looking for something to clean up a yellowed bezel. Found some good info, will give it a try.
Also saw some of you are trying to remove magic marker. I work for an electronics remarketer and we get a ton of equipment with magic marker on it. Good ol' car brake fluid works wonders!
Be careful on some surfaces though. Depending on what you're taking the marker off of, you might leave a discoloration, especially on a dark surface. Works really well on beige bezels... simply put a couple drops onto a paper towel, dab onto the affected area. Wait about 30 seconds and start to lightly rub. Apply a little more, rub a little more. Keep doing light circles until all gone. Clean off with a little 409. Doesn't take any real effort and comes off in minutes. OH, and some plastic hard drive labels may be affected, lettering could come off.... rub LIGHTLY!!! You don't even have to put any pressure on it, just roll up a paper towel to a point, put a couple drops on the tip and "brush" the affected area until marker is removed. Again, clean up after with 409 or even glass cleaner.
Good idea to do some "test" surfaces first. And of course, use goggles and rubber gloves for safety. Brake fluid isn't caustic or noxious, but it can't be good long term.