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Posted

I choose basic chemistry (confirmed by my materials engineer wife who specializes in thin film engineering) over low res pictures done by some guys as a kitchen table science experiment.

Posted (edited)

Well yesterday was nice and Sunny. I kept checking the jar to see what was happening and from what I could see not much was going on. Mid afternoon I had to go into town to run some errands and when I returned the jar was nice and warm in the sun and the bits were all covered in bubbles. Things alway happen when you are not looking.

This is as per the pictures in the transformers forum listed above. The best bit though was the bits are very much whiter than they were. In fact some I would say are ready to take out. The rest of the bits could do with longer due to being shaded by bigger pieces.

There is no residue or deposit in the solution. etc the parts just look like they have had a very good clean. I'm going to leave them in for today as it's sunnyish again and then take them out and shoot some more photos to use as a comparison. I will then post em here so you can all see.

I figure you'd rather see what it does to something relevant than to some random bit of Transformer or plastic figure. remember guys this is with 6% vol and not the 20-30% that others were using. This stuff is easy and cheap to buy at your local Drug store. I figure the effect it produces is the same but just takes longer, add that to the lack of sunshine and it being all winter like. I reckon Summer will produce some more speedy results.

I'm quite happy to do this to a bunch of 1/55's as I have plenty of them and more than enough spares to replace bits if they suddenly turn to toy dust next week.

I'm actually thinking of leaving a few bits in long term to see what long term exposure does.

Chemistry was one of my strongest subjects at school but I have forgotten so much. It's kinda nice to be doing something vaguely experimental. I feel a bit like the mad Proffessor !!

Edited by big F
Posted

so the sunlight helps the H202 break apart to H20 and 0, the bubbles you're seeing are the newly freed oxygen molecules.

leaving bits in a weak solution longer is not the same thing as using a stronger solution. The weaker solution will be broken down into water + oxygen faster (since you have less H202 to begin with and in the presence of a catalyst and with light breaking the bonds). So, the richer the concentration, the more bleaching effect you'll get.

Posted

Why do I keep getting this feeling if you place your jar on a lab stirrer / shaker under a UV light, you'll hasten the whitening? Maybe I don't need a 30% solution after all... it too damn hassle to get it. :lol:

Posted (edited)

It sounds worthwhile for items that have turned a horrible shade of discoloration. But I'd really have to think about bothering with it for pieces that aren't so degraded, or which would require extensive dis-assembly or decal removal & replacement.

My giant Takatoku Macross has some minor annoying yellowing on some of the white areas. I'd have to decide if it would be worthwhile to bother with this if it would only gain back a year or two of pristine white, or simply leave it alone for a while longer and eventually paint the white areas.

Humn....

Edited by AcroRay
Posted
Why do I keep getting this feeling if you place your jar on a lab stirrer / shaker under a UV light, you'll hasten the whitening? Maybe I don't need a 30% solution after all... it too damn hassle to get it. :lol:

should work, the sunlight isn't anything magical it has a known effect on hydrogen peroxide... which is why h2o2 is sold in dark brown plastic bottles and not clear glass bottles like other acids.

Posted
so the sunlight helps the H202 break apart to H20 and 0, the bubbles you're seeing are the newly freed oxygen molecules.

leaving bits in a weak solution longer is not the same thing as using a stronger solution. The weaker solution will be broken down into water + oxygen faster (since you have less H202 to begin with and in the presence of a catalyst and with light breaking the bonds). So, the richer the concentration, the more bleaching effect you'll get.

This is exactly what I was thinking but for the sake of experimentation one must follow all lines of investigation, regardless weather you know the out come. But im sure that the use of U.V would speed up the reaction, that is after all why the stuff is always sold in brown glass.

Just to throw fuel on the fire I have some plastic similar to the 1/55 stuff that has gone yellow despite being in a sealed container in the loft out of sunlight for years.

So maybe the plastic will go yellow over time anyhow U.V just helps it along some what.

Posted
This is exactly what I was thinking but for the sake of experimentation one must follow all lines of investigation, regardless weather you know the out come. But im sure that the use of U.V would speed up the reaction, that is after all why the stuff is always sold in brown glass.

Just to throw fuel on the fire I have some plastic similar to the 1/55 stuff that has gone yellow despite being in a sealed container in the loft out of sunlight for years.

So maybe the plastic will go yellow over time anyhow U.V just helps it along some what.

yeah, I bet most plastic dyes are organic to begin with in some part. Organic dyes will react with oxygen as well as energy (like heat or light). So depending on how it's formulated plastic sitting in a nice cool closet can still yellow. Most modern plastics have anti UV chemicals mixed in but after awhile they too will fail.

Here's the thing, if the dye used in those plastics ARE organic based, the free oxygen will actually destroy the pigmentation in the same why it destroys organic pigments in hair and whatever else H2O2 is used for. So it's very may well be that the ABS *plastic* is resistant to the acidic effects of H202 but the *dye* is not and that's why you're seeing a bleaching effect but not necessarily the sort of damage to the plastic itself that you would expect from dumping plastic in acid.,

But again, H202 in these concentrations is a mild mild acid.

  • 3 weeks later...
Posted (edited)

Well as promised I am reporting on my findings.

I decided to just go and leave the bits in long term. Everyday I looked and everyday bubbles formed on the plastic. Each day I also gave them a shake to let the bubbles off and to re orientate the parts. not sure that this made any difference but I made me feel like I was actually doing something other than watching a jar full of mild acid and some 20+ year old toy parts.

After about 10 days I was noticing that all the parts were turning into dust................................................................

Only kidding after that 10th day I noticed no actual difference, the parts were minty white already. So as eugimon said I suspected the major part of the H2O2 had broken down after a few days. I must add at this point that they were in a sealed jar. I did open the jar once or twice to let out any trapped gases as the tamper button in the middle did get a bit harder as gas built up.

jar1uv0.jpg

Good old fashioned Jam jar available in most grocery stores comes with free food inside. This one had Tomato and herb stock base mmmmm!!

old1es3.jpg

The test Pilot. He's old , He's bold , and his head fallen off

The test pilot complete with previous owners detritus and my addition of Boot leg arm and back pack after I robbed them for another Valk. You can really see the difference between the minty white Bootlegs plastic and the yellowed out Bandai equivalent.

legpreiy0.jpgwingspresr6.jpg

You can really see the difference in colour on the leg parts between the painted and plastic sections. Next step was to dissasemble and clean in warm water with a nail brush all previous owners gunk off which mostly consisted of food and several bath times as far as I could tell, I didn't want this reacting with the H2O2 in any way.

jar12il9.jpg

Just add to the jar and cover with H2O2, you can already see the bubbles forming only after the few minutes it took to get my camera and take the picture.

Leave in sunny window and wait...

Fast forward 24 days and you get

jar30daysup1.jpg

Not so many bubbles forming now as The reactive ability has almost gone. When I opened the bottle I noticed the Bleachy smell had almost gone suggesting the H2O2 was nearly all converted to plain ole H2O. A good rince under the Tap/Faucet, some drying and assembly later and you get.

legafterot0.jpg

The only casualty here was the paper based decals which had all lifted when they dried they just fell off leaving the backing and the glue behind. This cleaned off easily and left no tide mark of colour showing the plastic was back to factory white again. The decals were shot any how so no real loss, a quick trip to reprolables for me :)

wingsafteryw6.jpg

The wings aside from the obvious red paint scuffing, an easy fix were as Bandai intended.

legcomparisonnt5.jpg

A comparison shot showing the non treated leg next to the Treated one.

jar2su2.jpg

A trip to the local hardware store and I go myself some of those old fashioned preserves jars with the snap fast lid these are big enough to fit the whole torso in in one go. This will do for the rest of the old timer.

One thing to note the previous owner did leave some plasticine inside the legs to keep the landing gear inside I don't know why as it worked just finemaybe it was to stop little fingers getting hurt. I removed this from all the parts except one where by mistake some got stuck on a sticker, the area covered was undamaged by the H2O2, although as mentioned above it fell off due to it being paper. This merits some experimentation with the likes of Rubsigns and paper decals etc.

Next stage after this will be to treat my Brothers original Bandai Jetfire as it is so yellow that its almost the right colour for a VF1 D.

Hope this helps some of you out there.

Edited by big F
  • 1 month later...
Posted
Looks like another way to return yellowed plastic to its youthful white appearance:

http://retr0bright.wikispaces.com/

I have an old Matchbox SDF-1 that I might try this on.

Dah - never mind, it looks like it is just the same trick posted in this thread. I thought it was something new, but they are just using Hydrogen Peroxide mixed with Oxy.

Oh well...late to the party as usual...

Posted

I know about the peroxide, but is the oxy something that can be bought at any supermarket ? I would like to try this, but rather than taking the Valk apart, I will simply emmerse the whole valk. don't worry, it is an old 1/60 ver. 1 that i bought for spare parts anyway. my goal is to have the same effect without the pain in the ass of having to take it apart and put it back together.

Posted
Hydrogen Peroxide. In this case, they aren't using normal grocery store stuff, either, but 30-35% solution, which you can only get from specialty stores in most cases, or online in large quantities, and will melt your lungs if you breathe its fumes. Do not try this without adequate ventilation and preferably a breathing aparatus of some kind.

I was lost at "melt your lungs". I keep my stuff out of direct sunlight, but from what I have heard, these toys turn yellow regardless. I love to look across my desk at my collection, but other than keeping these beauts boxed up, what would you guys suggest for keeping them looking minty fresh? As of right now they get a compressed air blasting once a week. Dusting from the cleaning service resulted in a busted up Hikaru VF-1J in GBP armor. :blink:

Posted

The whole proccess is sped up the stronger the solution. I think the strongest you can get over the counter in the U.K is 10%

At that strenght it will lightly bleach your hair and take the dye out of your clothes, but wont melt your lungs unless you decided to try and drown yourself in it. You do really need a nice and sunny place for it to work well though.

Just for intrest the bits I bleached are still minty white. They have been stored in a Hasegawa kit box and left on the top of the cupboard in th esame room they were bleached. direct sunlight only helps the yellowing process along. I have stuff that has spent 20+ years in a sealed box in a dark dry cupboard and it has still yellowed out.

  • 1 month later...
Posted

I have some yellowing Yamato toys that i am thinking of bleaching.... but the thing is, I can't find hydrogen peroxide off the shelf... besides hair bleaches, which i don't think is suitable with this purpose.

Most household bleaches won't list their ingredients and for those who do, only contain sodium hypochlorite as an active ingredient and in very low concentrations.... like less than 3% . Would any of you guys have tried that as an substitute?

Nope...Oxiclean(which contains sodium peroxide) isn't available in the places that i have visited....

Posted
I have some yellowing Yamato toys that i am thinking of bleaching.... but the thing is, I can't find hydrogen peroxide off the shelf... besides hair bleaches, which i don't think is suitable with this purpose.

Most household bleaches won't list their ingredients and for those who do, only contain sodium hypochlorite as an active ingredient and in very low concentrations.... like less than 3% . Would any of you guys have tried that as an substitute?

Nope...Oxiclean(which contains sodium peroxide) isn't available in the places that i have visited....

No household bleach the type that you put in the Toilet bowl or use to clean the kitchen wont work. it will only clean up the dirt.

Try a chemists as its the sort of thing they sell it in the U.K so I'd assume unless its restricted in your country, thats the best place to try. Its usually under the counter though.

Posted

Is hydrogen peroxide 6% even available in our U.S. pharmacy? I've checked sites and it seems that they are only available in 3%. Any suggestions or directions on where to go?

Posted
Is hydrogen peroxide 6% even available in our U.S. pharmacy? I've checked sites and it seems that they are only available in 3%. Any suggestions or directions on where to go?

3% will work on a really sunny window ledge but will just take longer, maybe a month or so depending on how much sun you have in your part of the world.

Posted

I just saw this today! I need to get out into the tiy section more ^_^ One thing I do know, the second oxygen atom in Hydrogen peroxide has a loose bond. That's what makes it work so well. The down side - DON'T SHAKE THE CONTAINER! Even that will dilute the diluted solution you already have!

Like was said earlier, tooth bleaching compounds spread on the surface might work. As always, test something first!

If possible, you may be able to coat your cleaned parts with a UV resistant clear coat spary. That should add some stabilization to the plastic after cleaning it. I have a yellowed 1/55 E-1 that looks almost tan! It's been wrapped up and in a box for years (kept cool too)! It seems age catches up with plastic too. Plastic breaks down easier than what a lot of scare mongers say-personal experience! Like people, the skin is always the first to show the signs! :lol: - MT

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