Sounds like a good set up - next time you come across an a2k faceplate let me know - I will be happy to pay for it and your time to retrobright it the next time you do a batch. 
Retr0bright warning!!!
- Thread starter abraXXious
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@ Abbraxious
It appears that you have had the same 'blooming' effect that Lorne over at Vintage Computer Forums experienced with some of his parts when he was doing tests out in Arizona.
ABS is a bit like human DNA in that no two batches are ever the same; the sequence of acrylonitrile, butadiene and styrene can be in any order over 1000's of molecules. You also can get some butadiene at the end of the polymer chain and this can be attacked and converted to the peroxide by Retr0bright under some conditions.
Drying out is a major hazard with Retr0bright, as this can send the peroxide concentration through the roof. Until now, I was under the impression that covering the parts with cling film reduced or eliminated the drying out as the water can't evaporate as quickly. I suspect that the drying out was maybe the start of the problems.
I look forward to seeing the pictures and seeing if we can maybe salvage the parts to an acceptable cosmetic standard, along with investigating why your treatment failed.
It appears that you have had the same 'blooming' effect that Lorne over at Vintage Computer Forums experienced with some of his parts when he was doing tests out in Arizona.
ABS is a bit like human DNA in that no two batches are ever the same; the sequence of acrylonitrile, butadiene and styrene can be in any order over 1000's of molecules. You also can get some butadiene at the end of the polymer chain and this can be attacked and converted to the peroxide by Retr0bright under some conditions.
Drying out is a major hazard with Retr0bright, as this can send the peroxide concentration through the roof. Until now, I was under the impression that covering the parts with cling film reduced or eliminated the drying out as the water can't evaporate as quickly. I suspect that the drying out was maybe the start of the problems.
I look forward to seeing the pictures and seeing if we can maybe salvage the parts to an acceptable cosmetic standard, along with investigating why your treatment failed.
Hi Merlin,
well, I had to re-apply a couple of times as it appeared to be drying out in certain areas. Also, it should be noted that a typical summer day in Australia is in the late 30s (38 C etc) and uv index 13 and above.
well, I had to re-apply a couple of times as it appeared to be drying out in certain areas. Also, it should be noted that a typical summer day in Australia is in the late 30s (38 C etc) and uv index 13 and above.
And I have been looking to do this myself to some cases... Good luck with sourcing replacement parts, but glad you managed to recover some of it.
Slayer
New member
This sounds the way to go, can you elaborate and is there any way the liquid could be poured out and kept to be reused? could freezing it be an option perhaps? I guess extreme cold and or heating could have dire consequences, I do not know...
But I like this approach... sometimes more IS better
Once the Vanish is added to the peroxide the solution will totally spent in a couple of days, no possible reuse.
Pure peroxide can be stored on a half-closed bottle (don't squeeze the cap! Peroxide must be allowed to "breath" or the bottle will explode due the outgoing oxygen gas!).
Pure peroxide can be stored on a half-closed bottle (don't squeeze the cap! Peroxide must be allowed to "breath" or the bottle will explode due the outgoing oxygen gas!).
Strange. I've done a lot and almost all of the results have been great. I did have some blooming but mostly on Atari ST/XE gray cases. I used cream developer and nothing else and it worked great. Used it outside and reapplied it every 30 min or so, so it wouldn't dry out.
Hey guys I just gotta ask, what accellerates the 'yellowing' effect so much. I see a lot of dreamcasts which arent as old as miggies getting really dull, some even look like theyre from the A600 / A1200 era theyre so yellow, yet my year older than most '98 jap Dreamcast is white as a sheet with a halogen bulb shining on it. What am I doing right? 
@AmiSonicNeo
the yellowing effect is protination of the bromine in the ABS. This protination can come from a combination of factors but the real culprit is the mix of the plastic (ABS) - this determins the how - likely and fast the plastic will protinate ( yellow out)
Another key factor is UV energy, this resonates at just the right frequency for the bromine atom, with the bromine on loose ends of the chain, it will vibrate its hydrogen off and it will be surplanted with an oxygen atom (hence protination)
Retr0Bright creates an environement that is Oxigen Hungry and Hydrogen Rich, by placing the item in said solution, using both TAED and UV energy as accelerants, the solution syphons off the Oxygen atom at the end of the ABS chain and replaces it with a Hydrogen atom
the yellowing effect is protination of the bromine in the ABS. This protination can come from a combination of factors but the real culprit is the mix of the plastic (ABS) - this determins the how - likely and fast the plastic will protinate ( yellow out)
Another key factor is UV energy, this resonates at just the right frequency for the bromine atom, with the bromine on loose ends of the chain, it will vibrate its hydrogen off and it will be surplanted with an oxygen atom (hence protination)
Retr0Bright creates an environement that is Oxigen Hungry and Hydrogen Rich, by placing the item in said solution, using both TAED and UV energy as accelerants, the solution syphons off the Oxygen atom at the end of the ABS chain and replaces it with a Hydrogen atom
Rofl at 'AmiSonicNeo', lol.
...So pretty much the fact that I havent left it in direct sunlight and likely have a good mix of chems in the plastics...
I wonder if the jap models had superior plastics in this respect...
Heres a couple of pics of her from my mod thread. Bare in mind shes 13 years old!...
...So pretty much the fact that I havent left it in direct sunlight and likely have a good mix of chems in the plastics...
I wonder if the jap models had superior plastics in this respect...
Heres a couple of pics of her from my mod thread. Bare in mind shes 13 years old!...
Now a bit of injection process: the injector machine is made by two molds that close one to the other and have one or more holes where the molten plastic is injected by a reciprocating screw (also known as "spindle"), which turns when filling the pre-injection chamber or directly the tip of the screw at the same time the screw goes back. When the tip of the chamber is filled with the exact amount of molten plastic, then the spindle stop turning and an hydraulic motor pushes the spindle to front at full strength.
For a piece like an Amiga A500/1200 case you need an injector with at least 150 TON of closing force, or more.
The plastic and additives (the anti-flame included, as long as pigments) is fed to the screw by gravity from a funnel over the back of it.
It's easy to know that process is not perfect: plastics and additives have different weights, so as the machine shakes (because the multiple motors and pumps it have), the weightier pellets will go to the bottom of the funnel, leaving the lighter ones at the top.
So, some final parts have more pigments, other more anti-flame, other even no anti-flame at all. Modern-day injectors have multiple auto-feeders so this problem is minimized, but not in 80s an early 90s plastic plants.
That will explain why some cases have more tendency to get yellow while others are still in mint out-of-box condition.
For a piece like an Amiga A500/1200 case you need an injector with at least 150 TON of closing force, or more.
The plastic and additives (the anti-flame included, as long as pigments) is fed to the screw by gravity from a funnel over the back of it.
It's easy to know that process is not perfect: plastics and additives have different weights, so as the machine shakes (because the multiple motors and pumps it have), the weightier pellets will go to the bottom of the funnel, leaving the lighter ones at the top.
So, some final parts have more pigments, other more anti-flame, other even no anti-flame at all. Modern-day injectors have multiple auto-feeders so this problem is minimized, but not in 80s an early 90s plastic plants.
That will explain why some cases have more tendency to get yellow while others are still in mint out-of-box condition.
Wow so basically its pot luck if you get one that will stay white seemingly forever or look like its been on holiday in the south of spain for a month after a couple of years...
I suppose the best workaround as a manufacturer is to not make white plastics
But then again even some SNES and NES which are grey have a nasty colour changing effect. The only way to stop them fading is likely to coat them in paint then...
---------- Post added at 03:24 ---------- Previous post was at 03:22 ----------
OMFG! I just realised, that Dreamcast will have been with me for exactly HALF of my life as of November...
---------- Post added at 03:53 ---------- Previous post was at 03:24 ----------
Just to add, it also appears that dusty / unclean conditions lead to accelerated yellowing. Such as when people leave things in storage in dusty attics for lengthy periods. I've seen dreamcasts and older consoles come down from attics looking like they've been rolling in orange juice for a few months
I suppose the best workaround as a manufacturer is to not make white plastics
But then again even some SNES and NES which are grey have a nasty colour changing effect. The only way to stop them fading is likely to coat them in paint then...
---------- Post added at 03:24 ---------- Previous post was at 03:22 ----------
OMFG! I just realised, that Dreamcast will have been with me for exactly HALF of my life as of November...
---------- Post added at 03:53 ---------- Previous post was at 03:24 ----------
Just to add, it also appears that dusty / unclean conditions lead to accelerated yellowing. Such as when people leave things in storage in dusty attics for lengthy periods. I've seen dreamcasts and older consoles come down from attics looking like they've been rolling in orange juice for a few months
Weemus
New member
Yikes!
Yikes!
Glad I didn't try to buy the Retr0bright product. I believe a certain amount of patina is good for the soul, anyway.
Yikes!
Glad I didn't try to buy the Retr0bright product. I believe a certain amount of patina is good for the soul, anyway.
Our injection molding machines have mixing screws and nozzles that are also supposed to help with this problem. Depending on the operator, however, we can still end up with color and/or strength issues if they don't carefully monitor for buildup of material in certain areas. Even our newest machines can occasionally cause problems, while our 80's vintage machines are very difficult for new operators to configure.
I recently purchased several TI-99/4A's as a lot; these have the beige ABS bodies. It's amazing that 2 of them with serial numbers less than 100 apart are so different in color. One is nearly dark yellow, while the other is still close to its original factory color with the exception of the keys.
@ All
The Retr0bright process works perfectly well as long as the instructions are followed. The most important ingredient you need is patience.
There have been far more successes than failures from the use of Retr0bright.
The Retr0bright process works perfectly well as long as the instructions are followed. The most important ingredient you need is patience.
There have been far more successes than failures from the use of Retr0bright.
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