Green Anodising Dye

[Engine Doctor ( Phil )Participant @enginedoctorphil]

Getting Dye to take

[Engine Doctor ( Phil )Participant @enginedoctorphil]

hello . I am new to this forum having been a forum member on sister magRCM&E for some years .

I have recently been converting model Aero glow engines from Glow to Diesel by making new cylinder heads . I have anodised the heads in variious colours but Green eludes me ! Im trying to get a bright green . The problem I have is that I can get a good green after the soak in the dye but as soon as I try to seal the anodising in a hot bath the yellow component seems to wash out leaving various shades of blue

I have used various dyes including Rit, Ink jet printer ink and dedicated anodising dye . All of these work fine in any colour apart from green or yellow . All parts are Polished to a chrome like finish prior to cleaning and anodising .

Any suggestions please ?

[SteviegtrParticipant @steviegtr]

I did not have a lot of luck with yellow. But after practice i found that leaving it in the Anodise bath for around 2 hrs at 0.5 amps , i got better results. The small parts i did took on a slightly dull grey look after that time. The yellow took much better then.

Steve.

[pgk pgkParticipant @pgkpgk17461]

Brilliant green? I've not tried anodising but historically it was used as an antiseptic/antibacterial and I’ve seen old farmers dosing pigs with it – certainly very green and as far as I know the green-ness isn't from a mix of blue and yellow.

pgk

[Michael GilliganParticipant @michaelgilligan61133]

Sorry ; I have no idea what dye they use … but Pimoroni can certainly produce beautiful green anodising: **LINK**

https://shop.pimoroni.com/products/aluminium-heatsink-case-for-raspberry-pi-4?variant=31116597690451

… it may be worth asking them

MichaelG.

.

P.S. __ if this page can be taken literally … they manufacture in the U.K.

https://shop.pimoroni.com/pages/about-us

Edited By Michael Gilligan on 08/09/2021 14:45:45

[JasonBModerator @jasonb]

Have a look at Ramon's article in MEW 194, gets a nice shade of green there

[Dave SParticipant @daves59043]

Pretty sure pimoroni only manufacture electronics and laser cut plastic stuff.

There was no machining or anodising line there last time I visited.

Does the anodising dye have recommended current densities and times? Sound like the die is washing out of the anodised pores before they become hydrated.

Edited to add:

Is the dye water based? You could try boiling the part in dye rather than plain water if that’s the case.

Dave

Edited By Dave S on 08/09/2021 16:57:22

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Dave S on 08/09/2021 16:55:55:

Pretty sure pimoroni only manufacture electronics and laser cut plastic stuff.

There was no machining or anodising line there last time I visited.

.

In which case, it seems the statement to which I referred cannot be taken literally.

I’m not entirely surprised.

MichaelG.

[Engine Doctor ( Phil )Participant @enginedoctorphil]

Thanks for the heads up on Ramons anodising. That green he has would be OK. I'll have look through and try contacting him.

Regards

[Engine Doctor ( Phil )Participant @enginedoctorphil]

Hi Thanks for all the suggestions . I finally found a dye that worked for me. Green Ink ! It had to be ordered from China to get at a reasonable price but gives a good effect . The pic below is a crankcase I made for this little Boddo Mills as the original was made of rubbish metal and just plit open while in storage ? The spinner nut is the original and you can probably see the anodising is flaking off ! glad i didnt anodise the cylinder !! 

Id still like to know what Ramonused on his engine ?

Edited By Philip Fearn on 14/02/2022 13:33:01

Edited By Philip Fearn on 14/02/2022 13:35:12

[Pete.Participant @pete-2]

Posted by pgk pgk on 08/09/2021 13:58:38:

Brilliant green? I've not tried anodising but historically it was used as an antiseptic/antibacterial and I’ve seen old farmers dosing pigs with it – certainly very green and as far as I know the green-ness isn't from a mix of blue and yellow.

pgk

I noticed in some supermarket bacon it has a coloured tinge if you hold it up to the daylight, is that what it is?

I buy all my meat from a local butcher now which doesn't have this added extra.

[pgk pgkParticipant @pgkpgk17461]

Posted by Pete. on 15/02/2022 00:43:58:

Posted by pgk pgk on 08/09/2021 13:58:38:

Brilliant green? I've not tried anodising but historically it was used as an antiseptic/antibacterial and I’ve seen old farmers dosing pigs with it – certainly very green and as far as I know the green-ness isn't from a mix of blue and yellow.

pgk

I noticed in some supermarket bacon it has a coloured tinge if you hold it up to the daylight, is that what it is?

I buy all my meat from a local butcher now which doesn't have this added extra.

As far as I’m aware the colour wasn't absorbed from the bowel and I doubt it's used much these days anyway. There are a number of dyes with some antimicrobial activity that had a historic use – brilliant green, methylene blue, carbol-fuchsin – but mostly topical use. Rainbow bacon isn't on the shelves.
A lot of possible additives and cure types in bacon – Nitrates can be high as well as salt. One of the simplest bacon cures I've seen was in beer. You've also probably seen the amount of water that comes out of some frying bacon as cure additives that hold water add weight. I'd be surprised if your local butcher is curing his own bacon – may just be more selective in the source.
The most likely source of green is from sulphur interacting with haemoglobin? Sulphur dioxide is often used as a preservative in packaging.

pgk

[nigel jones 5Participant @nigeljones5]

The green seen on bacon is a result of added Nytrogen (injecyed when it is packed to preserve the meat) forming nitrate (Nitrogen and oxygen) and then reacting with the myoglobin on the surfave of the meat. Not all profesional boiler makers know that!.

[pgk pgkParticipant @pgkpgk17461]

Mechanism Underlying Green Discolouration of Myoglobin Induced by Atmospheric Pressure Plasma

Link
https://www.nature.com/articles/s41598-018-28096-4

pgk

[Engine Doctor ( Phil )Participant @enginedoctorphil]

Thanks guys , so are you suggesting my anodised crankcase is cured bacon green or just a pig? it's was a pig when it was made but it's IMO much better now . Who know how the Chinese make their green ink ? Possibly from left over bacon curing chemicals ? Themselves thing is it worked. Do t know if it will withstand heat and sunlight , time will time.

Time we moved back to topic , like anodising ?

[Nick Clarke 3Participant @nickclarke3]

Posted by Philip Fearn on 15/02/2022 11:06:34:

Time we moved back to topic , like anodising ?

While I agree in the long term, I am moving on first to a bacon sandwich for lunch!

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