Cleaned PW hands with lemon juice and blue disappeared

[penjunky]

These ''used to be'' fairly descent looking blue hands but a lot of rust so figured I'd clean the rust off with lemon juice. Well, the lemon juice took off the rust but also took off the blue, completely gone.

I wouldn't think the lemon would remove the blue heat method so figure might be dye or something. Anyway going to have to get the blue back. Plan to soak them in baking soda for a long while then going to try a little heat trick see what happens will post pics when I get finished.

Couldn't get a good clear picture try better next time, but I think you can see them enough to see they are bare.

 

[Skutt50]

Just make sure they are polished before you blue them. They need to be realy shiny to look great after heat treatment....

 

[gmorse]

Hi penjunky,

I wouldn't think the lemon would remove the blue heat method so figure might be dye or something.

Yes, any acid will remove the oxide film that causes the blue colour, as I'm afraid you've discovered the hard way! It's extremely thin and very fragile, and wasn't created by any dye.

If you're going to try and recreate the colour by heating, there are several methods, but they nearly all involve heating a larger mass, of brass, brass filings, fine dry sand, etc, which allows you to control the process and take it slowly, because the colours will change too quickly to catch just the right blue if you apply heat from a direct flame.

Regards,

Graham

 

[penjunky]

Hey Skutt

I'm trying to get the hands clean as I can for now. Just picked one up, got a muscle twitch in my thumb and threw the hand in the floor, luckily I had a backup, my 4 yr old granddaughter found it.

Going to try brasso and flat-tipped toothpick if that don't do I'll try the 1200 grit wet sanding.

Thanks and good to see you again

Roger

 

[penjunky]

Hey Graham

Seems almost every project I'm always learning what not to do but after I do it, as I did this one. But, maybe this might turn out to be a happy accident in the end because even though the hands looked descent as blue as they were they were still pretty rough to look at, light, dark, faded, scratched and so forth, so they needed attention, and I really didn't know the lemon would take all the blue off. But, now I know how to remove the blue fairly easy.

I don't have anything like the brass shavings, maybe some day if my health holds out I'll get what I need. I was first going to try a little trick but with another hand I have just to see what happens and it will be a slow heating process. If it works out I'll tell how I did it, if it don't I won't.

To me the hands are the showcase of a watch so this will be good practice for me.

Thanks and good to see you again

Roger

 

[Bernhard J.]

What is seen as blue surface is nothing else than rust, i.e. iron oxide. Thus, it shows the same behaviour against chemical agents.

The blue appearance (instead of rusty brown) is due to the oxide layer being very uniform and thin (sub-µm). The color of such an oxide film depends on its thickness, which in turn is a function of the temperature used for treating and the duration (diffusion of oxygen from the surface into the iron matrix).

 

[gmorse]

Hi Roger,

As Bernhard has said, the oxide film is very thin, so thin that it produces colours by an interference effect, like a soap bubble, a butterfly's wing or some beetles' carapaces.

Regards,

Graham

 

[penjunky]

What is seen as blue surface is nothing else than rust, i.e. iron oxide. Thus, it shows the same behaviour against chemical agents.

The blue appearance (instead of rusty brown) is due to the oxide layer being very uniform and thin (sub-µm). The color of such an oxide film depends on its thickness, which in turn is a function of the temperature used for treating and the duration (diffusion of oxygen from the surface into the iron matrix).

Hi Roger,

As Bernhard has said, the oxide film is very thin, so thin that it produces colours by an interference effect, like a soap bubble, a butterfly's wing or some beetles' carapaces.

Regards,

Graham

Hi Bernhard and Graham. This will be one lesson well learned.

I'm highly impressed, never heard the hand bluing effect explained like this before. I have seen many forms and many colors of iron oxide even blue iron oxide but never in my wildest dreams would I think it could be the blue on watch hands. I have known for many years that you get a certain color of metal by heating it at certain temperatures, but I didn't know until now that it's all merely a thin layer of rust.

I was thinking the hands had blued all the way through and all I had to do was clean them and touch them up a bit even though I have seen several videos of heat bluing watch hands and saw them take off the blue for preparation, so why that didn't stick with me??

The reason I used lemon juice, just a few days ago I found on this forum another guy used it to clean a rusty hairspring, even said it took off the blue. Again, it didn't dawn on me the spring and hands might have been blued the same way and the blue would come off

Anyway, for a long time I have wanted to give the bluing a try and now by way of another one of my happy accidents I have an opportunity. Since the brass shavings is one of the preferred methods, going to order me a bag and try that route and put my other idea aside for a while. And if they don't turn out good, I know how to get the blue off to try again.

So thanks guys for taking the time to guide me I really appreciate it. I feel like I'm in the middle of an advanced chemistry class but my level of understanding is stuck in grade school

Roger

 

[penjunky]

Don't know how two post popped up nor where those funny faces came from. Having a bit of trouble figuring this "how to quote" works

 

[penjunky]

Apparently it is because...

View attachment 718776

Hi roughbarked

I think you hit the nail on the head

Roger

 

[penjunky]

I said I'd post back when I got the hands finished so here is a pic of one. It's not as bad as it looks from the spade to the tip, just against the spade and hub, probably wouldn't have hurt to left it on the heat a little longer. This was my third try at it and it really ain't that bad looking through my loupe but it could be better. The hour and minute hands are pretty rough shape to begin with. The brass hub was loose on the seconds hand, probably did it when I took it off so it didn't take much to push it on out so will have to try to fix it (one hard whack with a three pound hammer should do it LOL) I was a bit surprised how much easier it was to work with the seconds hands than the other two.

Oh well, back to the drawing board.

 

[Incroyable]

Apparently the way to clean small bits of rust from blued steel is to use some linseed oil and a pencil lead. The pencil lead acts as a mild abrasive without harming the bluing.

I was Googling around for ways to clean blued steel and came across this tip on a gun board. Worked like a charm.

 

[gmorse]

Hi Jeffrey,

The pencil lead acts as a mild abrasive without harming the bluing.

Now, the important question is, 'B', 'HB', 'H', '2H' or what?

Regards,

Graham

 

[Incroyable]

Hi Jeffrey,


Now, the important question is, 'B', 'HB', 'H', '2H' or what?

Regards,

Graham

The poster was suggesting a 4H pencil which makes sense since a harder lead would be less likely to crumble.

I used an old 2B pencil on a slightly rusted blued hand with a bit of mineral oil and it worked perfectly.

 

[gmorse]

Hi Jeffrey,

I see, more graphite and less clay makes it much softer. I suspect that the oil had more effect than the pencil.

Regards,

Graham

 

[Incroyable]

A carpenter's pencil might be ideal since the shape of the lead would be useful for scraping off bits of rust.

 

[penjunky]

Apparently the way to clean small bits of rust from blued steel is to use some linseed oil and a pencil lead. The pencil lead acts as a mild abrasive without harming the bluing.

I was Googling around for ways to clean blued steel and came across this tip on a gun board. Worked like a charm.

Hey Jeffery, interesting.

Was the rust just mostly stuck on , or eat into the hands? The rust was eat into my hands, as the picture shows gaps. Seems I recall something about some sort of penetrating oil to loosen stuck on rust but never heard of using a pencil, will keep this in mind if I decide to try to clean a couple of watches and most of my tools.

Had a fire and most all of my tools and the two watches I was working on and all the extra hands are now a total rust factory, many of them are history. Since the lemon juice did such a clean job on my hands, thinking to soak in it first and hoping the rust hasn't yet eat away at them. But getting back to it depends on how much of what I can salvage.

Roger

 

[Incroyable]

Hey Jeffery, interesting.

Was the rust just mostly stuck on , or eat into the hands? The rust was eat into my hands, as the picture shows gaps. Seems I recall something about some sort of penetrating oil to loosen stuck on rust but never heard of using a pencil, will keep this in mind if I decide to try to clean a couple of watches and most of my tools.

Had a fire and most all of my tools and the two watches I was working on and all the extra hands are now a total rust factory, many of them are history. Since the lemon juice did such a clean job on my hands, thinking to soak in it first and hoping the rust hasn't yet eat away at them. But getting back to it depends on how much of what I can salvage.

Roger

The rust was mostly on the surface so it hadn't eaten into the hands yet. I think the pencil method only works on minor rust. I do wonder if this method also works on slightly rusted black polished steel.

The hands I cleaned also had a lot of rust on the underside which the pencil got rid of entirely. I stuck the hand onto a piece of pith wood, dabbed a bit of mineral oil on the pencil lead and rubbed it over the hands.

It seems a light coating of a microcrystalline wax like Renaissance Wax after cleaning should prevent any foreseeable rust.

 

[Incroyable]

Hi Jeffrey,

I see, more graphite and less clay makes it much softer. I suspect that the oil had more effect than the pencil.

Regards,

Graham

I initially tried it with just the pencil and rust was coming off but the oil made it more effective.