Old metal finishing/protection techniques?

[bolus]

Unless you are already aware of it there is oil blackening. I have used this many times, up to recently on the front sight of a muzzleloading rifle. When done correctly (and it ain't difficult) it produces a very nice finish on small parts.

that is with a blow torch though right? I'm worried about messing up the hardening on the small parts or thin metal parts with that method.

 

[RVTECH]

I have never used this method with parts where I am concerned about heat being an issue but I have not used a torch when doing so either. What I have done is to set the parts on the coil of my stove and let them heat until dull red then pick them up (with needle nose pliers!) and drop into the oil (used oil from after an oil change) I doubt the stove coils would heat anything hot enough to affect heat treating but as an experiment I will heat a small metal part and shoot it with a laser thermometer to see how hot it gets.

 

[Geardo]

I have never used this method with parts where I am concerned about heat being an issue but I have not used a torch when doing so either. What I have done is to set the parts on the coil of my stove and let them heat until dull red then pick them up (with needle nose pliers!) and drop into the oil (used oil from after an oil change) I doubt the stove coils would heat anything hot enough to affect heat treating but as an experiment I will heat a small metal part and shoot it with a laser thermometer to see how hot it gets.

If its glowing.... It is tempering the metal. 400 F is enough to Temper steel.

 

[etrain16]

Unless you are already aware of it there is oil blackening. I have used this many times, up to recently on the front sight of a muzzleloading rifle. When done correctly (and it ain't difficult) it produces a very nice finish on small parts.

I posted a video in Post #13 that talks about using oil and a torch to do just that - is that the same thing you're talking about?

 

[RVTECH]

I posted a video in Post #13 that talks about using oil and a torch to do just that - is that the same thing you're talking about?

I didn't watch the vid but went back and did - yep - thats it.

 

[jbett98]

Doesn't the heat affect the metal in as much as heat treating it differently then the manufacturer made it?

 

[thorborg]

Here is a thought, especially for small parts. Though this vid is zinc, other coatings like nickel gold, silver etc. can be applied just as easily (find appropriate DYI on the internet) Color / blackening can be added to some extent in some processes. Again online research. I've done nickel, anyone can do it with locally available material. As with Bluing, the texture of the metal surface you start with, will be nearly equal to the texture you end up with.

 

[BillM]

My old gunsmith was a master at bluing. For itty bitty parts (screws, pins etc) in the winter he would polish
them and toss them on top of the old wood stove they used to heat the shop. When the parts got to the color
he wanted he would just pull the part and oil quench.

 

[bolus]

Found some orthophosphoric acid in the local hardware store. Apparently phosphatizing instead of oxadizing so more like Parkerizing than rust bluing. Anyone use this for home parkerizing or have any recipes or techniques? I believe I need a metal salt (iron, zinc or manganese). Problem may be I dont have a way to sandblast parts.

 

[bolus]

I had very good results using Laurel Mountain Forge products.

It showed up today so at least I know of one thing that can get shipped to me. Thanks again.



I etched some scrap metal in vinegar last night and left it out with the plan to do the rusting tonight as practice. Already completely rusted. Slow rusting in Hawaii is actually pretty fast. no wonder mold grows on cast iron in my kitchen.

So glad I'll be able to blue a bunch of my tools to keep them from getting ruined.

 

[Wombat of Doom]

Accidently oil blued a knife recently. Oddly, a hard coating, but it adds mass. and I removed it, because it was not an even coating. Granted, I was using a forge and messing around a bit. I use ferric chloride to patina the knives I make currently, but it does essentially eat a thin layer. Just keep that in mind when using the acids. On small parts tiny tolerances matter a lot.

 

[jbett98]

It showed up today so at least I know of one thing that can get shipped to me. Thanks again.



I etched some scrap metal in vinegar last night and left it out with the plan to do the rusting tonight as practice. Already completely rusted. Slow rusting in Hawaii is actually pretty fast. no wonder mold grows on cast iron in my kitchen.

So glad I'll be able to blue a bunch of my tools to keep them from getting ruined.

One thing about using the Laurel Mountain product, is that you don't want to rub it on when using a clean cotton ball, just gently coat the metal with a nice even wetting.
If you rub it on it will discolor the part and it will look uneven next to other areas that wern't rubbed.

 

[Member 34319]

Found some orthophosphoric acid in the local hardware store. Apparently phosphatizing instead of oxadizing so more like Parkerizing than rust bluing. Anyone use this for home parkerizing or have any recipes or techniques? I believe I need a metal salt (iron, zinc or manganese). Problem may be I dont have a way to sandblast parts.

A bottle with sand in it connected to an air compressor will do the trick in a pinch.

Another option not mention is case hardening.

Pretty straightforward method, but stinky if you go traditional and use cow dung. Otherwise it's just charcoal.

 

[Member 34319]

Here is a really technical video on case hardening.

 

[bolus]

This is definitely going to be a trial and error learning experience.

There are some roll pin punches that are rusting despite being kept in a sealed container. They are my experimenting pieces


This is after degreasing, vinegar etch, and then peroxide+salt rusting. Several passes through that processing and then carding the rust off. Got some black oxide but then the next day new rust forming again.



So I have some new formula's Im going to try and I'm getting stuff for some hot salt bluing as well.

 

[bolus]

Brownell's Oxpho blue ingredients are:

COPPER SULFATE PENTAHYDRATE 2.5 - 10%
PHOSPHORIC ACID 2.5 - 10%
NICKEL SULFATE 1-2.5%
SELENOUS ACID 1 - 2.5%

Copper Sulfate is in the drain section of hardware stores because it kills roots entering sewer lines. It is also used to kill algae and mold and is a fungicide so used for gardening.

Phosphroic acid is available in every hardware store near me as a metal prep to remove rust for painting.

Nickel Sulfate I cant get. It is used in electroplating but cant ship by air

Selenous acid darkens non-steel metals (copper, brass) and is an oxidizing agent. it darkens with abrasion so that is why oxpho-blue recommends rubbing it on with steel wool. I cant get that shipped either.

Amazing the stuff that you start to find in the hardware stores once you start to learn what chemicals are used in metal finishing.

If I was back in Oregon I could get all this stuff shipped to me and make some cheap cold bluing solution.

I'm sure some 3 letter agency is watching me with all these chemicals I'm buying

 

[bolus]

Bit of a Bob Ross happy accident.

Copper colored steel? So far does not come off with 0000 steel wool. Hard to get a good picture of the color

 

[bolus]

Well, its a bit odd looking. silver to a darkish copper color. Now to see if it provides any rust protection

 

[Rick4070]

I know ammonium nitrate is hard to get, but can you get sodium nitrate??
Lots of garden supply stores carry it.
Lye should be available as drain cleaner in hardware stores.
Google: "homemade bluing salts" by Blindhogg, he has a good recipe for hot bluing salts.

 

[bolus]

I know ammonium nitrate is hard to get, but can you get sodium nitrate??
Lots of garden supply stores carry it.
Lye should be available as drain cleaner in hardware stores.
Google: "homemade bluing salts" by Blindhogg, he has a good recipe for hot bluing salts.

Yes, I have sodium nitrate and lye now and that was one I was going to try. I'm just waiting on a pot I ordered that isnt made out of aluminum since I cant find any stainless steel pots locally.