# Can I cold blue 12L14?



## websterz (Jan 12, 2010)

I started building my new QCTP today and the only suitable sized block I had on hand was 12L14. Man I love working with that material!! I made the toolpost body out of that, and found a nice piece of 303 to make the cam and retaining post from. The pistons and handle will be O1 drill rod. So how about it...will leaded steel take cold bluing?


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## Metal Butcher (Jan 12, 2010)

I used tool black on the crank when I built Elmer's Open Column Twin. I don't see why cold bluing wouldn't work. You can try it on the bottom side, or where it wont be seen before committing to the entire piece.

http://www.homemodelenginemachinist.com/index.php?topic=6552.0

EDIT; I just went down to the shop and dabbed a bit on the end of a saw cut bar of 12L14. It took like a rat at a block of cheese! :big:

-MB


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## shred (Jan 12, 2010)

12L14 blues nicely, either with hot or cold bluing. Cold tends to more of a drak gray color than true black like you'd get with hot blue.


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## websterz (Jan 14, 2010)

And here (except for the bluing) is the completed project. I started out with a 2" cube of 12L14 which turned into the post body. The cam is a piece of 303 stainless round I had knocking around the shop, and the center post is 3/4" drill rod. 1/4" drill rod was used for the handle, and 1/2" for the 2 pistons. Here it is all fitted together:







Here is a view showing the parts spread out a bit: 






My solution to the problem of keeping the pistons from falling out is shown here. I drilled holes up from the underside of the body that bisect the piston holes. 8-32 setscrews hold short lengths of 1/8" drill rod in place. Each piston is cross drilled with a 3/16" hole to allow it plenty of movement while still being trapped in the hole by the pin:







The tool holder shown is just a quick test piece I made from a scrap of 7075 so I could check the function of the post. Future holders will be made from steel for extra mass and rigidity. A test with the parting tool shows the setup to be extremely rigid. I am a happy camper. It took me 3 days of on and off work to build, probably 10-12 hours total. I apologize for the less-than-stellar pics. My wife has the camera in her car and I was forced to use my cell. :doh: I will get some video of it later on this week (if I get my camera back that is ).


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## SAM in LA (Jan 14, 2010)

Great looking work. I spent the same amount of time adapting a store bought QCTP that you took to build your QCTP. You are much more efficient than I am.


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## websterz (Jan 14, 2010)

SAM in LA  said:
			
		

> Great looking work. I spent the same amount of time adapting a store bought QCTP that you took to build your QCTP. You are much more efficient than I am.



Nah...I'm just a tightwad. :big:


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## Rolland (Jan 16, 2010)

12L14 takes a cold blue very well, I use Brownells oxphoblue. It will come out a deep blue if you do your part. 
If you are interested in using that product, I can give you the steps I use.


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## websterz (Jan 16, 2010)

Rolland  said:
			
		

> 12L14 takes a cold blue very well, I use Brownells oxphoblue. It will come out a deep blue if you do your part.
> If you are interested in using that product, I can give you the steps I use.



I'm all ears! :bow:


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## Rolland (Jan 16, 2010)

When I blue 12L14 I take the following steps
Clean the parts very well, I use acetone let them soak for a while to get the oil out of the pores. once they are clean don't touch them with your bare hands use latex/vinyl gloves. (Important keep the parts free from oil until your done)
warm the parts just over room temp. You will need steel wool, be sure to soak the steel wool in acetone as well to remove the preservative oil. I use a small piece of steel wool to scrub the part on the first application of the bluing solution to get an even coat for the subsquent coatings. I normally make at least three coats then go from there. It is important to polish between coats with the wool, I think they recommend "O" wool but not sure, anyway it is listed on the bottle. Brownell also has the applicators, they are wire with a fuzzy end, that way you can use a clean one between coats. 
The most important part is to keep the parts free from any oil while bluing. Then follow the directions on the bottle. 

Of course the bluing will only be as good as the finish you put on the part. If you get a good smooth polished finish you will get a really pretty color. 
Sounds kinda drawn out but it is easy to do and get a nice finish. When you get the color like you want it then put a coat of oil on it and let it soak for a little and wipe it town. Once the bluing gets oil on it will stop working. 
Hope this helps. ;D

If you seen the photos of my Gatling gun most of the blued parts are 12L14 its in photo section


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## Deanofid (Jan 17, 2010)

Looks like you have your answers on the bluing issue, Webster. Just wanted to chime in and compliment you on the tool post job. It looks to be a nicely done project.

Dean


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