Black oxide coating

OK, someone emailed me with questions/concerns so let me clarify...

The threaded rod and the torque nuts are grade 12.9, 4140 heat treated. I jumbled a sentence down below. Yes indeed, normal threaded rod like you buy at the hardware store would not have a candle's chance in a windstorm to stand-up to mill table clamping pressures... Simple threaded rod is usually grade 2 or metric 5.5.

Also, yes, this is for a PM45/932 mill which uses 12mm studs and 14mm slot width. The threaded rod was (as I recall) 20 bucks for 1 meter and the torque nuts came in packs of 20 or 25 and cost about 8 bucks a pack.

1:3 mixture means: Take 1 part of the concentrated etching/oxide solution and 3 equal parts of distilled water. I think it's important to use distilled water as I recall getting weird results using tap water. The instructions in the chemical kit do not specify heating the parts but, those are tricks I figured-out along the way.

-Sorry about the confusion...


Ray
 
Finally got top those hinges.
Sand blasted the brass plate off.
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The Caswell blackening kit.

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The finished product, the sealer is still wet here.

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Greg

IMG_1291.jpg IMG_1292.jpg IMG_1294.jpg
 
That looks great Greg.

A timely post too. I bought the Caswell plating kit also and I will be doing my parts tomorrow. I was ready to do it last month but too many other things came up and I put this job on the back burner. I spent the last 2 nights re-cleaning parts getting them ready for dipping.
 
Let me think about this, if I setup a hot tank for blueing like James - near to the 30 Gal tank I'm using for electrolytic rust removal, and since it is visible from the
street, and if I save all my empty sudefed boxes for decoration, I should have a visit from some suits in no time. Could be interesting.
Perhaps if I were to put up some of those chemical placards... :biggrin:
 
calstar said:
Is this brew very toxic, safety precautions? Do the salts then solidify on cooling to be reused? I assume this is categorized as toxic waste when deposing .

thanks, Brian
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There is nothing worthy of note to dispose of, other than the hot water used to remove the residual salt before dipping in hot oil; the salt is used over and over, and only needs to be "cleaned up" by adding the manganese dioxide powder occasionally to remove trace amounts of dissolved iron that tends to make the finish blotchy. The advantages of this method are worth any amount of trouble to set it all up; the main two are the durability of the finish, much superior to the fluid method, and also that no care at all is needed so far as cleanliness is concerned prior to bluing.
 
I read of a blueing method I have not tried but it's what I would try if I had to blue anything small. All you do is clean the part well as with any other blueing. Then put the part in a container with a few small cups with a few drops of hydrochloric acid and nitric acid in separate cups then put the lid on the container and let it sit and the fumes do the blueing. I read it in a bill Holmes blacksmithing book I believe. If anyone's really interested I could look up the exact process. I think there was something about varying the proportion of acids to vary the color some.
 
f350ca said:
These are the hardware store variety brass coloured steel hinges. Will sandblast them to get back to raw steel.
Think it was 25 pair of hinges for the complete set of cabinets, at what they charge for solid brass hinges now, these will work fine.
The first two sections of the cabinets. (pardon my deviation from metal to the dark side)
View attachment 76670

View attachment 76671

Thanks
Greg
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Very nice cabinets, my missus would like me to do something similar for the bathroom, but I don't think she realizes how much work/time is involved.

Cheers

Ed.
 
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