Question: shaping belt buckles after coloring

[Marrinan]

During conversations at the Engrave-In I decided to make up some steel buckle blanks that will eventually be color case hardened as well as blued. The blanks I have made are 3/32 and 1/8 inch cold rolled carbon steel. I talked with the folks at Turnbull to check on the appropriate steel and was told that at the thickness I am working at, that distortion will be an issue after case coloring. They explained that they sometimes have to correct the flatness of items after the process. I had planned to micro weld the belt loop and hook to the blank back prior to engraving or selling but after shaping. I can setup my press in such a way that the buckle could be shaped after color case hardening but i am not sure that those who buy the buckles will be able to re-shape the buckle with the loop and hook on the back. Welding the loop and hook after color case will probably not work as it may damage the engraving and coloring. Any insight would be greatly appreciated. Thanks Fred

 

[DakotaDocMartin]

I talked with the folks at Turnbull to check on the appropriate steel and was told that at the thickness I am working at, that distortion will be an issue after case coloring.

I wonder if it might be worth your while to form a buckle the way you want it to be, assemble it, etc. and then anneal the whole works to stress relieve it? That may be a useful experiment to see if you get distortion during the color case process.

 

[DKanger]

Fred,
Many thin items are backed with a block of heavier metal to miniminze distortion during case hardening. However, they can usually be screwed together. I don't know how you might do this with something like a buckle.

I have had some success hardening and coloring thin metal without using the bone/charcoal canister method. It might work with your buckles.
1. Float a layer of thin oil on top of water.
2. Suspend the item from a piece of iron wire.
3. Evenly heat the item to non-magnetic with an oxy/acetyl flame set slightly to a reducing flame (acetyl rich). I try to keep it just below the point where scale starts to form.
4. Plunge the item "straight" into the quench can, immediately pull it out, replunge quickly, and rapidly repeat about 10 times. Then let the item sink to the bottom until it's cool.

Quench can temperature is the key to the colors. Done at 35 degrees ambient will yield very dark blues. Done at 90 degrees ambient will yield lighter blues, grays, and other colors. Colors are somewhat dependent on your metal's characteristics. On the first quench, oil is deposited on the metal and is washed off and re-deposited with subsequent dunks. The colder the oil, the more it will stay on the piece, giving the darker colors. If the alloy is a hardenable one, it will be hard all the way thru. This is an alternative to conventional pack hardening and should serve for something like a buckle. Experimentation with your items will lead to the colors you are satisfied with. Also, if you aren't satisfied, you can reheat and do it again.

Dave

 

[Marcus Hunt]

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[Marrinan]

Doc Martin, Since the hanger and the hooks are welded with oxy/acetyl I would think that I will accomplish stress release by allowing slow cool before engraving. Since these are being prepared "in the white" I hope the stress is gone anyway. Thanks for your feedback. Fred

Dave, I certainly appreciate the formula for case coloring/hardening without the antler/bone canister method. I have added it to my personal tips archive. When you decide that you want to redo because you are not happy with the results do you have to remove the first attempt? Seems that sanding the engraving at this point would not be advisable. Thanks again for this info.

When someone else makes up one of these buckles and sends them for coloring, is it he responsibility of the colorer/hardener to correct the warpage created?

 

[KSnyder]

1/8th inch sounds like overkill / too thick to me. 1/16th is plenty thick and forms nicely. I've made a few of these and nitre blued them never case hardened one though.

 

[DKanger]

Fred,
Here's a picture of one done with the quench solution around 75 degrees. One's done at colder temps are more toward the blue/black variations.

Some guys selectively wrap their items with iron wire, which holds the oil on the item for a bit longer, to get different patterns.

It's normally not necessary to re-polish as the colors disappear as the item goes thru its heating stages.

Ignore the engraving. It was transferred from an original lock and matches the quality pretty close.

 

[Marrinan]

KSnyder, Thank you for your input. I usually make silver buckles out of 16 gage, 14 on occasion for larger buckles. These usually provide the strength required and allow for overlays and not get the buckle to heavy. When I do buckles with silver over steel i usually use 16 gage steel. Eight inch steel provides a solid, strong buckle. It also allows the ability to do some pretty deep work and solid inlays that are strong enough to retain their shape and not flex to where the gold inlay is subject to pop out. Three thirty-seconds provides a substantial buckle that can handle deep sculpted work and retain its integrity during case hardening per Turnbull and other engravers during conversations with those engravers. One further note on the thickness-it is what the engraver requested and in this case, he is the boss-Thanks again.

Dave, Thanks again for your info. I am going to have a ball with the cut-offs and experimenting. How do you adjust the temp of the quench. Use warm water and add oil when it cools to a predetermined temp. This is going to be fun. Many thanks for the guidance-Fred

 

[DKanger]

How do you adjust the temp of the quench. Use warm water and add oil when it cools to a predetermined temp.

Fred,
I don't adjust the temp. I've got a large metal coffee can with the oil and water in it that I keep with the plastic lid on when I'm not using it. I've just done it at different times of the year using whatever the ambient temp in the shop is and noting the results. I found out about the dark ones before heating the shop in the winter and the lighter ones in the spring and summer. I never really experimented with trying to control the temp to achieve a specific result. I used 10w auto oil. You might also try Trans fluid which is thinner and will give different results. Both the reducing flame and the oil will add some carbon to the skin of the metal. I should also add that the oil layer is about 1/4" thick.

 

[Dave London]

Fred
How about useing a lazer weld to attach the hook and bail, after the color case or blue. A few folks here have the laser welders, no me though