highveldt
Elite Cafe Member
In one of my posts of the past I have indicated that I am a hobby English gun restorer who learned to engrave in order to be able to carry out a complete restoration of same.
Currently I am restoring the engraving on a 1889 Stephen Grant & Sons SLE gun. In the past history of this gun one can see where is was greatly afflicted by neglect causing rust and corrosion and someone in the past used abrasives to remove the rust on the action body and took away much of the case hardening and unfortunately the engraving. As a result I have been able to restore the engraving (tiny, tiny fine English scroll) on the action body using both M42 and Carbalt gravers. However, some of the other parts of the gun such as the forend thimble, the trigger plate forward end and so forth have very thick case hardening that only allows a few seconds of engraving with a Carbalt graver before having to re-sharpen (even with dubbing the point and running on bare minimum air.
I was going to send some of these smaller parts up to Turnbull for annealing, but I decided to try an alternative method that I "dreamed up". The desire on these other small parts is to soften them and at the same time preserve what outlines of the former engraving as possible to use to re-engrave after softening. Of course, if one is going to anneal such gun parts in a furnace, one needs to "anneal" the piece in an inert atmosphere such as Argon to preserve the surface of the steel of the piece, or at least to wrap the piece in stainless steel foil (or something) to do this. I use "anneal" only as a word to describe the heating at high temperature of the piece of steel as on these older English guns the underlying steel is of such low carbon content that it can barely be called steel--it is hardly likely it is even something like 1005 steel. And I doubt that any metallic stresses were introduced into the steel in its original color case hardening of 120 years ago, that need to be relieved in an annealing process.
In my shop I use "KEEPBRYTE" brand anti-scale compound to heat treat springs that I have to make. In order to keep oxidizing scale forming one heats the steel piece (spring or whatever) to about 450 degrees F and while the steel is at this temperature it is coated with the powdered anti-scale compound until a heavy coat of about .030" thick is accumlated. Then the steel piece is raised to the heat treated temperature required. After heat treating the steel piece is placed in boiling water and in a few minutes the part comes out of the hot water nice, clean and fairly bright.
Just recently I coated a small engraved and case hardened part (from the Stephen Grant gun) using the process as described above, and then heated it with a MAAP torch to bright red color (about 1600 degrees F) and allowed the part to cool to room temperature. I boiled the part in water as above, and afterwards all the former engraving was there with no scale and all the case hardening surface was gone, and the steel was nice and soft. I assume, and for a lack of better words, the carbon in the case hardening "cooked" and migrated into the anti-scale coating.
I would not do this on an action body, however, (unless I had a electric kiln or furnace) just small parts and maybe lock side plates. I carried through the above process on the forward end of a trigger plate to remove about 1 1/2 inches of case hardening--with success. The trigger plate was about 6 inches long, and I only heated the area I needed to remove the case hardening.
If you were to try this you do it at your own risk and liability, as I warrant (either express or implied) nothing in the process discussed above.
There was a former discussion about this anti-scale compound in 2009 and here is link to that (see page 2):http://www.engraverscafe.com/showthread.php?5411-Gold-inlay-and-heat.
Currently I am restoring the engraving on a 1889 Stephen Grant & Sons SLE gun. In the past history of this gun one can see where is was greatly afflicted by neglect causing rust and corrosion and someone in the past used abrasives to remove the rust on the action body and took away much of the case hardening and unfortunately the engraving. As a result I have been able to restore the engraving (tiny, tiny fine English scroll) on the action body using both M42 and Carbalt gravers. However, some of the other parts of the gun such as the forend thimble, the trigger plate forward end and so forth have very thick case hardening that only allows a few seconds of engraving with a Carbalt graver before having to re-sharpen (even with dubbing the point and running on bare minimum air.
I was going to send some of these smaller parts up to Turnbull for annealing, but I decided to try an alternative method that I "dreamed up". The desire on these other small parts is to soften them and at the same time preserve what outlines of the former engraving as possible to use to re-engrave after softening. Of course, if one is going to anneal such gun parts in a furnace, one needs to "anneal" the piece in an inert atmosphere such as Argon to preserve the surface of the steel of the piece, or at least to wrap the piece in stainless steel foil (or something) to do this. I use "anneal" only as a word to describe the heating at high temperature of the piece of steel as on these older English guns the underlying steel is of such low carbon content that it can barely be called steel--it is hardly likely it is even something like 1005 steel. And I doubt that any metallic stresses were introduced into the steel in its original color case hardening of 120 years ago, that need to be relieved in an annealing process.
In my shop I use "KEEPBRYTE" brand anti-scale compound to heat treat springs that I have to make. In order to keep oxidizing scale forming one heats the steel piece (spring or whatever) to about 450 degrees F and while the steel is at this temperature it is coated with the powdered anti-scale compound until a heavy coat of about .030" thick is accumlated. Then the steel piece is raised to the heat treated temperature required. After heat treating the steel piece is placed in boiling water and in a few minutes the part comes out of the hot water nice, clean and fairly bright.
Just recently I coated a small engraved and case hardened part (from the Stephen Grant gun) using the process as described above, and then heated it with a MAAP torch to bright red color (about 1600 degrees F) and allowed the part to cool to room temperature. I boiled the part in water as above, and afterwards all the former engraving was there with no scale and all the case hardening surface was gone, and the steel was nice and soft. I assume, and for a lack of better words, the carbon in the case hardening "cooked" and migrated into the anti-scale coating.
I would not do this on an action body, however, (unless I had a electric kiln or furnace) just small parts and maybe lock side plates. I carried through the above process on the forward end of a trigger plate to remove about 1 1/2 inches of case hardening--with success. The trigger plate was about 6 inches long, and I only heated the area I needed to remove the case hardening.
If you were to try this you do it at your own risk and liability, as I warrant (either express or implied) nothing in the process discussed above.
There was a former discussion about this anti-scale compound in 2009 and here is link to that (see page 2):http://www.engraverscafe.com/showthread.php?5411-Gold-inlay-and-heat.
