High relief engraving on brass furniture

[eddillon]

Don't know if this belongs here or in the collecting category but here goes.  Were the butt plates, trigger guards and etc. chiseled and engraved or were they cast and just the fine detail added by engraving?

[jerrywh]

 Both.  Some were done both ways.  I have seen the exact same trigger guards on different guns and even some of the same marks of defects on them. There were sometimes cast in a very fine sand and some were cast in clay molds that were smoked.  They were mostly all done by the silver smiths. The silver smiths and the gold smiths were in the same guild in England and I think the engravers were in the same guild. Going over a cast part and detailing it is called chasing and was done by engravers.  I am talking about the stuff in Europe and England. However the Ames sword company did basically the same thing in this country from the time of the revolution. I have made spare parts for some revolutionary swords that were done this way.

[PPatch]

"...and some were cast in clay molds that were smoked."

Jerry; Tell me more about this process. What did the smoking achieve?

dave

[jerrywh]

"...and some were cast in clay molds that were smoked."

Jerry; Tell me more about this process. What did the smoking achieve?

dave

I don't know a whole lot about that process but I have seen some of the molds. When I say they were smoked I mean they were covered with black soot like you do when you smoke a part for inlaying.  I think the smoke stopped the metal from sticking on the clay. The molds I saw were two part.  I know also that silver and brass can be cast  in plaster two part molds. The molds have to be dried in an oven for some time and preheated before casting. That process needs some study. The shape of the part has a lot to do with  how the molds are made.  The ones I saw were over 150 years old and came from the ames sword company. http://en.wikipedia.org/wiki/Plaster_mold_casting

 

[James Rogers]

Delft casting can take on very minute details that can be cleaned and chased to nice work.  Jim Hash made some detailed work using a local silty type of fine clay particle.
Those heavy detailed early pieces were I am sure cast in and cleaned and chased. I have seen a lot of identically made pieces underneath with varying styles of added hand work. Like Jerry mentioned, there are some cast in details in some that scream they're from the same run.
I am always fascinated, trying to get a grasp on those 18th century production aspects. Lots lost, much to recover.

[smart dog]

Hi,
I think many high relief decorations were cast and then chiseled and engraved.  That way some could be reproduced many times.  I used that exact process to make the sideplate below, which I will reproduce once more in full scale and again in reduced scale for a pistol.  The first photo shows the hard wax models (actually an earlier version that I changed after learning the process) before they were placed in the Delft clay mold.  During that process, they are dusted with talcum powder rather than smoked. I also show them fresh out of the mold before chasing and engraving.  I made the piece in 3 parts because my molding frame was small and I could handle maintaining heat for metal flow better with a small mold.  I designed the sections so they could be soft soldered together and the seams were invisible.  Detail was cut with die-sinkers chisels and gravers.  Polishing was with diamond burrs held in a handle and hardwood sticks dipped in mineral oil and then pumice and rottenstone.   

dave

[David Rase]

Hi,
I think many high relief decorations were cast and then chiseled and engraved.  That way some could be reproduced many times.  I used that exact process to make the sideplate below, which I will reproduce once more in full scale and again in reduced scale for a pistol.  The first photo shows the hard wax models (actually an earlier version that I changed after learning the process) before they were placed in the Delft clay mold.  During that process, they are dusted with talcum powder rather than smoked. I also show them fresh out of the mold before chasing and engraving.  I made the piece in 3 parts because my molding frame was small and I could handle maintaining heat for metal flow better with a small mold.  I designed the sections so they could be soft soldered together and the seams were invisible.  Detail was cut with die-sinkers chisels and gravers.  Polishing was with diamond burrs held in a handle and hardwood sticks dipped in mineral oil and then pumice and rottenstone.   

dave

That side plate is beautiful Dave.  Very nice.
David

[Acer Saccharum]

Brass can indeed be high relief chiseled. It does workharden, which makes it more difficult to cut the more you work at it. Probably an occasional annealing would help.

Steel/Iron cuts much more consistently with little tendency to workharden. So yes, steel is harder than brass, but in the end, it's easier because it doesn't workharden.

This makes me think that most relief brass hardware was cast. Not all, but most.

[Acer Saccharum]

I think the smoking of a mold helps with gas escape, and provides a little insulation between molten metal and mold surface which allows a longer flow and better filling of the details. It might also act as a mold release.

[PPatch]

I think the smoking of a mold helps with gas escape, and provides a little insulation between molten metal and mold surface which allows a longer flow and better filling of the details. It might also act as a mold release.

Thanks Acer (and the rest of you), makes sense. Nice chasing!

dave

[Jim Kibler]

If you start chiseling metal of any kind you'll soon realize that casting is much less labor intensive.  In the period pertaining to these guns, only nonferrous metals could be cast.  "Cast iron" (Carbon greater than 2.1%) could also be cast, but it wasn't used on guns.  So if they could cast it and then refine the shape afterwards they did.  This is why chiseled iron (wrought iron) hardware was more expensive than silver in the 18th century English gun business.

[jerrywh]

 Somebody always had to do the original piece. That piece was always hand engraved and chiseled.  No reproduction is ever the exact same in detail as the original. Something is always lost in the process of reproduction however minute. I have been doing lost wax for about 20 years for my own stuff and sold the over runs to others. I have reproduced pieces that were so exact that you could actually see fingerprints on the finished part that were accidently  left on the waxes. Still there was some loss either in size or defect somewhere.  Now days the process has been so perfected that the turbines of jet engines are precision cast.  One of the most knowledgeable people on this board on the subject is Dave Crisalli.  
  A hand chiseled side plate with screws. I made a mold of this but have not yet cast any.

[smart dog]

Hi Tom and Jerry,
Beautiful chasing work!!  I think the smoke soot or talc may help with gas escape but it also makes sure you can remove the model from the mold before pouring molten metal without picking up grains of clay or sand.  

dave

[Acer Saccharum]

Very nice inletting on your sideplate, Jerry. Gold inlay on the screwheads? Very nice.

[whitebear]

I have  to agree with Acer I was always told to smoke the cavity of a mold before casting balls to make the balls extract easier.

[eddillon]

Thanks, all.  I really appreciate the education that I receive here on ALR.

[Dr. Tim-Boone]

lost wax using a centrifuge is an amazing thing... Years ago I did a lot of jewelry using that method.  I used to put bees in the plaster of Paris mold and produce replicas of the bee that were covered with the very fine hairs that you can barely see on the live bee.. The gold bees were beautiful reproductions. 

[jerrywh]

lost wax using a centrifuge is an amazing thing... Years ago I did a lot of jewelry using that method.  I used to put bees in the plaster of Paris mold and produce replicas of the bee that were covered with the very fine hairs that you can barely see on the live bee.. The gold bees were beautiful reproductions. 

I once had a friend that was a dentist and he made his fishing lures by that process. He would produce castings of bugs and use them for lures.

[eddillon]

 
[/quote]
 I once had a friend that was a dentist and he made his fishing lures by that process. He would produce castings of bugs and use them for lures.
[/quote]

I had a dentist friend in the Air Force who did lost wax tie tacks in dental gold.  His middle finger salute sold like hot cakes.