Bronze smelting, need some advice

[anka0311]

So i am fairly new to bronze casting. I have dabbled some, but never really made a go of it until now. 

I have gotten in to my head to make a valsgärde helmet. In order to do this i need to make a few bronze plaques. It is a very, very long story. 

I made my fist pour today and the result was not satisfactory. I would truly appreciate some more experienced casters insights to what i need in order to reach success. 

I have used an investment powder, ses silk, made the mold. I did not have th proper chance to prevent the mold. I suspect that maybe than can be a problem. I do not have access to a vacuum set up. Which otherwise would be ideal... But if you can lend some advice that would be truly appreciated.

[Steve Sells]

First you cant smelt bronze.  You can smelt tin and you can smelt copper, then blend them to make bronze. Second make a well to hold a supply of the bronze to prevent the final item from shrinkage, third after MELTING the bronze preheat the mold to near casting temperatures, and fourth you should de gas the liquid before pouring

Have you taken a casting class yet?

[George N. M.]

Welcome aboard from 7500' in SE Wyoming.  Glad to have you/

I can't help with casting except to guess that it looks like your mold was too cold.  What kind of mold medium are you using?  Sand? Soapstone?  As Steve says, preheat your mold.

The question arises of why you are casting for a Valsgarde helmet.  As far as I know, there were no cast elements in the originals.  And which Valsgarde helmet?  There are several, over a dozen.  The ones with decorative plates were made with an iron cap covered with thin pieces of decorative gold or bronze with the decoration raised by repousse (raising the metal from the back with various punches and chisels) and then attaching the panels to the iron cap, probably with small rivets and the rivet lines covered with decorative strips.  The use of cast panels would have made the helmet very heavy.  And one made up of decorative cast panels would have been pretty flimsey and suitable only as a wall hanger.

So, depending on how authentic you want your reproduction to be you may have to reevaluate the techniques you are useing.

Finally, I don't know how much casting experience you have but it is a skill that can be VERY dangerous unless you really know what you are doing.  Dealing with liquid metals, particularly high temperature metals like bronze, is much more dangerous than working with soft and solid hot metal when blacksmithing.  One small mistake can result result in horrific injuries, disfigurement, and death.  And it will hurt a lot too.  So, be very confident that you know what you are doing.  If you have any doubts about your skill level take a casting or foundry class somewhere or find someone to teach you.  DO NOT rely on You Tube videos for instruction.

"By hammer and hand all arts do stand."

[anka0311]

4 hours ago, Steve Sells said:

First you cant smelt bronze.  You can smelt tin and you can smelt copper, then blend them to make bronze. Second make a well to hold a supply of the bronze to prevent the final item from shrinkage, third after MELTING the bronze preheat the mold to near casting temperatures, and fourth you should de gas the liquid before pouring

Have you taken a casting class yet?

No i have not taken any classes, wish i had. But no, and for missclassifications, smelting bronze etc. Im Swedish so my English isnt all that great. But your points all prove worthy hints on the road towards success. So thanks for that

 

4 hours ago, George N. M. said:

Welcome aboard from 7500' in SE Wyoming.  Glad to have you/

I can't help with casting except to guess that it looks like your mold was too cold.  What kind of mold medium are you using?  Sand? Soapstone?  As Steve says, preheat your mold.

The question arises of why you are casting for a Valsgarde helmet.  As far as I know, there were no cast elements in the originals.  And which Valsgarde helmet?  There are several, over a dozen.  The ones with decorative plates were made with an iron cap covered with thin pieces of decorative gold or bronze with the decoration raised by repousse (raising the metal from the back with various punches and chisels) and then attaching the panels to the iron cap, probably with small rivets and the rivet lines covered with decorative strips.  The use of cast panels would have made the helmet very heavy.  And one made up of decorative cast panels would have been pretty flimsey and suitable only as a wall hanger.

So, depending on how authentic you want your reproduction to be you may have to reevaluate the techniques you are useing.

Finally, I don't know how much casting experience you have but it is a skill that can be VERY dangerous unless you really know what you are doing.  Dealing with liquid metals, particularly high temperature metals like bronze, is much more dangerous than working with soft and solid hot metal when blacksmithing.  One small mistake can result result in horrific injuries, disfigurement, and death.  And it will hurt a lot too.  So, be very confident that you know what you are doing.  If you have any doubts about your skill level take a casting or foundry class somewhere or find someone to teach you.  DO NOT rely on You Tube videos for instruction.

"By hammer and hand all arts do stand."

I am well aware of the dangers and are not a person liable to take risks. But yes, it is certainly very dangerous. I would like to take a class and most likely will. 

I have some experience, so this is not first turn, but previously i have mostly made smaller trinkets.

In regards to the helmet, i am making bronze matrisses to make pressblechs, is that the correct word? Anyway suggestion of finds like the Torslunda plates indicates that this is the way that the heavily decorated foils where created. And for the helmet, i am reconstructing the Valsgärde 8 helmet.

 

[anka0311]

My apologies, you asked for the medium, i have made that master in carving wax, reproducera that in silikon than copied that in softer artist wax and embedded that in investment mass, SRS SILK. Hope that was an answer to your question.

 

[George N. M.]

That was a quick response.  My grandparents were Swedish immigrants.  My middle name is Nels and my last name is Monsson.

I don't know the word "pressblechs" but I suspect that it is a term for a decorative plate which has thin metal pressed over it to make a repeatable design.  I believe that they were often made of a hard wood since the pressing is done cold.  Or, they could be done as male and female dies so that the thin metal could be pressed between them.

And you English is much, much better than my Swedish.

GNM

[George N. M.]

PS Where are you in Sweden?  I still have a cousin in Gothenburg?  Also, my wife has gotten intrigued with Sweden and has been studying Swedish.  If it wasn't for covid we would have visited there before now.

GNM

[anka0311]

Im living in Uppsala, quite a bit north from Gothenburg. But Gothenburg is nice, been there a few times. My wife lived there for a while. 

 

Really nice to hear that your wife has taken on the task of learning Swedish! I Imagine it can be rather hard. But i wish her luck!