# Bubbles in my sheet ingot; Help!!



## Fishnchamp1 (Mar 2, 2020)

Can anyone help explain why I’m getting bubbles (voids) in my pour? If you see other problems, feel free to point em out! This is the first time I’ve ever poured silver and I want to do a better job. Sorry for the crummy photo, this stuff is shiny! :G


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## anachronism (Mar 2, 2020)

Frankly if that's the first time you've poured Silver I would suggest you've made a pretty good job of it. 8) 8) 

Jon


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## FrugalRefiner (Mar 2, 2020)

Silver absorbs oxygen when it is molten. Figures range from 10 to 20 times its volume. When the silver freezes, it tries to expel the oxygen. Depending on how fast it freezes, and under what conditions, bubbles can remain trapped. Trying to create your own sheet is extremely difficult.

For more information, see a recent thread where the issue was discussed in Silver Cracking.

Dave


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## Fishnchamp1 (Mar 2, 2020)

Thanks Jon, my second piece turned out well enough that I tried to roll it down; feelin better about that one (needed to anneal better, I see cracking)...




Dave, I appreciate that link. I’m not sure how to change my environment... I’m just casting in an open air barn (maybe I’m just too much of a novice to understand all that tech speak!  ) Is there some sort of practical method I should be applying? My only common sense idea was to richen up the propane flame... wondered if it also had to do with pour speed or mold temp?


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## FrugalRefiner (Mar 2, 2020)

A rich (reducing) flame can help. Excluding oxygen from the melt can be done in various ways including melting in a furnace, covering with a gas like argon, covering the melting dish/crucible with a physical cover, floating a carbon on the melt, etc. There are a lot of other discussions about it here. Read through the threads in the Silver section and beyond.

Your book mold will keep oxygen from being absorbed after the pour, but it can also hinder the escape of any that's already absorbed, so prevent that as mentioned above.

Dave


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## galenrog (Mar 2, 2020)

You have done well for a rookie. Do as Dave has suggested. Especially study of the Silver section. Many do not understand the chemistry of molten metals vs solid. Each can be worlds away from the other. It took me much study to learn about refining silver, and I will never be done. The practical application of lessons learned here were a bit challenging, due to short term memory issues after stroke. 

While learning, my best advice is to make notes. Not mental notes, but rather real notes on real paper. Mine are extremely valuable to me, as are the flow charts I make for every procedure. As you progress, you will find understanding of what you are doing comes faster, and recovery from errors and the unexpected less onerous.

Enjoy.

Time for more coffee.


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## ION 47 (Mar 6, 2020)

Use a reducing flame. Before casting, put pieces of charcoal in the silver melt and mix with a dry wooden stick. This will reduce the amount of oxygen in silver.


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## Fishnchamp1 (Dec 19, 2020)

Took y’alls advice, covered up by using a 3kg furnace at Rio... pouring around 2050F into molds that are about 825F... cannot get them to pour solid. Each one of em is about 15-17 ozt so my mistakes are getting pricey and I’m getting frustrated by it. Have had been successful with about 4 sheets out of 25... any more ideas to help?


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## Lou (Dec 19, 2020)

Pour hotter.

You're getting short pours (voided and not filled) because of too low of temperature.


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## Fishnchamp1 (Dec 19, 2020)

Roger that. Thanks Lou... will try again tomorrow. Bein frustrated and angry hot metal don’t mix!


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## Fishnchamp1 (Dec 20, 2020)

Furnace only goes to 2102F... I preheat my ingot molds in a Camp Chef sear box bbq grill (I’ve measured temps right around 900F).... Those are both variables I cannot change without great expense. 


The only thing I haven’t done is pour under heated conditions. Went to orange big box store and picked up a Mapp gas torch and hung it off my bench shelf directed into the mold. Still a little frazzled and have a woodworking project today but will report back in the next day or 3, hopefully with positive results!!!


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## Fishnchamp1 (Dec 21, 2020)

Not perfect, but good enough for government work. :lol: :G Feelin like there’s a bit of an art to pour speed that is just gonna require practice. Thanks y’all!


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