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Bullion.Forum
Making a gas furnace... _gasmeltfurnace_
- Thread starter samuel-a
- Start date
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Interesting way to introduce gas to the furnace burner, also a neat idea with the variable speed fan.
The underwater camera shot with sound is amazing, I wonder how that was done without damaging the camera from water or hot metals...
As usual Sam, I love seeing your videos, they are always great.
The underwater camera shot with sound is amazing, I wonder how that was done without damaging the camera from water or hot metals...
As usual Sam, I love seeing your videos, they are always great.
rewalston
Well-known member
I wasn't able to view the video, I have audio but no video. I've had no problem watching any of Sam's other videos though. Maybe a little stuttering, tried both the system default player as well as youtubes html5 player (chosen under settings on the video). Any ideas?
philddreamer
Well-known member
Awesome video Sam!!! 8)
Thanks!
Phil
Thanks!
Phil
Cool video, I like the idea of using ceramic wool as a furnace liner.
To embed the video just drop the s in the "https://..." like this
[youtube]http://www.youtube.com/watch?v=0XlCcQMRM9E[/youtube]
Göran
To embed the video just drop the s in the "https://..." like this
Code:
[youtube]http://www.youtube.com/watch?v=0XlCcQMRM9E[/youtube]Göran
GotTheBug
Well-known member
- Joined
- Sep 25, 2012
- Messages
- 373
Loved it Sir. A mix of bentonite clay and sand as a refractory lining seems to help the ceramic last longer in my "little furnace". Excellent build I think! Looks like you had it up to enough temp at one point to "remove" the paint on the outside of the pail also. 
rewalston
Well-known member
Go figure the video wouldn't play on youtube, but I can watch it just fine from Goran's post...
Rusty
Rusty
Irons
Well-known member
g_axelsson said:
Goran,
I have found that Flux vapors quickly degrade the Ceramic Fiber. It becomes brittle and just crumbles away. Coating the inside with a Refractory Clay wash solves the problem.
Great Vid, Sam. I like the holes in the crucible to pour shot. Clever.
etack
Well-known member
I have to agree with Irons that holey crucible ROCKS!
Eric
Eric
Nice work, if you want spherical casting grain, use highly agitated, cold water. Alternatively, you can make nice shot by putting a wood board or piece of graphite and pouring onto that.
samuel-a
Well-known member
- Joined
- Oct 7, 2009
- Messages
- 2,190
Thank you guys for the kind words.
Butcher - The camera i used for the underwater shot is GoPro, it is an "extreme" camera as they call it and it has a casing that is designed to be water and shock proof.
Göran - Thanks for the embedding tip!
GotTheBug and Irons - Yes, i totally agree. The blanket is indeed more susceptible to degrade by flux fumes. There are "spay on" refractory clay/cement and also silicate based nano-suspensions to rigidize and protect it. I hear a good rigidizer makes it hard as a brick, you position the blanket in any shape you need and after the first heating run it sets, however i never tried it.
Lou - Thanks, i actually am using a water pump inside the bucket to circulate the water around, but i couldn't get a clear shot while the water was spinning around. I have seen it done similarly in Umicore, where they had a huge water tank and the water was swirling like crazy. the tank sits under the vertical "tapping" hole which is basically a multple holes grphite die, about 10-15 holes.
Anyways, the silver/gold shot are later screend for re-cast small and large rejects, Here below is a screening kit i'm using:
For size reference, each tile on the floor is 1ft long
Butcher - The camera i used for the underwater shot is GoPro, it is an "extreme" camera as they call it and it has a casing that is designed to be water and shock proof.
Göran - Thanks for the embedding tip!
GotTheBug and Irons - Yes, i totally agree. The blanket is indeed more susceptible to degrade by flux fumes. There are "spay on" refractory clay/cement and also silicate based nano-suspensions to rigidize and protect it. I hear a good rigidizer makes it hard as a brick, you position the blanket in any shape you need and after the first heating run it sets, however i never tried it.
Lou - Thanks, i actually am using a water pump inside the bucket to circulate the water around, but i couldn't get a clear shot while the water was spinning around. I have seen it done similarly in Umicore, where they had a huge water tank and the water was swirling like crazy. the tank sits under the vertical "tapping" hole which is basically a multple holes grphite die, about 10-15 holes.
I think i have an idea, but could you elaborate more? how should it work?Lou said:
Anyways, the silver/gold shot are later screend for re-cast small and large rejects, Here below is a screening kit i'm using:
For size reference, each tile on the floor is 1ft long
What do you do with oversize, remelt it?
Be careful in melting the silver too much--it will be useless for making bullion bars because of the oxygen. Your size distribution is odd--typically mine are no smaller than 2 mm and no bigger than 5 mm. Shovels nicely.
I melt silver with induction usually when shotting with an argon cover, but I greatly prefer gas furnaces (for silver, at least) for the reason of atmosphere control. A slightly rich flame does wonders for cast bars. There are other things to remediate silver instead of refining. A gram of lithium per 1000 oz is rather effective, causing a quick boil as dissolved oxygen reacts with the lithium that dissolves in the silver.
Also, I suggest you look into some ITC-100 for the kaowool...will greatly extend its lifespan.
Another trick for that little bit of oxide smut in the video: a pinch of sodium carbonate and a small piece of pyrex glass. Clings all the oxides away and sticks to the crucible. If it's really heavy in slag/using old crucible, a stainless rod can be used to roll up a ball of flux glass--just be careful not to get it on you (far worse thermal burns due to the viscosity!).
I melt silver with induction usually when shotting with an argon cover, but I greatly prefer gas furnaces (for silver, at least) for the reason of atmosphere control. A slightly rich flame does wonders for cast bars. There are other things to remediate silver instead of refining. A gram of lithium per 1000 oz is rather effective, causing a quick boil as dissolved oxygen reacts with the lithium that dissolves in the silver.
Also, I suggest you look into some ITC-100 for the kaowool...will greatly extend its lifespan.
Another trick for that little bit of oxide smut in the video: a pinch of sodium carbonate and a small piece of pyrex glass. Clings all the oxides away and sticks to the crucible. If it's really heavy in slag/using old crucible, a stainless rod can be used to roll up a ball of flux glass--just be careful not to get it on you (far worse thermal burns due to the viscosity!).
samuel-a
Well-known member
- Joined
- Oct 7, 2009
- Messages
- 2,190
Thank you for the tips Lou.
Here's the PSD i took from the last silver pour:
0.41% <0.85mm (reject)
3.3% 0.85-2.38mm
38.45% 2.38-4mm
57.84% >4mm
It also has a lot to do with the pouring holes size. Originally i used 3mm diameter holes (with swirling of water) which produced smaller grains and tighter PSD.
But demand from clients was for bigger grains so i'm now pouring through 4mm pouring holes.
For gold i'm still using 3mm pouring holes.
Here's the PSD i took from the last silver pour:
0.41% <0.85mm (reject)
3.3% 0.85-2.38mm
38.45% 2.38-4mm
57.84% >4mm
It also has a lot to do with the pouring holes size. Originally i used 3mm diameter holes (with swirling of water) which produced smaller grains and tighter PSD.
But demand from clients was for bigger grains so i'm now pouring through 4mm pouring holes.
For gold i'm still using 3mm pouring holes.
Glad to help! I like the educational aspect of your vids. I'm next door to Israel this week. Shame I won't have time to visit Israel this trip, I have some friends/customers I could have seen..
Seems like the polydispersity index isn't too bad. Normally, I just put the tundish on the top of the furnace exhaust and heat it until it glows.
Seems like the polydispersity index isn't too bad. Normally, I just put the tundish on the top of the furnace exhaust and heat it until it glows.
philddreamer
Well-known member
Hi Sam!
I just finished a prototype for incinerating black chips. It worked! 8)
I used 1 inch x 3 inch x 18 inches kawool bricks.
After pre-heating the furnace for about 15 minutes, I tested several types of chips; square black ones burned within 5 seconds. Same as the long IC. A BGA, same. The green fiber from a pin less P4 was the worst! About 10 seconds and some smoke.
Thanks for sharing!
Phil
I just finished a prototype for incinerating black chips. It worked! 8)
I used 1 inch x 3 inch x 18 inches kawool bricks.
After pre-heating the furnace for about 15 minutes, I tested several types of chips; square black ones burned within 5 seconds. Same as the long IC. A BGA, same. The green fiber from a pin less P4 was the worst! About 10 seconds and some smoke.
Thanks for sharing!
Phil
