I guess this is one way to make a metal model of your shoes!
Home Foundry
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ajoeiam
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I checked using the wayback machine (your search term) and it seems like there were a lot of 'snaps' (snapshots) of the forum.
You would be able to tell if everything is still there but to me it looked like everything was.
My problem would be that I would have to page through each tread to find what is useful and that's time consuming!!!!
Any suggestions on highlights or things to look for?
At time a foundries was simple.
They locate the foundry witch had good molding sand.
The furnace was just stack of bricks and used coal or charcoal AKA Blacksmith forge. The curable was just a household clay pot.
Today most use think oil bonded sand but large foundries still use water not oil.
I started a thread using Sodium Silicate with great for just few parts needed for model engine.
It is very strong and buy all materials from local stores.
Any can melt aluminum in simple backyard BBQ.
Patterns are still same as clay sand but less is need.
Hope this helps
Dave
Hi Dave !
Thanks for informations .
I have read a lot about casting here , watched many youtube videos about casting , but the Big Problem is not practice
I want to cast some parts for the engines I will make - just a few parts - like the picture attached
Build a small smelter - cast a few small samples - to practice before I can cast something more complex
Thanks for informations .
I have read a lot about casting here , watched many youtube videos about casting , but the Big Problem is not practice
I want to cast some parts for the engines I will make - just a few parts - like the picture attached
Build a small smelter - cast a few small samples - to practice before I can cast something more complex
If you are hoping to eventually cast something as complex as the above manifold then forget sand moulding , investment casting is the way to go.
Although some extra equipment is required and the process costs more , the learning curve is far less steep and results are easily achieved which far outway anything that the home sand foundry could produce.
This is a very simple steam manifold for a 5" gauge railway engine cast in red brass (gunmetal)
To cast this in sand would require core boxes to produce cores for the internal spaces as well as patterns .
As an investment casting the cement flows inside the hollow wax pattern to create the cores , this makes the production of such parts quite easy.
Although some extra equipment is required and the process costs more , the learning curve is far less steep and results are easily achieved which far outway anything that the home sand foundry could produce.
This is a very simple steam manifold for a 5" gauge railway engine cast in red brass (gunmetal)
As an investment casting the cement flows inside the hollow wax pattern to create the cores , this makes the production of such parts quite easy.
I haven't done investment castings, and so I can't add any information on that process.
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I was on Alloy Avenue (backyard casting forum) from 2011 to about 2017, and I read everything that was posted, daily, for about 8 years.
In the beginning, people were trying a lot of different methods/materials/techniques, and there was not so much a consensus about what worked and what did not work.
One guy who was learning how to cast gray iron was called "scavenger", and his posts were very interesting, since he poured a lot of iron for about 2 years, and he tried quite a few furnace and furnace lid designs, as well as burner designs.
The racing motorcycle cylinder castings by Jeff Henise "jhenise" were very impressive.
There were a lot of failures by myself and others over the years, and it became important to understand why a certain process or technique failed, and everyone weighed in on how best to do things.
Alloy Avenue was somewhat of a collective thing, group learning over time.
If you have a particular interest, such as "lost wax", or "investment casting", you could perhaps do searches for that, if searches work on the wayback machine.
I tried many types of burners and burner configurations, including siphon nozzle, drip-style, and Ursutz oil burners, propane burners, large burners, small burners, two siphon nozzles in a single burner tube, two siphon nozzle burners mounted at 180 degrees on a furnace, combination oil and propane burners, etc.
In the end, I decided to use a siphon-nozzle burner with diesel as a fuel, and I really like the controllability (wide operating range), and the fact that it will operate down to at least 34F without any problems with the diesel fuel being too cold, etc.
A siphon nozzle burner will light instantly using diesel, and no propane preheat is required, and can output full power without any warmup.
I still use a propane burner for small aluminum melts.
Several backyard casting folks use drip-type oil burners, but I could never get any significant fine control out of those, and they don't operate as smoothly and consistently as a siphon-nozzle burner.
Every type of homemade refractory was tried, and the consensus was finally reached that commercial refractory was well worth the expense, and it will typically hold up well over time.
I use a Mizzou 1" thick refractory hot face in my furnace.
And another big advantage to that forum is you could post your casting defects, and folks could generally zero in on what type of casting defect it was, and tell you how to avoid those defects.
The moderator for the Alloy Avenue forum was a mechanical engineering student named Ben Baker, and wrote a backyard casting guide, which is a pretty good resource in my opinion.
Ben's book is not the final word in backyard casting ideas, but is definitely a good start, and is free.
http://prometheus-foundry.com/The Hobbyist's Guide to Casting Metal--2nd Edition (web).pdf
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Here is a pretty good summary of common casting defects.
https://www.intouch-quality.com/blog/21-casting-defects-and-how-to-prevent-them-in-your-products
Casting defects that I have experienced include sand inclusions, when I used Petrobond with an iron casting, and the sand eroded due to the iron temperature and metal velocity, gas bubbles in aluminum castings, caused by overheating the aluminum and holding the aluminum for too long at elevated temperatures, and hard spots in thin gray iron parts due to a lack of the correct amount of ferrosilicon, and cooling that was too rapid.
I have seen hot tears in other's castings, and that can be caused by uneven solidification in the mold, where one part of the casting solidifies before the other, and thus metal is drawn across the mold from the hot part to the cold part during shrinkage/solidification.
I have seen people use too much ferrosilicon in iron, and this causes excessive shrinkage and hot tears.
You only need a slight amount of ferrosilicon in gray iron.
Pouring at too high of a temperature is probably the #1 cause of poor surface quality on castings.
The pour temperature should be as low as possible while still allowing full mold fill.
I often seen interrupted pours on youtube, where someone begins to pour metal down the sprue, then pauses for a fraction of a second (for whatever reason), and then begins to pour again. This should always be avoided.
And people often fail to keep the sprue full, and thus they entrain air into the metal stream.
You should always try to avoid any waterfalls, ie: keep the lip of the crucible as close to the top of the sprue as possible.
I often rest the crucible on the top of the mold when pouring, to eliminate almost all of the vertical column of molten metal.
Youtube backyard casting folks can often be seen vigorously stirring their aluminum melts, which is about the worst thing you can do with aluminum, and this mixes all sorts of oxide bifilms, slag, etc. into the metal, which will show up in the casting as defects. One should NEVER stir aluminum melts. Heat aluminum as fast as possible to pour temperature (about 1,350 F), then a quick skim to remove slag, and pour immediately.
Degassing is seldom required for aluminum if you don't overheat the melt, and if you pour immediately after reaching pour temperature, before the metal has time to absorb gas.
I failed to vent the top of one mold, and it trapped large air bubbles, and ruined the castings by leaving two voids that were perhaps 2" across, and about 1/2" deep.
The high points of the cope mold (cope is the top half of the mold) should be vented with small holes, perhaps 1/16" diameter holes or even a little less.
Some say that greensand does not need to be vented, but why take chances with something that can be added so easily and quickly?
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https://www.intouch-quality.com/blog/21-casting-defects-and-how-to-prevent-them-in-your-products
Casting defects that I have experienced include sand inclusions, when I used Petrobond with an iron casting, and the sand eroded due to the iron temperature and metal velocity, gas bubbles in aluminum castings, caused by overheating the aluminum and holding the aluminum for too long at elevated temperatures, and hard spots in thin gray iron parts due to a lack of the correct amount of ferrosilicon, and cooling that was too rapid.
I have seen hot tears in other's castings, and that can be caused by uneven solidification in the mold, where one part of the casting solidifies before the other, and thus metal is drawn across the mold from the hot part to the cold part during shrinkage/solidification.
I have seen people use too much ferrosilicon in iron, and this causes excessive shrinkage and hot tears.
You only need a slight amount of ferrosilicon in gray iron.
Pouring at too high of a temperature is probably the #1 cause of poor surface quality on castings.
The pour temperature should be as low as possible while still allowing full mold fill.
I often seen interrupted pours on youtube, where someone begins to pour metal down the sprue, then pauses for a fraction of a second (for whatever reason), and then begins to pour again. This should always be avoided.
And people often fail to keep the sprue full, and thus they entrain air into the metal stream.
You should always try to avoid any waterfalls, ie: keep the lip of the crucible as close to the top of the sprue as possible.
I often rest the crucible on the top of the mold when pouring, to eliminate almost all of the vertical column of molten metal.
Youtube backyard casting folks can often be seen vigorously stirring their aluminum melts, which is about the worst thing you can do with aluminum, and this mixes all sorts of oxide bifilms, slag, etc. into the metal, which will show up in the casting as defects. One should NEVER stir aluminum melts. Heat aluminum as fast as possible to pour temperature (about 1,350 F), then a quick skim to remove slag, and pour immediately.
Degassing is seldom required for aluminum if you don't overheat the melt, and if you pour immediately after reaching pour temperature, before the metal has time to absorb gas.
I failed to vent the top of one mold, and it trapped large air bubbles, and ruined the castings by leaving two voids that were perhaps 2" across, and about 1/2" deep.
The high points of the cope mold (cope is the top half of the mold) should be vented with small holes, perhaps 1/16" diameter holes or even a little less.
Some say that greensand does not need to be vented, but why take chances with something that can be added so easily and quickly?
.
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At the risk of being repetitive, I will add a few more comments on backyard casting, and how I learned the process (to date).
Chances are I may have already mentioned some of these items, given my current state of memory (or lack thereof), but some may get some use out of this.
When I got interested in building model steam engines in about 2007, I tried hogging/machining some engine parts out of large chunks of cast iron.
My machines are not very high quality, and not very rigid, and I found the hogging (heavy cutting) process to be inaccurate, time consuming, boring, and very tedious.
I decided that there must be a better way to make model engine parts, and so I started looking at foundry technology.
I looked at what others were doing on model engine forums, and backyard casting forums, and the only folks I recall who were doing extensive 3D modeling work for model engines were Brian Rupnow and a fellow from the UK named Rob Wilson.
It seems like Brian has been doing 3D modeling forever, and I could tell from his work that this was the future of modeling.
Rob Wilson built his own foundry, and began casting his own model engine parts, some of which were in gray iron.
Rob vanished from the internet after a short while (at least as far as what I can find), but his combination of 3D modeling and foundry work basically were what caused me to start learning foundry work.
I found a backyard casting forum called Alloy Avenue, and was on that for years.
A number of backyard casting folks are the art-casting type, and their work is often sort of avant-garde, as is often their attitude towards life, if that is a correct use of the description.
Alloy Avenue was useful for learning the fundamentals of melting metal, but the artwork castings are typically a bronze alloy, and the methods used to melt metal are often as simple as possible, and only complex enough to get bronze to pouring temperatures.
Art castings don't have to be perfect, and so any imperfections (large and small) are often just brazed up after the castings are made.
I had trouble finding anyone who was doing what Rob Wilson was doing, ie: designing his own steam engines, making the patterns, and then castings his own engine parts.
I ran across myfordboy on youtube, and those videos were pretty helpful in getting started with some rudimentary pattern making (in wood), and basic aluminum casting.
https://www.youtube.com/c/myfordboy/videos
I noticed that the guy who started Alloy Avenue was melting and casting gray iron, and so I decided that I had to learn how to do that.
I ran across "ironman" (he has many names; goes by "100model" on this forum).
He goes my "luckygen1001" on youtube.
https://www.youtube.com/user/luckygen1001/videos
Ironman is the best description for luckygen1001 because he has mastered the art of iron castings in a spectacular way.
I have learned a great deal from ironman's videos, and from direct conversations with him.
He has a long history of backyard iron casting, and makes excellent iron castings of all types.
He is by far the most knowledgeable iron caster I have ever met.
I ran across "olfoundryman", whose name is Martin, and he has some serious aluminum casting experience, and was a metalurgist at a foundry (as I understand it).
Martin is the best aluminum casting person I have ever run across.
https://www.youtube.com/channel/UC90RoN_IjSRF18jAG0HIA6g/videos
.
Chances are I may have already mentioned some of these items, given my current state of memory (or lack thereof), but some may get some use out of this.
When I got interested in building model steam engines in about 2007, I tried hogging/machining some engine parts out of large chunks of cast iron.
My machines are not very high quality, and not very rigid, and I found the hogging (heavy cutting) process to be inaccurate, time consuming, boring, and very tedious.
I decided that there must be a better way to make model engine parts, and so I started looking at foundry technology.
I looked at what others were doing on model engine forums, and backyard casting forums, and the only folks I recall who were doing extensive 3D modeling work for model engines were Brian Rupnow and a fellow from the UK named Rob Wilson.
It seems like Brian has been doing 3D modeling forever, and I could tell from his work that this was the future of modeling.
Rob Wilson built his own foundry, and began casting his own model engine parts, some of which were in gray iron.
Rob vanished from the internet after a short while (at least as far as what I can find), but his combination of 3D modeling and foundry work basically were what caused me to start learning foundry work.
I found a backyard casting forum called Alloy Avenue, and was on that for years.
A number of backyard casting folks are the art-casting type, and their work is often sort of avant-garde, as is often their attitude towards life, if that is a correct use of the description.
Alloy Avenue was useful for learning the fundamentals of melting metal, but the artwork castings are typically a bronze alloy, and the methods used to melt metal are often as simple as possible, and only complex enough to get bronze to pouring temperatures.
Art castings don't have to be perfect, and so any imperfections (large and small) are often just brazed up after the castings are made.
I had trouble finding anyone who was doing what Rob Wilson was doing, ie: designing his own steam engines, making the patterns, and then castings his own engine parts.
I ran across myfordboy on youtube, and those videos were pretty helpful in getting started with some rudimentary pattern making (in wood), and basic aluminum casting.
https://www.youtube.com/c/myfordboy/videos
I noticed that the guy who started Alloy Avenue was melting and casting gray iron, and so I decided that I had to learn how to do that.
I ran across "ironman" (he has many names; goes by "100model" on this forum).
He goes my "luckygen1001" on youtube.
https://www.youtube.com/user/luckygen1001/videos
Ironman is the best description for luckygen1001 because he has mastered the art of iron castings in a spectacular way.
I have learned a great deal from ironman's videos, and from direct conversations with him.
He has a long history of backyard iron casting, and makes excellent iron castings of all types.
He is by far the most knowledgeable iron caster I have ever met.
I ran across "olfoundryman", whose name is Martin, and he has some serious aluminum casting experience, and was a metalurgist at a foundry (as I understand it).
Martin is the best aluminum casting person I have ever run across.
https://www.youtube.com/channel/UC90RoN_IjSRF18jAG0HIA6g/videos
.
There was a fellow in Texas who went by the screen name "scavenger", and he built an iron foundry, and was in the iron casting business for a while, selling replacement hit-and-miss mufflers (full sized) on ebay.
I watched scavenger's threads carefully, and since he did a lot of iron melts, he basically had to discover what would hold up long-term at iron temperatures, as far as refractory, construction methods, etc.
Scavenger has vanished like many others, into the internet ether, never to be heard from again.
.
I watched scavenger's threads carefully, and since he did a lot of iron melts, he basically had to discover what would hold up long-term at iron temperatures, as far as refractory, construction methods, etc.
Scavenger has vanished like many others, into the internet ether, never to be heard from again.
.
Another person I ran across was Bob Puhakka, and he use to have a number of foundry videos online.
Bob uses John Campbell's methods, and he operates his own foundry in Canada.
Bob's story is that he started a consulting firm to teach foundries how to apply and use John Campbell's and I guess some of his own methods to improve productivity and casting quality.
Bob ended up purchasing an aluminum foundry, and applied John Campbell's techniques.
Bob makes world-class aluminum castings, certified by xray and other means.
Bob is a colorful and outspoken individual, and backyard casting people either seem to love Bob and his castings/methods, or profusely hate him and his castings/methods.
I don't really care what sort of personality Bob has.
I appreciate his frankness, believe in his and John Campbell's methods, and aspire to making world-class castings as he does.
Bob Puhakka and John Campbell are very close friends.
.
Bob uses John Campbell's methods, and he operates his own foundry in Canada.
Bob's story is that he started a consulting firm to teach foundries how to apply and use John Campbell's and I guess some of his own methods to improve productivity and casting quality.
Bob ended up purchasing an aluminum foundry, and applied John Campbell's techniques.
Bob makes world-class aluminum castings, certified by xray and other means.
Bob is a colorful and outspoken individual, and backyard casting people either seem to love Bob and his castings/methods, or profusely hate him and his castings/methods.
I don't really care what sort of personality Bob has.
I appreciate his frankness, believe in his and John Campbell's methods, and aspire to making world-class castings as he does.
Bob Puhakka and John Campbell are very close friends.
.
In one of Bob Puhakka's videos (they have all vanished into the internet ether unfortunately), he discusses "bifilms", and talks about why they are important to control.
If you think about molten aluminum as it is poured and flows into the mold, the outer surface solidifies into a very thin skin as the metal is flowing.
The skin does not cause problems as long as the metal flow into the mold is smooth and uniform.
If the molten aluminum is disrupted during the pour, the outer skin on the metal is churned into the flowing metal, and the end result is weak spots in the casting.
If you are making structural-grade aluminum castings, or pressure-tight castings, you should pay very close attention to controlling bifilms.
Lucky for me, gray iron does not seem to have bifilm problems, at least as far as I can tell.
.
If you think about molten aluminum as it is poured and flows into the mold, the outer surface solidifies into a very thin skin as the metal is flowing.
The skin does not cause problems as long as the metal flow into the mold is smooth and uniform.
If the molten aluminum is disrupted during the pour, the outer skin on the metal is churned into the flowing metal, and the end result is weak spots in the casting.
If you are making structural-grade aluminum castings, or pressure-tight castings, you should pay very close attention to controlling bifilms.
Lucky for me, gray iron does not seem to have bifilm problems, at least as far as I can tell.
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So as I have learned about casting methods and materials from various sources and people, I have taken notes.
I compare what each successful casting person is doing with the patterns, molds and sand types, sprues, runners, gates, risers, burner types, refractory types, etc.
Along the way, I have discovered a few myths that are very pervasive, because they were seen on popular youtube channels, and so got viewed and repeated over and over.
One myth is using washing soda as a degassing agent for aluminum.
If you dump washing soda into molten aluminum, you will see a gassing effect, and so one would think that the washing soda is removing dissolved hydrogen from the melt.
But if you do like I and others have, and bake your washing soda in the oven to get it completely dry, then you discover that when you add it to molten aluminum, there is no gassing at all, and it has no effect at all on the aluminum, but instead just floats as a powder on top the melt.
There is a degassing agent that does work with aluminum, and I forget the name of the product.
"Masteryoda" (a member here) told me what he uses.
If you do use any material for aluminum degassing, be aware that it may produce very toxic fumes that must be avoided.
.
I compare what each successful casting person is doing with the patterns, molds and sand types, sprues, runners, gates, risers, burner types, refractory types, etc.
Along the way, I have discovered a few myths that are very pervasive, because they were seen on popular youtube channels, and so got viewed and repeated over and over.
One myth is using washing soda as a degassing agent for aluminum.
If you dump washing soda into molten aluminum, you will see a gassing effect, and so one would think that the washing soda is removing dissolved hydrogen from the melt.
But if you do like I and others have, and bake your washing soda in the oven to get it completely dry, then you discover that when you add it to molten aluminum, there is no gassing at all, and it has no effect at all on the aluminum, but instead just floats as a powder on top the melt.
There is a degassing agent that does work with aluminum, and I forget the name of the product.
"Masteryoda" (a member here) told me what he uses.
If you do use any material for aluminum degassing, be aware that it may produce very toxic fumes that must be avoided.
.
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Another item that I consider a myth is the need for a pouring basin.
Many folks, even very experienced casting folks, will insist that a pouring basin must be used in order to get good castings.
But if you look at what happens when you pour any liquid, including liquid metal, into a basin, you should realize that this process churns air, bifilms, slag, sand, and other unwanted material into the melt, and does far more damage than any perceived good that it is suppose to deliver.
Here is a video of a liquid pouring simulation:
Some will point out that they use a pouring basin, and they get great castings.
For hobby work, and non-structural work in aluminum, few things are critical.
If you do more critical aluminum work, you should consider eliminating the pour basin.
.
Many folks, even very experienced casting folks, will insist that a pouring basin must be used in order to get good castings.
But if you look at what happens when you pour any liquid, including liquid metal, into a basin, you should realize that this process churns air, bifilms, slag, sand, and other unwanted material into the melt, and does far more damage than any perceived good that it is suppose to deliver.
Here is a video of a liquid pouring simulation:
Some will point out that they use a pouring basin, and they get great castings.
For hobby work, and non-structural work in aluminum, few things are critical.
If you do more critical aluminum work, you should consider eliminating the pour basin.
.
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I often hear that you should never pour straight down the sprue, but this is indeed the method I use.
Most folks on youtube pour their metal with the crucible elevated some height above the top of the sprue (the sprue is the hole in the sand into which you pour the metal), and this should never be done.
The lip of the crucible should be as close to the top of the sprue as possible, to avoid a waterfall effect, which can entrain air and slag into the melt.
There should be a trap at the end of the horizontal runner, such that the initial flow of metal that contains air and slag has somewhere to go before metal begins to enter the mold cavity.
The sprue should be sized so that it fills very quickly, and remains full during the entire pouring process.
If the pour is interrupted for any reason, you will aspirate air down the spure, interrupt the mold filling process, and generally ruin the casting.
The sprue should transition smoothly from vertical to horizontal, to prevent turbulence in the metal.
Turbulence anywhere in your sprue/runner/gate/mold system will churn air, slag, bifilms, and often mold sand into the casting, causing defects.
I generally use a 3" diameter short length of steel pipe (perhaps 1" long) at the sprue, just to catch any initial spill from when the pour starts.
You can practice pouring water from a container into a small opening or basin, and try to keep the sprue full, minimize splashing and turbulence, and avoid the waterfalling. Pouring metal from a crucible into a sprue is a bit of an art, and you get better at it as you go.
Ironman (luckygen1001) has excellent pour control with minimal spill, most of the time.
Watch his videos to get an idea of good pour technique.
.
Most folks on youtube pour their metal with the crucible elevated some height above the top of the sprue (the sprue is the hole in the sand into which you pour the metal), and this should never be done.
The lip of the crucible should be as close to the top of the sprue as possible, to avoid a waterfall effect, which can entrain air and slag into the melt.
There should be a trap at the end of the horizontal runner, such that the initial flow of metal that contains air and slag has somewhere to go before metal begins to enter the mold cavity.
The sprue should be sized so that it fills very quickly, and remains full during the entire pouring process.
If the pour is interrupted for any reason, you will aspirate air down the spure, interrupt the mold filling process, and generally ruin the casting.
The sprue should transition smoothly from vertical to horizontal, to prevent turbulence in the metal.
Turbulence anywhere in your sprue/runner/gate/mold system will churn air, slag, bifilms, and often mold sand into the casting, causing defects.
I generally use a 3" diameter short length of steel pipe (perhaps 1" long) at the sprue, just to catch any initial spill from when the pour starts.
You can practice pouring water from a container into a small opening or basin, and try to keep the sprue full, minimize splashing and turbulence, and avoid the waterfalling. Pouring metal from a crucible into a sprue is a bit of an art, and you get better at it as you go.
Ironman (luckygen1001) has excellent pour control with minimal spill, most of the time.
Watch his videos to get an idea of good pour technique.
.
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Another myth that I see over and over is the need for a very tall sprue in order to get a complete mold fill.
Ironman pointed out this myth to me.
I never use an elevated sprue, and I don't have mold fill problems.
If your mold is gated correctly, you should not need an elevated sprue.
An elevated sprue just exacerbates problems with excessive metal velocity.
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Ironman pointed out this myth to me.
I never use an elevated sprue, and I don't have mold fill problems.
If your mold is gated correctly, you should not need an elevated sprue.
An elevated sprue just exacerbates problems with excessive metal velocity.
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I'm enjoying this thread, and appreciate all the links to informative videos. But without actually watching all of them, it's hard to tell what exactly you all are doing in order to cast good iron engine parts in your back yards. Can you summarize the process for us? I gather this involves melting iron in a crucible furnace and pouring it into a mold. But what sort of furnace are we talking about? Is it one of those naturally-aspirated propane-fired things that are so popular these days? Or do you have to do something special to get up to iron-melting temperatures?
Are you making sand molds or doing some kind of lost-material casting? If it's sand, does regular Petrobond work, or is something more refractory required? For the lost-wax (or whatever) molds, are people really mixing up ceramic shell and keeping it perpetually mixing, or is there a simpler method? I've done a lot of non-ferrous metal casting, (being one of those Bohemian arty types) but never tried iron. Is it maybe not as problematic as I've always thought?
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