Very interesting sand molding method.

[airmodel]

If you think that you have good sand molding skills watch this video and try this method.
<a href="https://www.youtube.com/watch?v=LqJlKLDUJLI" target="_blank">http://www.youtube.com/watch?v=LqJlKLDUJLI</a>

[CI]

That's some trick molding there.
Amazing what they use to do with greensand.
.

[CI]

An example of how the above type of intricate molding was used to make engine, look at the Soule Speedy Twin steam engine passage molding.
I was surprised at how intricate the cores and patterns were/are for a Soule Speedy Twin.
I am pretty sure they used greensand molds with linseed oil cores.
Lots of chaplets to secure the cores, and you can see the surface of some of the chaplets if you look closely at the exterior of the engine where the passages are located.

Fascinating engine because the steam chests at each side are not pressurized like a typical steam engine, although I think they do see some momentary pressure when the engine is reversed.
The pressurized steam chest is on the top of the engine, and it contains the reversing valve, which is a simple manually operated D-valve.
The valve is like three D-valves connected.
Two eccentrics, with no reversing gear, but totally and quickly reversible.

Edit:
The actual passages have rounded edges/corners, not square as I model them.
.

[vtsteam]

I like it a lot @airmodel , not only for the skill involved, but I think the finished product is really handsome -- at least to me. Ought to be in a museum somewhere.

I'd like to try it, with little chance of not spoiling the mold a number of times -- question is, how many times before I give up? You have to have very steady hands for a lot of it, maybe steadier than I have. Then there's the problem of how hard the various greensand cores get compacted. And then there's the pour. And then...

Luckily my casting area is presently snowed in and way too cold to work at, so I have an excuse not to even try!

[vtsteam]

The two worst parts, for me at least, would be removing the ball with tweezers without dropping, and hanging the handle's greensand core with gaggers. How does he do that? -- The only way you can come in on it with the nail is though the end. But those ends are blocked by the flask sand.

I guess you could dig away a small section, then nail into the other side, and re-fill. Not shown, but that's all I can figure. That particular greensand core must have a lot of binder in it to hang together after removal, replacement, and pinning. I'd add a little more clay for it alone.

You also want to pick a cup with a mostly cylindrical handle hole, beefy squarish handle and a mostly conical cup shape (all of which his has) to make it a little more do-able.

[airmodel]

question is, how many times before I give up?

I had the same thoughts. I remember when I purchased for the first time sodium silicate because I was having trouble using green sand. The foundry supplier said to me that any fool could use sodium silicate to make a mold and it was a replacement for green sand and skilled molders. About 3 years later I started to use green sand again and I would never go back to using sodium silicate. Complex statues of humans and animals were made with green sand before lost wax was developed.

[airmodel]

You also want to pick a cup with a mostly cylindrical handle hole, beefy squarish handle

I think the most difficult part is making a green sand core with prints and removing that core without breaking and then replacing it back into the mold.

He makes it look easy but I know from experience green sand cores can be a problem.

[vtsteam]

@airmodel, maybe you could use some of those semi-circular shaped needles -- or a wire equivalent -- to pin the handle core without digging away some of the sand?

I also don't get exactly how he held it there while fastening, and keept it intact. It must have been very strong sand.

Tweezers have to extend down past the marble midline so will damage the bottom of the core there. Will need repair.

Big question... do you think the final product had some grinding/clean-up on it?

I'm keeping my eye out for a cup somewhat like that one....

[vtsteam]

You also want to pick a cup with a mostly cylindrical handle hole, beefy squarish handle

I think the most difficult part is making a green sand core with prints and removing that core without breaking and then replacing it back into the mold.

He makes it look easy but I know from experience green sand cores can be a problem.

Prints? The handle core is just flat to the edges of the handle, I thought. So free-standing -- which is why it had to be pinned in place.

[petertha]

I'm not into casting (unless you include YouTube grazing, in which case I'm practically Yoda level haha). I'd like to one day, but it seems to be a whole hobby & specialized equipment setup unto itself. But I have a naïve, novice question after watching videos like RotarySMP casting aluminum parts for his Redrup radial replica. He uses 3DP parts to make patterns, but many of the casting molds are 'plain' sand with water glass (sodium silicate) mixed, tamped around the pattern & cured by CO2 gas. Aside from all the common trials & tribulations specific to preparing the aluminum melt, temp, ingredients, mold design... the resultant parts look pretty darn nice. Many castings with more complex internal shapes requiring cores. Why isn't this method a lot more popular with model engineers vs Petrobond or shop made oil/sand/clay recipes & the muller & recycling the more valuable sand? It would seem to me like a no brainer to buy very inexpensive clean sand, the goop, CO2 gas from any weld shop & you are off to the races. Maybe even finer sand mesh from ceramic supply shops for better detail. Yes, the spent molds become waste products, no recycling of material. OTOH essentially low strength 'rocks' wherever one can safely toss them. What am I missing, surely something?

https://www.youtube.com/@RotarySMP

[vtsteam]

I'm not into casting (unless you include YouTube grazing, in which case I'm practically Yoda level haha). I'd like to one day, but it seems to be a whole hobby & specialized equipment setup unto itself. But I have a naïve, novice question after watching videos like RotarySMP casting aluminum parts for his Redrup radial replica. He uses 3DP parts to make patterns, but many of the casting molds are 'plain' sand with water glass (sodium silicate) mixed, tamped around the pattern & cured by CO2 gas. Aside from all the common trials & tribulations specific to preparing the aluminum melt, temp, ingredients, mold design... the resultant parts look pretty darn nice. Many castings with more complex internal shapes requiring cores. Why isn't this method a lot more popular with model engineers vs Petrobond or shop made oil/sand/clay recipes & the muller & recycling the more valuable sand? It would seem to me like a no brainer to buy very inexpensive clean sand, the goop, CO2 gas from any weld shop & you are off to the races. Maybe even finer sand mesh from ceramic supply shops for better detail. Yes, the spent molds become waste products, no recycling of material. OTOH essentially low strength 'rocks' wherever one can safely toss them. What am I missing, surely something?

https://www.youtube.com/@RotarySMP

Why doesn't everybody use aluminum for models? Easier to machine, etc.etc?

Same thing, it's personal choice. I don't think there's any lack of people using waterglass/CO2 .........or Petrobond, or clay and sand greensand, or 3D patterns, or wooden, or composite patterns, or lost foam process, lost wax, etc. etc.

People are varied in their tastes, skills, experience, relative wealth, training, reference material, materials access, etc., etc. This is a varied hobby which is a good thing -- something interesting pops up every day. Least I think so.

For me, I like traditional clay/sand greensand with mostly wooden patterns, simple basic inexpensive materials,,,,,and I get results I'm happy with most of the time. It's a personal interest to do the best I can that way.

Different folks, different strokes.

[airmodel]

Big question... do you think the final product had some grinding/clean-up on it?

I'm keeping my eye out for a cup somewhat like that one....

There has to be some cleanup because there were 5 ingates connected to the saucer and maybe in other parts of the casting.

It took me a long time to find that exact style of cup and a few months before I thought of making this video I threw that cup out!

Something great happened, one of my viewers decided after watching my video to have a go at making the cup,saucer, spoon and ball bearing in green sand. It took him about three hours to make up the mold and poured it with a zinc alloy. Click onto the link to see the photos of the casting and sand mold. https://www.youtube.com/post/UgkxF5YVfAhOo3rZv25QowqnFykeUm2P0Dal

[vtsteam]

Excellent -- especially with zinc alloy! I've cast a fair amount with it, and there isn't a big margin of retained heat between melting and fuming temps, so to fill a thin cavity, and as you say fill to the handle end of the spoon is fine achievement here. Also avoiding a shrink cavity in the marble part -- Hat's off!