unobtanium seems to be out of stock.
Sand casting unobtainium parts at home.
- Thread starter 56 Fregate
- Start date
Those of course are reo drawings, I have an inexhaustible supply of discarded A1 and A0 paper
As long as you don't get your projects mixed up! 
Meh! Filled with naïve optimism and arrogant confidence I made my second attempt at home sand casting for amaters. This time it was hinge components made in a closed sand mould and in the process I learned/re-learned many things.
Thing 1: I have never enjoyed working in aluminium
Thing 2: Working with cast aluminium is not enjoyable
Thing 3: I need to allow more fat for metal shrinkage
Thing 4: the composition and moisture content of greensand is critical to success
Thing 5: There is enormous potential for making things with the home sand casting operation
Thing 6: Sand casting is not rocket science and well within the scope of the home hack
I made 3 attempts at casting a pair of hinge components,
1. Was a complete failure due to metal shrinkage and will be scrapped
2. Was better and I just got away with it
3. Was a tad better again and after a bit of a clean up it is ready for drilling and machining
These components will be mostly hidden from view in the final stage and the bit that is visible will be painted anyway so any inperfections in the 'show bit'can be filled with epoxy. I had no issues with gas bubbles or porosity.
Baby steps yes but look out world here I cometh.
Thing 1: I have never enjoyed working in aluminium
Thing 2: Working with cast aluminium is not enjoyable
Thing 3: I need to allow more fat for metal shrinkage
Thing 4: the composition and moisture content of greensand is critical to success
Thing 5: There is enormous potential for making things with the home sand casting operation
Thing 6: Sand casting is not rocket science and well within the scope of the home hack
I made 3 attempts at casting a pair of hinge components,
1. Was a complete failure due to metal shrinkage and will be scrapped
2. Was better and I just got away with it
3. Was a tad better again and after a bit of a clean up it is ready for drilling and machining
These components will be mostly hidden from view in the final stage and the bit that is visible will be painted anyway so any inperfections in the 'show bit'can be filled with epoxy. I had no issues with gas bubbles or porosity.
Baby steps yes but look out world here I cometh.
Monsieur Ando.
In attempt 1: I made the gate too small and the shrinkage depleted the metal reservoir in the gate
In attempt 2: I made the gate bigger which helped but still not ideal
In attempt 3: I did away with the gate and had the sprew spewing metal straight into the guts of the sand mould which can lead to sand erosion and therefor not ideal
In any case after some consideration I have decided tro scrap all three examples and accept last Fridays effort as a day in the classroom learning the craft. I have since fattened up my timber patterns to account for shrinkage and will try again another day.
In attempt 1: I made the gate too small and the shrinkage depleted the metal reservoir in the gate
In attempt 2: I made the gate bigger which helped but still not ideal
In attempt 3: I did away with the gate and had the sprew spewing metal straight into the guts of the sand mould which can lead to sand erosion and therefor not ideal
In any case after some consideration I have decided tro scrap all three examples and accept last Fridays effort as a day in the classroom learning the craft. I have since fattened up my timber patterns to account for shrinkage and will try again another day.
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Ando, I would be interested to see if the Chinese have managed to eliminate small gas bubbles in the their sand castings, any pics? I've made this art-deco door handle and have many small bubbles which are too small to measure but it won't matter in my case because I will be getting my parts chromed. There is a bit of science involved in eliminating these small gas defects involving degassing wands and argon gas.
I see your work is coming along nicely...
The object I received has a smooth surface with no obvious air bubbles, though to be fair, I dare say whoever made it does it for a living!
It's about 120mm long. I can find no record of ordering such a thing, and haven't the slightest idea what it is!
The object I received has a smooth surface with no obvious air bubbles, though to be fair, I dare say whoever made it does it for a living!
It's about 120mm long. I can find no record of ordering such a thing, and haven't the slightest idea what it is!
Hey, neat photo Ando, is that you in the reflection with a smoke hanging out of your mouth? As for what the object is, I couldn't begin to guess!
Well your photographer added a nice arty touch Ando!
Yeah nice try, I think it's a setup..
In other news; After 11 failed attempts I have two hollow castings to add to my collection, these will get linished tomorrow ready for chrome plating. The core was made of weak sand/plaster mix and broke up easily after casting. The blind feeder shown in the pic is huge but is what it took to get a solid casting (s).
Doubting Thomases everywhere.
More adventures from the home hack sand caster. Personal best today cos I got one right the first go. This object gets painted so no more linishing required. Granted the logo didn't come out but it was a little ambitious for a sand cast anyway. All is not lost though because I know this guy who knows acid etching..
That looks like the Q/C has finally caught up! Brilliant!
