Beautiful job. Doesn’t get any better than that!
Triumph T120 Boneville 2 cylinders, castings with Petrobond and Lost PLA
- Thread starter Foketry
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I think he talked about this in another thread.
I can't recall the details, but plaster is inexpensive and readily available about anywhere.
I would guess as long as it does not crack during burnout, it would work (obviously it did work, or we would not have photos).
I also seem to recall that it is more a matter of cleaning off the investment material after casting.
Some investment materials may be easier to clean off of the cast metal.
I have seen some attempt to use concrete for furnace refractory, and concrete does somehow trap moisture, and it will explode when heated, even if it is fully cured.
Apparently plaster does not trap moisture when it cures.
.
I can't recall the details, but plaster is inexpensive and readily available about anywhere.
I would guess as long as it does not crack during burnout, it would work (obviously it did work, or we would not have photos).
I also seem to recall that it is more a matter of cleaning off the investment material after casting.
Some investment materials may be easier to clean off of the cast metal.
I have seen some attempt to use concrete for furnace refractory, and concrete does somehow trap moisture, and it will explode when heated, even if it is fully cured.
Apparently plaster does not trap moisture when it cures.
.
The plaster was at about 300 degrees C, aluminum 750 degrees C
It's not perfect but it's acceptable, but I made 4 scrap pieces before I got an acceptable head.
The double cylinder instead came out fine right away
Some 3D printed pieces covered in plaster.
For these I didn't use plaster but a first layer of about 5 mm of ceramic powder and filling with white cement grade 500
I use these 2 powder materials for 2 reasons:
1) Ceramic powder is more heat resistant than foundry plaster, but it is much more difficult to remove from the casting. Foundry plaster is often cracked, allowing molten metal to escape.
For safety reasons I always put the ceramic/cement block in a steel container to avoid the leakage of molten metal that could get on my feet
2) I use filler cement because it costs much less than plaster
For these I didn't use plaster but a first layer of about 5 mm of ceramic powder and filling with white cement grade 500
I use these 2 powder materials for 2 reasons:
1) Ceramic powder is more heat resistant than foundry plaster, but it is much more difficult to remove from the casting. Foundry plaster is often cracked, allowing molten metal to escape.
For safety reasons I always put the ceramic/cement block in a steel container to avoid the leakage of molten metal that could get on my feet
2) I use filler cement because it costs much less than plaster
I would really like to try some investment casting, especially after seeing these castings.
Perhaps one day I will get the time to give it a try.
Nice work !
.
Perhaps one day I will get the time to give it a try.
Nice work !
.
4 heads rejected, the fins did not fill or in areas with a lot of material, the material shrinkage caused cavities and depressions
I solved it by changing the size and the areas where to position the sprues
I solved it by changing the size and the areas where to position the sprues
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