Here is the objects after they spent the night in the "Pickle Jar" actually a mild acid called "Sparx"
GENERAL OBSERVATIONS AND CHANGES THAT NEED TO BE MADE
The MAJOR problem in the casting was my own fault. The investment is a critical step and I could not perform it totally because of the HUGE amount of investment that was required.
The objects burned out very well. No indications that there was any ash that remained after the vacuum with the sprue hold toward the vac plate. The investment is porus enough to pull air through the investment and pull the ash out. Then the canister is turned over on the vac plate and a vacuum is pulled while the molten metal is poured in.
MEDALLIONS
The Medallion canister required a HUGE amount of investment and I couldn't do a proper vacuum. The fix is for me to reshape the container to require less volume of investment.
The Medallion is too large. The fix is to see if we can reduce the size without losing the detail.
The Medallion surfaces are not all equal. The flags seem to be lower than the circle surfaces. Hopefully the depth of detail on the flags can be increased
The stars in the American Flag need to be more pronounced. Just dots would be ok as long as they are deeper
The Medallion mass is 114 g 4.1 oz avdp. Hopefully we can get the size down to get the mass down to about 31g or 1 oz troy
The 10 stars around the perimeter are outstanding in detail showing that I can cast the detail.
The maple leaf is also very very good.
It would help if the sprues could be directly built on the Medallion but it is far less critical on the Medallion when compared to the Weapons
WEAPONS
The Weapons are outstanding in terms of castability
The fins on the tails turned out exactly as the models
The fins on the models did not reproduce very well on the Stereo Lith OR they were damaged in transit. The fix is to make the fins somewhat thicker
The Weapons at this size need to be ONLY the actual shape. It is a waste of time to try to make them flat on the back
The best way to cast the Weapons is to sprue them about mid way on the length with a sprue that is about 30% of the diameter. OR two sprues that are about 25% of the diameter and at about the 1/3 points on the Weapon and coming to a single sprue sort of like a Y shape. The BEST fix is to have the sprues done while the StereoLith is being formed. Perhaps the sprue would be the support during the laser process and allow the fins to develop more securely.
Questions Welcome, they will make me think through the process being used.
----- Caster (RLW) -----