Casting Fail – sorta kinda
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Well … if I were a ‘Glass Half-Empty’ type I would call my first attempt at making a Two-Part RTV mold and then casting something in resin .. a FAIL! Since I’m basically a ‘Glass Half-Full’ type I will say .. *ahem* .. “It was a learning experience” …

Lessons learned –

  • *Pressure Chamber* – and say that again .. Press-urrre Chammm-berrr. It is obvious that I need this for both making the RTV mold and casting the parts. The RTV failed to fill the voids in the parts. The reason in part at least is the viscosity of the RTV I am using. This OOMOO 25 is rather thick stuff. I have been using it since it is for use WITHOUT a vacuum chamber etc.
  • Brush the RTV first: Ok. One thing I COULD have done is use a disposable brush and ‘paint’ the RTV into the recesses. This would force out the air that gets trapped simply from pouring RTV (and without using a PRESSURE CHAMBER)
  • The mold release I used wasn’t the best – which I found when separating the RTV halves. GET NEW MOLD RELEASE!
  • I printed the parts (Bridge Shoes) in WSF. MAKE THE SPRUES/RUNNERS LARGER!! reduce the size where they join to the part but make those suckers larger .. at least 2mm dia
  • Flat/Open Face molds: Try doing that using the piece of plexiglass to flatten the open side

Thee may be .. heck .. will be more items but that’s all I can come up with at this minute

This entry was posted in Casting, MicroMimesis, RTV by etraxx. Bookmark the permalink.

About etraxx

Retired from the Army in 2006. Served during Vietnam - 1969-1972 as as 72B - Communications Center Specialist (Teletype Operator). Got out .. and went back in 1987 as a 19K - Armor Vehicle Crewman - (M1/M1A1 tanker) getting out in Korea in 1999. Went into the Reserves .. got mobilized in 2001 .. stayed active until my retirement with 20 years in 2006.

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