FAIL!!!
Posted: Sat May 08, 2010 2:50 pm
well I cannot let JSR have all the fail fame so, here is what happened
Today I decided that the time has come that I am going to make myself A hybrid. the hybrid I am going to make is going to be made from T6 aluminum (6061) and every thing went smoothly except I forgot one small thing and that ruined the combustion chamber.
I started out as usual, to make a mold for the item I want to reproduce in metal (sorry for the crap picture my shop ain't well lit)

the mistake that ruined the chamber is visible in that picture I forgot to remove the paint from the metal pipe used as a core this created mold gas and this gas caused the failure.
here you can see a picture of the finished casting in its rough stage

every thing was still fine then, until I started to cut off the sprue's then I discovered a flaw in the casting

yep that is a bubble, it was caused by the burning paint on the steel pipe. this ruined the casting (the finished product will look much better than this, this is just before any finishing took place)
anyway I will try again next weekend
when I get a casting that I am satisfied with I will start a thread in the discussion aria
just out of curiosity this chamber has id of 35mm and a wall thickness of 10mm anybody care to calculate the burst pressure?
Today I decided that the time has come that I am going to make myself A hybrid. the hybrid I am going to make is going to be made from T6 aluminum (6061) and every thing went smoothly except I forgot one small thing and that ruined the combustion chamber.
I started out as usual, to make a mold for the item I want to reproduce in metal (sorry for the crap picture my shop ain't well lit)

the mistake that ruined the chamber is visible in that picture I forgot to remove the paint from the metal pipe used as a core this created mold gas and this gas caused the failure.
here you can see a picture of the finished casting in its rough stage

every thing was still fine then, until I started to cut off the sprue's then I discovered a flaw in the casting

yep that is a bubble, it was caused by the burning paint on the steel pipe. this ruined the casting (the finished product will look much better than this, this is just before any finishing took place)
anyway I will try again next weekend
when I get a casting that I am satisfied with I will start a thread in the discussion aria
just out of curiosity this chamber has id of 35mm and a wall thickness of 10mm anybody care to calculate the burst pressure?