Re: Steam explosion
Posted: Wed Jun 24, 2015 3:43 am
mite5255 wrote:Here's a photo of the casting
The casting cut in half
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Steam explosion
http://founddreaming.com/metal_casting/forum/phpBB3/viewtopic.php?f=10&t=563
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Re: Steam explosion
Posted: Wed Jun 24, 2015 5:49 am
I had a long winded reply typed up but acted the stupid part and hit the escape key and lost it.
use a smaller wire, push it in from the outside of the mold, so that the small point almost touches the pattern or if its like a plaque its on the back side. put in lots of vents some of my molds I act like a mad witch with a voodoo doll when I vent them, you need a lot of vents with really fine sand, or old sand that's filled up with fines over time, and especially with oil bonded sand which can ram up almost rock hard.
use a smaller wire, push it in from the outside of the mold, so that the small point almost touches the pattern or if its like a plaque its on the back side. put in lots of vents some of my molds I act like a mad witch with a voodoo doll when I vent them, you need a lot of vents with really fine sand, or old sand that's filled up with fines over time, and especially with oil bonded sand which can ram up almost rock hard.
Re: Steam explosion
Posted: Wed Jun 24, 2015 4:14 pm
Vent, vent, VENT!! I use a coat hanger wire to vent mine and I do a LOT of 'em across broad flat areas. Bugs do, on rare occasion, get in my molds, resulting in a loud audible "POP" and a backlash out the pour cup. RARELY that extreme though. I've learned to stick a shop vac up to my molds with all risers wide open to allow for good suction, just prior to make'n my pour. Nothing's more unnerving than having a volcanic eruption out the pour cup cause of them buggers. Keeping the vents plentiful and thin makes it easy to pop them off with a chissle and sanding the nubbins smooth. Another option would be to spray a light mist of mosquito repellent across the risers and pour cup after you set the mold on the bench to pour. That'll keep the buggers away from the holes and it don't mess with the sand mix much... if at all. Haven't noticed any derogatory effect so far. Just a light mist is all, no more.
Re: Steam explosion
Posted: Wed Jul 01, 2015 6:26 am
any updates on the problem that you were having. the curious are eagerly awaiting an update on the problem
Re: Steam explosion
Posted: Wed Jul 01, 2015 3:10 pm
dallen wrote:any updates on the problem that you were having. the curious are eagerly awaiting an update on the problem
These two are finished, photobucket won't let me turn them around the right way for some reason
Re: Steam explosion
Posted: Wed Jul 01, 2015 3:58 pm
don't you just love it when castings come out of the sand looking like that.
one thing most people don't know or think about is the expansion of water when it is flashed off in steam. a gallon of water flashed off to steam at 300 degrees will take up about 1700 cubic feet of space. and when it doesn't have anyplace to go like in an unvented sand mold things get interesting real fast
Thems some damn fine looking castings, bet the lady of the house is happy with no erupting molds on the patio
one thing most people don't know or think about is the expansion of water when it is flashed off in steam. a gallon of water flashed off to steam at 300 degrees will take up about 1700 cubic feet of space. and when it doesn't have anyplace to go like in an unvented sand mold things get interesting real fast
Thems some damn fine looking castings, bet the lady of the house is happy with no erupting molds on the patio
Re: Steam explosion
Posted: Wed Jul 01, 2015 4:32 pm
Because your in Australia.mite5255 wrote: These two are finished, photobucket won't let me turn them around the right way for some reason
Re: Steam explosion
Posted: Wed Jul 01, 2015 4:44 pm
I was venting. but nowhere near enough, up until this point I was getting away with it, from here on the way that I vent will most deafeningly will be different . Thanks for the complementdallen wrote:don't you just love it when castings come out of the sand looking like that.
one thing most people don't know or think about is the expansion of water when it is flashed off in steam. a gallon of water flashed off to steam at 300 degrees will take up about 1700 cubic feet of space. and when it doesn't have anyplace to go like in an unvented sand mold things get interesting real fast
Thems some damn fine looking castings, bet the lady of the house is happy with no erupting molds on the patio
Jammer wrote:Because your in Australia.mite5255 wrote: These two are finished, photobucket won't let me turn them around the right way for some reason
Re: Steam explosion
Posted: Wed Jul 01, 2015 6:02 pm
your welcome, those are some nice casting, you gonna powder coat the recessed area.
and like we say in Oklahoma, you learn something with every mold that you pour.
and like we say in Oklahoma, you learn something with every mold that you pour.
Re: Steam explosion
Posted: Wed Jul 01, 2015 6:12 pm
All I do to finish is I bead blast the coaster,that darkens the background, I then linish the raised area and and flashings, I then spray with Dulux pressure pak clear coat, job done