Mal Paso
04-22-2012, 10:47 PM
I had a thermometer when I first started casting. Between spout freeze ups and imperfect fillout I found out fast Lee's suggestion to run the 4-20 at 650F was NUTS! I used a burner under chunk of steel to preheat my molds, even so 750F was my Minimum Temperature to get perfect fillout. After I installed a PID 750F became the Set Temperature. Geargnasher, as well as cluing me in to the property's of Brass, suggested in one of his posts that alloy heat over what was necessary was wasted. And I remember him saying Hotter Mold several times. I've been gently cranking up the mold preheat and dropping alloy temperature for a month now. Below is a picture of the first 1200 boolits cast from 650F alloy. I'm pleased with the quality and the mold is running cleaner.
This is Mutt Alloy, range scrap and alloy to make about 95/3/2. Casting rate is a hair over 31/2 pours a minute with a Brass MP 432-256 4 cavity mold. The PID sensor is permanently mounted 5/8 inch from the pour valve 1/2" off the bottom of the Lee 4-20. I have a cooling fan running on the left side of the cedar block I set the mold on while the sprues freeze and set the mold under it when necessary. Sprues go into a pan beside the drop towel or water bucket. Sprues would destabilize the temperature of that little pot and there's no time. 3 1/2 pours a minute keeps you pretty focused too. 20 minutes, the pot is down to 5/8" and I've made about 300 Boolits. Below is my first MP Mold which survived all my mistakes and produced about 15,000 Boolits so far.
I still read more than I post but this is where I am so far.
This is Mutt Alloy, range scrap and alloy to make about 95/3/2. Casting rate is a hair over 31/2 pours a minute with a Brass MP 432-256 4 cavity mold. The PID sensor is permanently mounted 5/8 inch from the pour valve 1/2" off the bottom of the Lee 4-20. I have a cooling fan running on the left side of the cedar block I set the mold on while the sprues freeze and set the mold under it when necessary. Sprues go into a pan beside the drop towel or water bucket. Sprues would destabilize the temperature of that little pot and there's no time. 3 1/2 pours a minute keeps you pretty focused too. 20 minutes, the pot is down to 5/8" and I've made about 300 Boolits. Below is my first MP Mold which survived all my mistakes and produced about 15,000 Boolits so far.
I still read more than I post but this is where I am so far.