zargnut

really small stuff... The biggest crucible I have is #4 Graphite, maybe 15cm high x 10cm wide. I have definitely seen the method you are describing. I will need to find an alternative investment slurry, one that does not cure chemically, as this one won't remain liquid for repeat dipping. My stuff is small enough that I can use this up making solid forms... I can then look for an alternative investment ceramic slurry. I do have some petrobond, and suspect I will have to use that for any larger pours I wish to do. d

Helpful. I will monitor the temp once I can get a thermocouple into the furnace. I luck out on scrap... I do more recreational fabrication and welding than any forgery work... My metal shop has a great scrap shelf and frequently has aluminum block cutoffs that are clean, uniform alloy, and small enough to fit into a crucible. I just got a small burnout oven, 6x6x4.5" that should work for these small castings.. I figure my kids can use it as a low temp 2000F clay kiln. I will report back once I get my act together. thx

Hi thanks for the welcome. I live in Baltimore, MD. I added to my profile. Sounds like a good plan. I also got some green sand, but thought this would be "easier"... think I misjudged the complexity of prepping lost wax... This will be a great opportunity to learn.... I have a thermocouple on order, will see how well I can regulate my furnace... But worth a shot. thanks again for your advice. d

Hi, Thanks for the correction.. I will look for a local class, would be fun. The investment came as powder in a bag in a box... no instructions. I did just find an online instruction sheet which does note a gradual burnout 2 hr at 150 C, increase over 5 hr to 1350 C. This part would be hard to do without a formal burnout oven. RE: PPE. I am using leather welding jacket and bib , 3M 7500 series respirator with P100 filters, Safety Glasses behind a rated faceshield. Outdoor only work. Heavy insulated furnace gloves. I like to think that I am novice, but not stupid...

Hi, I am a novice to casting. I made a nice 16gal propane fired smelter and am working with small volumes of aluminum. I have been making silicone molds and trying to use lost wax to cast some aluminum. The smelter, metal prep, and silicon molding and wax creation has been fine. I first tried a plaster of paris shell, which disintegrated. so I got some Ransom and Randolph Ultra-vest Maxx Investment and poured a solid form, suspending my wax in it. I first used a convection oven to melt out most of the wax with gravity into a can. Then I fired the form in the smelter, and within about 5-10 minutes it essentially crumbled? I can speculate on several points of failure, but was hoping folks could point me to a "duh" reason, to cut down on failed attempts. 1) I didn't let the form really dry before heating it 2) I am not using a burn out oven, don't have one... firing it in the smelter 3) I mixed the investment about 8:1 with sand (investment:sand) to make up some volume I was hoping to do the investment / sand / investment / sand layering technique, the the investment powder I got seems to cure chemically within a really short time period.. so won't permit keeping a bucket of liquified investment, for repeat dipping. Did I get the wrong stuff? Can I still use this stuff up making solid forms around my waxes? thanks for any newbie advice you can give. dan I inve