Found Dreaming

Yeah!! only took about 4 hours to make a post.

what browser you using Jammer, I loaded up windows 7 when my machine crashed and had all kinds of problems with IE9 so I loaded FireFox and its been a different world like when the old lady left, nice and quite, no browser fighting since the swap.

barryjyoung wrote:My crucible furnace accepts a #20 SC crucible. It has no Kaowool at all, just solid refractory walls 3 inches thick on all sides. I have run it full tilt for 8 hours where the inside is very bright yellow and the outside is barely above ambient temp. Why do you guys use Kaowool at all? I hope that doesn't sound stupid, I just simply do not know.

Thank you

Barry

Barry, all of you actually , what are you using for a burner, My concern is not if the furnace getting hot on the outside. as long as I can stand next to it it is fine, My problem is the 2+ hours it is taking me to get 32Lb ( a #10 crucible) up to pouring temp. If my business is going to step up, I have to get melt times down. I need to be able to get home at 6 PM, ram up, and pour off before bedtime, not midnight.

[quote="HT1"Barry, all of you actually , what are you using for a burner, My concern is not if the furnace getting hot on the outside. as long as I can stand next to it it is fine, My problem is the 2+ hours it is taking me to get 32Lb ( a #10 crucible) up to pouring temp. If my business is going to step up, I have to get melt times down. I need to be able to get home at 6 PM, ram up, and pour off before bedtime, not midnight.[/quote]

Thats way too long, 32 lb I can do an A10 full of cast iron in about half that.

Vacuum Cleaner blower and a 1.5 inch pipe and a little trick I got hiding in the tube, I'll photograph it for ya

My small furnace is a 3 inch outer shell of local clay/sand with a 1/2 inch Mizzou hot face. I use a Lionel Hot Shot oil burner. I melt bronze in a #8 Starrbide crucible. I pre heat to maybe 300 F with a Reil. From there I turn on the oil and it takes less than 30 minutes to my pour temp of 2300 F. This Hot Shot can make more heat than I need. I don't want to melt that local clay.

Richard

The two crucible furnaces we made were made of 3200 degree castable refractory cement. It was very expensive cement at $65.00 per bag times 6 bags. Since this furnace needs to last for as long as possible, cost was a secondary consideration. We made each of the three layers with a 1/8 inch thick projected portion which fits inside the layer below it. This is a good fit and no gas that I can feel leaks between the layers. Not enough to make it hot to the touch anyway. It heats up to yellow hot in less than 30 minutes and red in under 20. My buddy made his with the same refractory two inches thick and regular portland cement for an inch on the outside of that and it seems to be about the same.

I was thinking that all this business about insulation was overrated. Unless of course you are using a little propane burner in your garage in the suburbs. This Hot Shot makes more heat than I can use, and for free—except for the electricity to run the blower.

I'm building a new big furnace for my #30 crucible, and I plan to use three inches of Kaowool and a 3/4 inch hot face simply because of the weight factor.

Richard