reverberatory furnace questions

Hello all
finally got ahold of some nice scrap to make foundry stuff, so here are
the doubts:
1. I'm considering a making reverberatory furnace. If so, do I need one
for each metal? (I guess this is so). I read somewhere they put a sand
bed in the hearth before putting the metal in, but did not say if it was
for different metals. I could also make a removable hearth lining made of
castable refractory.
2. It the reverberatory furnace adecuate for melting brass, meaning you
can still put in the flux to avoid loss of zinc? And BTW, can borax be
used as flux instead of crushed glass.
3. I plan to heat the furnace with an oil burner. Any problem with this?
4. Any advice on the depth of the heart and in the shape of the lid? The
design i'm stealing from is here:
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any help thanked in advance
regards,
Mongke
Reply to
mongke
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Mongke, I'd suggest you try to correspond with the author of the web page you listed in your query. Without a "tilting" mechanism the design looks a bit awkward to use. Of course there is no crucible to worry about. Good luck.
Glen g.
Reply to
Glen G.
Hi :)
Yup, I like it because it melts fast and doesn't wear out. At least yet. ;) Not all that hard to use, although I need to remember to wear safety goggles when I pour it into the ladle..(with one foot on the far end of the frame to balance it, one hand tilting the furnace and the last one holding the ladle, my face gets a bit close for comfort...).
I'd like to try bronze in this unit but am afraid of contamination: first, I can't get all the aluminum off the walls. ASecond, the bronze (and certainly flux) will get stuck to the walls, putting copper in my aluminum melts. So yes, another furnace or at least some sort of lining (perhaps slather on some clay or patching compound) should be used to prevent contamination.
I don't need a sand bed in this unit. You might for some sort of open-bottom device, but I suspect you may be thinking of a cupola rather than a reverb.
An oil burner should work just fine. If not better, since then there's heat going all the way back (that is to say, the burner's chamber is hot, whereas a propane burner is just a pipe).
I designed the hearth and lid to give 2" of insulation on all sides (a little more on the bottom to insulate it better). You can use pretty much whatever shape you want. I used about 30lbs. of refractory in this, so you should be able to build an 8 or 10 lbs. capacity unit with a full 50lbs. bag of similar material.
Tim
-- "I have misplaced my pants." - Homer Simpson | Electronics, - - - - - - - - - - - - - - - - - - - - - - -+ Metalcasting and Games:
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Reply to
Tim Williams
Hey, it's your design I'm stealing from ;)! The reason I want one single type of furnace is space. I'm severely space limited. There is room for only a melting device. Plus a cupola would spew a lot of smoke from the backyard and the neighbors would be pissed off. Oh I might use the fireplace to place the cupola as it has the space and the chimney comes from the third story, but setting a foundry operation in the middle of the living room will not make the family happy.
I'm thinking that one could make a standard crucible furnace as long as the heat came from the top and not the bottom. Is there a need for the flame to bounce off the lid and into the molten metal or indeed the reflected heat is enough?
regards,
Mongke
Reply to
mongke
Yeah, you can do it that way too. Generally if you have a crucible you might as well direct some heat down around it, but I'd think a nice warm bed of Kaowool or something beneath the crucible would be real good. Although, I'm not sure how much temp difference a cruc. can take - it'll be real hot on the top rim and at the very bottom, cooler than the melt.
Yeah, when the lid is nice and orange to yellow hot, most of the heating is radiation inside there! Flame contact with the melt will certainly help, of course.
Tim
-- "I have misplaced my pants." - Homer Simpson | Electronics, - - - - - - - - - - - - - - - - - - - - - - -+ Metalcasting and Games:
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Reply to
Tim Williams

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