Plans for building a home made furnace

[Noxx]

Hello,
I just called some places and I could buy 5L of refractory mix for 30$ (up to 1600°C). Is this a good deal ? And can it be used as a good hot face ?
I already have regular firebricks but I haven't find the lightweight type yet...

 

[Lou]

Regular fire bricks will take a hell of a lot of abuse.

1600C is pretty good, and the price is ok, but it's measured in liters, which would make me think that it is a rammable material rather than dry mix. Sounds like a great deal then, that's probably 50+ pounds and not bad for where you live.

 

[Noxx]

It's not dry mix...

Firebricks will take lot of abuse but do they'll absorb a lot of energy as well ? Does a kiln made with firebricks and refractory mix has a good efficiency ?

Thanks

 

[Lou]

No. You want kiln brick for insulation, they insulate very well and you can cut them with a cheap bread knife. You'll have a tough time cutting a fire brick with most anything.Obviously they are fragile, that is when a hot face refractory comes into play, it takes all the abuse from tongs, crucibles, slag, etc that would ruin your kiln brick. Fire brick is just vitrified fireclay, and in my opinion, is useless outside of the industrial setting, unless you're lining ladles or cupolas for iron melting...

 

[dixie]

A couple of years ago the welders in my area switched over to PROPANE because it was a little cheaper than ACETYLENE. Now they have all switched back because it will not produce the same heat and does not burn as clean.

Why could one not use an old torch set-up with a rosebud tip to heat their furance.

MIke

 

[Lou]

Oxypropane isn't as hot as oxyacetlyene, not by 1000 degrees. It's much cheaper, and much higher pressures can be used (no 15 psi limit), but yep, doesn't get as hot.

But why can't you use an old rosebud? Well, I would think it's because they're not designed to run inside of a furnace, and that they run way too rich without having additional oxygen to lean out the flame. More importantly for me, the oxygen required is really expensive, why not use compressed air and adjust the ratio, or better yet, just use a Reil burner which works and works well.

 

[zauggart]

im new to here and read the post upwards about useing a casting home made furnace . wouldent the air pressure from the fan blow the gold particles and leaf all over the place?
ian

 

[Lou]

Just use a piece of graphite as a cover to your crucible. I do that for silver powder melts. Also helps to wrap up your powder in coffee filters.

 

[gotgoldfever]

This site has some really cool propane burners for sale. Perfect for a home made furnace.

http://www.hybridburners.com/index.html

 

[ashir]

i want prepare a home made tilting furnance. i wast use waste oil as fuel, have any one idea that i can follow?