unable to superheat melt
- Well, I melted and created my first ingots today! While I'm happy my
propane furnace was actually able to melt metal, I'm a little
concerned with it's performance. From reading other posts the 20
minutes it took for the aluminum to melt seems OK. I gave it an extra
5 minutes before pouring however and the metal was freezing as I was
pouring the third 1/2 pound ingot. I was pouring pretty quick too!
I suspect either my furnace isn't insulated enough to heat much
higher than melting temp or my burner isn't kicking out the BTU's.
I'm using a stainless steel stock pot with 2 inches of commercial
2800 degree refractory, a 2 inch drain, a 4 inch exhaust, and the
burner is a modified Reil sidearm burner (naturally aspirated). 12
psi seems to be the sweet spot as far as I can tell. Oh ya, I'm
using a 4" diameter schedule 40 pipe crucible and on my second
attempt I had most of the exhaust port covered with a plinth - same
I'm going to use the wifes hair dryer for a forced air melt tomorrow
to eliminate the burner from the equation. For those familiar with
the modified sidearm burner, I couldn't find a 1.25" x 1.25" x 0.75"
reducing tee so I had to use a 1" x 1" x 0.75" one. As a result I'm
getting less airflow than the design calls for.
If it turns out my burner isn't the problem, would coating the
refractory with ITC-100 be enough to save this furnace?
Thanks for any advice!
> While I'm happy myDon t know if this helps?
> propane furnace was actually able to melt metal, I'm
> a little
> concerned with it's performance. From reading other
> posts the 20
> minutes it took for the aluminum to melt seems OK.
From what I can tell your Burner is operating
correctly, or it wouldnt melt ally in the 20 min
timeframe from cold.My monster Burner melts a 3/4
full Steel Crucible(10mm Thick)of ally in about that
time frame. I had a burner prob when I first got mine
together and it wouldnt heat half the area of a 2mm
thick cookie tin in half an hour,when I put a small
chunk of ally in it,it took 40 mins before the ally
just started warping. The problem was low fuel supply.
> 5 minutes before pouring however and the metal wasSnip---How Full was the crucible? more ally charged
> freezing as I was
> pouring the third 1/2 pound ingot. I was pouring
> pretty quick too!
in the crucible usually means longer melt time?
I find that Smaller melts cool and solify faster,
Bigger melts usually give more working time.
> I suspect either my furnace isn't insulated enoughSnip----If your burners working correctly yor furnace
> to heat much
> higher than melting temp or my burner isn't kicking
> out the BTU's.
doesnt need to be super effeciant, I can run my
furnace with the lid off it and the burner will have
the 10mm thick steel crucible up to a red heat in
>rating of the refractory is 1650 deg/c. Usually higher
> I'm using a stainless steel stock pot with 2 inches
> of commercial
> 2800 degree refractory
> -----Snip My walls are approx 4"thick,The Temp
temp rated refractorys are poorer heat insulaters,They
are used to line blasting faces and are backed up with
lower temp rated refactorys for insulating heat. your
2" walls should be ok though!..as far as im concerned
a furnace is just somwhere to put a crucible to blast
with heat....he he
> burner is a modified Reil sidearm burner (naturally---------Snip ..Your Base plinth should raise the
> aspirated). 12
> psi seems to be the sweet spot as far as I can tell.
> Oh ya, I'm
> using a 4" diameter schedule 40 pipe crucible and on
> my second
> attempt I had most of the exhaust port covered with
> a plinth - same
Crucible into a position so it can recieve heat from
the burner 1/3 from the bottom of its base.
>Snip-----The Burner is burning at the tip of the tube
> I'm going to use the wifes hair dryer for a forced
> air melt tomorrow
> to eliminate the burner from the equation. For
> those familiar with
> the modified sidearm burner, I couldn't find a 1.25"
> x 1.25" x 0.75"
> reducing tee so I had to use a 1" x 1" x 0.75" one.
> As a result I'm
> getting less airflow than the design calls for.
right??.....NOT INSIDE THE TUBE!!!!!!, by the way from
what I hear Blown burners are unreliable and are hard
to tune - I think Ron Reil actually said that
somewhere on his site.
> If it turns out my burner isn't the problem, wouldSnip-----I think if anything you may just have to wait
> coating the
> refractory with ITC-100 be enough to save this
a little longer until the entire melt is heated to a
point where its fully liqufied .....but hey thats just
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