First casting

[NormanV]

I have done a fair bit of casting aluminium using peat, charcoal and these days propane as fuel. I've never used oil. For material I use alloy wheels which provide quite good quality material. From your description it sounds as though you poured too hot. I can always look into the top of my furnace and pour soon after the last piece of metal has melted. If anything I probably pour when the metal is on the cool side. I rarely produce a porous casting and I do not degass.

[oldskoolron]

ive watched a lot of docos about using peat which was really interesting also about the way the Vikings made their metal for swords axes ect .always thought the Japanese had cast the best metals but apparently the Vikings made better .

[Pete O]

Well I took to heart all the advice given here as well as a little googling, made a second effort today at a somewhat simpler casting, a gear quadrant for the Paradisi universal dividing head.
Had the brilliant idea to break the donor transfer case housing down with the log splitter
   

I ran the furnace with much less oil flow, needed nearly as much air as the previous time as I had the furnace in the shed which made the smoke very obvious. The shed roof survived and the canoe did not come crashing down.

I used plain table salt for flux (old post on another forum) and degassed with bicarb soda, both doses wrapped up in tinfoil packages (thanks myfordboy). Pretty much as soon as the charge was liquid I opened the furnace, scooped off the dross, added salt to taste then stirred in the bicarb (which brought up a whole lot more dross) then scooped again, looked much cleaner than last time.

Poured the mould with a couple of muffins left over..
   

The casting came out looking a whole lot better, I buried it in the sand to cool slowly after breaking out but here's a photo before the phone battery went flat.
   

I got a real kick out of this, felt great to get what appears to be a good casting on my second attempt. Lots of machining to do on this so plenty of opportunity to find flaws (or make them) but looks good at this stage.

A few more simple aluminium castings and I might have the confidence to try some iron. Need to try my hand at core making too to give that gearbox case a real shot.

[Mayhem]

Well done Pete.

[dallen]

(10-28-2016, 06:50 AM)Pete O Wrote: A few more simple aluminium castings and I might have the confidence to try some iron.

They all say that, believe me Iron isn't nearly as easy.
nice looking part you dug out of the sand

[oldskoolron]

[Dr Stan]

(10-30-2016, 08:00 PM)oldskoolron Wrote:

[Dr Stan]

(10-28-2016, 02:23 PM)dallen Wrote:

(10-28-2016, 06:50 AM)Pete O Wrote: A few more simple aluminium castings and I might have the confidence to try some iron.

They all say that, believe me Iron isn't nearly as easy.
nice looking part you dug out of the sand

Indeed pouring iron is not nearly as easy as aluminum.  Iron melts at 2800 degrees F or 1,538° C.   Just a bit warm for the backyard foundry.  It's also harder to pour as it tends to freeze/solidify faster than aluminum.  I poured bronze when my wife made some bronze sculptures, and even that was pushing the limit on a Johnson Crucible Furnace.  It was a bit long in the tooth, but eventually did the job.  BTW the melting point of bronze is about 950 °C (1,742 °F) depending on the alloy and we used the lost wax method of casting.  Not absolutely necessary, but it produces more accurate castings if the process is followed appropriately.