Aluminium smelting furnace

[Andy from Workshopshed]

I found that the first couple of burns cause cracking around the top, I just patched it up with fireclay

 

[SteSteSte]

Sorry not posted for a few days, been allowing the refractory to dry out naturally before any firing, but couldnt resist any longer tonight, so been playing with the burner.


Not going to fine tune it any more until ive made the crucible.

With my upwind burner, that I quickly made the other day

Only took about 5 minutes to make, but seemed to work remarkably well considering the amount of time it took to make!

Once placed inside the furnace, it seemed to be struggling for air, and it insisted on burning inside the tube, so I opened up the upwind holes, and turned up the pressure... Success, the flame moved to the end of the tube.

It started "put put put put" ing, and the flame looked too blue..

So i blocked the end of the tube, which helped massivly...

Video here :- CLICK the image



This got me wondering about making an adjustable choke for the end of the burner, however, I then realised that it worked better and didnt seem to do this with the lid shut, and considering it'll be used with the lid shut I decided until i had my crucible made to take up space, i wouldnt mess with the burner any more.

Basically, im pretty happy... I experimented dropping the pressure back down, and discovered it happily works with the pressure dropped to just under half of the regulator, so id guess around 12psi is the lowest it'll burn out of the tube at...


Anybody got any thoughts for me?


Decided to stop for the night, as there seemed to be quite a lot of moisture coming out as steam, so decided not to overdo it, and will refire a bit more tomorrow.


Thanks for looking.

Ste

 

[wyn]

It looks good.
Maybe you could knock up an adjustable disc that can pivot and cover the end of the burner tube. That could well give you enogh adjustment over the air to set the burner up for different propane pressures.

 

[SteSteSte]

Aluminium melting furnace

Cheers Wyn, I did think that, but i found by adding a piece of larger diameter pipe to the back helped with the burning.




Finalised my burner holder today - turned out a large nut in the lathe to the same size as my burner, which holds in place with a bolt to trap it.

Also added another bolt to hold the burner in the correct place.

Got it up to tempereture a few times, then allowed the steam to disperse before relighting again.

Last time it was lit for over 30 mins, with very little remaining steam.

A small crack has appeared in the lid, but nothing in the main part which im fairly pleased about.


Will make the crucible over the next few nights, and will finally get to melt some metal!


(placed a large piece of thick walled steel pipe into the furnace whilst burning, and put a tiny bit of aluminium in, just to ensure it was getting hot enough to melt, which it was)


Thanks for looking guys, your thoughts are always welcome



Ste

 

[wyn]

I've had a go at making a few propane burners and it's suprising how a small breeze can affect the burner.

 

[SteSteSte]

Bought a stainless steel biscuit tin, and a large spoon the other day, so stole a design id seen on youtubr for my crucible - sorry! Myfordboy

Today was finally time for a melt, so I set about an old inlet manifold from a VW 4 cylinder engine (got all the engine to melt eventually, its all ally) (block, head etc)

Cut it / smashed it into small enough pieces to fit into the crucible, filled the crucible, and fired it up...

Molton aluminium was in the bottom after about 15 mins, so i kept feeding more and more in as it melted down.

Ended up doing two melts, and poured them into small ingots... not got adventurous enough to make a mould for anything yet, but atleast the ingots will easily remelt when im ready.

Thanks for looking

Ste

 

[Shox Dr]

Well done, what are you going to cast when you get round to it?

 

[SteSteSte]

Nothing particular.. Historic Karting is one of my hobbys, and bits can be difficult to get hold of, so being able to cast parts will be a godsend.

Its more a 'ive seen it being done, and though "I reckon I could do that" kinda for the sake of it' project!

 

[SteSteSte]

OOps, just realised i posted my crucible pic twice, when the second one should be this:

Ste

 

[pidgeon chit welder]

May I suggest that you change the rubber tube for a steel pipe and make the rubber to steel connection a fair bit away from the furnace & fire tube incase you get a burn back or drop molten metal on the pipe work and also that you have a quick shut off ball gas valve with a long operating lever at the gas cylinder end for the same reason.

If you mount the whole furnace on frame with heavy duty lockable castors for ease of moving around you will be able to affix the rubber tube to there.

 

[SteSteSte]

Finally got round to painting it today. Looks much better now :-)

Ste

 

[SteSteSte]

Who'd have ever thought, a few months on from this project, I now work in a foundry!

 

[Andy from Workshopshed]

Congratulations. What is their powersource for melting?

 

[feathers]

Great little project. Have you managed to get anything cast yet??