New chum from Western Australia

G'day Everyone,
At last I have found a forum about casting!

I have been casting aluminium using green-sand and soluble-oil as the binder since 1985, mainly making automotive parts for my collection and more recently making parts for sale to fellow enthusiasts – see my avatar for part of the current order.

My hobby is restoring old cars, but as I approach retirement, I hope my part-time business may become more full-time.

What interests me at the moment, is to make a new furnace powered by waste-oil and put the LPG one into retirement. I have Peck's book, but the information on this site is most valuable as well,

Cheers Charlie

 

Welcome Charlie. I got Peck's book early on too. I found it useful but the only thing my furnace ended up having in common with Colin's is the beer keg! Others have built his furnace almost to the letter including the burner design and seem to do just find. If you are able to obtain commercial refractory and bypass the homebrew stuff I think you will be better off.

Pete

 

Welcome!

Looks like you know what you're doing.

I've been using waste oil for a while with a pressurized drip (does that make sense? Just a piece of brake line feeding the oil with a needle valve for control). I'm using a cheap leaf blower for air and the system is working really well. I do use propane to start and again when I shut off to burn up any residual oil but I'm getting no smoke and lots of heat. I burn motor oil, transmission fluid, old gasoline, cloudy diesel, and cooking oil. Super simple system. My furnace is posted on this site, insulating firebrick and it works great. About 260 melts in it so far.

 

Thank you for your wonderful welcome everyone!

Yes, I didn't like the look of the smoke and flame colour in Colin's photos, it seemed to be starving for air perhaps.

I used to have a furnace I made from broken fire-bricks and fire clay, formed inside a 13 gallon oil drum; it worked incredibly quickly on LPG, until I received a visit from a Government inspector who threatened me with prosecution for making an unsafe gas appliance. I managed to calm him down, by seeking the expertise of a licenced gas-fitter and promising to get rid of said furnace, which I did.

Anyway, the new one will be much the same, but this time I will line the interior with old fire-bricks cut to shape with mortared joins, as the previous attempt disintegrated after a relatively short time. The blower is a Makita hand blower; in the past I used a vacuum cleaner, which worked well.

The only concern I have, is how potentially dangerous a waste-oil burner might be, if the flame was to go out and then fresh fuel-gas reignites on the hot bricks and causes a gas explosion. This is what concerned the inspector all those years ago, so I fitted a flame-failure regulator to the one I have now. Any thoughts or experiences about this?

Cheers Charlie

 

OK second question – can anyone tell me where to find the User CP? I want to create an album,

Cheers Charlie

 

Welcome aboard. I'm an oil burner guy too. It's the only way to roll. No shortage of nasty black goo in texas! Fwiw, I run the kwiky all fuel burner.
Propane is for lazy suckers. I'd run one, but I'm CHEAPER than I am lazy.

 

Thanks Jason, I had just read that link before you posted

LPG is probably very similar to propane, but it isn't cheap where I live and my current set-up is taking about 2 hours to get a decent melt going.

Like you I would like to get my fuel for free, from the sumps of my ridiculously large fleet

Cheers Charlie

 

If it's Free, It's for me, I'll take Three!

 

I've had bumps, thumps, and whooshes out of my furnace but nothing resembling an explosion. My bore is 10" and around 16" deep (can't remember exactly) and the lid has a 4" exhaust hole so incidental reignition caused by air bubbles or something like that in the fuel line doesn't concern me. I think my eyebrows are in more jeopardy than my life or limb. But in rare instances when the flame goes out and stays out I turn the fuel off immediately and leave the blower on to evacuate the vapor before swinging the lid open. Although I'm sure a catastrophic explosion is possible I haven't heard of any at our level. I respect the potential, but proper considerations in building your fuel system and sensible operation should win the day whether using propane or oil.

Pete

 

Look at Media at the top of the page to find where to create an album.

We call propane LPG, but depending on where you live it could be a mixture of butane and propane. If so it has a lot less heating value.

Once the brick is hot the flame will just never go out with oil. It is very stable a self regenerating. Getting it started can be a trick and the easy way for me is to use propane. After it's got a hot spot (less than five minutes) I add a little oil, then more, and after a couple of minutes cut off the propane. If I'm doing back to back pours the furnace will reignite propane as soon as I get the crucible back in and I can go quickly to oil.

Sorry to hear about your inspector. I don't have anybody to protect me here so I can do what I want. I feel privileged. After the firebox is hot there is just no danger. Sometimes I cut the fuel and air to remove copious amounts of slag then just turn them back on. Instant fire. When I was using a naturally aspirated burner on propane there was also no chance for the propane to not reignite after a short hiatus. I can't see the reason for an automatic fuel shutoff if you are there monitoring the furnace and it really is not a good idea to walk away from a furnace like this and expect everything to operate on it's own. But the danger is overheating and crucible failure rather than flame failure and explosion.

You said your current setup is taking two hours. Air infiltration? It took me a lot longer with a loose stacked brick furnace. Now, with aluminum, I'm ready to pour in about 20 minutes from cold and 15 from hot, depending on the quality of scrap I'm melting. Too much foreign material and small pieces takes me a lot longer but hey, the fuel is free. Those times seem to be typical of home furnaces people report here.

Oil will burn hotter with a yellow flame than propane with a blue flame. I don't know why, but it really is. I adjust the air until the flame barely licks out of the flue and the flue is kept clean of carbon. When I put in a window frame with silicone caulk I get lots of flame and some smoke but as soon as it burns out the flame is back down. I do wear a respirator when using dirty scrap and probably should anytime I'm burning oil since there are metals in the oil.

 

Yes, none of the User CP seems to be available to me and the Media tab has nothing relevant. I might try using Photobucket and see if that works,

Cheers Charlie

 

NO PHOTOBUCKET!!!

Sorry, did I say that out loud?

Just load some photos directly from your computer using the "Upload a File" button. It's quick and easy. Just start a thread in the forum for the casting media you use, it is quick and easy.

 

I've heard of the gas inspector problem before, but in Queensland from about 30 years ago. It turned out there was a category of furnace the inspector wasn't aware of, a "Manned furnace" where there is an operator at all times. Examples of this were the ore roasting furnaces used at some very large mining companies throughout Australia. I don't know if this has changed in the meantime, but it was enough to get the gas inspector to allow the furnace. The furnace had to be attended at all times, you couldn't stop to take a leak without another operator to take over or by shutting it down. There may have also been an element of grandfathering in an old furnace that would not be allowed with a new unit.

 

Here are a couple of hot-restarts I did on diesel.
No big deal.

See 2:25



.