Thread: Oil Burners for Casting Furnace.

Hi Barry,

The drum is actually an old 44 gal drum, yup a whole 200 liters

The actual entry to the furnace is a piece of 6" pipe lined with clay etc and reduced to maybe 3" i think a beer bottle actually fits there as a form The position of the fuel/air delivery pipe when being used is the same as in the pics. With it in this position it also draws in secondary air from outside, in with the main air stream.

The 44 gal drum has one row of fire bricks on their edge as a liner and is backfilled with clay. The floor and roof and chimney are the same but a lil thicker. At the first heat up the unit was also lined or coated on the inside with glass to help with heat reflection. This was done by crushing what was a full window of glass from an old mini and literally throwing it into the furnace through the chimney with it running and lots of care. The improvement could be seen almost imediatly at the flame and heat distribution inside the furnace cause by the reflective surface.

The comment before about the EPA is prolly more than just a lil right, BUT, with the ability to finely adjust the fuel and air deivery it is easy to adjust how rich or lean the furnace is running and it can be run with absolutely no smoke from the exhaust!!! The only smoke from the unit is at the initial start up, first 30 secs maybe or when someone gets a lil eager to make a lot of heat or noise and gets a lil carried away with the fuel and air and gets a lil smoke from it being rich and likes the look of the flames 3 or so feet high out the top of it

I do have a few pics of it in action with a pot with about 6.5Kg of aluminium just out of it about to be poured into a sand mold. But these are on film somewhere and may be a lil harder to find and transfer, but i'll look none the less

Some links on oil/gas burners,foundry techniques etc.Have not found a clear set of how- to plans for an oil burner

http://www.backyardmetalcasting.com/index.html
http://home.iprimus.com.au/cmckeown/foundry.htm
http://l.webring.com/hub?ring=hobbyfoundry&list&page=0
Regards,

Harry, the EPA do love waste oil burners, since if they produce heat that is used for a legitimate purpose, then it's considered recycling which they will typically endorse whole-heartedly.

I sure as heck wouldn't want a poor running burner since it wastes fuel, isn't very hot, produces large gobs of smoke and soot and is generally a waste of time.

Mick, very interesting. Does the thing run a blower of some sort, or is it strictly a fuel pressure thing?

Looks like something I could most certainly rig up.

We got rid of all the oil burners at work, the furnace/gas train engineer's(and CSIRO) could not make them comply to emission regulations.
Not to mention the safety factor of unburnt fuel in an combustion chamber, oil doesn't dissipate like gaseous/light distillate fuels while purging the chamber.
I have 1st hand experience at what can happen... blowback is not fun.
Just because there's no smoke doesn't mean there's no emissions, otherwise car's wouldn't be polluting would they?

Hey guys,

Just stumbled across this thread and thought 'Hmm!'. I work at the Mount Isa Copper Smelter as a converter operator, so I thought if you guys want to know anything that I might be able to find out from work or might already know, feel free to ask. Not sure how much help I can be with hobby casting, but I might know a few things. Got a bit of experience with converters, anode furnaces, casting etc.

Cheers,

Mitch

Schtoo,

Yes the unit runs a blower. Am useing the exhaust from a small industrial vacume cleaner that is connected to the back end of the 65mm pipe with a short piece of Skeet tubing. The vacume is useally bolted to the bracket thats sticking out to the right of the large oil pot in the 2nd pic, may be a lil hard to see, it's covering up a lil piece of the tappet cover thats laying in the background.

Originally Posted by Mick C.

Schtoo,

.. in the 2nd pic, may be a lil hard to see, it's covering up a lil piece of the tappet cover thats laying in the background.

You bet it's hard to see - where are the pictures?

The 2nd pic would happen to be the one on the previous page as part of the 8 or so pics i provided the other day

Originally Posted by Mick C.

The 2nd pic would happen to be the one on the previous page as part of the 8 or so pics i provided the other day

Sorry Mick, I got confused about which pictures were being referred to.

G'day you blokes.

I've started construction of the furnace and have enclosed some pics. I have used basic plans from one of the casting books I have to hand.....although not right to hand as I type this. .....it's out in the shed which is closed up for the night.

I have used a 25 litre paint tin with an inlet and outlet pipe of 52mm O.D. Internal size of chamber is approx 160mm diameter. I used a large coffee can with a thin sheet of polycarbonate wrapped arround it for the internal former. A bag of Moral Cast refractory was used. I will need another bag to complete the job.

Bottom layer of refactory is approximately 80mm thick and has a 26mm (approx.) hole through the bottom for molten material escape. This was cast last night and was still a bit soft this morning. I didn't have any mix instructions so I added enough water to make a regular type pouring cement.

Bottom 52mm dia. inlet pipe sits just above this bottom layer at approx. 110mm on centreline and is aimed at the left side of the internal chamber. This will create a clockwise swirling action.

Exhaust is on the left side of the chamber and positioned approximately 70mm down (on centre line) from the top edge.

Both pipes have been plugged for casting purposes. Once this current pour has all set I'll be able to remove (hopefully) central former. Then punch out the tape on the ends of the pipes and open out the passages which "should" only have minimal refactory in the way.....well that's the theory ?? .

Once another bag of refactory is sourced, probably next week, I'll finish off the top 30-40mm and cast a 3" lid with sight hole in the top.

That's about it for the moment. Pretty simple so far.

Catch ya' later............Barry.

Quick question/suggestions.

Is the castable you are using insulating, or just good at taking the heat? If it's not insulating (read as light!), then I would suggest putting some insulating material (kaowool) between the outer skin and inner hotface or leaving a gap so some kind of insulator (perlite) can be poured in after it has all set up.

I did this on the sides of mine, but still made the hot face too thick. It takes a bit of heating up, but it's not too bad. When the inside is orange/red, the outside is warm enough to touch barehanded. If the thing was solid, then the thing would take an hour or more to heat up and would cause no end of problems.

If that castable is alumina based (99% sure it is) then pouring is probably a little too thin. Make sure it dries thoroughly and slowly heat the first time to make sure all the moisture is out.

Problem is this stuff goes from too stiff to too sloppy with a drop or two of water.


I also made my exhaust out the top so long bits of scrap can be shoved down the hole into the pot. Worth thinking about.

What you got so far looks pretty slick to me though.

G'day Barry,
I used Darley Refractory Densecrete for my foundry, and their mixing instructions were 1:1 with water, by weight.

Here's an article about a guy in the US who made his casting furnace in a galvanised garbage tin (click on Heat Treating in the menu on the right hand side of the page).

The site has quite a lot of interesting stuff on woodwork (inc sharpening), planes and wood-related metalwork. Some of the links are interesting too (has anyone got GBP 3,200 space to buy a plane!!!!) .

G'day,

Thanks for the input's.

Schtoo, the Moral Cast refactory I'm using has a type of wool in it as well as perlite, or at least I think it's perlite. Considering that the 25Kg bag of Moral Cast is the same size as a regular 40Kg bag of cement I'm guessing it must have the other ingredients in it, otherwise it would weigh similar to a bag of cement ?. I may have to put some insulation material arround the outside in any case as it's only 2"-3" thick on the outside at the thickest.

I found a "mix your own" castable refactory mix on one of the links (Lionels Lab I think) provided on this forum. Might try that one out in a Coffee Can furnace if I can find some fireclay.

Yes, you are right, it doesn't take much more water to go from a dough consistancy to slop !. I found that out in the last pour.

When I pour the lid (when I get the next bag of refactory) I will put a 2 " diameter hole in the middle for sighting and adding material to the crucible. I reckon I'll put a sliding lid or something over the hole.

The casting books all recommend caution when heating the furnace for the first couple of times to "burn off" moisture.

Thanks for your interest and I'll keep you all posted with progress.

Cheers...........Barry.