PDA

View Full Version : Recommendation for first furnace



OxxAndBert
20th May 2020, 04:51 PM
Making a furnace suitable for alumium (and ideally brass/bronze) has been on my project list for ages. I recently had to shell out some reasonable dollars for a couple of short pieces of larger (150mm) round bar for other projects. I could have easily cast at least a solid blank for almost nil dollars if I already had a furnace - so decided its time to make a start.

My problem is there's just too much info online, and my only furnace experience was at high school - far too many years ago to remember.

My thoughts so far:
- about beer keg size.
- just LPG fired for a start, but I've got plenty of waste engine/transmission oil to fuel an oil fired burner down the track.
- sufficient to melt around 4kg of aluminium (1.5L).
- a swing lid style arrangement so I'm not having to manually lift the lid etc.

Does that seem reasonable?

The next decision is what to line it with - fire bricks, ceramic blanket, or castable refractory.
I want it to last more than a dozen firings, but if its going to turn into a $1000 build then there are probably better options.
I'm leaning towards ceramic blanket with a rigidiser coating as its probably easier to freight in the current climate.

Thoughts/suggestions??

Steve

clear out
20th May 2020, 11:24 PM
This is at a local men’s shed.
From memory pretty much as your proposing but not a swing lid.
He used 2 gas bottles, it would reach 1200.
OK for about 9kg of Brass.
When the lockdowns over I can find out more from looking at it.
The guy who made and used it has gone back to Canada.
Everything was left except his personal temperature probe.
I did one pour with him and have been meaning to do more but too many other projects.
H.

OxxAndBert
20th May 2020, 11:42 PM
Thanks. Some more info would be great once you can get to have a look at it again.

Steve

Pete O
24th May 2020, 08:02 PM
It's a pity you're on the wrong side of town Steve, you'd be so very welcome to use my furnace. I bought the Artful Bodger's book a few years ago and my build is on that other forum. I spent a few hundred with refractory and insulation etc, got sick of waiting for the ideal size steel cylinders to show up so had a couple of sheets rolled by a local supplier and that blew the cost out but got the thing happening.
The author is a good guy and happy to offer help, the book was only a few bucks and well worth it.

OxxAndBert
24th May 2020, 09:49 PM
Thanks Pete - probably lucky for you that I AM on the other side of town or you'd never get rid of me!

Think I recall your furnace build, but I'll dig up that thread and refresh my memory.
I'm still tossing up between using the castable refractory and going down the ceramic blanket and ridgidiser path.
I'm assuming yours is still holding up OK with the castable?

I thought all the refractory companies were over your way, but found there's a company "Morgan Thermal Ceramics" not far from work that has both castable and blanket, so I'll get hold of them and get some prices as that might be a factor.

Steve

Pete O
25th May 2020, 12:29 AM
I think it was Morgan that I got my castable from, they brought 3 bags down from Sydney for me and one of the guys from the LR forum picked it up for me from over your way. No-one over this side was able to get me the high temp (1600deg) stuff. Seems to be holding up just fine, although the furnace doesn't get as much use as I'd like. I think I recall about $80 per bag and I used 3 bags.

12bolts
1st Jun 2020, 09:52 AM
Hi Steve,
You will really want a castable hotface at a minimum. At least 15mm but 25mm would be better for thermal strength. The rigidizer over the ceramic blanket wont stand up to constant firing. Especially if you do go to oil fired
I used to live outside of Melb and I was able to get most of my supplies from a place in Dandenong. I dont recall the name atm

Cheers Phil

OxxAndBert
1st Jun 2020, 02:28 PM
Thanks Phil.

I think I'm going to build along those lines, which is like the "Artful Bodgers" furnace design that PeteO has built.

Inner layer of castable, then the ceramic blanket between that and the outside of the furnace for insulation.
Once I've worked out what quantities I need I'll contact Morgan Thermal Ceramics near work and see what they can provide for starters.

Steve

TIG_Is_My_Jam
2nd Jun 2020, 06:26 AM
I would like just to add to the topic that you should make sure to abide by all safety precautions.. :)
It is wise to have a fire extinguisher nearby or atleast a bucket full of water but that will not help as the extinguisher.

Have fun smelting!

Karl Robbers
9th Jun 2020, 05:06 PM
I would like just to add to the topic that you should make sure to abide by all safety precautions.. :)
It is wise to have a fire extinguisher nearby or atleast a bucket full of water but that will not help as the extinguisher.

Have fun smelting!
Be very careful with water around molten metal as you could easily make things worse. Metal fires are possibly the hardest fires to tackle and a shovel and some sand or dirt will outperform just about anything other than specialised extinguishing media.

Turbine Builder
13th Jun 2020, 07:37 PM
Making a furnace suitable for alumium (and ideally brass/bronze) has been on my project list for ages. I recently had to shell out some reasonable dollars for a couple of short pieces of larger (150mm) round bar for other projects. I could have easily cast at least a solid blank for almost nil dollars if I already had a furnace - so decided its time to make a start.

My problem is there's just too much info online, and my only furnace experience was at high school - far too many years ago to remember.

My thoughts so far:
- about beer keg size.
- just LPG fired for a start, but I've got plenty of waste engine/transmission oil to fuel an oil fired burner down the track.
- sufficient to melt around 4kg of aluminium (1.5L).
- a swing lid style arrangement so I'm not having to manually lift the lid etc.

Does that seem reasonable?

The next decision is what to line it with - fire bricks, ceramic blanket, or castable refractory.
I want it to last more than a dozen firings, but if its going to turn into a $1000 build then there are probably better options.
I'm leaning towards ceramic blanket with a rigidiser coating as its probably easier to freight in the current climate.

Thoughts/suggestions??

Steve
G'day Steve,

Yeah it adds up, so far $1000 still need a melting crucible and some other bits but it will last a long time, i would go with the fire bricks and go with LP gas set up more simple. All depends how anal you wont to be with the build. LOL in my case i am very anal in my build projects :U
I can send you plans on the keg furnace build i made and has the plans for the oil burner as well, just send me a PM

Cheers,
Mark.

OxxAndBert
14th Jun 2020, 11:42 PM
Thanks Mark - PM sent.

I called Morgan Thermal Ceramics over a week ago. Spoke to the sales guy, and got the “send me an email with details and I’ll send you pricing and specs”
Since then - crickets....
On Friday I happened to be over the East side of town for work. Took the opportunity to visit Darley firebrick for some 1600degC castable, some ceramic blanket and a bag of fire clay.
Castable was just over $60 per25kg bag.
Also got an A8 crucible from Refractory & Ceramic. They were out of stock of the A4 and A6 sizes.

Steve

Turbine Builder
15th Jun 2020, 08:46 AM
Thanks Mark - PM sent.

I called Morgan Thermal Ceramics over a week ago. Spoke to the sales guy, and got the “send me an email with details and I’ll send you pricing and specs”
Since then - crickets....
On Friday I happened to be over the East side of town for work. Took the opportunity to visit Darley firebrick for some 1600degC castable, some ceramic blanket and a bag of fire clay.
Castable was just over $60 per25kg bag.
Also got an A8 crucible from Refractory & Ceramic. They were out of stock of the A4 and A6 sizes.

Steve
Hi Steve,
no worries. What did you pay for the A8 crucible ?

Mark.

OxxAndBert
15th Jun 2020, 10:04 AM
Hi Steve,
no worries. What did you pay for the A8 crucible ?

Mark.

$108 + GST
Its a decent Salamander one. Price seemed quite reasonable compared to what's available online on ebay etc.

BTW - Refractory and Ceramic are now part of Skamol group. Still the same website, phone number and address, but a bit confusing when you rock up or call them.

Steve

Turbine Builder
15th Jun 2020, 11:38 AM
$108 + GST
Its a decent Salamander one. Price seemed quite reasonable compared to what's available online on ebay etc.

BTW - Refractory and Ceramic are now part of Skamol group. Still the same website, phone number and address, but a bit confusing when you rock up or call them.

Steve
Thanks mate , yeah that's not a bad price for that A8 crucible will pick up one next week :)

Mark.

OxxAndBert
15th Jun 2020, 07:35 PM
Best to phone and order it before you head over.
They aren’t doing over the counter transactions due to COVID so it’s pay by cc over the phone or I guess bank transfer.
They bring it out to the car park when you get there - you can’t go into the building.

Steve

Harry72
17th Jun 2020, 11:21 PM
Have you looked at Devil Forges, $557 will get you a ready made 10Kg furnace(free postage too)

LINK (https://www.ebay.com.au/itm/FB2Mb-10KG-GAS-METAL-MELTING-FURNACE-Propane-Forge-Copper-Brass-Bronze-Silver/253796844325?hash=item3b17788325)

OxxAndBert
18th Jun 2020, 03:44 PM
Thanks, I hadn't come across those.
They look like a nice "instant" furnace. Probably build the same for $200 or less depending on what materials etc you already had around the place (sheetmetal, and LPG regulator etc), but I think they are well priced for a complete out of the box furnace that you only need to paint the rigidiser on before use.

Having already bought castable refractory etc I'm now committed to building one from scratch :)

Steve

Mk1_Oz
18th Jun 2020, 05:01 PM
Have you looked at Devil Forges, $557 will get you a ready made 10Kg furnace(free postage too)

LINK (https://www.ebay.com.au/itm/FB2Mb-10KG-GAS-METAL-MELTING-FURNACE-Propane-Forge-Copper-Brass-Bronze-Silver/253796844325?hash=item3b17788325)

An American forge delivered from Lithuania at an AUD$ price half that quoted direct from Devil-Forge? I might be a bit worried about that one???? I have watched many YT vids using Devil-Forge and they look great but I agree that you could probably make one the same much much cheaper.