Thread: Furnace Build(likely to be very slow)

You should ask Josh & Ray a few questions. I remember Josh saying they spent a heap of money buying the fire bricks or heat matting or something only to find another much-much cheaper way of going about it. Or I could be completely wrong I was quite overwhelmed with all their equipment as it was my first visit.

The link Sawdust posted in fxst's thread has some good info. Foundry Tutorial Book
I was going to use the stuff Sawdust did, from this place. Castables, High Temperature Concrete
Keep on the lookout for a burner like mine, looks like it will work a treat. Spraybooths use them, as well as big hot water boilers etc.

Hi,
I believe Josh and Ray used Pyrocrete 165 but said they think blanket would be better.

Hi Ewan,
Yeah working on that link thanks.
I dont recall having seen Sawdusts furnace.
The reason I am using blanket is I am told "for guys like us" as it doesnt have the thermal mass to heat up so is better suited for us "one pour" wonders...........
I dont like my chances of stubbing my foot on a burner like yours but I will keep an eye out.
I'm just going to use bottle gas to start with as I have a 40kg bottle for the shed heater anyway. I'll have a chat to a plumber I know about whats involved in on mains gas.. though its a little early for that lol. would be nice to have a kero burner at least I go tend to use a bit of that.. I'd use more if it could be "reused"

What am I going to be paying for crucibles in oz? The only place I have found online so far in in WA.(why is all the good stuff in WA? hehehe)


Stuart

salamander crucible | eBay
Yeah, those damn WA blokes hogging all the good stuff.......

I thought a thinish hard face and then blanket would be better.....

Originally Posted by Stustoys

With apologies to Matt for not being able to cut the keg he so kindly gave me(over a year ago now) in half just yet.

I've got myself a hot water tank thats about 900mm high and 400mm diameter. Now(I think) its a little on the high side but the diameter should be fine if my dimensions of crucibles are correct.(something else to buy)
So my first question is how thick does the lid need to be and how big a hole for the exhaust? The dome is about 80mm high and its about 80mm from there to the bottom of the outlet fitting. 80mm of straight would give me enough for 4 layers of blanket, but would an air gap above that be an issue?

I have some fire bricks that I might use in the bottom as I may end up playing with oil burners.
The Isowool I have I'm not so sure about, its 14-10SP from Isolite Ceramic Fibers SDN. BHN. I thought it was good for 1600C but now I'm not so sure and cant find out any info. Anyone happen to know anything or of a way to test it?
Mine isowool didnt come in rolls, its a 300mm square block 150mm thick, the blanket is about 20mm thick conertinaed, I'm guessing there is about 2400mm in block and I have 4 blocks.

Is it listed on this brochure
http://www.owencorp.com/Isowool.pdf

What do you want to melt Stu?
The Isowool only looks to be rated to 1500, a bit low for CI. If your burning oil i think you will want a sacrificial brick to take the brunt of the flame as it hits the side of the furnace. Or so i have read......

Hi Bob,
Thanks but I can't see any numbers that match
Not sure I like the "14" in my numbers though.

Hi Ewan,
I'm after CI..........nothing like jumping in at the deep end.
I was planning on putting fire brick at the bottom for that reason.
As above with the "14"
Might have to run a piece up to Ray and Joshs and see what damage they can do to it.

Stuart

Originally Posted by Stustoys

Might have to run a piece up to Ray and Joshs and see what damage they can do to it.

Stuart

Stuart

A few years ago I bought a cruvible and hi temp castables from a place in Geddes? Street, Mulgrave. Their name possibly started with R

IIRC they had blanket and firebrick. How many firebricks do you want. Trouble is the the trip would be worth more than buying new firebrick.

Ken

Originally Posted by Stustoys

The Isowool I have I'm not so sure about, its 14-10SP from Isolite Ceramic Fibers SDN. BHN. I thought it was good for 1600C but now I'm not so sure and cant find out any info. Anyone happen to know anything or of a way to test it?
Mine isowool didnt come in rolls, its a 300mm square block 150mm thick, the blanket is about 20mm thick conertinaed, I'm guessing there is about 2400mm in block and I have 4 blocks.

If it's isolite in block form then it's either Uniblok or Saber Bloc.
See ISOWOOL Uniblok and Saber Bloc - イソライト工æ¥#æ#ªå¼�会社 ｜ ISOLITE INSULATING PRODUCTS CO.,LTD.

I'd say the 14 refers to 1400 ºC.
But all the Isolites don't melt until they get to ~1750ºC
My understanding is a 1400ºC classification a service temperature, ie will withstand multiple heatings to that temp.
Depending on how much CI you want to cast I would think the 14 should survive a couple of CI castings.

my furnace has 18mm hard hot face , with 50mm of kiowool behind it

Hi Ken,
That would be Refractory & Ceramic.
Refractory & Ceramic - Crucibles, Furnaces and Master Alloys
I'd found them, wasnt sure if they would want to talk to me. Looks like I'd want just about the smallest crucible they sell(they they say they are only good to 1400C.......

I have "some" firebricks(heavy like a solid house brick not the light sandy white ones). I have no idea how many I need as I hadnt planned on using them(other than maybe a couple of rows in the bottom). I'll check

Hi Bob,
Its not a block, its a blanket.... but its folded not rolled. make sense? I think not. I'll take a picture. Takes up less space I guess.
Can you tell me more about the rigidizer you used in your furnace? If I stay with the blanket I assume I'll need to use that also?

Stuart

Originally Posted by SawDustSniffer

my furnace has 18mm hard hot face , with 50mm of kiowool behind it

18mm, I wouldnt have thought it could be used so thin(based on nothing at all lol). One of the things that had worried me about the "hi temp cement" route was the weight........ I would like to be able to move the thing. 18mm wouldnt be a show stopper as long as it stays together.
Any pictures on the forum?

Stuart

OoooHHH! I had missed the start of this thread. Bring on the liquid metal Stu.

You were right we used pyrocrete as the outer shell for the pressure tank, We then lined the inside with 2 layers of CeraChem (just like any other thermal ceramic stuff just rated just a little higher). We melted it when we first changed over to a forced air LPG burner (later we figured it was the heat of the furnace but the flame temp that made a hot spot and with a high volume of air washed it out. When we rebuilt it we added some thin high density firebrick (from Refractory & Ceramic) at the contact point for the flame so as to not wash out the cerachem when we crank up the burner to 20m/s air. Another place to pick up crucibles is Foseco in dandenong they stock a reasonable range of silicon carbide and clay graphite crucibles not that you could tell from their website.

Foseco

19-21 Nicole Way

Dandenong