Furnace build

[Ueee]

Hi Guys,
I have a mate coming over on Sunday with some Koawool and hard face so i thought i had better cut my drum up and sort out a lid removal mechanism. It's almost there, just need to sort out a handle for the lid.

The burner is likely to be a 1" gas unit from Corin at this stage. These can be drilled to give up to 60kw and it won't ruin the hard face like the oil burner will. I am making the furnace to suit an A25 (4.8l) crucible. Just waiting for it to arrive and then i will make some tongs and a pouring shank, most likely on wheels like Geisser/luckygen's.

I think i will get some petrobond from that guy in QLD.

Ew

[Ueee]

Wow, those crickets are loud indeed! Was that a baby i heard crying?

My mate came over today and we lined the furnace with isowool, painted it with rigidizer and then coated it with a product called Super 3000, which is actually a mortar, but he uses it to line gas forges with and was sold to him as an alternative hard face that will cope with up to 1600deg. Just need to get the burner in now and then i can fire it up.....

Ew

[variant22]

Wow, those crickets are loud indeed! Was that a baby i heard crying?

My mate came over today and we lined the furnace with isowool, painted it with rigidizer and then coated it with a product called Super 3000, which is actually a mortar, but he uses it to line gas forges with and was sold to him as an alternative hard face that will cope with up to 1600deg. Just need to get the burner in now and then i can fire it up.....

Ew
Funnily enough I had a barrel turn up out of the blue last week. The thing that is stopping me with putting my furnace together are the coatings (rigidizer and Super 3000) for the Kaowool. Where did you source these from?

Additionally, what size drum are you using?

[Ueee]

The drum is a 60l I think. The rigidizer and hard face came from field furnace in sydney, my mate makes gas forges for knifemakers so he had it all already. I bought the crucible from refractory and ceramic in Melbourne, I think these guys have similar products and are a little closer to you for freight.

Ew

[pippin88]

Ew,

Would you mind sharing how much the crucible is costing you?

Cheers,
Nick

[Ueee]

Ahhhh....OUCH! The SiC (Himelt) A25 was $253+GST. Smaller ones can be had on ebay for less but the shipping gets pricey on the larger ones.

Ew

[desbromilow]

Hi Guys,


The burner is likely to be a 1" gas unit from Corin at this stage. These can be drilled to give up to 60kw and it won't ruin the hard face like the oil burner will.

Ew


Ew,

what's this about oil burners ruiing hardface? - is this a Kaowool issue, or something about oil burners?
I'm running diesel/WMVO mix into 1" hardface (kiln shelving) and was unaware of any issues regarding fuel choices

thanks,
Des

[Ueee]

Ew,

what's this about oil burners ruiing hardface? - is this a Kaowool issue, or something about oil burners?
I'm running diesel/WMVO mix into 1" hardface (kiln shelving) and was unaware of any issues regarding fuel choices

thanks,
Des

From my reading (and nothing else) oil/diesel burners should have a sacrificial brick that takes the brunt on the flame. Otherwise it will eat away at the refractory. I think its an oil problem not a refractory problem, the unburned oil maybe?

Ew

[desbromilow]

From my reading (and nothing else) oil/diesel burners should have a sacrificial brick that takes the brunt on the flame. Otherwise it will eat away at the refractory. I think its an oil problem not a refractory problem, the unburned oil maybe?

Ew

OK - Thanks for that - another thing learnt today!!!!!

[texx]

looks like you are making good headway ( its all fun ). i have not long ago built my furnace and am currently building a muller for the sand mixing.
in my furnace i used "superwool " and zircote paint , hopefully its up to the task . i have made an lp gas burner for it too..

johno

[Ueee]

Mine is a bit of a rush as i need a few one off castings.

The furnace had her first decent heat up yesterday, about 5 minutes. Enough to make the lower half of the hardface glow red. My petrobond arrived yesterday so now i just need to make some flasks and crucible tongs.

Ew

[12bolts]

From my reading (and nothing else) oil/diesel burners should have a sacrificial brick that takes the brunt on the flame. Otherwise it will eat away at the refractory. I think its an oil problem not a refractory problem, the unburned oil maybe?
My oil burner furnace gets to bronze temps. I have a refractory lined drum and it is holding up well. There is no unburned fuel on the furnace wall once the temp comes up. At the start it sprays a bit of a mist onto the hotface but once its running properly the atomised oil just vaporises

cheers Phil

[Ueee]

Well i did my first full fire today, i only stopped cause i ran out of gas. :doh:

Ew

[Ueee]

Some pics of my first few cast hubs. These are molded in petrobond and poured with nothing but chips i collected from the lathe!

The first one i ran out of ally, the second my riser was not big enough and it solidified before the hub did, meaning the hub pulled itself apart internally with shrinkage. These are a nice shape to mold as the rim is the thinnest part, follow by the plate and then the hub, meaning shrinkage is not so much of a problem.
Still a few air bubbles after machining but getting there. Next stop die casting......

Ew

[pippin88]

Nice work.

I'm interested in solid mould casting. How will you be generating / applying the pressure for die casting.

[Ueee]

Depends on how i mold them. I think if i make them flat as above i won't need pressure once the mold is up to temp. I would like do them with the feed on the edge however, so i can mold in the bearing registers etc and the feed is on the edge so any roughness left from cutting the riser off ends up covered in rubber. This way i will probably set up an extended steel riser and make a steel plunger and use a fly press or arbor press.....

I was looking into ceracote to protect the dies but i think the hi-temp version is only good for 700C, not enough for full temp ally. My other thought was the spray on graphite lubricant, although once the mold gets hot the propellant may ignite.....

BTW they are linisher contact wheel hubs.....

Ew

[DSEL74]

How did you find the chips?? I was under the impression that they weren't a viable source due to the amount of surface area in comparison to the small amount of material. This leading to more slag than good casting material.

[Ueee]

Hi Dale,
I found the chips under the lathe.......

I had heard that chips were not so good due to the large surface area and its potential for oxidizing. My mate that built the furnace suggested trying them and just making sure I had a good reducing flame. It seemed to work fine, although how it would go with another fuel is anyone's guess.
These guys can forge weld without flux in a reducing atmosphere gas forge, pretty damn good evidence of just how little free oxygen is left in the forge with these burners tuned correctly.

Ew

[DSEL74]

I meant how did you find using them not where did you find them :roll:

Are these more grinder wheels your making? The previous one you outsourced the casting yeah?

[Ueee]

Yeah i had 20 cast, the larger ones at considerable cost. I'm not so keen on making any more 14" wheels, if i do i will probably pay the price to get them cast again. The smaller wheels are not so bad, but i really want to get into die casting to cut the machining down. From the sand cast, mine or the foundries, i have had to machine 100% of the surfaces as they are too rough and not perfectly flat/round so i have to balance them. 100% machined means they are balanced perfectly, but of course takes time.

Ew

[Ueee]

Some pics of my first few cast hubs. These are molded in petrobond and poured with nothing but chips i collected from the lathe!

The first one i ran out of ally, the second my riser was not big enough and it solidified before the hub did, meaning the hub pulled itself apart internally with shrinkage. These are a nice shape to mold as the rim is the thinnest part, follow by the plate and then the hub, meaning shrinkage is not so much of a problem.
Still a few air bubbles after machining but getting there. Next stop die casting......

Ew

Here is the finished wheel from the above hub. 12"x2", 75duro serrated rubber, ground on the face and both sides.

Cheers,
Ew

[retired_eka]

Hello Ewan

Nice project building the furnace. Good to see your recycling of metals from your lathe/mills/shapers goes towards new toys and tools.

Q. How do you go about creating / moulding the rubber and serrations onto your fresh machined metal wheel.

Cheers Eka

[wheelinround]

:2tsup: just skimmed through this coming back to read fully. After seeing the video of the rubber torture this is one to follow.

[Ueee]

Thanks guys.
The rubber is slotted on the mill with a dividing head. It's a bit of a pain to do but once you get the RPM's and feed right its not so bad.

Cheers,
Ew

[retired_eka]

Ewan

Can you elaborate how you get the rubber onto the machined aluminium.
Do you bond it , glue it or mould from raw materials?.
Reason being i have some old wheels that i would like re rubber and you method appears do-able in the home workshop.

Cheers Eka

[DSEL74]

The rubber is cast on. The wheel goes in a large wgg ring and the rubber mixed and poured in around it and set. Later turned etc. Sounds easy but not as much as you think

[Ueee]

Dale has it...but there are a number of tricks that i will not post on an open forum.
The other issue for one offs is you need to using a bonding agent to get the rubber to stick and whilst you only need a tiny bit you need to buy a certain amount and it is not cheap, plus it is a DG so shipping is not cheap.....

Once it is on you then have to machine it.....depending on the rubber this can be a nightmare, soft rubber would rather push out of the way than be cut, even with the sharpest of tooling.

It is then best to grind the rubber concentric with the bearings.....

It may sound easy but it's not. I've now done about 35 wheels, and still don't have it 100% right.

[Grahame Collins]

Some pics of my first few cast hubs. These are molded in petrobond and poured with nothing but chips i collected from the lathe!

The first one i ran out of ally, the second my riser was not big enough and it solidified before the hub did, meaning the hub pulled itself apart internally with shrinkage. These are a nice shape to mold as the rim is the thinnest part, follow by the plate and then the hub, meaning shrinkage is not so much of a problem.
Still a few air bubbles after machining but getting there. Next stop die casting......

Ew

Hmmm?

Linisher belt pulley ,perhaps- or have a missed something?

Grahame

[wheelinround]

:doh: I knew there was someone who could use that ally I turfed recently.