Home Alloy Sand Casting

[Lionelgee]

Hello All,

I have always had an interest in alloy casting and blacksmithing. I have just not been able to follow those interests and convert them into practice - yet. I did do metalworking in high school. This was added to slightly when I learnt basic oxy and arc welding as part of a farm machinery subjects back when I studied Horticulture in the mid-1980s, at Queensland Agricultural College. Bearing these significant gaps in my knowledge and my lack of recent hands-on experience; what sort of gas would be required to make a little home furnace so I can melt some cast iron? I have only found YouTube clips from America or the UK and I am not sure if the gas combinations they mention is available here in Australia.

I would be using cast to make a new bracket for a lathe that broke after a long and very heavy length of timber accidentally fell on the handle bracket and broke it. I will be using a sand cast Oh the lathe was made over twenty years ago either Asian or India so there are no spare parts available

With the advent of 3D printers now available from Aldi; where does this fit in with such things as sand casting? A 3D printed version of the bracket would not be strong enough for use on the lathe. Would a 3D printer just provide a more accurate mould than my super-gluing the broken pieces of cast together so I can use them in the sand cast? That is if I have not thrown the pieces out after having my latest shed clean-up.

Oh and how good are the Aldi 3D printers? Are they just too cheap to be worth even the initial expense? I studied an introduction to CAD course some years ago. Plus I have used Autosketch in my former trade Landscape doing garden designs; so I am interested in these little 3D printer gadgets.

What does the advent of 3D printing do for such an old traditional space as sand cast alloy manufacturing techniques? Is it going to be a boon or a bust for sand casting?

Kind Regards
Lionel

[incisor]

el techo friend of mine with more money than sense but with a fetish for miniture turbines has been casting some very sophisticated metal alloys and uses a 3d printed pattern last time i was talking to him.

and sorry, i have no idea how he goes about what he does.

next time he is back in AU i will rattle his cage...

for a computer programmer he certainly knows how to make serious noise from little engines...

[Lionelgee]

Hello All,

I had another squiz on YouTube and found two similar clips about casting. When it comes to the pour - gee there is a big difference between the "old bull" and the "young bull". Maybe the young bull should watch more YouTube!



Old Bull A.K.A "luckygen1001" Melting cast iron for my projects - YouTube (https://www.youtube.com/watch?v=t5kP1wika4k)

& Young Bull A.K.A "Fair Weather Foundry" Steam Engine Build: Cast Iron Engine Cylinder Pour : Part 1 - YouTube (https://www.youtube.com/watch?v=EwcSqG67CN8)

It would be good to learn more about the waste oil furnaces though - they both really roar!

Would the pattern mould that the Young Bull made be the result of 3D printing, or was it a wax mould of some type?

Both videos accessed December 2nd 2017.

P.S. Yes Incisor just answered my pattern making question about the role of 3D printers. Thanks Incisor

Kind Regards
Lionel

[bee utey]

Unless the lathe is some kind of rare museum piece, either make a new bracket out of plate steel or braze the broken bit back together.

[Bigbjorn]

I suggest you find a TAFE that still offers adult education classes in casting, or, a TAFE that still offers the four level course in Foundry Practice. There is quite a bit to it. Not just boiling up some ally and pouring it. Mixing the sand is almost a black art. Foundry sand comes in many varieties. Most common is green sand, then red sand for better finish also CO2 sand. I did the foundry practice course as a young tradesman almost 50 years ago and worked in the foundry at Walkers for 5 months as a TA way back. We could and did pour 7 tons of iron regularly making big bits for sugar mills and ships. The guy that mixes the sand and melts the metal is called a foundryman & is not a tradesman but practices the black arts sniffing and feeling the sand and looking at colour of melting metal. When making your patterns don't forget shrinkage. Get pattern makers shrinkage rulers if you can find them. I considered the patternmaker who worked from engineering drawings to be the most skilled of the metal trades even though he rarely worked in metal. Try working out for yourself how many pieces in a pattern for a complex casting. Where do the core prints and cores go. Where do the sprues and runners and whistlers go. How many of them. What sections are likely to chill off and stop running. Sand is mixed from sand, isinglass, cereal. This is where the black art comes in. The foundryman rubbing his mix between his fingers, raising his eyes to the heavens, sniffing the humidity, and so on. Probably prayers to Vulcan.

[Lionelgee]

Hello All,
On a similar note - well it involves a cast product - I came across a YouTube clip a while ago about pot metal and metal spraying for old chrome ornaments on cars. It is a very interesting clip - Pot Metal Repair Demonstration - YouTube (https://www.youtube.com/watch?v=jjX_Sul43G0) Accessed December 2, 2017.

Kind Regards
Lionel

[workingonit]

As bee utey says, try brazing it. I know the feeling. I broke a winder handle on my mill, thinking I could braze it I found instead that it was plastic or bakerlite! What's with Chinese who can make good gear, but go on the cheap with the handles?

Do you live on some acres? If not, then gas is probably going to suit better than waste oil. My waste oil is a 'bit' smokey on start up, but as you say sounds like a jet engine when to temperature, easily heard 60-80 metres away. Gas requires more safety features - think oxy/acet.

My furnace project has been on the 'back burner' for a long time now, and at the point I left it only occasionally melted steel wire - some tuning of air and oil needed to lift temps. To melt iron you'll need high temp 1800 C furnace liner, as you'll be wanting somewhere around 1400-1500 C operating temps - a lot of people seem happy to settle on casting aluminium and other lower temp metals.

An induction furnace would be ideal and allow you to work in steel as well.

My son bought a Prusa 3d printer, took about 1 1/2 days to put the kit together. I was surprised at the ease of set up, calibration, and quality of output overall. Some difficulties in getting the object to adhere to the base board while being constructed (overcome). Like working metal, there was distortion on parts where the plastic was much thicker in some places than others. He designs in Fusion360 CAD (I use FreeCAD and Salome at a basic level). I believe his Prusa came with software that converts the CAD design to print layers (g-code). Moderate sized objects can take hours to print, and quite noisy - so if you're like most and set it up on the dining room table, others watching tv in the lounge with a machine running will be annoyed.

NT Uni has a 3D machine that builds using metal dust travelling in an air jet stream at more than twice the speed of sound. More ideal for aluminium and brass, not so good for harder alloys like steel. I believe they have built turbines, but the surface still needs finishing with CNC.

I wanted to study machining etc at the college years ago, but told I would need an apprenticeship to get into the courses - at 50 years of age?!

As usual the technology is moving very fast.

Got to go - those young whippersnappers, Jason and Simon, are on TV now.

[crash]

If you still have the bits - as mentioned can be brazed or nickel welded with an arc welder.

Waste oil in my opinion is the best BTU's for melting cast. You will need a decent blower for your air and a carbon crucible to melt the iron in.

I have a small LPG fired furnace and larger waste oil furnace. Both of my burners are very simple design.

So far I have only mucked around with aluminium.

An alternative to using green sand you can use a lost styrofoam technique - to make your pattern out of styrofoam and place into dry sand - and pour your melted metal into it. It works amazing well and I have duplicated the little styrofoam ball pattern in the metal. I have only done this with aluminium - do not know how it would go with cast iron.

Patterns can be made from any material you like working with - I make most of mine from wood.

Check this forum out - a wealth of knowledge to get lost in. AlloyAvenue network (http://www.alloyavenue.com/vb/forum.php)

[gromit]

Hi Lionel,

Maybe post up a picture of the broken bracket, is it possible to fabricate something as a replacement ?
Any details on the lathe ? Picture ? You'd be surprised how many are mass produced and sold under different names, maybe Hare & Forbes could source the spare part if they imported something similar.

Getting into casting to make one bracket seems a big exercise unless you intend to do a fair bit of casting in the future.
Chazza on the forum casts aluminium and I'm sure Pod was also casting aluminium.


Colin

[Didge]

That was a fascinating video Lionel - thanks for the link. Have never seen that process before.
cheers Gerald

[Didge]

That was a fascinating video Lionel - thanks for the link. Have never seen that process before.<br>cheers Gerald

[loanrangie]

Speaking of 3d printers, hows this little beauty for the price.

Geeetech E180 Mini 3D Printer with WiFi Module EU-$245.99 Online Shopping| GearBest.com (https://www.gearbest.com/3d-printers-3d-printer-kits/pp_1166685.html)

[CookyMonsta]

Hi Lionel, I'm a mature apprentice moulder and have just finished my block release at TAFE. I've been in a foundry for about 15 years now. You can do cast iron at home with a small crucible and a home made blast furnace running on lpg with a high air flow, problem is it will take quite a while to melt (average temp to pour cast iron is around 950 - 1100 degrees). Another option is to 3d print the part to use as a pattern and approach a foundry in your area. The only TAFE left in Australia still doing a moulding and casting course is Skills Tech at Acacia Ridge here in Brisbane. Mike McCabe is the teacher and also runs hobby courses for people interested in doing moulding and casting at home.

Another option for you is to get it welded. I've welded a lot of cast iron over the years.

There are also many different mediums you can use to make your moulds out of too. The best one for use at home is called green sand. It's non poisonous and is reusable, I get amazing clean results doing aluminum, brass and cast iron in it.

If you want a hand etc I can put you in touch with Mike another group worth asking are those into hobby railway steam engines like 1/5 scale live steam stuff. They would definitely know who could help you with casting etc.

Cheers for now

[whitey56]

Join "metalworkforum.com" they started Foundry and Blacksmithing sections about a year ago + a General section for all your lathe questions. It's also Australian based.

[POD]

I built a casting furnace based on a book purchased online: 'The Artful Bodger's Iron Casting Waste Oil Furnace', also built a moulding bench with a bathtub full of greensand under a hinged benchtop, unfortunately I just have not had the time to do much casting at all and have not even made an attempt at cast iron yet. All sorts of projects on the list but no time to attack them.

[Lionelgee]

Hello All,

Thanks for the link to furnace POD - and for the link to the Australian site Crash...

Here in Bundaberg we are in the middle of a series of storms that have extended over this weekend. So I have not done much outside today. This has given me time to chase up some YouTube clips about oil fed furnaces. I found a couple of sites that are interesting.

This is the first in a series of 7 parts... Make a Waste Oil Fired Furnace
Metal Casting at Home Part 49 Oil Fired Furnace Build Part 1 Wheeled Base

YouTube (https://www.youtube.com/watch?v=ZbnroanPt4g&list=PLD2A7F5FD2D3C3088&index=49)


Here is a different type
YouTube (https://www.youtube.com/watch?v=QK6iSgRrNXM)

I did find an Australian version by Luckygen1001 which also shows a crucible pour trolley that looks safer to operate than hauling hot metal around by hand. YouTube (https://www.youtube.com/watch?v=t5kP1wika4k)

Luckygen also has a clip where the dimensions of the furnace are run through... YouTube (https://www.youtube.com/watch?v=gXlQ7ZoRdMo)

Plus there is one of the furnace being overhauled YouTube (https://www.youtube.com/watch?v=MgsU5EibFbA&t=18s)

Kind regards
Lionel

[goingbush]

Check this out , clever way to convert 3D printed part. To an Alloy casting

YouTube (https://youtu.be/HVgPM1ojyLw)

[JohnnoK]

Take a look at this bloke's work for inspiration.
Air cooled 2-cycle motorcycle racing cylinder - Page 2 (http://www.alloyavenue.com/vb/showthread.php?11802-Air-cooled-2-cycle-motorcycle-racing-cylinder/page2&highlight=air+cooled+cylinder+motorcycle+racing+cy linder)

[gromit]

Called on a company earlier today that cast magnesium alloy, possibly the only company in Australia doing this.
I turned up just as they were doing a pour.

Mainly race parts for bikes & cars. They had a Repco Brabam block & pistons that they'd cast.

Interesting stuff, spent far too long chatting to the owner (better than working).


Colin