sad

It is difficult to say specifically what is causing your casting defects. However, I can speak in generalities. First, it is important to know which alloy that you are using. The most common casting alloy is A356 and is the main alloy for aluminum wheels. It is a high Silicon (6.5% to 7.5%) content alloy. It is slightly hypoeutectic so porosity during solidification is minimized. If you are pouring a lower Si content or Zn content alloy the castings will not be as good. Cylinder heads may have Zn added for strength and higher temperature strength. Castings such as the alternator and starter motor castings may be low Si and are likely pressure die cast. I haven't seen how thick your casting is at the beginning of the video, and this may be part of the problem. Some of the defects that you showed on the casting look similar to freeze outs and cold shuts. If your casting is relatively thin you may need to preheat your mold or increase the superheat on your melt; or, both. Thin castings are difficult to do in sand castings because the metal will cool before the mold is filled. If this is the case, then just a slight adjustment is needed. Depending on the scrap that you start with, you can adjust your melt. For example, if you are using aluminum cans as your raw material, this is a poor choice for a casting alloy but you can handle that. Aluminum cans are usually made from 3104 which has almost no Si but is alloyed with Mn and Mg. To use aluminum cans, make your melt, refine and cast into ingots. After the ingots have cooled, weigh them. Then when you go to remelt, add about 7% by weight Si. You will then have a good casting alloy. The small amounts of Mn and Mg won't have much effect. hth. PS: @5:15 the results look like shrinkage during solidification. Again, it depends on what your starting alloy is. It is definitely a lack of fluidity and possibly cold shuts. PPS: On the 200 kilos of scrap that you have, don't throw it out straight away. Make some ingots and have them tested for composition. Once you know the composition, you can possibly adjust your chemistry. Another good scrap source for you would be extrusions which are a 6000 series and would only require some additional Si to make it a good casting alloy.

At what temperature is the cast iron ready to pour

Castme a snare drum shell!

At 14:18 I was thinkink "what an interesting pink slag on top of the sprue". Then I was thinking "why would there be a layer of slag there". I guess it is just still glowing metal?

I'm glad you have video of this facility. I'm over in the USA and still admire those casting facilities.

Brought back lots of memories when I was in the field for Inductotherm. Thanks, enjoyed.

What a great film, thank you for posting it. These boys seemed a bit cavalier about safety, like no glasses and no gloves. Although they really knew what were they were doing, do you think if that was done today they’d have more protective clothing, and more safety regulations? Thanks1

Who got to decide that a trade wasn't needed anymore....... and that youngsters were to be indoctrinated instead...? ☹️😡☹️🇬🇧

Who needs the trades when ya got KZfaq? 😂

Thank you for sharing. I wish this school was still around, I would have never left.

Interesting to see the lack of PPE in a school setting.

Wow. If this existed when I was at school only a few years later my trajectory would have been a lot different. Bummer

Да, это печально.

Tafe Qld at Acaica Ridge in Brisbane is home to pretty much all the nation's casting and moulding apprentices they also run evening classes for hobbyists, where they will help you cast all the model and project parts you want pouring aluminium, bronze, cast iron and SG.

And they throw sand in our eyes with slogans like “build back better” and “green revolution”

Bill, Thanks for putting this up. I made castings in the RMIT foundry that the one you show here replaced - a long time ago - 1965 in fact during my metallurgy study years. Tobho is right it - is incredibly sad to see such facilities vanish but then all of us old-timers age going sooner or later to that great foundry in the sky. I make no comment about some of the less than scientific techniques shown....Martin

Really interesting. I remember that hobby course, but I was never able to do it (waiting lists). I still think there'd be interest if somewhere or someone ran a course like that. Any idea what happens today in regards to training? I would guess there'd still be some foundries and foundryman needed.

I used to go to RMIT on Saturday Mornings, mostly in the non ferrous section. I can remember Jim Willetts was a patient and knowledgeable teacher. I took my camera in and have a few photos , a very enjoyable time. If you were a good student, and wanted to come back the next year, Jim made sure you Failed, and had to come back and try again next year. If you pissed Jim off, you passed, and were never seen again....

Spent many Saturday mornings there with Jim instructing us. It looked like him in the yellow hard hat. Also enjoyed the visits to yours and Robs foundry. How is Rob these days? Cam

Was that Wally Gore in the video? I wonder if a fellow Dennis Keenan was in that video, he used to work at rmit, he was a great mentor to me. Shame these skills are gone.

TPTB mandated that there's no need for people with real world skills.

What a sad thing to see such a resource disappear. Seems short-sighted to let those skills disappear. Thanks for sharing this

Spent a couple of semesters in there while studying MechEng. Thanks for a blast from the past.

all these good people probably deceased, and woke to replace them?

This should not be allowed to fade to China and the East.

How are we going to maintain those expensive submarines ? I guess we'll have to import everything as we do now.

The water in the scap was tame compared with some video I've seen. May be a good practice to preheat befor loading into liquid steel.

Wollongong TAFE had a similar set-up, with an induction furnace capable of melting cast iron. I believe it has also closed down now.

Just in case some one asks R.M.I.T. stands for royal melbourne institute of Technology. I never attended that course as there was a long waiting list to get in. (it was very popular) Another reason why I did not attend was I had a complete set up so I could pour castings any time I wanted to instead of trying to do too many things in three hours a week. So I would go once a month and watch and see how they did things. The best thing I learnt from there was how to make cast iron from steel. After it closed down many former students had a go to set up their own foundry, most failed because there was a steep learning curve on how to do things which they did not teach there.

Very cool to see. I can’t find many videos about small foundries. Which I suppose makes sense because of economics of scale.

Hi Luckygen What pressure do you use to feed your oil

I still have the horseshoe I cast in the 9th grade 45 years ago

Mmm,..maybe just spend us$85 for a cheap china made DC welder? Lol! Ya, you're right, where is the fun in that, hereyou learn to learn how or utterly confuse youself.

Is the air of the vacuum cleaner sufficient for the cupola stove? can you please answer

Are the 7-8% bentonite in the greensand mixture measured by weight or by volume? I found mine does not seem to get the desired strength so I added by feel. It ended up being way more. Does anyone have some resources (books, papers, KZfaq channels) where I can find more details about moulding materials? :)

My dad did this in early 60s

Thank you for the video, I got one of the tungar bulbs as a gift today and I find this vid on the 10th anniversary of its release date.

You are awesome

Which did you use sand?

Ese defecto es por aluminio contaminado ,puede ser antimonio ,zinc u otro metal de aleacion .Quizas con una temperatura mas alta podria mejorar ,pero no es seguro que pase . Para desgasificar el aluminio uso cloro en polvo (el que se usa en las piscinas ) una cucharadita de te por kg de aluminio ,luego una cucharadita de sal comun de mesa ,quitar la escoria y verter en el molde .

Do angle grinder discs leave traces of impurities in the alloy when cutting? Just a thought, maybe plasma cutter or sledge hammer would be better. .🤔

You didn't mention the rod you were using to stick weld. I think 20 volts would be a little low.

Very interesting

Lucky, if you not going to use all of them we can buy leftovers (for a fair price)

good on ya mate sort of well done

How are you charging discharging indivedual cells? Are you removing the connector straps? And if so, how are you reconnecting them?

not sure what I got out of the video, but it was interesting and held my attention all the way thank you

I wouldn't trust them very much, it's hard to tell the internal electrolyte damage from the idle voltage drain. It's less risky than recycling high C lipoly cells though still need to be cautious.

Very interesting. I have one of those old SIP welders. It's been rather average as a welder, but perhaps I can make use of it, like you have. Curious to know more about the ad for the batteries. I thought a 20v drop with the redgum was pretty good actually, I expected more.