Metal Casting at Home Part 12. When Castings Go Bad

[@scottneels2628]

Thank you so much for this. I asked questions on one of your later videos. Since watching more I see you've already answered them all. Thanks again.

[@myfordboy]

Hope you have found answers to your questions.

[@RencoSC]

Been there !!! When I had my first wooden flasks I had a similar hydraulic blowout which quickly set the flasks on fire so I added some clasps to keep it from happening again. I always enjoy watching your projects, keep up the great work ! -Hank

[@85rocco]

Once again, great stuff! It's always better to learn from the mistakes of others than one's own mistakes. There's one mistake I won't be making now, thanks for sharing!

[@myfordboy]

It was interesting watching the video after the casting was done. I thought I hadn't closed the flasks properly but you can see on the video how they were forced apart when the metal was poured.

[@barumman]

You are very honest as well as skillful, Not many would admit to failure.

[@myfordboy]

@olsonr The patterns are made 2% larger than the finished item needs to be. his allows for shrinkage as the metal cools. if a surface is to be machined i would add about 3 or 4mm on these areas.

[@myfordboy]

I think your both sugestions are correct. I dont normaly add a vent for small castings, but will in the future ( and add the bicks). Thanks for your ideas rocco.

[@TheSMasa]

Yes, great method. That came to my eyes too, since the degasser tends to float on top of the oxide layer and I've had problems with that.. :) Definely worth watching, thanks!

[@otterprincebacon6500]

I have found that you have to stir the degasser, down to the bottom to mix it up. Be careful, it will bubble up

[@myfordboy]

@Erniz2 When the metal is melting it absorbs hydrogen from the air. The washing soda ( sodium carbonate) is a degaser and drives this off. The salt I add is a flux and makes the metal more fluid and brings up the dross.

[@myfordboy]

@drhulp Without the salt its like trying to solder without using flux.The salt improves the flow. If you made a mould from concrete or plaster you may not be able to get the casting out, the heat would crack the concrete or plater and there is the danger of explosion due to moisture still in the plaster.

[@BuickDoc]

@RBTCLD Actually, you can put it your washing machine. if you have very hard water, it will soften the water and help conserve soap or detergent and make your nappies softer.

[@myfordboy]

@diannagal My video Metal Casting at Home Part 9 shows this and there is a link to the myfordboy blog where you will find plans and instructions.

[@myfordboy]

The problem here was just that the flasks were not tight together. I now always put clamps on the sides or weights on the top. Same technique is used for other metals too.

[@myfordboy]

Yes parts for the Stickney; Coil case, main bearings and cylinder head.

[@BarneySaysHi]

I never realised that that is what a riser is for!

[@Surfacesofie]

Most interesting! Thank you very much for the wealth of info! Dave

[@drhulp]

A few questions here: I see where you said the salt makes the aluminum more fluid, it looks almost comparable to water, is that about right? How is it without salt? syrup? molasses? Do you want it more fluid for less voids and/or more detail or something else? I'm still in the learning planning stage. Could you use a two piece mold made from concrete (or plaster) so you could use it over and over (for solid not hollow castings)

[@85rocco]

As I watch that video, I think one of two things, maybe both, are happening, I don't see a vent in that mold, maybe hydraulic pressure opened the mold. Either that or the sand is floating. We don't normally think of sand as being able to float but it is less dense than molten aluminium so if there's enough volume of aluminium and surface area at the parting line, it can happen.

[@RBTCLD]

that is just pressure seperating the cope from the drag as metal is poured. it happens often with heavier castings.

[@myfordboy]

@sfuk89 Too hot to touch. You could wait until its cold but I can't wait to see the results. Leaving it longer just cooks the sand anyway.

[@diannagal]

Thank you! Great ifo! Can you make a video how to make the furnace?

[@myfordboy]

@marcuslb95 Table salt works fine but I am now using LoSalt which I think gives better results.

[@fpego]

hi, always accompany their videos ... that its shield is made of any material, steel? you wear it long or just boring?

[@dieselmotorcycle]

Love the vids, you have a great setup. What are these parts? Are they for the stickeny?

[@myfordboy]

@AmmarSidi In my furnace it would take about 20 minutes to melt 5Kg

[@coldpak82]

M.F.B. What type of sand is it your using,perhaps petrosand ?

[@myfordboy]

A painted pattern will come out of the sand easier. Sand will not stick to it. Sand needs to correct consistancy, not too wet but holds together.

[@_sunsor]

Do you account for solid cooling contraction when making the wooden positives? or are they roughed out, and then adjusted as necessary with more machining? I guess I'm asking what kind of tolerances you see with DIY casting.. a few mm?

[@fpego]

whenever I pull out my wooden model of the mold, just dropping a piece of sand the border, such as the thinner parts ... the sand falls out, leaving a strain on the number ... will be little moisture in the sand or because I do not paint the molds?

[@Erniz2]

what does Soda do? Kinda helps to improve aluminum grade or what , thanks in advance? E.

[@myfordboy]

@nolandandfriends Sand and metal can both be reused.

[@feenixb1o7]

What is that black sand and where do I get it?! I just started building my own forge today, brake drum design for melting tin and lead etc so I need some of that stuff. I was just going to use wet kids play sand.

[@robertsulley]

Another great video!

[@myfordboy]

I usualy put a couple of bricks on the top of the flasks to hold them together but as these were only small castings I didn't bother. Mistake!

[@85rocco]

The few times that I've done larger castings, I used weights but, for small stuff, I haven't bothered, I think I'm going to change that.

[@myfordboy]

Its not petrosand. but it is from a foundry supplier. not sure of the specification.

[@RBTCLD]

what the hell is washing soda? im from australia and ive not heard that before. is that the powder you use to wash clothes in a washing machine? also the salt you use as flux is it normal table salt?

[@MikaelRudolfsson]

How hot is the metall when you're removing the sand?

[@backyardmetalcasting]

what he put more weight on top of the flasks?

[@Shermstyle23]

Would you be able to reuse the sand?

[@myfordboy]

Yes you can, over and over.

[@DMalenfant1]

I would have expected that wood to catch fire the moment that molten metal touched it.

[@beavis8167]

i no its a degreaser like u said but what is it. compare it to somthing. please explain

[@ponhand]

I love your vids

[@beavis8167]

HEY BUD QUESTION. WHAT IS WASHING SODA??

[@myfordboy]

Sodium carbonate,(not bicarbonate). Sold in the UK as washing soda.

[@hypo40]

how do u prepare scrap metal for casting? do u have to clean it or scrape the paint off?

[@myfordboy]

+hypo40 No need to to clean it unless it is really oily .The paint and muck comes to the surface and can be scraped off.

[@myfordboy]

Please visit myfordboy.blogspot.com and look at the "How to make greensand" page. You can't just use wet sand it has to have a bonding agent like clay.

[@joeyjackson3414]

How much salt and sodium carbonate?

[@RBTCLD]

thanks mate. im glad i asked . but it would have been funny if t threw washing powder in my crucible. i would have wondered where i went wrong.

[@myfordboy]

Washing soda is Sodium carbonate. Not the same stuff you put in the washing machine.

[@dbb6663]

can i use somehow the dross? was it like normal salt or something special? best regards

[@myfordboy]

+D Bb You can use table salt for flux or better still Losalt.

[@dbb6663]

ok thx and what about the dross?

[@myfordboy]

+D Bb The dross is the crap you scrape off after adding the flux.

[@dbb6663]

ok ty mister

[@RencoSC]

Absolutely ! I am subscribed to your channel too Marcelmx3 !

[@YoeyYutch]

I love the random crap from the garage being used for the raw material. I feel like melting some of my worthless belongings and making something cool!

[@agushermanto8722]

Ya

[@myfordboy]

The sand is reusuable.

[@sweetenedicedtea]

you have to be careful man, If the sand too moist and you go to pour metal into it, It will explode, Trust me lol I work in a professional foundry

[@sweetenedicedtea]

you always have to keep fluid hydraulics in mind, Next time try adding some weights around the edge of the flask

[@ac11dc110]

Thats not to bad 😜👍🏻

[@Recklessford]

@tquinn51 There is no way to get the core out without destroying the core.

[@myfordboy]

Half to 1 teaspoon for 5kg metal.

[@beavis8167]

ok thank u.

[@backyardmetalcasting]

oops I didn't see the other comments

[@fjoa123]

too high risers will give the liquid metal inside the mold too much pressure!

[@RichLeespage]

Talk about some casting flash, lol

[@myfordboy]

Sorry do not understand.

[@mu6luvr]

dont worry.. we can from this mistake

[@DmitryKoshkin]

Dude.you should comment on the process,aim not fast enough to read the subtls.But you rule!