Hi chemical engineering graduate here, what you need to find is a phase diagram for your alloy of tin. I had a whole material science class on this. Basically even within one alloy mix there are different crystal structures. Cooling rates, pressures, and other factors greatly affect what crystalline structures can form. A phase diagram will help you to figure out what exactly is going on and how to change it to your liking.

@johncannon669

Жыл бұрын

Pewterer for years here. I found your temp has a huge affect on centrifugal casting and gravity casting. And talcom coating helps greatly. I know this isn't about casting just bar pouring. But that's just my observation.

This video has way more interesting detailed information in it than I expected! Great video 😊

@TheRecreationalMachinist

2 жыл бұрын

Thanks for watching 👍 🇬🇧

About 10 years ago, I collected up a good deal of pewter from thrift stores and melted it down into ingots. I always wondered why it sometimes turned yellow. Really enjoyed this video!

I thought I had seen some bizarre things used to cast metal in but a chocolate mold and a cardboard tube takes the cake !

Crystals that are forming are tin, which indicates that there is very little lead in the pewter you have. The lead suppresses the formation of the tin whiskers above a certain level, so you have nearly pure tin in there, with other contaminants likely being copper, antimony, silver and arsenic, as they are all common to find in tin ores as a trace level, though generally you need to add more antimony to get a harder alloy. you could also add some copper shavings to the mix, which should dissolve in the melt, and get a somewhat harder alloy as well, and of course you can buy rolls of plumbing solder, which will add more tin in the mix. For your next melt try using a flux, rosin works well, and while it will give off a pine smell, it will clean the surface of oxide quite well. You can even look for some pine wood with knots, and use a piece with the knot as a stirrer, which will contain a lot of the rosin in it.

@TheRecreationalMachinist

2 жыл бұрын

Thanks for the advice 👍 🇬🇧

@AddamSantana

Жыл бұрын

I have 100 lbs or so of pewter I've melted down, never knew the crystallization meant a higher purity of tin. I have a lot of it with crystals through it. I recently made a video of anthill casting with pewter. kzread.info/dash/bejne/o6l8tM6dmdHXdMY.html

Everything i never knew i needed to know about pewter ! Wonderful video, unexpected but very welcome.

The yellow color will be removed by boiling in water with bicard soda. The yellow tinge is an indication of the high quality ( 92% min ) tin. Also the bars will ring like a Bell when banged.

@TheRecreationalMachinist

Жыл бұрын

Thanks for the tip! I'll give that a go next time 👍 🇬🇧

Now that was very interesting. That machined pewter came out amazingly well. Thanks for sharing. Cheers, Aaron

neat! ive always loved the color of pewter, i didnt know it machined well though!

Amazing video

Hello, Interesting video... Looking forward to seeing what you are going to do with the bars... Take care. Paul,,

Ok thanks/ now I will be searching for and collecting pewter ! My very first job as a young lad was at THE PEWTER MUG. When we received a new shipment of mugs we opened them up and banged them around a bit to make them less desirable for people to carry out of the bar.$1.75 an hour

@TheRecreationalMachinist

2 жыл бұрын

Great story! 👍 🇬🇧

This was a great video Very well presented

Great video with lots of helpful info., Thanks!

This was a fascinating video! Thank you for putting it up. The "bridge" to casting higher temperature metals is a great idea. It's causing me to wonder a bit about casting zinc/aluminum alloy...

Id like to see more casting and machining pewter!

@AddamSantana

Жыл бұрын

My anthill pewter pour video here... kzread.info/dash/bejne/o6l8tM6dmdHXdMY.html

What a cool video...I enjoyed it very much ....and thank you for the kind words...!

Hmm, I didn't realize pewter would machine that nicely. Not sure why I thought that.

Really enjoyed this, thank you

Good to see you back 🙏

Tin is a pretty interesting metal and it has many strange properties. Tin grows crystals when cooling pretty fast. It is crucial to cool mold and cast as fast as possible to get better casts. Molds made from insulating materials (silicone, paper, wood) are bad because cast stays liquid too long and cools too slow in them and crystals grow too big affecting material strength. Tin can grow crystals with age and can change crystal form all together (read about white tin and grey tin) but thats another rabbit hole. Different tin alloys act a little different each but faster cooling the cast is always helpful.

@TheRecreationalMachinist

2 жыл бұрын

Interesting stuff K K. Thanks for watching 👍 🇬🇧

I’ve been trying to find what metal I had melted Finally The same crystalline structure the same coloration I’ve been unbelievably confused and after months of research you have given me the answer Thank you so much

Interesting that the pouring temperature of the pewter is almost the same as the max temperature generally quoted for silicon kitchen accessories.

Commercial tin ingots are around 25kgs, they are quite golden in colour, oxidation due to the time that bulk takes to cool. Smaller ingots of high purity tin 99.9%+ poured into a cast iron mould will solidify to a bright smooth silver colour, any crstalisation indicates impurity.

A quick test to see if the colour was due antiminous oxide, which is faintly yellow, would be to drop the bars in a base solution like lye and see if the coating dissolved. It should dissolve in both acidic and basic solutions so that would lend some support to the idea. I don't think it would be the copper oxides as they are all the both wrong colour and the Sn(IV) oxide allegedly needs concentrated mineral acids to disolve. I also wonder if the colour might be due to diffraction from the surface finish? the fast setting looks to have a lot smoother surface finish compared to the others which might have micro-pitting causing a colouration effect similar to how case hardening.

Hurray, your back!

Thanks for the video. Useful information and a great maker channel. Keep safe and stay well.

Very informative. Thanks 😀 👍

I was amazed the cardboard survived after having had molten metal poured into it. I’m interested to see what you do with the rod’s. Cheers Peter

Damn. Now I gotta buy an Areo bar. Why are they so good?

@BM-jy6cb

2 жыл бұрын

They *used* to be good when they were Rowntree. Once Nestle bought then they turned into chewy brown sludge - same with KitKat, Yorkie, etc. Sorry, bit off topic but a real pet hate of mine!

Good job 👏

Silicon is known to out gas heavily which makes it pretty frustrating to work with in high vacuum systems. Probably the same reason it ruins the first few castings and leaves that oxidization on the ingots.

Very nice!

I would concur with your oxidation theory for the discolouration. Daft as it may seem at the temperatures, this might have been introduced by your cast iron pot. Otherwise I would consider adding some flux during your melt. I would guess the crystalline structure is due to the presence of Ni. If you can polish a section up and view it under a microscope and you should see it in the microstructures. The above is guess work as I am an iron founder by trade and haven't worked with pewter before.

@brightwell127

2 жыл бұрын

Hi there , I've seen the mention of flux being used before , would this e flux that a plumber would use to solder pipes ? Thank you in advance

@dickturpin3115

2 жыл бұрын

@@brightwell127 hi, in aluminium casting its mostly a mix of chloride / fluoride salts with other additions depending on what you are trying to achieve. Most are potassium chloride/ sodium chloride. I believe that plumbers flux is mainly made up of zinc and zinc ammonium chlorides so whilst this would technically be an impurity, it might increase your tensile strength without greatly affecting hardness but could impact corrosion resistance. If the section of your castings isn't too large you could probably get away with plumbers flux. Probably best not to overdose it though, I would aim for 1 to 1.5%. Hope that helps.

@brightwell127

2 жыл бұрын

@@dickturpin3115 just looking to do some pewter similar to the video, but watching several videos just trying to discover more about the flux process do I even need to ? Thank you for a very knowledgeable reply I appreciate it

I think the crystalline surface happens when the metal is vibrated while cooling

what to make yout of the round stock?

My uneducated guess is that yellow finish on your bars is due to carbon level. Try adding flux (pieces from a simple wax candle will do) to get rid of that.

Thanks

7:24 made me jump!

Hi would pewter be good for coin casting, for example pirate treasure, it just sounds like fun, and would be cheaper than buying a forge

@TheRecreationalMachinist

Жыл бұрын

I'd say definitely. I'd try to avoid the really old leaded variety of pewter (if you'll be handling the coins). You could attempt it for almost zero outlay, just the stove top and an old saucepan would get you started. Post back with how you get on 👍 🇬🇧

@yorkshiremad

Жыл бұрын

@@TheRecreationalMachinist Cheers

Was it easier to turn than aluminum or brass?

Nice, next one up temperature wise would be die cast alloy which is zinc and aluminum alloyed, it can de quite strong and machines well

@tinayoga8844

2 жыл бұрын

I have started casting with zinc. I have not seen pewter where I am. As Mark says, zinc is the next practical material to use. (based on melt temperature) I do want to eventually use aluminum.

Pewter bar stock! I love it!

i melted some pewter picture frames. about 10% of it was difficult to melt. after pouring what would pour nicely, it was left in the heating pot and was soft and lumpy while cooling down. any idea what it was? it's not slag, it's silvery and heavy like tin and lead.

@TheIntermont

Жыл бұрын

Maybe zinc die castings mixed in with your pewter?

@samboheena

Жыл бұрын

@@TheIntermont that's what i'm thinking now, having played with some zinc wheel weights and seeing how zinc mixes (or doesn't) with other alloys including aluminum and lead. the big question I have is, how did they get it to alloy with the tin so well if that was the case?

Is the silicone mold just a standard mold I could buy for cooking ?

@TheRecreationalMachinist

Жыл бұрын

Yes! Molten pewter is a bit hotter than recommended for silicon moulds, but they seem to work for quite a few goes before they start to degrade.

@sandrallewelyn4896

Жыл бұрын

@@TheRecreationalMachinist Thank you , this is a new hobby for me, was introduced to it by a woodlands group.

@TheRecreationalMachinist

Жыл бұрын

Take a look at @JimmiePorterAtStuartArts He's done some nice videos about pewter casting (check out the playlist section on his channel)

Argon - yep I was thinking that. Or cold Nitrogen.

Would pewter be suitable for casting a handwheel for a lathe?

@TheRecreationalMachinist

2 жыл бұрын

I find pewter has a certain warmth and tactile quality that might lend itself to a handwheel. It's somewhat soft, so might need a bushing loctiting in for strength and wear resistance in the centre, but once you get up to several mm of thickness it's relatively robust stuff. If you have a go, be sure to film it and send me a link!

Fucking cool!!!

Is there actual talcum powder in baby powder as talcum powder is carcinogenic. So if I want a stronger pewter I need lead in it. I play around with diecast cars and want to cast replacement parts. As pewter good because the low melt point. I can 3d parts and make a silicon mould. But been told pewter is to weak. Cheers for the informative video

The yellow being from sulphur?

try preheating your mold

About strange color - its seems like oxidation process, that was/is used in metallurgy, only info i found is german - de.wikipedia.org/wiki/Anlauffarbe. In electronic production we used tin baths and clean liquid metal surface just before soldering, sometimes flow attachment is used and tin stay clean all the time due to mixing - it also helps to reduce tin waste. I remember pouring the entire bath of old lead+tin solder, so we could fill it with new lead free stuff - heavy as hell and same scary. when you have used water it seems that due to cooling time and heat flow difference metal didnt get yellow oxide layer, i believe if you use heavy cast iron pouring form you get different color as well.