Scrap Alloy ~ Again

[odoh]

I salvage what I can from the scrap yards and frequently haven't a clue what it is.

Most recent were some ingots cast in tobacco can. Lee hardness tester indicated about bhn of linotype ~ should be elated right? Well upon melting, it produce cottage cheese. I scraped it off thinking zinc but, upon pouring into the ingot mould, it produced large metallic bubbles:shock: upon cooling, did another hardnesss test plus, did the ball bearing test using know lino and still seemed to match. Made a point to pour half ingot and secured in my bench vice and whacked it w/a hammer. Sure enuff, it shattered unlike lino in that the break appeared satin, not crystaline which I expected it would like zinc. Texture looked like concrete or broken pottery. Its tuff to get out of the mould and have shrinkage depression in the middle of the ingot.

Any thots what it may be? Needless to say, I'm not gonna take on any more stuff that I don't know for sure what it is. Any comments appreciated ~ have about 8lbs and have a mind to toss it ~ ~ ~

[justashooter]

babbit metal, if the density is similar to lead. was used years ago to cast wearable bushings around greased shafts, etc. was also used to cast toy soldiers.

[lwknight]

It sounds like some of the 5-15-80 sn-sb-pb that I got. It cast bubbly till I heated it up to 700 degrees then it was just beautiful alloy.
You may notice that it conducts heat very poorly and will even have craters in the ingots.
Mine melted at 500 degrees but was not fully melted till it got to 650 or so.
If it works out that just a little more heat makes it behave , you probably can just add 20 percent more lead and end up with linotype.
Its a gamble anyway.

[runfiverun]

high antimonial alloys frequently require higher heat to come around once it does you can flux and turn down the temp.
you might have depleted linotype and the low tin content is showing up.
try pouring and comparing to a known alloy in a mold.

[odoh]

I've 70-30 lead antimony alloy that exhibits courser crystals when broken, unlike this unknown alloy. However, I did add an additional 30% lead to this alloy seemingly w/o any effect.

If it were babbit based, I'd think it would have made a difference and it didn't. Howabout pewter? Absolutely no experience w/it but seems to be the last possibility ~ I'm thinking about its appearance at the break edge. Kind of fine texture like 600 grit wet and dry paper in appearance.

I've a 22lb ingot that I need to smelt into smaller ingots and it too is an unknow at this point 'til I can get it down in a workable size. Hope its not the same stuff ~

ON EDIT: I recall that after adding more lead, the large, pea sized bubbles didn't appear during the pour.

[lwknight]

You might have gotten it hotter too.
Unless you get real scientific with specific gravity and melting / phase temperatures and hardness you will likely have mystery metal.
You can always thin it out till you get the desired hardness.

I do thin kthat with the pea sized bullbes , its high antimony and at least 5% tin.
What is the melting temperature?