Too Much Tin?

[Mozz]

I picked up a few kg of 'Solder Joints' basically taken from old plumbing.

I smelted the joints and cast with the alloy, I was expecting a good pour however they have not formed right out of the molds.

I estimate the solder to be 60 lead and 40 tin, with similar pipe weight of pure lead. Giving a 20% tin count.

Contamination ? Zinc? Calcium? Arsenic? or its just too much Tin.

Any ideas?

Mozz

[6bg6ga]

Could be acid core?

[zuke]

Mold's clean?

[imashooter2]

If those were poured joints in iron pipe they aren't solder.

[fryboy]

what he said .....

details helps ... not formed right ( no matter the amount of tin ) is usually too cold somewhere and sometimed too hot , pewter ( 99 fine even ) cast sweet looking boolits .... a bit light but fine castings

[Mozz]

Sorry guys to be clear.

These are soldered joints joining lead pipe tougher, not poured lead.

Soft lead (roofing lead) produced better bullets.

Maybe tempture?

[fryboy]

tin rich should cast fine , a lil light but it'd just be a waste of tin , some things can mess up a pour, a wee bit of zinc is a well known one but for just a lil bit turning up the temp usually works , yeah most of us will think temp is too low , either mold melt or both , when the temp is too high it also "shy" away from the grooves and bands , often on the side that's the hottest

[lwknight]

Its hard to imagine a high tin alloy not casting well. I have not used more than 5% tin but did note that when molds get too hot t hey do not cast well with the higher tin content.

[bangerjim]

You have problems OTHER than too much Sn!!!!

I have an alloy that is 52% Sn and it casts perfect edges and details. Tested it just to see. I use it to sweeten pure. Same with pure Sn bars I melted down. Pewter is almost pure Sn and casts details wonderfully!

Your pour temp was proably way too low. Get it up higher. And flux/reduce to get rid of any garbge B4 poruing into your ingot molds.

bangerjim

[Mozz]

Thanks you guys, it did seem strange. I will experiment with the heat.

[30Carbine]

Mozz take a look at this and tell me if you have to much tin. this is what the ingots started to look like after my wife put all my pewter collection in the big pot.

the mark in the right one is where I put my gloved finger going ***.

[Ballistics in Scotland]

Were those particularly big pipes? It is possible that those are what used to be termed wiped joints, i.e. done with heat and flux alone, and consist entirely of lead.

[lwknight]

From what I see in the picture is just normal cooling. You could have a near eutectic alloy that actually hardens on top before the middle sets up then as it cools it will cave in like that. Pretty much all alloy ingots of any size get a rough and/or hilly surface. If you poured it into a thick iron mold that cooled it quickly it would probably be smoother.

[30Carbine]

lwknight that divot in the one was from my finger. like I said above, and those are 43.3% gunned at the scrap yard tin in those. these were from a 1000 pound melt I was doing
that the wife was well did put over 400 + pounds of my pewter into. I keep these 2 as a reminder and to show what really high tin looks like. the pics don't do right on how shinny they really are.