Smelting solder drippings?

[aussie460mag]

Hi, I have recently smelted some solder drippings from a radiator shop into small bars to add to my lee 10lb pot of clip on WW, I cast some boolits and found nearly all 200 to be rejects, what looked like small inclusions and splashes that had not re melted and bonded in the mold even thou the mold was hot enough (its a lee 6 cav 45 300gr alu mould)

I decided to remelt all boolits and make a large batch of clip on WW with enough solder to bring it up to 2% tin, once melting in my large cast pot, a black sludge started to form on the surface, i then fluxed using wax the sludge increased in volume and couldn't be skimmed (it ran like water and would coat my skimming tools).

I let the pot solidify, the black stuff did also and then scraped of the suface of the lead, the under side of the lead was dimpled like a golf ball and all sides of my cast pot had a thin coating, once scraped and wiped off i remelted the metal back into ingots.

Is this black stuff from the solder drippings? Has any one else had this? I haven't experienced it will any other smelting (WW ect)

[Ausglock]

G'day. I too smelted 60/40 Solder droppings from a radiator place.

There was a large amount of dross.
I fluxed with "Blue and Grey" lead flux.
No worries. The ingots came out nice and clean.
I added 1lb to 12lbs of Clip-on WW.
water dropped 3 days ago.
hardness is now up to 18 BHN with a Lee tester.
These are Lee 356-125-2R.
for a 38 Super.

[lwknight]

The goo on top was probably zinc cloride flux core solder. Normally you would not get that much flux from drippings.

The tiny inclusions were probably oxidized antimony. That happens when the mold is too far below the spout. Stirring and working the pot will get most of the inclusions up to the top and I bet the solder flux in your remelt took care of that as well.

[220swiftfn]

I'm sure that others will second this, if you have that much "stuff" in the drippings, use lots of sawdust when you ingot them. (the cleaner you get them in the smelt, the better for your pot and boolits.....)

Dan

[lwknight]

When I melted rosin core solder , the flux goo was very annoying at best but it cannot contaminate the metal. It will sjudge up everything that touches it though.
Maybe paper towels would soak up the goo?
I just put the dipper barely under the surface and skimmed all that I could then raked the rest out of the ladels path and dipped up for my ingots.

[Baron von Trollwhack]

Do not be forgetting the sludge from the WW. The "goo" is likely to burn off shortly. Remember the mix temperature is usually at its lowest at the point you first rake out the clips, rubber, valve stems, and etc..

BvT

[GLL]

Were the WW and solder both in clean and well fluxed ingot form before you alloyed them together in your LEE pot or were the WW in the form of "dirty" clip on weights?

I have cleaned and fluxed a lot of radiator drippings into ingots and never run into your problem at the time of mixing with clean WW ingots. If they were both clean I cannot figure what the black sludge might be !

Jerry

[aussie460mag]

WW where clean, solder may have been a little dirty because I only had about 1 lb and didn't even cover the bottom of my cast iron pot.

Does anyone now what would cause the golf ball like dimples on the bottom of lead ingot from my cast iron pot once i let it cool? i have seen this once before when using a muffin tray as a mold.

[lwknight]

Probably oil or some cure agent like baked on greas that is gassing off as the hot lead makes contact.
When I get new ingot molds like bread pand , I burn them out to redf hot on the buener before using them.