Sooting up skimmers makes slag separate more easily

Discussion in 'Foundry tools and flasks' started by Melterskelter, Jul 3, 2019.

  1. Melterskelter

    Melterskelter Silver Banner Member

    I have noticed in a couple instances brief reference to applying soot to skimmers to make removal of skimmed slag/ iron from the skimmer easier. In one case the video maker mentioned use of a old-school smudge pot. When I was a kid these were very commonly used for nighttime marking construction zones etc.



    To have one of those around dedicated to simply smudging a skimmer seems a bit impractical to me. That is especially true since a fossil-fuel-burning furnace properly run for melting iron should be burning with a mildly reducing flame and so should be a good source of soot.

    Today I experimented with sooting my skimmers in the exhaust stream of my diesel-burning furnace. Sure enough, I could get a nice coat of soot with maybe a 5 to 7 second exposure. And I notice the slag and iron did not stick to the sooty skimmer so I could just knock off the slag by banging it on a heavy piece of steel I have on the ground near my furnace. It is there to serve a an “anvil” for the purpose of knocking slag off skimmers using a 2 pound hammer. If I skimmed a few times on one sooting, I notice some weak adhesion of iron to skimmer. That adhered iron and slag popped loose pretty easily and very cleanly with a hammer blow or two.

    Overall, I felt cleaning my skimmers was much easier if they had been sooted.

    If I am just the last guy to learn this and everyone else has been sooting their skimmers, my apologies.

    Last edited: Jul 3, 2019
  2. Jason

    Jason Silver Banner Member

    You're showing your age Denis....:D I bet you could spray your skimmer with fifty dollar a can Boron Nitride too... ;) Soot is cheaper.
  3. Tobho Mott

    Tobho Mott Silver Banner Member

    You're not the last to learn this; all my dross skimmers currently have thick buildups of various frozen metals stuck to them. I'll have to try the soot trick too...

  4. Mister ED

    Mister ED Silver Banner Member

    I never thought about soot being helpful with such high temps (of course I am a toddler compared to you guys).

    That being said, soot is all I use on mandrels/shafts when pouring babbitt (of course, much lower temps). Gives me a great finish and never any sticking.

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