Using Two-Part Silicone to make a Repro-One (Cast Plastic) Pattern

Discussion in 'Sand Casting' started by Melterskelter, Feb 12, 2023.

  1. Tops

    Tops Silver Banner Member

  2. Al2O3

    Al2O3 Administrator Staff Member Banner Member

    Compositions vary. Generally referred to as paste waxes, some are Carnuba and some Pariffin based. Carnuba is naturally occurring and produced by/on Carnuba Palm leaves. Somtimes called Brazil or Palm wax. Parrifin is petroleum based. Either seem to work fine for parting compound but I prefer Carnuba based products. It's harder and has a considerably higher melting point than paraffin and seems to be able to be worked to higher gloss. That's why it was a staple for furniture wax and car polishes because of the gloss and ability to mask light scratches. Well know to furniture makers for many years. Carnuba is yellowish and has a sweet smell. Paraffin is opaque, colorless, and odorless, but as paste wax, both will be reduced in some sort of solvent.

    I didnt know about Johnson's being discontinued. It does seem to have dissappeared from retailers. I searched it and some say it was being abused by kids getting high some how? Others said that was urban myth. And others said it just wasn't a commercially performing for SC Johnson. Plenty of sources for Carnuba waxes though.

  3. Melterskelter

    Melterskelter Gold Banner Member

    Johnsons was a parafin-based wax, evidently as is Minwax. I read that Johnsons has a suspected carcinogen as an ingredient. In our litigious environment, most companies will just deop a product as soon as that, often vague, concern is raised (uness you are a tobacco producer or a beer maker, winery or distiller---all producing federally registered and proven carcinogens! :cool:). class="p1">SC Johnson Paste Wax-02/18/2015/p>/19-001-640

    Just for kicks, I may try one of the many carnuba waxes that Kelly likes. As he said, they seem to be widely available.

    Do you have any favorites, Kelly? I see
    Meguiar's Deep Crystal Carnauba Wax - 16 Oz Bottle
    Claims to be a primarily carnuba-based wax.

    Last edited: Mar 14, 2023
  4. Melterskelter

    Melterskelter Gold Banner Member

    I promised some pics of the results from the old core box (actually the original pattern for this casting) and the new corebox which is a silicone to Repro One copy of the original. The copy had inset resin-printed letters as I was changing them from the original pattern. The original pattern had plastic resin=prointed letters too, but they were not as ddep as I liked. So, I printed some new ones and routed out the copied letters in the plastic copy and inset new ones with the results compared below. Both castings were made yesterday. Both were 18 inches overall and each weigh about 13 pounds.

    The new core box casting is above.
    Old Core Box vs New COre Box.JPG

    New above---detail of casting lettering.

    I like the new lettering much better than the old.

    Tobho Mott, Rocketman and Tops like this.
  5. Al2O3

    Al2O3 Administrator Staff Member Banner Member

    -Very good definition, especially in iron. Well done.


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