Page 1 of 2 12 LastLast
Results 1 to 10 of 16

Thread: Wax pattern wash

  1. #1

    Wax pattern wash

    I am usually cleaning wax patterns into concentrated professional cleaner of some kind, before applying the first ceramic shell layer.
    I am not getting a perfect wax coverage by the slurry, some spots remain uncovered. But I need a perfect primary shell layer, due to the particular secondary slurry I use.
    Does anyone have a good DIY formula to properly clean/etch the wax surface?


    Thanks.

  2. #2
    Administrator Site Admin
    Join Date
    Dec 2005
    Location
    Huatulco, Mexico
    Posts
    3,172
    I don't use ceramic shell. I use traditional plaster/sand investment, but I believe the problem is the same with both. I use propylene glycol. The two most commonly available varieties of this are "Photo Flow" for treating photographic negatives in the darkroom, or the stuff you put in the dishwasher to prevent water spots, available in any grocery store. I dilute it with a lot of distilled water (maybe 20 to 0ne) and swab it on. The investment flows on nicely and doesn't try to bead up. (Ethylene glycol works well too (common automotive anti-freeze.)

    Richard
    When I die, Heaven can wait—I want to go to McMaster-Carr.

  3. #3
    Junior Member
    Join Date
    Feb 2017
    Location
    Elkhart Indiana
    Posts
    28
    Roost, I have not cast in lost wax only have done light reading on the subject. I am assuming your professional cleaner has some type of citrus acid plus perhaps a solvent of some type. Which will need to be washed off for your shell layer to better adhere. As for DIY I've heard people using baby oil, lighter fluid, pantyhose, Goo Gone a name brand made from natural ingredients but still has acid and solvent in it. I would suggest to try any new method on a sample piece prior to using on one you intend to cast. Especially if you use different varying waxes. Aric
    Last edited by AricMettle; 03-01-2017 at 12:52 AM.

  4. #4
    Hmm, must have something to do with his slurry. I haven't done jack to my wax so far with the suspendaslurry. PG I've got loads of it. Don't ask.
    I'm going to have to go smear some on my micro crystalline and see whats what. Let's see your wax pattern roost. Never happened without photos ya know! ;-)
    WWW.TheHomeFoundry.org
    Visit me: WWW.HandcraftedLanterns.com
    "Sometimes by losing a battle you find a new way to win the war"
    -- Donald Trump --

  5. #5
    Thank you for your reply.

    Rasper: I will try propylene glycol. After swabbing your patterns, do you leave it on or do you rinse it with water?
    AricMettle: I don't know exactly what are the ingredients of my cleaner. It has a lemon smell, but his Ph is about 9.5, so should not hurt the slurry in small amounts. I do rinse it with water.
    jagboy69: I use stuff from Remet, modified to need a quick stir just before dipping. Will make some photos later.


    My research turned out two interesting possibilities:
    - Citric acid; should etch gently the wax surface, and so promote the adhesion. Cons; could damage the slurry.
    - Mix of acetone and light oil; should also etch the wax and evaporates quick. Cons; fire danger, horrid smell, probably afterwards needs a cleaner to wash residues.

    Regards.

  6. #6
    Administrator Site Admin
    Join Date
    Dec 2005
    Location
    Huatulco, Mexico
    Posts
    3,172
    I will try propylene glycol. After swabbing your patterns, do you leave it on or do you rinse it with water?
    Don't rinse it off. If you do it will loose most, if not all, of its effectiveness. I brush on my first coat of investment while the propylene glycol solution is still wet.

    R
    When I die, Heaven can wait—I want to go to McMaster-Carr.

  7. #7
    Senior Member
    Join Date
    Sep 2012
    Location
    South of France
    Posts
    151
    Hi Roost,

    I saw this mentioned in a rather excellent thread that covered many excellent topics on ceramic shell casting, here is the excellent thread link
    http://www.alloyavenue.com/vb/showth...flip-pour-demo

    OH OK THEN!... Its my thread!!!!
    But i did mention the coating. My coating (used for the same reason youve been having) is to take ordinary pure shellac and mix it with alcohol. 7 to 10 parts alcohol to 1 part shellac. Pour over your wax and let dry. Done. Just start shelling as you would normally. Have a look at the thread, it gives a bit more info. The shellac is covered in the first post (look for the second and third pictures if you dont want to read the rambling start of the thread) but im sure once youve started reading therell be no stopping you!

    I used to use the propylene glycol rasper metioned on my trad plaster based moulds and this worked fine for them but not tried it on my ceramic moulds.

    John

  8. #8
    Rasper ; I feel somehow not not enthusiastic about introducing propylene glycol into the slurry tank. I dip my patterns, and due to the shape of them, some liquid can be left on them.

    John; thanks for the link. I have to find out what shellac is in Europe.
    ------

    I have tried submerging my pattern into acetone. Left it to dry and then dip. I had 100% spotless slurry coverage I will give acetone a longer tryout, since it is easily available and quick to dry and also of very low toxicity.

  9. #9
    Senior Member
    Join Date
    Sep 2012
    Location
    South of France
    Posts
    151
    Quote Originally Posted by roost View Post
    John; thanks for the link. I have to find out what shellac is in Europe.
    Shellac is shellac in the UK (we are still in europe so far!), and in france it is gomme laque. Cant help with anywhere else im afraid. It is usually bought as a none toxic furniture coating, bought in ready mixed liquid form or flakes to be mixed with alcohol. It is sometimes used for sealing wooden patterns fo sand casting and sealing plaster of paris moulds.

    It sounds like acetone is working for you, as you say easy to buy and low toxicity.

    How did you get on with using graphite powder in your primary slurry coats? Did you do any experimenting?

    John

  10. #10
    I found the name in my language, is quite the same as in English, at least the pronunciation. Found it on an online store.
    I retried acetone, it works indeed. Maybe even a bit too much of etching at points where droplets stay for a longer time. But the primary layer sticks like never before. When I used degreaser only, I experienced buckling many times.

    I did try using graphite. It did not work that well; to burn out the graphite particles very long firing time was required. Fyi, I do the burnout in an electric kiln at 550°C max, I do not want any sintering to take place, I need my shells soft.
    The second problem was, that the test batch I prepared with the graphite addition did gel, so graphite was out for good.
    And later I found that the problem I was having was not the permeability of the shells, but hidration of the mineral additives - the H2O bound did outgas during the pours.

    Regards.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •