Sodium Silicate RU

Discussion in 'Sand Casting' started by PROSTOCKTOM, Apr 3, 2019.

  1. Hey Guys,

    I trying to find a place that will sell me a gallon of Sodium Silicate RU. Would anyone be able to direct me?

    Thanks,
    Tom
     
  2. oldironfarmer

    oldironfarmer Silver Banner Member

    Budget Casting Supply has a sodium silicate product for cores. They don't stipulate whether it is RU grade, if that is really what you want.
     
  3. Melterskelter

    Melterskelter Silver Banner Member

    You may have to buy 5 gallons as I did. But even so it was relatively cheap. I use the RU and find it very useful. If you don’t use something to weaken its bond, it will make your cores nearly as hard as concrete when you want to shake out your casting. Sugar is a convenient weakener.

    Denis
     
  4. Thank for the post. Since they are not specifying what grade your getting I am betting that it's N grade. Either way they are out of there mind at $82.50 a gallon. You can buy a gallon of N grade on eBay and Amazon for about $35 with the shipping included. I think I'll keep looking for the higher Grade RU.

    Thanks,
    Tom
     
    Last edited: Apr 4, 2019
  5. Thanks Dennis, Yes I was aware that I needed to add an organic substance to make the core shake out and that sugar was the cheapest and easiest option. Although I've never ready if you should use regular sugar from a 4# bag or if you need to use powdered sugar. Would you happen to know? Also where did you obtain your RU at? I really don't need 5-gallons since I just started playing around with cores for a V-8 intake manifold.

    Thanks Again,
    Tom
     
  6. Melterskelter

    Melterskelter Silver Banner Member

    I bought RU from a local refractory/foundry supply house in Seattle. They are not exactly inviting hobbiests but will tolerate me. There have to be some in your area as there is so much industry in Indiana.

    I think I bought 5 gallons for on the order of 40 dollars. Sodium silicate is one of the cheapest and readily made chemicals in the world. It is commonl used in a wide range of industrial processes and food production.

    I use plain table sugar though powdered sugar just has a little added anti-caking agent (added later----cornstarch) added to finely milled table sugar.

    Denis
     
    Last edited: Apr 4, 2019
  7. Thanks Dennis, We have Gartland Foundry and Modern Aluminum here in Terre Haute. I'll do some backdoor checking around to see if either on of them has the RU. Yes, I live in the heart of casting country, but most as you mentioned are not interested in fooling around with a hobbyist.

    Tom
     
  8. Melterskelter

    Melterskelter Silver Banner Member

    I have to sort of muscle my way in the door and put up with disinterested attitudes. But, I try to have thick skin. The guys on the floor are more interested in being helpful than the front office. I also made contact with the delivery truck drive who is sympathetic to my foundry needs and will throw on a few bags of this or that with his next trip to my city a hundred miles from Seattle and charges me no delivery fee. I just pay for the product. So the back door swings open more easily than the front in this case.

    Denis
     
  9. Al2O3

    Al2O3 Administrator Staff Member Banner Member

    If you don't need a big quantity, highly concentrated sodium silicate is very easily made with caustic soda (lie) and silica gel (clear crystal cat litter). You need to exercise some care but no more/less than with foundry work. Search YouTube for making sodium silicate or water glass and you'll get lot's of hits. You can buy the lie and litter about anywhere for <$10 and have enough to do a lot of core work in a couple hours. Best done outdoors with a burner/hot plate.

    Best,
    Kelly
     
    Mark's castings likes this.
  10. Thanks Kelly, That is an interesting idea, however already having way more projects to do than time in a week allows I think buying it already made is a better option for me.

    Tom
     
  11. Just talked a friend of mine that owns a foundry south of me in another town about the process he uses in core making. He told me that they just use wheat flour and vegetable oil as the additive to the sand, them bake them out. He said, That depending on how hard you want the core you regulate the amount of oil added. More oil hard core, Less oil softer core. Since he has about 35 years experience in a production foundry I think I'll take his suggestions and try it out. At least you can get your supplies at Walmart 24/ 7 except Christmas day.
     
    Last edited: Apr 6, 2019
  12. oldironfarmer

    oldironfarmer Silver Banner Member

    Did he give a recipe? Or is that not a sand core, only wheat flour and oil?

    No yeast? Butter might go good on a hot core like that.
     
  13. Melterskelter

    Melterskelter Silver Banner Member

    Interesting he is using vegetable oil—-I did not know that was an option as I thought you had to use a polymerizing oil like boiled linseed oil for classic oil-bound core making. It will of interest to let us know what recipe(s) you find that will work well.

    You might want to keep your eye out for RU as you may find it a useful additional tool to have available. Since I use wood patterns and core boxes, subjecting them to significantly elevated temperatures would be damaging. I also like the essentially instant “setting” quality of Na-Si cores when gassed with CO2. A 15 second spritz of gas and they are ready to demold.

    It is impossible to have too many core making options...

    Denis
     
  14. DavidF

    DavidF Administrator Staff Member Banner Member

    Skip to about the 8 minute mark...

     
  15. oldironfarmer

    oldironfarmer Silver Banner Member

    I'm guessing that with wheat flour and vegetable oil the core would "dry" in a wooden core box and get hard enough to pull out and bake with no core box to hold it.
     
  16. ESC

    ESC Silver Banner Member

    Can you clarify that he doesn't use any sand at all?
    All the core mix recipes I have seen have more than 90% sand. I add flour to my linseed oil bonded core mix to increase the green strength, but do not change the amount of oil. I use a 40:1 by volume with Okie 90 core sand.
     

  17. I made some of this sodium silicate and it seems to be of very good quality to my inexperienced eye. I made it with an excess of silica gel which should give a neutral PH: the result is a thick honey viscosity liquid. The test cores made so far are over 6 months old and show no sign of getting wet in a very humid environment.
     
  18. I am going down this next Tuesday and get a first hand view of the process they use making the cores. He will have no problem sharing his ratio recipe with me.

    Tom
     
  19. Melterskelter

    Melterskelter Silver Banner Member

    Well, what did you learn? If you get time, please post some info on your visit and what you learned.

    Denis
     
  20. Beone

    Beone Lead

    SalVageable sodium silicate in gallon cans, online. Don't remember the price but it wasn't much .Don't know the grade.
    Dave
    That's WalMart. Don't you love autocorrect?
     

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