I am new to the core Making world. I am making core boxes for a new project. Looking for a supplyer and recommendations on what products to use. I don't want to bake the cores due to time. Would like to use the C02 method. Any help is appreciated.
I used n-grade sodium silicate that I got from a local pottery supply house. I've been told it's not the optimal type of silicate for this purpose but I was able to make it work, the process is pretty quick and easy. Here's an old video I made of my core making process, it was shot in real time, no cuts or edits. The sand was "brick" sand from a local building supply which I screened to remove the big chunks of grit, and it was mixed at ratio of 6% silicate by weight. Most of the literature you read will say 4% by weight but I found that was inadequate, maybe because I wasn't using the most appropriate type of silicate.
I put my core box into a plastic tub with a lid. Also put a cup of baking soda in the box. I pour some vinegar into the baking soda cup which makes CO2 and water. I put the lid loosely on the tub and wait about five to ten minutes. CO2 is heavier than air and purges the tub of air. For my hammer head cores, 1/2"x3" I use a gallon ice cream tub and about three tablespoons of vinegar. Pour of the water and leave the wet remaining baking soda in the cup. I don't vent my hammer head head cores. Bigger cores I vent with a small wire. I'm always surprised how the CO2 finds it's way into a closed core box. Of course the parting line is a crack as well. When I need pressurized CO2 I make it in a bottle with a hose coming from a hole in the lid which I can insert into a core. Quick, easy, and very cheap. And my CO2 supply is never empty.
If you search on past threads you will find a lot has been written about silicate core making. Here is one thread on core making including videos of the process: http://forums.thehomefoundry.org/in...temperature-and-sugar-content.794/#post-18177 Tom Cobett has a monograph on the web on core making including silicate cores. I have made 50 pounds of silicate-bound cores and molds this week. 95% was done with propanyl carbonate kicker, though I did gas one. Denis
I get my sand and RU from United Western foundry supply in Seattle. I think the propanyl carbonate came from Lancaster Foundry Supply. Denis
You know, I did put a thingamagig up for links to various suppliers. Be nice if guys actually put up links in there.... http://forums.thehomefoundry.org/index.php?forums/link-to-various-suppliers.41/
Ouch, I thought I had done pretty well to put up two out of 14 links in that sub forum for more or less obscure items. RU and propanyl carbonate are more generally out there. I would not consider putting up United Western as they are not about to ship it to anyone who can not pick it up. And propanyl carbonate is available a lot of places. Besides Lancaster, I got a gallon at a now defunct foundry supply in Portland, for example. It's a little tricky to know what to put up and what not to link there, not to mention even thinking of linking there. Denis
What? Another grumpy mod? Not sure we have room for another......it happens as you getter older pal.....LoL. Seriously though it would be great if folks added links like that to the thread. We can move them but there's power in numbers. Best, Kelly
