Petro Bond Mix 7 of 9

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Jammer
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Petro Bond Mix 7 of 9

Post by Jammer »

If anyone remembers Murray from AA. A professional Foundryman from British Columbia, Canada. He and I had been chatting on the side for a while and then he kind of dropped out of site. He had this recipe for petrobond sand that he developed for his use and I'm going to try to copy it as close as I can. OK, maybe I'm changing everything and hope it works.

Here's his original formula. I'm glad I saved it before AA went down. He called it 7 of 9 because he had tried 9 different mixes and batch #7 worked the best. I'm sure it had nothing to do with a Star Trek Voyager character. :?

Okay, 7 of 9

100 lbs # 92 silica

100 lbs # 58 silica

14 pounds of Petrobond clay, or Petrobond 2 no difference really, exept Petrobond 2 suposedly has the catalyst in it already, but I find no difference.

8 pounds of Sunoco Sunpar 115 Napthenic oil

140 ml of p-1 Catalyst I believe you can use alcohol with 10% water in it, the water is very important. The alcohol carries the water to the sand grains and finishes the catalization, you see a very noticable difference in the green strength immediatly after adding the cat.

This mix is designed to sit indefinately without changing and is way far outside the recommend recipes which call for far less Clay and oil. It is at it's best though after sitting for several weeks really but can be used right away.

Mix dry ingredients add oil slowly, mix for 15 minutes or so (that's what I do) then add catalyst and mix another 3-4 minutes and your done. Like I said I went through 9 mixes and this for me is the best combination of grain size, strength and wetness if you will.

Murray

P.S. I should state that this is "one use" only sand for me.

My Mix. 50 pound batch mulled by hand.

50 pounds of Silica sand
3.5 pounds of Petrobond
2 pounds of synthetic outboard motor oil
35 ml dry gas alcohol 90% water 10%


My sand is silica sand from a foundry but I don't know what size it is. I have petrobond clay that I got years ago from 4cylfoundry (I think).
The oil looks like it only come in 5 gallon cans, so I'll use sythetic Outboard motor oil because it's supposed to be high temp. I guess alcohol is whatever you can find but I have ethanol with 10% water.
Murray only used his petrobond once and just had it against the pattern and then filled the flask with his greensand or Pepset sand. He liked the surface he got with the petrobond.
quando omni flunkus moritati 8-)
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Harry
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Re: Petro Bond Mix 7 of 9

Post by Harry »

Man, I was so lucky to find the foundry supplier down south I dealt with. I purchased several barrels of mixed petrobond sand and it is infinitely reusable just adding a little oil from time to time (which I have not had to do yet).

I havent used it in several years but I was showing the setup to a friend awhile back and tossed some in the muller. It was dry and didnt think there was any chance but real quick it picked up the sticky and was just like I had been using it yesterday.

I will say however you get there I believe this is the way to go for ease of use and consistency without any worries of too much moisture.
I'd rather laugh with the sinners than cry with the saints the sinners are much more fun...
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Jammer
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Re: Petro Bond Mix 7 of 9

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Chucktn gave me about 20 pounds of petrobond mix, it was dry and wouldn't stiffen up with mulling. I brought it home and dumped it in a metal tub. I sprayed just a little WD-40 on it and hit it with a big propane weed burner. Kept mixing it with a trowel until it was hot to touch. It got all sticky and worked great. I just don't have enough for a project so I'm mixing up some more.
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Harry
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Re: Petro Bond Mix 7 of 9

Post by Harry »

Maybe a proper muller, something to give more action that you would ever get with a trowel?

I am no pro on this but have full confidence in the commercial mix and for it to have sat for a decade and come right back it impressed me nearly as much as it did when I was using it regularly.

When I was casting parts for castcnc I was turning it over at about 300lbs a day. After a couple years of that running 3 or 4 days a week it darkened quite a lot but never changed much in its molding properties.
I'd rather laugh with the sinners than cry with the saints the sinners are much more fun...
Muller
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Jammer
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Re: Petro Bond Mix 7 of 9

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I don't have a muller, most of the time I've used a screw type paint mixer. It works pretty well and has some shear action. usaully I only mix about 5 gallons in a bucket.
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quando omni flunkus moritati 8-)
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Harry
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Re: Petro Bond Mix 7 of 9

Post by Harry »

Yeah, I get that. The thought was just that the difference may be in that aggressive mashing stirring. Got to hand it to you though, I am far too lazy for that.
I'd rather laugh with the sinners than cry with the saints the sinners are much more fun...
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Re: Petro Bond Mix 7 of 9

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Finally mixed up some sand today. I poured a little sand into a 5 gallon bucket and then added some clay, more sand, more clay... and so on. Mixed it with the auger drill and it mixed up dry pretty good. Pour some mix into another bucket and added a little oil... Again, and so on. I added all the oil, let it set for a bit and then hit it with the auger. It mixed up real nice. I poured it back and forth between the buckets and mixed each time. It was packing pretty good and I haven't added the alcohol yet. I set it out in the sun to warm it, that should help the oil soak in. I'll check it later.
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Re: Petro Bond Mix 7 of 9

Post by Rasper »

Okay Jerry, good so far. Now what are you planning to cast in that nice new sand?

The only sand casting I have done was my first pour ever. I made a Gingery charcoal furnace back in about 1999 and melted aluminum beer cans. I poured a wine cup. I haven't melted aluminum since. Since then it has been bronze, lost-wax, investment casting. An entirely different set-up.

richard
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Jammer
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Re: Petro Bond Mix 7 of 9

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I checked it in the evening, and it was nice and warm. It has some green strength, and I haven't added the Alcohol yet. I've had this petrobond for years and never done anything with it. I'm kind of forcing myself to get out and do some things. Haven't felt good for a while now and I'm on some medicine that is dragging me down further. I don't know what's worse the disease or the cure.

I've got a couple projects that I have started a while back. Some bronze castings and some artsy fartsy stuff. Richard, you have done some really good items and sounds like you have sold some for a decent amount, like those little snail shells. How can someone working out of their garage and driveway get some notice from the artist community? "Art" seems to be so subjective.

I have some cast iron stuff to try out. I know the Petrobond is only good for one time in cast since it's so much heat.
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Re: Petro Bond Mix 7 of 9

Post by Rasper »

To understand the art world as contrasted with the business world is similar to trying to understand quantum mechanics when your thinking is grounded in Newtonian and Einsteinian physics. So far they live in two different worlds, both of which seem valid.
People don't buy art the way they buy washing machines. Clothing and furniture seem to lie halfway between art and washing machines. Clothing and furniture have utilitarian value, but they have some art value as well. And then there is decorative art, eg., paintings to hank over the sofa that match the decor of the living room. Whereas fine art has no utilitarian value whatsoever. Fine art is an emotional purchase, That's why there are galleries with their events and openings with lots of wine and canapes. When one person buys, another does, and another, and that sets up a feeding frenzy if the show is successful. People love to show off. The world of art can be a strange and wicked world.

For inexpensive art works, such things as Saturday mo0rning sidewalk art shows are great places to sell. Even there it's promotion. Talk like your work is the best in the world.

Richard
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