Zebra Clutch cover

[Harry]

You have some pretty high standards which is good, that part looks great from the picture.

Petrobond will get powdery like that when it is cold out and has sat for awhile. A muller should bring it right back.

[Jeff Clark]

Harry Thanks, The Petrobond really has to be packed hard to hold togeather at all, then is real brittle and powdery about the consistency of chili powder right when I opened the bags I knew it was going to be a problem. Ill get a muller built in the next week or so and mix my own and go from there. Guess I better get things in another section kinda done with the patterns for now...

[dallen]

I mix my own Jeff and here in Oklahoma in the winter time with the cold I have trouble with it acting like its dry, but the moment it gets hot metal poured into it the oil loosens up and the sand is like it was 75 degrees in the shade.

if your sand that you bought has been in the bag for a while it should be mulled to work the oil, also you may need to add a little oil to it to get the consistency that you want, but be careful of doing this as a couple once's goes a long way with this stuff. if you want I have all the paperwork that petro bond puts out, for mixing and using their product. I can scan the pages and email them to you.

Oil I buy a non detergent 30 weight oil, or whatever the supplier recommends. I don't think that you can over mull the stuff, but it will start trying to crawl up the wall of your muller the more you work it.

[Harry]

With my sand I can grab a handful in summer and slam it onto a coin and get a perfect impression when I pick it up and the coin drops out. The other day I had my brother out from back east who hasnt been visiting in about 8 years and went to show him how it will pick up the detail of a coin and got a big puff when the handful hit the molding board and none of it held together. I tossed a couple scoops into the muller for just a minute and when it came out it acted just as expected.

I have heard of BCS sand being very dry and have no clue as to their mix or if it is just a cold weather thing. Not sure where you got your sand but I am going to guess a little action on the sand and it will be up for the game. Like David said, some hot metal in it will sure make a change. You could just make a ingot like depression and heat up a flask of sand and mix it into some cold sand and probably get it up to snuff, or just take a bucket inside for the night and keep it by the woodstove if you have one and give it a little mixing while ward then mold with it. Bottom line... yep if you are going to use oil sand you want a muller and as David has pointed out many times a muller is a blessing with water based sand also.

[Jeff Clark]

I made a make shift muller last night and it worked quite well, so now I had a good batch of sand I was back to my practice, I decided to try a casting with 6061 again last night and I believe this is the problem with casting 6061?? no flow?


But my sand was great!! and has nice definition, im still have tons to lern but having fun knowing my parts will be 100% built by me when done.

[dallen]

find some high silicon scrap aluminum or mix it with something that was casted like the engine block from a lawn mower or car wheel. you can ram this stuff up pretty hard also because your not going to have the problem with steam that you get with waterbonded sand.

keep use posted on how it goes, nice pictures

[Jeff Clark]

I have some 356 I think I will mix some with the 6061 and see what I get, I have around 300lbs of 6061 one reason I was trying to see if I could get it to cast... Ill have some pics over the weekend with updates, im on a mission....

[dallen]

what size hunks the stuff machines great and I need some about 1X3X4 or 5 inches for a project I am wanting to try,

[Jeff Clark]

Most are end cuts from machine stock, I would think I might have what you need. One reason I would like to use it also is that it polishes so nice.

[Harry]

The 356 will also take a high polish and the silicon will make it flow better which will help a lot with the thin sections you have. Really have to hit your heat right on something big and thin.

Now machining is a whole nother story, the 356 can be machined but it can also cause some fits in gumming up tools if not done just how it wants to be done. My cnc is a router and the high speeds are something to deal with. I use Tap Magic for aluminum in a mister at a rate of about an ounce an hour. I tried KoolMist fluid but the rate was way too low and since I have a wood table top a high rate of flow just brings other problems.