My muller build

[dallen]

your right it does have quite a smearing action going on when its running, I will have to empty it out some so that the track behind the wheel is visible. I'm sorry that I took such a tearible video I know that there wasn't a lot of action to it, but figured that you would be able to translate what the machine was doing.

I was trying to figure up the other day how much I have in it in buying parts, purchasing metal, my time on machine tools making parts, my time fitting and welding. I figure that if you put 750 on it I would break even. The actual work wasn't too bad except for the fact that I was out in the sun no shade till late in the afternoon made for a miserable time building.

I was of the mind when I was using just greensand that you didn't really need a muller, after running my greensand thru this the one or two times that I did cast with it, totally changed my mind. I know that 5 gallons is a lot but I don't know about in Onyx but here when its hot everthing evaporates, it may not evaporate very fast from the tube but it will, I throwed in a shot last night to some that I had mixed with wet sand, had a bad texture to it, was really sticky like syurp had been poured in it. I put in want would run through am IV line in a minute and let the machine run for a spell and you could litterly see the change in the texture of the sand.

I have been doing some hunting trying to locate products that are local to oklahoma so I won't have to pay shipping (well I will it just won't be listed as shipping but as and increase of the price of what I am using). I found out by reading that paper I qouted last night that you can also use Methyal Hydrate as a catilyst instead of propalyene carbonate which is from what I have found quite expensive. The oil that I have used up to date has been O'Rielley's ND 30 an 10 weight oil, hopefully after conversation that I had yesterday with a man at a Oil distrubitor I will find out what I can use that is as close as I can get to what they used in the k-bond mix.

I'm going to lucnh, I been working on this damn computer all morning it seems like I had to replace its motherboard to get it back up and running. I will try for some video this evening, hopefully I can hire someone to stand around and act like a foundry man, otherwise I'll have to do it.

One last thought, Leon dude I know plays with 440 three pahse, he's used Petrobond for several years now or anyway for the two years that I have known him. His sand is black as the inside of ole Ab Lincoln's top hat, I don't think that he throws any of the burnt away, if I was having to mull it by hand I would thro it away but so far what I have casted all has went back in the tub. if your casting hard you can loose over a bag a day of sand, I'm not saying that there won't be times that you won't throw it away, say you do an iron pour and the sand turns to glass or binds up on the part hard enough that you have to use a grinder to get it off, I wouldn't want that back in my heap.
Wish that they made half barrels one same diameter as a 55 but only half that high with a lid.
David.

[Harry]

The video was great David and the action looked really good too which is what inspired my comment about the wheel dragging might be a good thing. May cause faster wear on the wheel but then you can fix that easy enough when the time comes.

Here is our weather report, looks like we might have some thunder storms coming in this weekend. Where I am situated with the shape of the mountains around me this can quickly turn into flash floods, funny the way it floods in the desert. We are at 3000 feet but it is still desert so most of the time it is pretty dry here and 100 degrees + is common for a couple months of the summer.

How about getting an EZ Up for working under when its hot David? I have a 10 x 10 I think I paid about $150 for. It sure has come in handy on many occasions, I originally bought it for my crew when I was working a regular job... they would use it in the roads when we were doing raise to grades (bringing utility access back up to the surface after paving) since they would spend some considerable time in one spot jack hammering out to pour the new concrete. Even after putting up with those clowns far a summer it is still in pretty good shape and will even put up with a good wind by weighting it down and it takes all of a couple of minutes to put up and take down.

I honestly do not think the oil is all that important with small changes from one type to another, smoke is probably this biggest difference with the proper oil being one that produces low levels on shakeout.

The loss I was seeing when doing long casting runs of say 800 to 1000 lbs of molds was probably around 10 lbs of sand so every few days of this I would add two or three scoops back into the heap. This made a difference in the color the heap settled in at as the new sand would mix in keeping it a little lighter in color. It certainly doesnt hurt for the sand to be black as long as it still binds well. I plan on running the current heap until it shows me some kind of degradation in casting quality then either cut half of it out and mix in new or simply replace the entire heap. I still lose a little when casting just from being messy but not more than a lb or two over a long casting session, if I kept the floor real clean I could recover this but the semi open nature of my shop it gets a lot of dust and grass bits blowing around and it would be more trouble than its worth.

[4cylndrfury]

I pretty much just toss all my sand back in, Ive never thrown any away. Mine behave rather well despite turning from a nice pretty green color (the oil I used was Green, so the whole batch turned grean as Kermit ) . Now its getting a pretty dull orangey/brown from the darkened sand going back in. All in all though, the moldability is still great, even after dozens of castings. Twice now (in 2 years) Ive had to mist it with some isopropyl alcohol to get strength back to where it belongs, maybe an oz or 2, but thats to be expected from what I read - just regular sand maintenance.

[dallen]

Heres a little video that I hope shows the action that is going on in the tub when its running. I emptyed it out so that its got most of a 5 gallon bucket of sand in it, this is new sand that only thing that has been casted with this is one cast of the fan blade and I think one Flask panels so there isn't a lot of burnt sand in the mix, I did throw in some golf ball sized chunks of some sand that had been bonded with Sodium Silicate. I did this to see how they would break down,



Harry was asking about the smearing action in the tub, if you look right behind the wheel you will see that it is leaving a pretty wide track in the sand. I have the wheel locked so that it raises up about half an inch. I do plan on making this adjustable, at the moment I have an angle clip welded in place to keep the wheel from raising up.
You will see in the video the material builds up on the outside of the wheel and then it gets knocked off and is broken up as the wheel passes by squeezing the material between the wheel adn the tub wall.

David

[dallen]

I pretty much just toss all my sand back in, Ive never thrown any away. Mine behave rather well despite turning from a nice pretty green color (the oil I used was Green, so the whole batch turned grean as Kermit ) . Now its getting a pretty dull orangey/brown from the darkened sand going back in. All in all though, the moldability is still great, even after dozens of castings. Twice now (in 2 years) Ive had to mist it with some isopropyl alcohol to get strength back to where it belongs, maybe an oz or 2, but thats to be expected from what I read - just regular sand maintenance.

4CF; I was just rereading your post, your saying the oil you use is green, what is it a two cycle oil?

[Harry]

I think more importantly his clay was tan not red, at least this was my impression. I used red bentone and green oil (synthetic 2 cycle, same brand mentioned on the K-bond page) when I was making my own sand and it came out green.

Your sand it looking a lot like mine as far as how it behaves when being mulled, wanting to clump up in balls then breaking apart.

[4cylndrfury]

yep, Harry is right, the clay (bentone 34) is a cream color, almost ivory. The oil was green in color, full synthetic 2 stroke oil (low in detergents and additives). The sand is regular playsand, so a light tan color.

Here are 2 pics: the earliest pic of my sand, and the latest:

[dallen]

throwing in some red oxide will give it the petrobond red color.
can you still get the powder and if so what cost per bag????

[4cylndrfury]

bentone 34 is $4 per lb, and the bags are 50lb, so $200 per bag.

[dallen]

I can get petrobond II out of Minnisota for 2.00 a pound and shipping, then all I need is oil, but I have 5 gallons of methyl Alcohol, just incase the muller needs a little something to perk it up or my lawnmower.