Stack flasks

From molding systems to gating, what goes on at the molding bench will make or break a casting.
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HT1
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Stack flasks

Post by HT1 »

Flasks are the current Stumbling block for my work, Since I'm a welder by trade, I whipped these us. If you have never worked with stack flasks I will explain, they are especially designed for use with flatbacked parts. mostly plaques

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Here is the drag ready for ramming. note that stack flasks have the pins pointing upwards from below

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Here is the completed drag

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Here you can see a cheek, you can use multiple cheeks. 4 being common. the only difference between the drag and the cheeks, is each cheek must have a sprue cut

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Here is the drag and the lower cheek complete and on the deck

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here is the cope ready to go on,

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Here is the entire mold
I intended to make 4 sections, that is why there is no labeled cope, but I ran out of metal one piece shy
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Here we have the resulting castings.

There was one neat thing that I did not think of, the heavy 1/4 inch steel flasks did not raise when being rammed, A problem I have alot, so I did not have to clamp the pattern to the flask while I rammed... Hope this helps a few of you out
barryjyoung
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Re: Stack flasks

Post by barryjyoung »

Thanks for showing this technique, I have never seen that before. Don't those flasks weigh a lot being made of steel?

Barry
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Harry
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Re: Stack flasks

Post by Harry »

HT1, that is really cool... thanks for bringing the the things you do to this forum. You have a basis in old school that feels like it is coming from a young perspective, very refreshing.

I have done this before myself on some small parts stacking to make a lot at once. I found it a little tricky in setting things up for easy removal from the sprues so I did not carry on with it. Certainly a way to cut down on the laborious part of molding by eliminating half of the sand used. I want to explore the vertical casting of the DISA systems along this same line which pours parts individually but still uses the back of one mold for the front of the nest.
I'd rather laugh with the sinners than cry with the saints the sinners are much more fun...
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HT1
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Re: Stack flasks

Post by HT1 »

I was initially worried about the weight of the steel, but since it is only 1/4 plate 3 in high, it is not that bad. now those are 12 X 12 flasks. you need a set of 16's, it might be a bit more then most want to handle. but because of the stack technique, in the end you are lifting less sand so it is easier on you.

well professionally we used to break those out HOT and most of the time the sprues would break, at the top of the splash basin, because the splash basin will get a shrinkage hole, and it weakens where the sprue enters it, and while still hot, the metal will normally break at that piont, which is the perfect point. Now as an amature, cant do that. what I mean by hot, is normally the sand would burst into flame HOT and we just dont want that happening . so the best way for most of you would probabaly be to sawsall where the sprue enters the splash basin. then you just have a bunch of regular castings. I use a bandsaw. but it is bigger then I suspect most of you have. 106 in, b ut if you have one big enough, I cannot suggest anything better
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Nudge
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Re: Stack flasks

Post by Nudge »

That is a sweet idea, I need to do 20 belt buckles soon so I might look into the idea.

Thanks
I like to build "Stuff" using Stuff that costs Stuff All!
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