separating two cast pieces

MikeO-WI · Aug 13, 2015

We are trying to take apart an irrigation pump that was sealed with some sort of gasket maker material that is like Permatex but appears to have hardened. The two pieces should have had a paper gasket installed instead. We have tried small chisels without it budging. Looking for any ideas here. Do we heat it? Cast area is about an 18 inch circumference and is about at least 1/2 inch thick on the outer ring.

showcrop · Aug 13, 2015

There is a model of commercial dish washing machine pump that we had to open up to replace seals pretty often. If they had been assembled with silicone grease they would come right apart. if not they would frequently break before coming apart. I would be planning on it breaking.

Steve@Advance · Aug 13, 2015

If it is held by Permatex, or whatever sealer, heat could help. Then try wedging something sharp, like an old knife blade, old kitchen knife, hammer it in slightly, move around going a little deeper until it gives.

dr sportster · Aug 13, 2015

If there are any holes where you can stick a wooden dowel in and bang them apart ,otherwise you have to pound a sharp knife into the seam and gently pry it apart.

Worldpowerlabs · Aug 13, 2015

Can you arrange the pump such that one of the two parts you're trying to separate is supported on something solid, then strike the other part with a dead-blow hammer in order to create a shearing motion? Or are there locating pins or other parts in the way?

old · Aug 13, 2015

Thinking a bit out side the box but can you cap off the outlet side then hook up the inlet side to say a water supply and let it build up pressure to pop it apart or even air might do it but air would tend to be a little bit on the less safe side but would likely do it

showcrop · Aug 13, 2015

(quoted from post at 11:33:20 08/13/15) Thinking a bit out side the box but can you cap off the outlet side then hook up the inlet side to say a water supply and let it build up pressure to pop it apart or even air might do it but air would tend to be a little bit on the less safe side but would likely do it

Or maybe a good charge of propane and a match on a very long stick, or better yet an electric igniter with some very long wires.

MikeO-WI · Aug 13, 2015

Thank you for the idea of using a sharp knife. I know someone else also mentioned it but we tried heat and the knife after reading your comments. Knife almost went in like we we cutting butter. Big hammer probably helped. Used two knives and then small chisels and it slowly came apart, no damage, nothing broken. Thanks again, this site and all those who contribute are appreciated.

lastcowboy32 · Aug 14, 2015

(quoted from post at 20:53:07 08/13/15) Thank you for the idea of using a sharp knife. I know someone else also mentioned it but we tried heat and the knife after reading your comments. Knife almost went in like we we cutting butter. Big hammer probably helped. Used two knives and then small chisels and it slowly came apart, no damage, nothing broken. Thanks again, this site and all those who contribute are appreciated.

I do quite a bit of wood working. I have one or two 3/4" wood chisels that I keep in my mechanical toolbox for just such an occasion.

I still sharpen them like my normal wood chisels at about a 25 degree angle. I just don't bother to hone them with the fine stone or strop.

The sharp edge, flat on one side, combined with the gentle slope of a 25degree bevel, combined with having a wooden or plastic striking surface for a mallet (which doesn't transmit shock like a steel cold chisel)...makes a wood chisel a very good tool for separating stubborn gasketed surfaces.

I'm glad that the knife worked out, but a couple of wood chisels might be a good addition to your toolbox if you do this a lot.

lastcowboy32 · Aug 14, 2015

And if they were only being used for this purpose...no reason that you couldn't sharpen them down to an even lower angle, like 15 degrees. That would probably give you the best of both worlds, the angle of a knife, the strength and strikability of a chisel.

separating two cast pieces

MikeO-WI

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showcrop

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Steve@Advance

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dr sportster

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Worldpowerlabs

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old

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showcrop

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MikeO-WI

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lastcowboy32

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lastcowboy32

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