Investment Removal

[daves1459]

Does anyone have a method to remove residual investment from a hallow brass casting. I'm casting condensers for sight feed lubricators. The attached photo shows a condenser casting sectioned to check wall thickness and to proof machining dimensions. The amount of residual investment is obvious. The sphere portion of the condenser is 1" diameter and the walls .060". I've tried the usual hot casting agitated in hot water. I tried a hooked wire. But the end holes are too small to reach very far off center. Is there a chemical method or any other trick. A long time in process or in solution is not an problem.

Thanks, Dave

[Charles T. McCullough]

Sand-blast it out... thin pipe sealed on the end, but with a slot in the side near the end. Blow mild abrasive through it while you rotate the ball and raise and lower it. Keep the large opening of the product aimed down so the casting material can fall/blow out. just don't overdo it and wear a hole in the ball.

[daves1459]

Sand-blast it out... thin pipe sealed on the end, but with a slot in the side near the end. Blow mild abrasive through it while you rotate the ball and raise and lower it. Keep the large opening of the product aimed down so the casting material can fall/blow out. just don't overdo it and wear a hole in the ball.

Thanks, Good idea!

Dave

[RONALD]

The Rail Braces in the photo below were sandblasted in a Sandblasting Cabinet.

Cabinets are available in cheap to expensive, my cabinet is a slight bit smaller than I would like, but it was given to me for free.

It was not needed by the company anymore, so the boss told my brother, "get rid of that!", which he did.

DSCN2634_2.JPG (356.02 KiB) Viewed 530 times

[Bill Shields]

Sand-blast it out... thin pipe sealed on the end, but with a slot in the side near the end. Blow mild abrasive through it while you rotate the ball and raise and lower it. Keep the large opening of the product aimed down so the casting material can fall/blow out. just don't overdo it and wear a hole in the ball.

kinda reminds me of things urologists do these days...