Material Removal of the "Barrel"

[HDS]

There was a previous post here viewtopic.php?f=2&t=47

in which the person wanted to polish the inside of a tanker trucker. Like the above example, the part is the barrel itself, although it is a 12" diameter pipe that has an inner coating of ~2mm that needs to be removed. The material to be removed has a Shore D hardness rating of 80. (For comparison sakes, a construction hard had has a rating of 75). The pipe can be sealed at each end and rotated if a liquid would be required.

What type of tumbling media and procedure should be used to remove that ~2mm inner coating?

Thank you in advance,
HD

[HDS]

One typo fix, that would be construction hard hat, not hard had.

[rmkramer]

re metal removal-- This can be achieved by putting meda almost half way up. The medea and compound choice is determaned by what the metal the pipe is consrtructed from. If stainless steel ,a mild acid compound such as our Kramco 1030 ,will accelerate the cutting. If mild steel like cold rolled or hot rolled , use a cleaner rust inhibitor such as Kramco 1510.
The media I would reccomend is a 1x 1inch or 1 1/2 x 1 1/2 cylindrical wedge in a KXF bond..This is a fast cutting bond that can abrade hard metals.The process can be speeded up by adding some silion carbide # 50-60 abrasive grain to the load ,about 1/4 to 1/2 lb per gallon of water.The water leval should be half way up the load ( half the volume) A 12 inch diameter pipe should be rotated 30- 45 RPM .
I can not predict the running time because we don't know what the coating is or how thick. It may take anywhere from 8 hrs to an overnight run rmk

[HDS]

Thanks for the quick response! The material to remove is actually polymer based, so it will probably be rather resistant to chemical treatments.

How much of the 1x1 or 1.5x1.5 cylinder wedge media would I need per foot of 12" diameter pipe? You mentioned using 1/4 to 1/2 lb of silicone carbide per gallon of water, is there a corresponding amount needed for the cylinder wedge media?

Thanks again, HDS

[emkayss]

About 65 pounds of ceramic media per 12 inches of 12" diameter pipe. Measure the amount of water required to just the level of the media in the pipe and then add the appropriate amount of Silcon Carbide grit based on that volume of water.

[HDS]

[quote="emkayss"]About 65 pounds of ceramic media per 12 inches of 12" diameter pipe.[/quote]

65 pounds seems like an awful lot of media per 12 inches? Was that a typo?

What is the main difference between wet and dry tumbling? I know the solvent can help dissolve the material to be removed, but are there any other benefits to the liquid? I would think that the liquid would slow down the removal by slowing the movement of the ceramic media.

Thanks,
HDS

[emkayss]

Ceramic Media is typically about 85 pounds per cubic foot and 12 inches of a 12" diameter pipe calculates to about 0.75 ft3. But since you would only fill the pipe 1/2 full, then 30-35 pounds is more accurate (sorry for the confusion).
The water and compound will allow for even breakdown of the media and release of the abrasive in the media to provide the material removal.