Removal of glass coat 2

[yakov1]

Is some body know what is the right way to remove glass coat from the shaft? Shaft is 6" dia, 168" lg. Material - carbon steel.

Best regards
Yakov.

 

[unclesyd]

Is this a vitrified glass as in a glass lined reactor?

 

[Cockroach]

Chemical dissolve in hydrofloric acid bath, then neutralize and wash piece.

Kenneth J Hueston, PEng
Principal
Sturni-Hueston Engineering Inc
Edmonton, Alberta Canada

 

[Compositepro]

Sand or shot blasting.

 

[GregLocock]

Why wouldn't the HF eat the steel?

Cheers

Greg Locock

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.

 

[MikeHalloran]

It would, quickly.



Mike Halloran
Pembroke Pines, FL, USA

 

[MikeHalloran]

Bend the shaft.

Finish up with a hammer.



Mike Halloran
Pembroke Pines, FL, USA

 

[harrisj]

What is the 'glass coat'? The exact meaning may have been lost in translation. It could be mill scale (which is fused ceramic - ie glass)if the shaft has come straight from the mill.

If so, impact with an air powered needle descaler is the normal way to clean it up.

 

[Cockroach]

Hard to say what the "glass coat" means.

I went with the conventional sense since glass is typically used over steel as a protective coat from highly corrosive acids. For example, "glass lined" tanks for holding sulfuric acid.

Kenneth J Hueston, PEng
Principal
Sturni-Hueston Engineering Inc
Edmonton, Alberta Canada

 

[JStephen]

I wondered about the HF acid and steel as well. My thought was that HF acid will attack glass, but if it attacks steel much faster than glass, then by the time you got ALL the glass off, you'd have eaten pits in the steel where it first penetrated the glass. Wondering if this technique has been tried, or was this just an idea?

 

[harrisj]

Please don't advocate using hydrofluoric acid, whatever the glass really is. This stuff is bad enough in the lab, but on an industrial scale it's evil. This shaft is 14 foot long and weighs over 1/2 a ton. That's some bath, cockroach! You'll have gallons of HF slurping around, with fumes and splashes.

By the time you've found someone foolish enough to do it, and paid lip-service to the health, safety and environmental guys, you could have made 10 new shafts.

Look up what HF does to the human body if you get a drop on the skin. Not nice.

 

[Chris0164]

Can it be done with ultrasonic vibration ??

Clean and safe

Kind Regard,

Chris