Found a copper trick that saved me 2 hours on a tube sheet repair

Last week I was wrestling with a leaky tube sheet on a condenser job in Gary. Old school way of rolling tubes into the sheet was taking forever because the tube ends kept slipping. On my third try I just hit the tube ends with a wire wheel for 10 seconds before rolling them. Cleaned off the oxide layer and the expander bit in way easier. Held tight after the hydro test too. Anyone else got a weird prep step that cuts down the headache?

3 comments

3 Comments

emeryj6610d ago

Wait, do you mean you wire wheeled the inside of the tube ends or the outside where they contact the sheet? I usually only clean the outside of the tubes before rolling, but hitting the inside could mess with the expander's grip if the mandrel isn't seating right. I've had good luck with just a quick pass of scotchbrite on the tube O.D. right where it meets the sheet, gets rid of the crud without taking off too much material. That oxide layer is stubborn but a light cleaning seems to do the trick for me too.

shane_clark9d ago

Inside and outside both. If you've got an old tube sheet with years of crap baked in, scotchbrite just polishes the grime. A wire wheel on the inside knocks down any raised burrs or scale that can throw the expander off center. Light touch though, just enough to see clean metal. Scratching the bore on purpose sounds backwards but it actually gives the mandrel something to bite into, keeps it from walking sideways on you.

phoenix5739d ago

Honestly, I'd argue it's better to hit the inside with a wire wheel too, not just the outside. If you're not cleaning that bore, you're leaving grit and old tube debris in there that can mess with the expander's alignment way worse than a little grip loss. Scotchbrite on the O.D. is fine for light work, but on a heavy duty tube sheet I want everything scoured clean so the mandrel seats dead nuts every time.