What is the best way to grind off the ends of tubes that are welded to the firebox tube sheet? We've cut out all the tubes of our boiler, and removed all the ends that were in the front tube sheet. I'm pretty nervous about just going after the welded ends with an ordinary grinder; I don't want to screw up the sheet. All suggestions appreciated. Thanks.

You can spring for this tool or just use a grinder
http://www.yourepeat.com/watch/?v=M4_hG7fnXDM&feature=youtube_gdata
Mike Tillger

I will assume that:
1) The tubes are rolled into the rear tube sheet, and
2) The tubes are beaded, and
3) The weld in question is a "seal weld" attaching the edge of the bead to the sheet.

Standard practice is to carefully use a cutting torch parallel to the sheet to nip off the bead, and then simply grind down the remaining weld.

This will leave the sheet in "as new" condition ready for new tubes.

If you aren't sure, find someone who has done this and get them to show you.

The bead removing cutting tool has to be used before the tube is cut off as the expanding pilot secures to the ID of the tube.
I have had good results using a aicair touch with rectanglar carbons the smaller size about 250 amps and about 25 psi air pressure with the carbon almost 90 degress to the tube sheet and just washing off the weld and tube bead. then finish with grinding. This method is fast if you are good with a aircar touch.
The old boilermakers just chipped off the weld and bead but I have tried this method with not much luck those guys were really good with a chipping gun I guess.
Grinding always works but is a real "GRIND" and hard work

welding with new tubes will just return metal back, 765 was air chiseled and grinded smooth.