Cleaning up anvil repair

Rob wrote: my attempts to put some sort of backing

I would try a file before ordering any exotic grinding stones. It might be too hard for a file, but it would be worth trying.

Dan

I am sure that it is too hard for a file. It also vitrified several generic die griding bits. I have a cutting torch, but I don't want to risk cutting something I don't want to.

Thanks for your help, Rob

"Rob" wrote: I am sure that it is too hard for a file. (clip) ^^^^^^^^^^^^^^^^^ Milwaukee makes a "power file," which is really a very small hand held belt sander. Harbor Freight has a conversion kit that fits on one of their hand-held grinders. If either one would fit into the hole, it would make fast work of this.

You can use standard pink mounted points with 1/4" shanks for any type of hardened steel. I regularly grind everything from mild steel to D2 tool steel, hard MIG wire and TIG rod, as well as HSS die buttons.

I don't know what you mean by "vitrified" (which has to do with producing abrasive products) but you probably glazed your stone, which is to be expected. You need to buy a dressing stone. They're typically black, and 1x1x6", although sizes may vary.

Mounted points *need* to be trued and dressed before *any* grinding as they are virtually never true out of the box, and regular dressing is required during use. Your grinder should feel as smooth (when it's on) with a point, as it is *without* a point. Any vibration means that you have not adequately trued your stone. This vibration will also result in a garbage finish on your workpiece, and could damage your hands during prolonged use.

Anyway, you can also cut hardened steel with carbide burrs, although this will kill the burr a lot earlier than when you're cutting soft steels. Burrs are expensive, but they will continue cutting, albeit slowly, when they're dull.

You will need coolant for none of the above work. I've never seen anyone use coolant with a die grinder before, and we do hours and hours of die grinding at work every day.

Good luck.

Regards,

Robin

If there is a lot of material to remove from your hardy and pritchel holes, I suspect in the long run that gouging away with the cutting torch and then coming back for another bunch of judicous welding to fill the gouges and holes created from doing that will end up being the most effective way to address this...

Just curious, what hardfacing rod did you end up using?

--Glenn Lyford

"Rob" wrote in news:1167413207.452650.50060 @a3g2000cwd.googlegroups.com:

But is it too hard for abrasives?

would seem to be "just what the Dr. ordered" for the hardy hole.

"1/2" BANDFILE BELT SANDER

Narrow 1/2'' wide belt quickly removes stock from scroll cuts, edge work and other tight areas. Gear driven power Head swivels 180 degrees up and down Removes stock at 2300 feet per minute Uses easy-to-install mini belts Lightweight aluminum body Comes with five belts

ITEM 92158-1VGA

$34.99 "

The belts, BTW, are also available

"5 PC. BANDFILE SANDING BELTS

Includes: 80 grit (2 pc.), 120 grit (1 pc.), 180 grit (1 pc.), 240 grit (1 pc.) Material: Aluminum oxide Size: 9'' L x 1/2'' W

ITEM 93990-0VGA

$2.99 "

"Rob" wrote in news:1167411958.504428.204740@

Before spending bigbux, try using a cheap cylindrical carbide burr and, if that doesn't work, a cheap cylindrical diamond burr with water coolant.

Don't expect unlimited burr life with either one - that's why I said "C-H-E-A-P" - but you may well be surprised at the results.

BTW, don't expect square corners from rotating burrs. Don't expect to have a perfectly circular pritchell hole, either, unless you can drill through the hardfacing with a suitably-sized bit from underneath.

I definitely glazed the stone when I tried it. I did it in a community college shop which had pneumatic die grinders. All I have at home is a dremel tool. The price of the CBN burrs I mentioned was $4-$12. Are you saying that all I need to do is to use a dressing stone when the point glazes over? It happened almost immediately before. Also, is the procedure to press the bit against the dressing stone until there is no more vibration and then go at it again?

Thanks for your help, Rob

P.S. For those who wanted to know, I used Lincoln metal to metal rod on my first attempt and then covered that with some Ranite rod (BX, I think).

Roughly yes.

If you don't press hard enough when you're grinding, you don't cause the mounted point to wear correctly. By using adequate force, the dull crystals will break off, exposing new sharp ones. It's hard to say whether the point you're using has a bond of the correct hardness for grinding hardened steel - ideally you want a stone which comes apart fairly easily. The grey stones have a softer bind and will work better. However, I think I may be splitting hairs for your application. Virtually any quality stone (pink, grey, brown) should work to some usable degree.

Yes, but you should learn to move the bit across the stone as you're pressing on it, or else you'll dig a ditch in the dressing stone, and basically ruin it for other jobs. I always dress with the mounted point at about 45=BA to the long axis of the dressing stone. After a couple of solid passes, I move the mounted point to the other side of the stone at the opposite 45=BA, thus making a cross-hatch pattern. You don't have to follow that exactly or anything, but I wouldn't just press the mounted point in one place - you will get a ditch.

I haven't looked at the CBN burrs you're talking about. Perhaps they're wonder tools. My point was that you can most certainly do the work you need to do with carbide burrs (for roughing) and mounted points (for finishing).

Using a die grinder correctly takes some getting used to. Right now your technique will probably have a greater detrimental effect on your work than the type of stone you use. Die grinders are very useful tools once you can control them.

Regards,

Robin