Glaze on 4.5 inch Angle Grinder Wheels

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I'm getting glaze on the grinding wheels I use in my 4.5 inch angle grinder - anyone got a suggestion for getting the glaze off?StoryI had replaced the original Canadian Tire (CT) grinding wheel when it got down to almost the depressed center.  The new wheel was a cheepie ($0.88) from Princess Auto (PA) - seemed OK for a long time but I noticed that the PA wheel didn't disappear anywhere near as fast as the CT wheel - guess the PA wheel was much-much harder material... but it started to glaze up and not grind so well as when new.I put on a Black & Decker wheel and life was great again... till that wheel too started to glaze up.  Like tonight, I'm grinding away on a weld and it seems to be taking forever - only a narrow trail of sparks.  I changed to a new CT wheel - and what a difference.. broad swath of sparks and the weld ground down real fast with little pressure on the grinder.Now, two questions:1 - Can we prevent a 4.5 inch grinding wheel from glazing?2 - How can we rejuvenate a glazed 4.5 inch wheel?  (I got two to do.)Thanks in advance!  Rick V
Reply:Each brand has it's own characteristics. Some brands even make fast and/or slow versions. None of the decent ones are going to be 88¢ off the shelf for a single. Some of the mediocre brands (norton) vary from time to time depending on who was in charge of the glue that day. It's all in the glue and the abrasive. How fast the abrasive does or doesn't break off to expose a new edge, and how much or little glue is there to hold it in place.The only way to unglaze one is a jagged edge. Most of my free hand torch cuts work good for that . Personally if I had a 88¢ glazed over disc it would be in the trash. Tiz my opinion  that you can reduce some of the glazing by using the leading edge as much as possible. I mostly use mental notes and boycotts. Once I find one that I know ain't worth a crap, I'll never buy another, no matter how cheap. Getting the work done is the goal. It's rare I'd buy a cut rate disc anyway. Anything that is going to spin from 8 krpm to 14 krpm needs to have some R&D in it. Try a Sait (sp), Norton or other brand.
Reply:I woulda said quit buying cheap crap...but you say it much more eloquently.Anything worth doing is worth doing RIGHT
Reply:But with the same thing happening with more than one brand I would suspect there is more to it than that.  Unless both brands are made by the same company and the same batch.My guess is that you are taking it too easy on the disc.  Like car brakes.  If you always just lightly apply them then the friction material cannot get hot and bite into the rotor.  I would try to apply a little more pressure to whatever you are grinding and see if that would help in any way.TimMiller Dynasty 200DX; MM180; Spectrum 625; Bobcat 3-Phase; and counting...
Reply:Originally Posted by olddadI woulda said quit buying cheap crap...but you say it much more eloquently.
Reply:I use the zirconia disks and they last much longer than anything I've tried.  They are more expensive but are worth it.  All zirconia is not the same.  I tried some discs from enco made in india that were zirconia and they were next to worthless.  The best I have used were made in canada and bought from MSC.  By the way, they are blue colored.
Reply:To remove the glaze just slam it into the concrete floor at full R.P.M....zap!I am not completely insane..Some parts are missing Professional Driver on a closed course....Do not attempt.Just because I'm a  dumbass don't mean that you can be too.So DON'T try any of this **** l do at home.
Reply:Originally Posted by MicroZone ...leave it to olddad to give you the blunt truth.
Reply:Fiber re-inforced discs cost a little more. Glue is cheap. If I was educated my educated guess would be that some manufactires try to solve the flying apart issues by overwhelming the grit with glue. Glue glazes over.
Reply:Zap is right on the de-glazing it on concrete, it actually works pretty good.  But as for the "slamming it on the concrete floor" thing,  I would say to use a bit more finesse.  Never use a grinding wheel that has been dropped,  Hobart 140 Handler w/ gasHyperTherm Powermax 380 Plasmaoxy/acetylene
Reply:Hey Fellows... thanks for all the comments.MicroZone - Did I miss what material you're grinding on? Mild steel and it's building up?
Reply:You are supposed to hold a grinder at a 10 to 15* angle to the worksurface, and only use the outer 1/2 to 3/4" of the wheel.  It will continue to keep a fresh surface as it wears to a smaller diameter.  Sounds like a case of cheap wheels or wrong RPM.Maybe your using a left-handed grinder on a right-handed project?  JUST KIDDING!Hobart 140 Handler w/ gasHyperTherm Powermax 380 Plasmaoxy/acetylene
Reply:Rick Moran - You are supposed to hold a grinder at a 10 to 15* angle to the worksurface, and only use the outer 1/2 to 3/4" of the wheel. It will continue to keep a fresh surface as it wears to a smaller diameter.
Reply:TO TRYI'm going to try a cast-iron, star-wheel deglazer. What these 4.5 inch disks need is something to 'pick' at their surface - to shatter the glaze by picking out pieces of material and generally roughening up the grinding surface.