# carbide rotary burr question



## arcotramathorn (Apr 16, 2013)

I have about 12' of inside weld to grind smooth and looking to use carbide burrs for the job. What is the difference between double cut and single cut and the advantages to each type? I'm assuming they would be similar to single and double cut hand files but not certain. Can anyone enlighten me?

Thanks,

Jay


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## Dave Smith (Apr 16, 2013)

12' of weld is a lot--what is it inside of and how much room do you have above weld, also is it all in a line or just 12'  of shorter lengths?  also is the weld size very small or large?  this should help us to get a better image of what you are grinding.--there may be a better way of grinding the weld off.   Dave


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## arcotramathorn (Apr 16, 2013)

I am making a motor stand to convert a line drive camelback drill press to electric. the welds are on the inside of 3/8 plate welded in an X pattern with more plate welded to the top and bottom of the X if you were to look at it in an extruded sense. Ultimately I am trying to mimic a casting so it doesn't throw the look off too far and the inside corner will look much better with a radius. I will post pics as soon as I can. 

And my math was a bit off as there is 16 feet of weld to grind..... And I hate grinding just as much as anyone else!


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## psychodelicdan (Apr 16, 2013)

Really sounds like you should start things out with a real grinder and get it close to start with. IMO a double cut is the way to go. A little more controllable 
Dan


Master of unfinished projects


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## arcotramathorn (Apr 17, 2013)

I went ahead and ordered a double cut so we shall see how well it works out. Thanks for the advice Dan.


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## Dave Smith (Apr 17, 2013)

I guess I am still wondering if most of weld could be ground off using an angle grinder or a small die grinder --it would be more efficient than carbide burrs---hope it goes smoothly for you ,  sounds like a good project     Dave


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## arcotramathorn (Apr 18, 2013)

Here are the pics I promised. 

Dave, I do plan on using a die grinder with the carbide burr chucked in it. I could possibly get an angle grinder in the corner but it would be very difficult to get a radius in there. stone wheels in the die grinder are an option but I dont think they would be as aggressive as carbide and they would wear very fast. That is just my assumption since I have never used the carbide.

All in all my welds are close but still look like crappy welds so if it turns out to be too much of a PITA then I could always slap some bondo in there.

The carbide burrs are due to arrive on Saturday so I will give them a try Saturday afternoon or Sunday.


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## davidh (Apr 18, 2013)

carbide burrs tend to jump around, and make slivers that will get into every part of your person.  carefully grind with a small 3-m type sanding disc mounted in your die grinder then apply good bondo and you will be really pleased with your accomplishment.  bondo type body filler will stick very well to the area you have sanded 

I use a product called "metal to metal" it works well and sands well and will be there for a lifetime. available at any body shop supply house.


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## Dave Smith (Apr 18, 2013)

If you are just wanting to hide the welds on the pedestal ---I was just thinking of four 1" strips of 16 to 20 gauge steel-- tack welded over welds would be quick and your primer and paint would blend in the sides so no welds could be seen --I'm always looking for cheaper and easier methods.   your stand is looking very nice    Dave


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## OldMachinist (Apr 18, 2013)

I would just knock off the high spots, then use body putty to smooth it out and make your radii.


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## arcotramathorn (Apr 22, 2013)

I got the burr in on Friday and went to town on the welds on Saturday and Sunday. The below pics are from the first 2' weld that I ground down. I was very surprised that it only look 10 minutes to get that first weld to where I wanted it. I was swapping back and forth between finish welding the base and grinding the radius in the upright to give myself, the welder and the air compressor a break. In total I have about an hours worth of grinding the radius with about another 15 minutes worth for the welds between the base and upright. I will use a small amount of bondo for the areas with voids from lack of filler metal and the light undercutting I did with the tool itself. All in all I am very please with the results. Thanks everyone for your suggestions and Thanks for the compliment Dave. I will probably start a new thread about the resurrection of my camelback in the near future.


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