I'm welding some panel on the bed of my truck to bring the sides up so the bed cover will go over the tailgate. I've welded one side and need to know what you guys are using to grind down welds. The wheel I've been using are to coarse and leave grooves I want this to look pretty decent since it will be visible once or if ever the truck is painted.

 

I usually use a 4.5" flap disc. They come in various grits as see here Buy Flap Discs and Wheels Online Direct from the Factory - Lehigh Valley Abrasives

 

Jaye - I use the same flap wheel that LEckart showed. Like many on here, I have three angle grinders (HF cheapos). I have that flap disc on one, a cutoff whell on another and a wire brush on the third. It's a PITA to keep swapping out the wheels on only one grinder.

I prefer to use an 60-80 grit wheel to grind down the welds. Coarser just leaves scratches behind and a finer grit takes longer to do the work and builds up more heat.

You can find these wheels at any good industrial supply store or at McMaster Carr (online). HF has some flap wheels that I have used also. They aren't as good as these, don't last as long have a flat profile instead of the angled face of these, which is really nice, but they will do in a pinch.

 

The problem with grinding a weld with an angle like that is that one side of the disc hits flush and the other gets the edge. I usually use a die grinder with a cutoff wheel (thin disc) to cut down the high spots and get the general flat shape I am looking for before I hit it with a flap disc or grinding wheel.

 

Guys thanks for the information I'll go to HF or home depot tomorrow to see if they have the discs, I'm still of for X-mas so I may as well do some work.

 

I would use an angle grinder, and use the face of a 1/8" thick 4.5" disc. You can clamp a piece of flat stock on the lower face to act as a guard. Then, if you have one, use a sanding disc to smooth it out, or even a belt sander with an 80 grit belt.

It's definately a two or three stage process - grind most of the excess off then finesse it flat then sand out the scratches.

Julie

 

The economical way is to use the red colored sanding disks from Home Depot or Lowes with a rubber sanding disk backer. Just be sure the rubber disk you buy has a nut that fits your angle grinder arbor size. Pick up a 5 pack each of 40 grit and 80 grit papers, use the 40 grit to knock down the heavy stuff and the 80 grit to bring it down to final level. The red disks are very stiff and surpringly durable! Finish the center of the V with a vixen file run along a piece of angle iron clamped to one side then the other. Keep reversing the side the angle iron is on and filing the other side until you have a perfectly straight crease. Use the same technique to sand any filler you might need to add. Another way to sand filler is to cut a wooden sanding block about 2' long with the proper angled V in the wider side (2x4 would make a good block, Run it thru the table saw with the blade set at 1/2 the proper angle.) Contact cement a couple strips of 40 grit paper to the bottom, folded at the peak of the V. Now clamp your angle iron the same distance away from the center of the V as the distance from the center to the edge of the block. Run the block along the guide until you have a perfectly straight line, flat on both surfaces. Nothing says good craftmanship better than straight even body lines.

 

Again thanks for the advice I used a combination of all what was said, went to HF & picked up a 4 1/2" grinder for $19 it runs quieter than my Craftsman. I knocked the welds down with a grinding wheel followed by an 1/8" cutting wheel to form the line, then three different flap discs. Its not perfect but I'm happy with it a little body filler and walla...next I'll put a cap or tear drop when I get some more sheet metal.

 

Hey that looks GREAT Jaye!

Happy New Year!

Julie