Frame Deburring (grinding)

[Phyberoptic]

So I'm going to clean up and paint the frame on the current project bike ('81 HS xs650).
I've seen a number of posts here that wave off grinding down welds in general, but the factory welds on the Yamahas are really ugly. I see better quality comming out of high school shop class (where they still have shop programs... :-( ).

Any advice either way as to if I should grind the frame welds clean before painting since I'm going to the work of stripping the bike anyway? I've got to take off some usless brackets anyway so the grinder will be out and revved.

I didn't do it on the '78 I've got and still wished I had when I go to fire her up.

 

[Travis]

You could grind the ones that are visible and re-weld them with your own pretty beads. Make sure the new welds are strong though because when you grind the old ones it's hard to tell how much is left holding it all together. Don't get too aggressive with the grinding. Stick to just the raised portion of the weld itself.

As an alternative, you might be able use some kind of filler to smooth out the welds.

 

[9c1cap]

I agree with travis. If yer goin for smooth knock off the tops of the welds and throw some filler in there (acid brush works well for spreading filler in areas like that). Realistically its prolly less work than grinding and smoothing the weld completely, and less worries about integrity.....

Craig

 

[Ghetto]

I grinded and putty'd my Nighthawk ones. Frame held fine and it wasn't too bad looking given the time I completed it in.

 

[David M]

I'm just starting a project but will also be doing some grinding. I was thinking about using a bit of filler to pretty up some of the ugly welds too. But, I'm going to powder coat the frame so I can't use conventional filler. I'm going to look into using lead filler - the same thing that was used years ago on body repairs but is still used in some places on higher end restorations. Lead melts around 600 F and powder coating is baked at about 400F.

I know this doesn't answer your question but maybe some more options before you start might help chart your course of action.

 

[Hairyblackdude]

The stone grinding discs are decent, but its too easy to gouge and scratch the metal all up.

Go to the hardware store & pickup a few of the sandpaper flap discs for your grinder. The homedepot around here only had 60 & 80 grit, but either one works very nice in my 4 1/2" grinder.

You would be surprised how quickly and well they knock down metal & leave it nice and smooth. They are easier to get in little gaps because they bend & flex some and it doesnt tear the metal up...

They looka like this !!! GO get some & you'll never use regular discs again.

Why are you still reading this??!! GOOOO !!!!

 

[jetero41]

Planning on cleaning up the welds on my '83 this fall and winter prior to paint.
I am planning on using a Dremel with a "barrel" for all but the worst and finishing with a "good" filler. I have, in a past life, been a Certified Weld Inspector and see no problem as long as, VERY IMPORTANT, you don't take too much.
You should have a 45 degree fillet between 2 parts at 90 degrees.
Clean up and fill.

 

[shaas]

I spoke with my powder coat guy and he suggested using brazing rod. I did that to my current project and the bronze did not 'hide'. I showed it to him and he had to sand blast and use a primer coat. No small job.