cleaning up frame welds?

[kev93]

will knocking down the high points of the welds on my frame hurt anything? I am gonna use filler after they are knocked down. anyone do this and have pics?

 

[angus67]

i filled in the upper down tube welds were the slide over the smalller down tube. looks fine. should be fine

 

[gordonscott]

Hi Kev, If using filler anyway just leave them, but to your Q no, knocking down the hi point (should not be one) of weld won't hurt just don't cut into it.

 

[kev93]

It just where the seat area connects. it has a tcbros hardtail. just where the weld was stopped, has a little bump that's higher than the rest. and its right where you can see it. I did use some 60 grit sandpaper and knocked just a little off. I think ill quit and just use fillet on it.

 

[gggGary]

I'm no custom builder, but in general cleaning up welds with an angle grinder is acceptable practice. Careful you don't cut into the frame tubes they are generally quite a bit thinner than the welds.

 

[kev93]

I took some pics of the area i am talking about. the area is about 8 o clock on the weld.

 

[kev93]

heres another one

 

[ember]

Hit the high spots with a flapper wheel. Those welds look fairly flat, so won't take much. Just hit the main structural parts lightly to knock the welds down to where they can be filled.

 

[kev93]

never used a flapper wheel before. do they come in different grit?

 

[kev93]

What about the welds running down the sides of the frame's downtubes? Anyone know how the factory built that section of the frame? I know the lower section goes into the the upper section but how did they hold it together. I cleaned the welds on the other side where there were little brackets for the tach cable. Now i need to clean the other side so it matches.

 

[Ironsled77]

You can grind them down. As said before just not deep. You shouldn't even touch the tube. Im guess in that you are going to paint the frame as opposed to powder coat. You can't powder bondo.

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[kev93]

i ground the ones on the side of downtubes flat to the tubes. Did i screw up?

 

[Rev D]

Well, the big thing is that you don't want to take any off the tubes, and nothing beyond level. I would smooth them but not level them, because unless the tubes were welded with a bevel or gap (not sure about factory set up) you run the risk of compromising the strength of those welds pretty quick. If there is a high spot on the welds that is driving you nuts then just level that spot to the height of the rest of the weld.

Also, not to contradict ember, but in my opinion a well wielded stone grinder or hard backed disk is better for this because you can better control that you are only grinding the weld and not the tubing or anything else, definitely less forgiving tough, so be careful.

Don't want to rant but when it comes to frames, welds, and the treatment of them afterwards, this is probably the one topic that gives me the most nightmares.

Just my two cents.

 

[gggGary]

What about the welds running down the sides of the frame's downtubes? Anyone know how the factory built that section of the frame? I know the lower section goes into the the upper section but how did they hold it together. I cleaned the welds on the other side where there were little brackets for the tach cable. Now i need to clean the other side so it matches.

View attachment 8144

 

[kev93]

Are the ones on the downtubes some kind of plug welds?

 

[650Skull]

+1

I wouldn't use a flapper, nor a new grinding wheel. . A new one is hard to control and will bite into the weld or pipe and you will have to get it done again.

Make sure the grinding wheel is a well used one

 

[kopcicle]

Old skool answer ...
Braze , that is use low temperature brass/bronze as initial filler and after cleaning use lead (or 50/50 tin lead , ie solder) to plug pinholes and complete the fillet . This leaves you with a minimum of putty to apply and actually adds to structural integrity somewhat IF you don't overheat the base metal while brazing .

Sometimes I like to give the left field answer

~kop

 

[kev93]

I am still trying to find out why the downtubes are welded.

 

[Ironriot]

Its Yamaha's method of bracing the frame. A tube wrapped around another tube and then welded together. Meant to cure the scary road manners that plagued the earlier models... well that and other frame tweaks also

 

[kev93]

so, does the smaller tube go all up to the neck then? and the top section just covers it?