Grinding...

[AngryInca]

Hi Folks,

I have been cutting some excess tabs off of a factory motorcycle frame. These tabs were welded on. I haven't cut too close to the tubular frame as I don't want to damage the frame.

I cut using an angle grinder and a cutting disc, I filed the first excess weld down using an hand file, but I am pretty sure from watching TV shows I can get a flexible flat grinding/sanding disc that will make short work of the weld...

Can anyone tell me what disc I need please?

Thanks!

AI :-)

 

[wobblemonster]

Try these, they give a superb finish, ebay has loads! also there is a company on here selling them

 

[AngryInca]

Do you have a link to anyone on eBay? I can't search for them as I don't actually know the correct name for them

 

[Country Joe]

They're called "Flap Discs"
Hope this helps,
Regards,
CJ

 

[AngryInca]

What do you think of these:

http://cgi.ebay.co.uk/12-PACK-115MM...Home_Garden_PowerTools_SM&hash=item3a5a01db8e

Thanks!

 

[wobblemonster]

For some reason there are "red" ones and "blue" ones, I have found the blue ones better, someone with more knowlege than me will probably explain why this is !!

 

[Chickenjohn]

You can also use a coarse sanding disc on a flexible pad for your grinder.

like this http://www.toolstation.com/shop/Abr...re+Disc+115+x+22mm+36+Grit/d130/sd1770/p84651

with a backing pad.

As finish is inportant on a custom motorcycle frame you could grind most of the remains off quickly with a 36 grit pad then finish with the file or finer grit flap wheel.

 

[AngryInca]

The frame is going to be powder coated, so I think that coveres a fair amount of nastness up Also, looking at the factory welds, anything I do is only going to improve the frame

I'll try those discs form eBay first. Thanks for the help.

 

[Flathead_Dave]

What do you think of these:

http://cgi.ebay.co.uk/12-PACK-115MM...Home_Garden_PowerTools_SM&hash=item3a5a01db8e

Thanks!

Note that the details in their blurb are wrong,40 grit is courser,not finer than 80 grit.
Higher the number,finer the disc.

I've found the ones marked for stainless seem to last longer on anything,including welds on mild steel.

In general,powder coating won't hide things,even bad rust pit marks tend to show through on bike frames.

 

[tux]

For some reason there are "red" ones and "blue" ones, I have found the blue ones better, someone with more knowlege than me will probably explain why this is !!

The red ones are (I think!) aluminium oxide while the blue ones are zirconium and I agree, the blue ones are much longer lasting.

 

[pedrobedro]

It's not a Divvy frame is it ? I had to weld all the luggage tags back on one last year so it could be used on a trip abroad as someone had cut them all off. If you need to make any I found tent pegs were good material for the job I use 80 grit fibre disks on a backing pad to clean up, they don't leave too many scratches.

 

[langy]

I was told Red for wood, Blue for metal, As the others have said get the blue ones as they are way better, Also you get what you pay for with flap discs.

The red ones are (I think!) aluminium oxide while the blue ones are zirconium and I agree, the blue ones are much longer lasting.

 

[langy]

Another good little tool for taking down welds is a finger sander.

 

[AngryInca]

Its a Suzuki GSX 250 frame.

I bought it for £80 to work on it for college as I was doing a motorcycle mechanics course. The engine was knackered, but I found a new engine for £60 and managed to get the thing up and running. So now I have a whole working bike thats in less, than good state.

I was going to do the full chopper thing with a hardtail and a top-tube, but thats probably a bit much for my skills, so for now I'm going to bob the back, put a Sportster style tank on it and swap all the gear, like leavers, cables, foot rests,.

That way the only fabrication and welding I have are end-covers that incorporate indicator mounts for where I've chopped the frame, seat pan and mount, tank mount straight through exhaust and exhaust mounts and mudguard mounts.

Only thing is, I'm finding annoying things like threaded screws where the rear shocks mount, and thats welded/part of the frame. Still, its a project I wanted, and it looks like thats what I've got

 

[wyn]

For some reason there are "red" ones and "blue" ones, I have found the blue ones better, someone with more knowlege than me will probably explain why this is !!

The red ones are a ceramic abrasive and are supposed to last a bit longer than the blue zirconium ones.

The flap discs can take a bit too much off..fibre discs are nice and finish off with a polishing flap disc.

 

[busastars]

Anyone got pics of results from the polishing flap discs. Got me intrested now. Ive only used the el'cheapo ones you can get from the local Whats, Biology, Home Bargins, etc.

 

[malcolm]

I tried some bit didn't take photos. I was working on a stainless steel strut brace that had been badly welded by some idiot.

Seemed to work OK - from a fine flap disc the coarse polishing disc was a good next step, then you work down to the fine one. Left a nice enough finish for me not to bother with actual polishing, but there are some polishing discs available for an electric drill that a friend went down to on alu window frames.

 

[graffian]

I always roughed off with a grinding disk then finished with a file.
I got one of those fancy disks with scotchbrite in them, leaves a nice smooth finish, no pics though.

 

[engybenjy]

I keep the old knackered flap disks for polishing with. They seem to do OK.

 

[AngryInca]

Typical!!!

I order the bloody discs and my angle grinder packs in! I've hardly used it, and its a DeWalt too - I thought DeWalt was supposed to be a good make?! They don't cut out of they overheat do they?

I managed to get a few excess tabs cut off tonight before the grinder packed in, and I ended up filing them down as I was determinted to spend an hour on the frame. Its still under the 12 month warranty.

Anyway, I can't tell you how I got on with the flap discs...