Welding the Frame!!

[wigs_1]

Has anyone any experience of welding frames etc whilst the bike is fully built up/on the road?

Basically, the brackets on the front of the frame where the bash plate is mounted have broken off thanks to a little rust and the previous owner and my dad dropping the bike on the bash plate.

I'm looking at getting some work pals (nuclear grade welders) to fix on a new bracket. HOWEVER I have seen the Long Way Round where they weld and fry electrics on the GS so before I go ahead I was wondering what I need to do (if anything) prior to welding to avoid catastrophy/melting the electrical system etc.

My thoughts on the subject (I'm a mech-eng not elec-eng) are:
- The welding earth needs to be attached as close as poss to the point of the weld.
- ECU needs unplugged/removed?
- All fuses need removing?


I've put a picture in the picture gallery (if you can't see the one above)
http://www.xrv.org.uk/gallery/main.php?g2_itemId=5934

Anyone got any experience on doing this sort of thing?

Thanks
Chris

[Dilbert]

No direct experience with welding bike frames in this way, but mucho experience with on site welding and electrics, basically as you've already said, but disconnect all electrical items from the frame, especially the battery, regulator and CDI units/ coils.
Clamp your earth as close as possible to the work area and make sure it's through to the metal, MMA (electric arc) will be fine, not sure what you mean by "Nuclear grade welders" welders are coded for pressure vessels, etc and approved for use by the likes of BNFL, I guess you mean a fab' shop that does work for the nuclear industry? any good welder should be able to do this quite easily and you may be better with someone from the automotive industries as they are more used to this sort of work (and know what they need to disconnect).
If you're welding close to the engine invest in a couple of those asbestos (or whatever) mats that you can get from DIY shops for soldering and drape these over any close engine parts, you don't want to get hot weld spatter on the engine it won't like it
I suggest removing as much as possible so your welder guy can get in to weld as far round as he can.
repaint afterwards with Hammerite or similar and work it into any crevices, this should keep the rust at bay (for a while).

[usatic]

Wigs_1,

Please let me know how you fair with the welding (components that you disconnected, etc...) as my right bashplate mount also needs to be welded to mend the crack. It's still affixed, but it's just a matter of time before it breaks off completely.

Thanks

[BobA]

Never had to weld before, but I would disconnect everything for safety and peace of mind.

1. Remove the battery
2. Remove the ECU
3. Unplug the cable coming from the pulse generator coils
4. Pull one wire off each of the ignition coils
5. Errrrm remove the fuel tank!!

I dunno if this is right or wrong, but it's what I'd do.

Good Luck, and no firework displays OK


Bob

[Simon]

depending on the sort of welding you do you should be ok. I had to get the bottom of my side stand welded and didn't need to disconnect anything. not sure what type of welding it was though

[Maverick]

As above just undo the battery and unplug reg/rect, ECU, coil wires and should be ok.

[Dilbert]

depending on the sort of welding you do you should be ok. I had to get the bottom of my side stand welded and didn't need to disconnect anything. not sure what type of welding it was though

Well spotted Simon, I had assumed for this type of job that you would be using electric arc welding, if you're using gas welding then none of the above applies, but whether you can get in or get enough heat in without melting something?, this would be fine for something like a side stand where you can get to it easier, it's probably not viable to use shrouded methods like MIG/ TIG, an electric arc "stick" will be easier to get all round and doesn't require as much heat.

[Dilbert]

Usatic
make sure you file or grind a vee into the crack, so when you weld you're getting down to parent metal, otherwise you'll just be welding over the crack and it will go again.

[Chad]

As above just undo the battery and unplug reg/rect, ECU, coil wires and should be ok.

on the money my good man!! welded up a few bits on my @ and all was ok just the battery and ECU will suffice

[Dilbert]

Regulators are notorious for going west if you put a reverse polarity through them, best to unplug this to be sure.