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arc welding thin sheet
Cita - 15/5/05 at 08:33 PM

probably very stupid question but...

I'd like to build a muffler for a 125 cc two stroker.The shape is to say the least a bit odd hence my attempt to build it myself.
Can i have some advize on how thin material i can arc weld and what rod size-amp's to use?

Many thanks

Cita

[Edited on 15/5/05 by Cita]


wilkingj - 15/5/05 at 08:56 PM

Hope you have a good design!.
The Can on a 2Smoke is critical for performance, as the backpressures created aid (or NOT) the next charge entering the cylinder. Hence the wrong design can give you very poor performance.
Its much more critical than on a 4stroke.
Cant advise more than that. Just it aint that easy.

Hope it goes well for you. Cant help with the welding, cos I can barely weld with a Mig myself!


NigeEss - 15/5/05 at 09:23 PM

Ditto the comments by WilkingJ regards design.

As for the welding itself.... v diff to arc thin sheet, thin rods, low power and sh*t loads of patience !
Far, far easier to mig it.
Best of luck !


owelly - 15/5/05 at 10:14 PM

I had 'some' success using a 'Kelarc' thingy. Basically, it was a solenoid that retracted the electrode just as it arc'd and you sort of buzzed/vibrated your way around!! With practice, you could weld very thin stuff with 0.6mm rods.
Dunno if you can still buy them.
If it is just the muffler you are making, the size/shape is not too critical but the expansion chamber is. But that also depends on the sort of bike/engine its fitted to. I have had (twostroke) off road bikes that just used a big fat header ino a small end can and at the opposite end of the spectrum, TZR125 race bikes that we used to swap the pipes to suit the weather!!
Good luck anyway.


Cita - 16/5/05 at 05:13 AM

Thanks for the reply's guys!
I just found some info to build your own Arc Weld Gun.
This seems to be the thrick to weld thin stuff with an arc welder.It's bassicaly the same as owelly's "Kelarc".
Only problem is that you need a self-starting (match-tip ?) weld rod and i have no clue what that is.

Cheers Cita!


johnjulie - 9/6/05 at 09:16 PM

For what it will cost for a decent set, I think you're best bet would to find a good TIG welder (person that is)
Cheers John


cassidym - 16/6/05 at 09:24 PM

Cita, I'm no expert weldor/welder but the other day a I was asked to weld 1mm sheet.

Did'nt have the correct rods and did'nt feel like dragging out my MIG or TIG.

Well, I took a 3.15mm rod, set the arc welder to about 60/70 Amps and made a lot of tacks. Rod stuck a bit but once it warmed up it worked nicely. All the tacks were on the cold side but I was'nt too worried about penetration; my aim was for the tacks to act as a heat sink.

Oh yes, I wait after each tack for the metal too cool down before proceeding.

Cleaned everything, got a 2.15mm rod at same amps and welded short beads over the tacks until whole seam was fully welded. No burn thro, very little distortion, full penetration.


Cita - 18/6/05 at 03:42 AM

Thanks Cassidym,
I think I'll give it a try.

Thanks!