Generator - Welding Broken Exhaust

I think welding voltage is somewhere around 24, so the generator output would not be suitable. However, if it has a starting battery, you might be able to get that to work. Exhaust components shouldn't be very thick, so you could use oxyacetylene welding, if available.

I mean the welding machine supply voltage is same a the generator voltage. would it be ok to use the same generaotor that that generates the Power to weld it exhaust?

What, while it's running?

I think so, but the pressure of the exhaust may blow out the weld as you try to do it. If this is a problem, you could minimize it by shutting off all other loads while doing the welding. If nothing else, give it a try. Or maybe you can temporarily disconnect part of the exhaust system while you are welding on it. Use good ventilation to avoid exhaust fumes. Let us know how it goes. Best of luck with your repair!

Daniel,

As far as your initial question, I do not see a problem if your generator powers a welder to weld the broken exhaust.

I just wonder if you will get a viable bead with the exhaust component being at operating temperature and under pressure of the exhaust gasses.

My personal experience with trying to weld my own gen-set exhaust is that you are better off purchasing a replacement part.

I had a break between the flange and pipe that bolt to the manifold. Initially, the weld held OK. After about 12 thermal cycles the joint re-cracked.

I found the time I pi$$ed away trying to repair was much more expensive (my time) than just biting the bullet and paying for a replacement part.

I realize your situation is different than mine as it sounds like you use yours for a sole power source were as I use mine for back-up power but you will be better off in the long run replacing the defective part.

Good Luck!

GA

That's the way to do it.....

He could repair the old one as a spare, but it will need to be reheated to about red hot to relieve the stresses made by the weld.....and checked that it hasn't warped, facing off any connections to the head......

You could braze it with a 45% silver brazing stick with flux. You can join unlike materials such as copper or brass to steel with 45% silver as well.

The machine will have to be shut down in-order to repair anything on the exhaust. If it is a turbo engine exhaust gases going through the system are in the 30-35 inch range in pressure. Will blow all molten metals out of the weld zone, causing a bigger issue.

I would 1st need a few more questions answered to define how I might repair this unit. But I will guess at a couple of things.

1. If the cast iron manifold is cracked you could braze with good bronze rod and make affective repair until parts could be procured.

2. If the exhaust pipe its self is cracked then you could gas weld and be on your way.

I would think you would have someone locally that could make this repair for you in the correct manner, using proper procedures. Other wise I would order the replacement parts and change them out.

I actually saw someone try this once at a site in the desert where we were crushing rocks. When you are in the middle of nowhere and the generator is your lifeline, I guess you have to try. In this case it was a small crack in the pipe between the manifold and the muffler. As soon as he started the arc it turned into a fountain of molten metal spraying all over him and the crack turned into a gaping hole in a matter of seconds.

If you can, it might be better to find another small generator or portable welder unit somewhere to affect the repairs. Otherwise your situation will likely go from bad to worse.

There is perhaps another way you could do this. It will be rather crude, but it could work for you. I have seen fellow offroaders connect jumper cables to the starting batteries and a welding rod to do makeshift trail repairs. Its typically just to cobble up the broken part well enough to get the vehicle back to civilization, where it can be repaired correctly, but it may work for you. That way you could do the welding without the genset running.

I figure, most welders have an open circuit voltage of only around 30V. So, 24V worth of starting batteries my work better than expected.

Low voltage rods are available which make it sometimes feasible to use a single 12V auto battery for welding. There have been numerous postings about batteries as a source of power for arc welding on CR4. Try an archive search. It could be very helpful.

Personally, I would either use a temporary mechanical "crutch" and a sodium silicate patch (common muffler patch) to seal the leak if it is not too large or preferably an oxy-acetylene weld. The pressure of the exhaust, especially if the leak is between the exh. manifold and the muffler, will be too great to get any type of weld if the unit is running. Welding requires a calm atmosphere to be successful. That is why you see many welders placing their free hand near or around the arc to stop breezes or drafts. Only much worse from an exhaust pipe.

Good Luck, Old Salt

Others have suggested it and I agree, use a car or truck battery on the exhaust without the engine running. If you are welding a rusted rather than cracked fault then you are probably not going to succeed as very thin rusty metal just disappears (from personal experience - you end up chasing a hole around).

You probably should add to extra support if you have a crack, to try and relieve the stress that cased the failure (there isn't a support missing or extra unsupported exhaust length added are there?)

Do you want to weld a cast-iron exhaust manifold or exhaust pipe or silencer?

Give enough information if you want a proper answer please.

Welding the exhaust stack during operation will not work. The pressure in the pipe will blow the molten metal away before it has time to solidify.

Take care on what is the base material, problably cast iron or low carbon steel. Bothe needs diferent electrodes and hand skills to be welded.

No further advice other than already written can be given without knowing which part is broken, what kind of welding are available.