Welding stainless steel exhaust systems

[saygold]

Question:  Should stainless steel exhaust pipe sections should be welded together, and if so, what is the correct welding rod to use?

Several years ago, a local shop installed a” Timevalve” stainless-steel exhaust system for my 230SL that I supplied.  They used the clamps supplied with the system rather than welding them together.  I contacted Timevalve about that, and they strongly recommended that the pieces should not be welded, and were not normally welded together.

When rebuilding my cylinder head recently, I found room to remove the head complete with the manifolds by unbolting the front exhaust pipe clamps and pushing the manifold ends into the front muffler section several inches to clear the exhaust manifold .  

I would appreciate any comments about stainless steel exhaust system welding.

[Cees Klumper]

I installed a stainless system two years ago, replacing a welded non-stainless system. Got it at Van Dijk's and asked about whether the new system should be welded or not. Their reply was they always only use clamps on the tens and tens of systems they have installed on customer Pagodas, never weld. So I used the clamps they supplied and the system is tight as anything. So now, if I ever need to remove a section, I can quite easily. With a welded system, you have to take the whole thing out and that's a difficult task. So if the system is built to be clamped, I would definitely not weld.

Cees ("Case") Klumper in Amsterdam
'69 white 280 SL automatic

[TheEngineer]

I have the s/s system and it is not welded together. I don't even use clamps. Where the pipes join there is about four inches overlap and any leakage is insignificant. If one were to weld it together, you'd have to do it in-place and that would be very akward. My '67 230SL had the factory system: It was carbon steel and one piece. To remove it, you had to raise the car at least six feet. Then you could tilt it out. When I did my head, it was fairly easy to remove the exhaust system because it came apart. But if you really want to complicate your life, go ahead. And while you're at it, weld the doors and the bonnet shut

[hauser]

My Timevalve system is also clamped together.  I don't think I've ever seen this done any other way.

1969 280sl 5 spd
Gainesville, Fl.

[Cees Klumper]

Joe Alexander explained once how the welding works: you fit the system such that it 'hangs' just right )orientation, hight, bends etc) then you spot-weld each connection. You then take the system out, weld all-around each connection and refit the system.

Cees ("Case") Klumper in Amsterdam
'69 white 280 SL automatic

[saygold]

I feel a lot better now about not welding my ss exhaust system together.  Theengineer's idea about not using clamps is also great - I hate being able to see a clamp hanging below the exhaust pipes.

Ken
'66 230SL (white, europe and running)