Can a muffler crack be weld repaired?

[TucmanXJ]

XSives- see pic

Can this vibration crack in the left silencer material be repaired? As one can see its very thin in this oem welded area. Because of it's low position the crack is not visible to the casual eye. I've heard stainless wire can be used to mig-weld plated steel- is this true? Anyone out there with experience in this type of repair?



Rob

[TomB]

Yes you can MIG stainless wire to chrome plated steel

If I'm using headers from a different bike and have to cut and shut I use stainless

Unfortunately your 'crack' is more to do with the silencer being rotten from the inside, and you'd blow holes in the silencer trying to MIG the 'crack'.

If as you say the crack is under out of view it might be possible weld a stainless patch onto thicker parts of the metal, to find a thicker area you can push a chisel through the hole and bend back the steel until you can no longer bend it easily, then its thick enough to weld....using stainless Mig wire.

I use Pub gas to weld with, CO2 that pubs use to gas beer, on steel and stainless wire.

Tom



Just remembered, you can very carefully using oxy-acetylene, silver solder or braze holes in thin steel, it will discolour tho

[TucmanXJ]

TomB -

Sounds like you've been there a few times afore. As you say my lil' hobby MIG welder likes to blast holes in anything less than 1/16th" Read your reply along with some web research.

Seems like the pros heavy duty gas-shielded MIG welders found in muffler shops can execute this type of repair with minimal damage to surrounding chrome because current v.s. gas flow is adjustable. Due to my "bear-cub-wearing boxing gloves" finesse I'm betting on a local shop that does custom / stainless exhausts.

Thanks, Rob

[tinman905]

You can't just use any stainlless wire it would have to be a 309 or 309L wire which is used when you need to weld dissimilar metals.

[motoman]

crack in silencer

Had some small rust holes in the outer chrome shell of my left silencer, underneath where the factory silencer mount bracket is located. Cut one of the welds on bracket with cut-off wheel on dremal tool, bent bracket out of the way, welded up holes with my Lincoln wire feed, bent bracket back in place and re-welded, sprayed area with Napa's best high-temp silver, and re-installed. Holes fixed, but since inner shell(baffle) apparently had finially rusted through in spots it sounds like there is an exhaust leak on left side of bike. To bad, since the mufflers have no dents and are other-wise factory perfect, shine and all. It only has that "leaky" sound after warmed up. Have a NOS set of Jardine slip-ons with the cross-over still in the box, and looks like to eliminate that "leaky" sound, gonna have to install them. Gonna have to add a short piece of pipe(painted with the silver high-temp) in order for the muffler mount bracket to align correctly. Guess it will be as good a time as any to fix the tranny too. Been riding it two years skipping second(dern, that torquey motor sure makes you procractinate the fix tho). Anyway, from your picture that is an easy fix with-out even removing the pipe! 15min. at the most, just unplug both plug-ins on your TCI unit before welding. Have done it both ways myself without any TCI problems, but have a couple extra TCI units for the ole' 81 Venturer, so don't concern myself much. You may wanna think about and look for a set of muffs' for the future as this is a first sign of them heading "south" on ya. Note: Also did this not using stainless wire, just the standard wire that comes with welder and Argon/CO2 for a shield.That little Lincoln 125 has been real handy for home use and being an ole' certified welder myself doesn't hurt any either.

[mro]

thin metal welds

Have found I can weld very thin/rusted muffs like in your pic.
I cut a small piece of steel just wider and a hair longer than crack.
Tac a two/three inch long screw on it for a handle.
Push open crack just enough to slip steel behind crack and then pull it out so crack edges line up.
Gives a solid point to weld to with out burn thru.
May need to just spot the welds together so not to burn out the thin muff metal. Grind XS when done.


mro

[TomB]

You can't just use any stainlless wire it would have to be a 309 or 309L wire which is used when you need to weld dissimilar metals.

I use 6mm 316S wire with no problems, its the same wire I use when making stainless exhaust systems, and often weld home made silencers to original chromed mild steel headers

I 'spose it ain't no pressure vessel and as long as my exhausts don't blow

[tinman905]

316 wire is a rich man's wire but you're right it will do a good job .

[TomB]

OOOOOPS!!

That should read 0.6mm 316S wire

[Jerry]

I had taken my XJ exhaust into a welding shop to repair a similar hole around the crossover tube. They brazed it instead of trying to weld it. The braze job takes a lower temp and is 'softer' than a weld, meaning the metal is less likely to crack / break in an adjacent area. Ran the brazed pipes for quite a while until I located the Jardines I am now running, never had a problem with the brazed joint. Color is different, but if the hole is in a place where it cannot easily be seen it doesn't make much diference.

[Hired_Goon]

I use 0.9 silicon bronze wire in my mig. Great for thin exaust material as it requires less heat to get it on.

Very similar to brazing with an oxy set but much easier.

Of course the SB wire is a fair bit more $$$ if you need to use it just for one weld, so check around some local fabricators to see if anybody uses it.

[planedick]

Welded muffler

I had a 79 with left side muffler broken completly in two. I was able to weld it with Oxyacetalene torch and coat hanger wire. Lasted until I was able to find replacements.