JB Weld and exhaust

[Diskman01]

I have dealt with exhausts several times both on the bikes and old Honda ATCs. Welding that thin of metal is an art form. You would be better off brazing patches with MAPP gas.

Head over to Fleabay or sometimes a local home improvement store, and get some silver-bearing brazing rods and get some brazing flux. Wire wheel all the metals clean and heat 'er up till red and flow the brazing material in.

I was able to fix a completely rusted out ATC110 gas tank about 10 years ago by brazing. Still holds gas today. Although it's now cheaper to buy a used tank than the $ I used on SilvAlloy. lol.

JB Weld probably isn't gonna work. Its simply epoxy (plastic resin) with metal filings.

For a ghetto fix, pop rivets and tin will work in a pinch too. Not purdy, but certainly much easier on the ears when riding.

[motoman]

The steel is very thin and, unless you have a lot of experience of welding, you'll more than likely blow holes in the muffler the minute a welding rod touches it. Brazing might do it...

Wire-feed is the best option.....less heat spread=less chrome damage.

Tried the JB weld thing as my left side had developed tiny pinholes on underside of left muff. Lasted till the popped out. I then pulled exhaust and plug-welded all the tiny holes. Chrome damage was confined to approx. 1/2"dia. Sprayed a shot of Dupli-Color high-temp silver to cover spots.

Have since replaced that left side exhaust with new(not take-offs) complete with #2 headpipe, heat shield and gaskets. Original still sets in corner of mancave.

[DGXSER]

So, just where does one buy brazing rod? I tried hardware stores, auto parts stores, and HF, no dice yet.

[Schming]

So, just where does one buy brazing rod? I tried hardware stores, auto parts stores, and HF, no dice yet.

Welding supply shops or auto paint stores sell them 'round here.

[Schming]

Hi Don, have you looked at the specs on the Super Alloy 1 soldering rods on the Muggy Weld site ?

Only 350* F melt temp while a bronze rod commands a melting temp above 800* F.

Check out their videos, interesting applications.

[Radioguylogs]

I'm thinking dissimilar coefficients of thermal expansion between the JB Weld and the steel will cause the epoxy to pull away before long.

[DGXSER]

Ok, time for brazing 101. I have a spare 2-1 header collector laying around. So I decided to practice on it. Got some 16 GA steel plate, rounded a piece to match the shape of the pipe. Got WB-5 brazing rod. Using MAPP gas torch, the steel is getting cherry red. Both the pipe and the plate, heating around the area patch on the pipe since it is thicker. Both are red hot, almost cherry hot. Will not melt the flux, only the flame melts the flux, and it will not melt the rod??? How can it get the material is cherry Ted that the rod is supposed to graze and the rod not melt??

[Schming]

Your probably just at the borderline of being hot enough.
You can try using some fiberglass insulation around the area to be brazed.
IMHO Oxy-Acetylene is your best bet.
I've tried a small MAPP- Oxy setup for small stuff before and it worked but you had to be quick, the oxy bottles didn't last long and are costly.

[Diskman01]

Ya. Those bronze rods are a BEAR. If you can, locate a Heating/AC guy. Ask nicely if you can grab a "SilvAlloy" stick from them. Or, hit up eBay or google.

I forgot that those bronze ones take ALOT of heat and are a bit moody.

Otherwise, I will root thru my tools and see if I can locate my silvalloy stash. If I find one, I'll mail it to ya. 1 stick should repair MANY exhausts.

[DGXSER]

I have some clean and brite. I tried it , but the plumbers flux I used is not compatible i seems. It just balls up and rolls off. I know the rods have the flux built in. I can run to an HVAC outlet in town and pick up some flux or rod.

[mharrington]

Whats needing repair- up by the cyl, mid header pipe or muffler? JB will disintigrate into powder near the head. It probably wont work on the header pipe- mid way or even at the transition to the muffler. JB is great but its greatness is over exaggerated and misunderstood. Now if you have rust holes in your MUFFLER you could use fiberglass as a CHEAP do it yourself immediate repair. The muffler is much coller because its further from the heat source and larger in diameter.

JB works great for moderate heat- non pressurized NON structural areas.

[DGXSER]

So, even with flux my stay-brite solder just runs off the steel.

There is a rusted out area where the drain hole was just past the collector on one, the other has several areas that got thin and became holes when wire brushed at the muffler end, really close to the outlet area.