Bondo On Muffler


i want to fill in some dents on my muffler, so is it a good idea to put bondo on it? or am i going to have to spend $100 on a new one? if you want to see what im talking about, then go to “if i can have a moment of your time”. THANKS-TJSCOTT


That’s a new one on me. Why would anyone want to fill in dents on a muffler??? Makes no sence what-so-ever. You going to paint it too???


It is a motorcycle muffler and yes, I am sure the OP is going to paint it. Here is a picture.


come on bud think! who would want to put bondo on a car muffler its a freaking motorcycle!


hey mike, howd you get that pic set up like that?


I would think that bondo would have a difficult time staying on the muffler with all the temperature changes and expansion and contraction along with the intense vibration.

Hey it is a motorcycle, dents are a sign of honor.


the name of the site is CAR talk. Come on bud, think :wink:


I went to your myspace site, right clicked on the picture and saved it to my desktop. I then returned to this board hit attach files when the window opens hit browse, navigate to the file you want to attach, double click on it. Then hit done, then hit submit.

Just so you know you can disable the feature in myspace that allows me to right click and save your picture.



I agree that bondo will not stay on the muffler very long. I would ignore the dents and use a high temperature flat black paint on the muffler. The flat color will make the dents less obvious.

You think those are dents? You should have seen the condition of the dirt bike I had when I was 15.


thats why i said to go to the thing “if i can have a moment of your time”.


i beleive bondo is flamable even when hard.

it will crack easily, and wont last


Buy the muffler. Even a good bondo job is obvious.


Bondo won’t stay on there for long. I used to build a few custom bikes with raked and molded frames. Even using Bondo sparingly, and with reinforcement (usually womens pantyhose, etc.), it was prone to cracking from vibration if it was a 1/4" thick.

That exhaust system is going to have more high frequency vibration in it than a frame would.


You can’t bondo it, but you might be able to use lead to fill the dents.

You’d have to be out of your mind to do it, but that’s a different question.


If I was fanatical enough to care about the dents, I’d make a fancy guard that bolts over the top of the offending area. That way, you block the view of the dents and get a nice heat shield to boot. Go black and you’ll never see it unless you look hard. Go fancy and make something out of stainless, cut some slats in it, brush finish with a rotary sander and you’ll be the envy of the local crowd.


In case it wasn’t obvious, the shield should have some standoffs to keep it off the muffler. Heck, take a look at various dirt bikes that already have this type of shielding on them. Maybe you can get something used and adapt it…


Here you go:


i cant build a guard, the exhaust is in a very tight spot already, maybe if i just did the end, but that stuff is hard to weld, thanks for the idea


You said you were looking to improve the looks of the muffler and it sure looks to be wide open back there. The guards are put on the exterior facing surface only. It would require several tack welds to attach threaded studs to the surface of the muffler. Any welding shop can do this and will likely charge very little to do it. Some things you just have to farm out if you don’t have the tools or skills. Just don’t be afraid to stop in to a local welding shop with your muffler and ask. They may even be able to fabricate the guard for you. Before I had welding equipment and experience, I used this route many times with great success. Good luck in whatever route you choose!