Has anyone try to solder a AL extension onto a muffer? I'm thinking about buying some Alumunim rod and giving it a go. Suggestion or tips would be great.
Thanks

chopper

I have used JB weld on mufflers befor and had good luck. Got to clean the metal as directed to , maybe hit it with some lite sand paper.

don't think solder would hold , unless you had the kind for alum. It might take a torch then.

sticks

A propane torch with aluminum solder will work. Move the torch along the work to heat it evenly. Melt the solder by touching it to the work, the torch should be aimed where the solder is melting. The solder will puddle and flow and can be guided by moving the solder stick and torch. After you're done, the joint can be ground and sanded to a seamless, smooth finish. The muffler can then either be polished (shiny) or bead blasted (matte) as a finishing touch.

Of course, clean, clean, clean the muffler and extension before you start.

I'm going to try to solder the extension. I've used JB weld and right after takeoff the extension came right off. But I must say that was a rubber extension not metal. All I've got to lose is another $8.00's I've already lost 3 of the rubber extensions[>:]
Thanks

chopper

Practice on a piece of scrap.

Can we assume you are talking about the inlet to the muffler or is it the outlet side?

I believe he is talking about the outlet side.

An outlet extension can effect back pressure depending upon size and shape and therefore engine efficiency/power in a negative manner.

I'm talk'n about the outlet of the exhaust pipe. This is what I have coming in the mail to put on the exhaust of a Magnum 91FS.
www3.towerhobbies.com/cgi-bin/wti0001p?&W=001128919&I=LXZ666&P=K

Thanks

hard to beleve you lost three rubber extensions. I clean the muffler exaust port real well and put the rubber extention on and then put a zip strip or two on it as tight as I can and they stay on. Its important to get both really clean so that they grip to each other.

sticks

I know what you mean. I've tried everything. tie wraps, heat silicone (aviation grade). JB weld. I've cleaned the ends as good as I could clean. I got lucky the last time, right after the plane broke ground I saw the extension come off so I was able to fine it laying out in the field. The best chance I had is when I used safety wire. That held for a while until the wire worn through the rubber and then it fell off. And I thought planes were expensive

I drilled a small hole in the end of the muffler, and screwed a teenie tiny screw into the hole. Pushed the extension over the screw head and zip tied it. Didn't fall off till I hit the ground at full throttle coming out of the down side of a loop with not enough altitude. I don't really blame the little bugger for jumping ship, But I found it and put it back on with no issues. The screw doesn't even protrude half way into the exhaust port.