3000W Chinese Gensets Info.

vmckague wrote:
Maybe fiberglass house insulation but would it burn? Any ideas?

Both Brad and I tried house insulation. The pink burned almost immediately when placed around the exhaust pipe. The yellow lasted longer and did not burn as badly.

If the exhaust pipe is long enough to dissipate heat, then the muffler will be cool enough to wrap with the yellow (Johns Manville} insulation. You "might" get some slight burning at the muffler inlet. You must make the outer covering over the insulation water proof if it is exposed to rain. Insulation will soak up water like a sponge

I have found another commonly available material for wrapping the exhaust pipe that works well. It is the cord used as a gasket on wood stoves. It comes in various diameters and is usually sold in a package with a 7' length. You can get about 30 turns on a 1" pipe with the 7' piece. If using the larger size gasket cord you can easily wrap a 2' length of 1" OD pipe - maybe more. Once wrapped with the gasket cord wrap again with heavy duty aluminum foil and mechanic's wire.

The stuff the Wiz is talking about works well, but is expensive as heck. An alternative is to visit a U-Pick-It auto wrecking yard and look around for a car or truck that has the silver covered fiberglass insulating material under the hood. It is typically used around wiring that is close to an exhaust pipe or across a firewall. Some of the so called luxury cars like old Caddy's may even have it under the front carpets. The bone yard boss should only charge you a few bucks for the stuff. When I pulled some I had additional parts so he just gave it to me. Take a razor knife and/or heavy scissors because it is often sewn into a sleeve that will need splitting to get off (or cut the wiring harness).

Edit added:

Another thought has come to mind. If the muffler is outside a shed, is it possible to stack some 4" or 6" cinder blocks around the muffler with a 4" block cap? No mortar should be needed. This will create a sound barrier and serve as a heat insulator.

Also consider the James Hardie 1/2" concrete backer board as material to make a box around the muffler. Pieces of aluminum angle iron join the corners and edges nicely. It is also unaffected by heat or rain.