Power Flow

[Rich]

Focus is poor, but this cut is what we came to do to remove the old insert. A buildup of what appears to be carbon formed between the insert and the muffler shell, producing an interference fit we just couldn't break until we made this cut, relieving the stress:

Speaking of the shell, I decided to check on what it would cost to get a replacement outer portion of the muffler or even the entire muffler itself (saving the new insert for the next time). This is a purely cosmetic decision. The original (13-1/2 years, 880 hours) is still completely serviceable, but it looks like any old exhaust component would:

Though Powerflow shows the muffler shell part number in the IPC (very good documents, BTW), they don't normally sell it separately. But through happenstance they did have one with the ceramic coating option (which I requested) in their assembly area and it's now on it's way.

[Steve]

Rich:

If the muffler shell is constructed of stainless steel, you might be able to improve its appearance a lot with some polishing compound and a fabric wheel.

[Rich]

Rich:

If the muffler shell is constructed of stainless steel, you might be able to improve its appearance a lot with some polishing compound and a fabric wheel.

Could be. It's polished stainless. I'll likely go through that exercise just to see how well it does recover.

[Steve]

There was a guy at KLFT (I forget his name now) who owned 40.048 (1 SN lower than my airplane). I stopped in to visit him on one of our trips to FL in 2002 or 2003. He liked to polish his exhaust stack (original exhaust configuration). The thing was like a mirror. Mine looked positively gross next to it (but it didn't motivate me to do the same)...

[Rich]

An interesting exercise is to check out their parts catalog for various aircraft to see how different they are. Out of curiosity I was looking at the one for the 177RG. There is a 177RG here in the shop that will be getting a PF as part of a gear-up rehabilitation. (Not his fault - a hidden hydraulic line rupture. In this situation the manual gear extension is inop.)

[perossichi]

I have powerflo with ceramic coating. After about 250 hours, the last 10 inches are still shiny but farther up the barrel the coating has darkened. Slight improvement with polishing with Flitz. Insert still looks in good shape.

[Rich]

I have powerflo with ceramic coating. After about 250 hours, the last 10 inches are still shiny but farther up the barrel the coating has darkened. Slight improvement with polishing with Flitz. Insert still looks in good shape.

Good to know. The insert does outlast the glass by quite a bit. As I note below, there was the merest little clump of the glass left. The insert itself had just a bit of a fairly uniform lead-bromide deposit on the screen. The nuts for the screws holding the insert in place were almost completely disintegrated and had become irreversibly merged to the metal of said screws. Hence the screws were drilled out.

[Rich]

There was a guy at KLFT (I forget his name now) who owned 40.048 (1 SN lower than my airplane). I stopped in to visit him on one of our trips to FL in 2002 or 2003. He liked to polish his exhaust stack (original exhaust configuration). The thing was like a mirror. Mine looked positively gross next to it (but it didn't motivate me to do the same)...

I did some work yesterday seeing if this oxidation could be buffed out. Results are promising - with enough effort. Ideally a rigid-mounted motor/buffer. Holding the shell with one hand and a buffer wheel mounted on a drill with the other are a challenge.

[Steve]

Holding the shell with one hand and a buffer wheel mounted on a drill with the other are a challenge.

Video could be amusing... Or at least before- and after- photos might motivate me to attempt it with my exhaust stack...

Steve

[Rich]

Holding the shell with one hand and a buffer wheel mounted on a drill with the other are a challenge.

Video could be amusing... Or at least before- and after- photos might motivate me to attempt it with my exhaust stack...

Steve

I see we have a grinding wheel in our EAA hangar. I'll put a buffer wheel on it and I should be able to take a serious stab at it.