another firewall insulated

[Steve Melton]

another firewall insulated and brakes installed but cannot remove air pocket from brake lines. any tips? air box stiffener made from alum tube.

[Wayne Gillispie]

Fly or drive to PMH and borrow my bleeder pot(garden sprayer type from ACS). Bleed from bottom up and purchase 1 Qt of MIL-H-83282 from Sky Geek.

[rzbill]

Just as an FYI, the stainless firewall is not what melts in an engine fire, it is the floor. Seen it.

[DanH]

Steve, I almost hate to comment, but.....

The insulator looks like Cereblanket or a similar aluminosilicate wool refractory fiber.

Cereblanket is an excellent insulator, and a good choice for the cabin side of a firewall for two reasons. It will not ignite when in contact with a red hot firewall, and it does not contain any significant quantity of binder material, meaning it will not generate much smoke.

However, loose refractory fibers in the air are considered a health risk (fibrosis, lung cancer and mesothelioma). So, if you install refractory fiber against a vibrating firewall, you really should do whatever is necessary to fully encapsulate the pads so that no loose fiber can escape into the cabin. Spending 1000 hours in a little box full of airborne ceramic fiber is a lot like the lab rats mentioned in the MSDS.

I don't see a fastening method. Remember, any glue or tape has the potential to negate the "no fire or smoke" advantages of refractory wool.

Much burn testing says insulating the engine side of the firewall is superior in every way. The inside of my own firewall is shiny unpainted stainless.

[Pat Stewart]

Dan, you make a good point. Not sure if my method is better or not but on my 10 I installed the ceramic stainless wrapped blanket on the engine side of the firewall and fiberglass aluminum faced on the cabin side.

Pat

Originally Posted by DanH

Steve, I almost hate to comment, but.....

The insulator looks like Cereblanket or a similar aluminosilicate wool refractory fiber.

Cereblanket is an excellent insulator, and a good choice for the cabin side of a firewall for two reasons. It will not ignite when in contact with a red hot firewall, and it does not contain any significant quantity of binder material, meaning it will not generate much smoke.

However, loose refractory fibers in the air are considered a health risk (fibrosis, lung cancer and mesothelioma). So, if you install refractory fiber against a vibrating firewall, you really should do whatever is necessary to fully encapsulate the pads so that no loose fiber can escape into the cabin. Spending 1000 hours in a little box full of airborne ceramic fiber is a lot like the lab rats mentioned in the MSDS.

I don't see a fastening method. Remember, any glue or tape has the potential to negate the "no fire or smoke" advantages of refractory wool.

Much burn testing says insulating the engine side of the firewall is superior in every way. The inside of my own firewall is shiny unpainted stainless.

[Wayne Gillispie]

Many of us have fiberglass ductboard duct work in our homes and businesses too. They typically run 2500 hours/year. I fly 75 hrs/year.

[Steve Melton]

the insulation doesn't burn or give off smoke. I put a butane flame on it and the surface fibers glowed but essentially no heat transferred to the opposite side because I could hold it in my hand. it is mechanically held in place the best I could behind tubes/cables/harnesses, no glue or velcro on the firewall but edges of insulation are alum tape and the tape has some glue. it is encapsulated with alum foil. the verdict is out on how well it will hold up. I suppose I'll be a lab rat for awhile.

I am not sure how best secure the small upper outer pieces where the firewall penetrations are. currently they are just sitting there.

[DanH]

Originally Posted by Steve Melton

the insulation doesn't burn or give off smoke.

Yes, I know. Cerablanket was a test subject some time ago.

The stainless sheet is red hot on the other side of this blanket section:



An aluminum cover sheet (like the aft-facing aluminum foil in your photo) improves performance by a factor of two. If you must insulate the cabin side, you're using the right stuff.

That said, overall performance remains poor compared to insulating the hot side. As you've noted, covering the cabin side is problematical. Labor is about the same, and the stainless foil cover sheet on the hot side wears well and looks good.

[lostpilot28]

Not to get too far off topic for this thread, but I'm still in favor of painting the engine side of the firewall with Contego. It's on my to-do list for the near short term.

[rv7charlie]

Originally Posted by lostpilot28

Not to get too far off topic for this thread, but I'm still in favor of painting the engine side of the firewall with Contego. It's on my to-do list for the near short term.

Given the earlier comment, maybe a better place would be on the *exterior* of the floor pan.

(I'm only about 20% joking.)

Seriously, what does the stuff look like after it's applied, & is it UV/chemical proof?

Charlie