Champ Firewall blanket

E

Eric Brown

Well-known member
Joined
Apr 7, 2021
Messages
162
Location
Belle Plaine, Mn
I have a 7CCM in for rebuild. I have an Airtex firewall blanket. When installing the firewall and the blanket to the airplane, does the one piece blanket actually get compressed between the fuselage structure and the firewall ? Seems like that will cause some problems. My factory photos show what appears to be a hardened insulation plate between the structure and the firewall. Procedural suggestions ?
 
When installing the blanket I cut the 4 holes in the blanket for the engine mount pads, installed the firewall and sealed with black RTV.
If you were to not cut the blanket out you might get proper torque readings from the motor mount bolts.

Chris
 
The factory method is as Chris describes. The steel frame and firewall must make metal-to-metal contact so the firewall is grounded. Refinishing specs for the frame say to remove the paint or powder coating from the front pads of the frame.

The OEM blankets are mostly cosmetic. Pleather with foam backing that compresses easily, so no problem leaving material sandwiched between the frame cross members and the firewall. If the airtex blanket is more substantial, it might not compress as well and you might need to remove more material.

I have been looking for alternatives to the factory material. Mind posting a photo or two of the airtex blanket?
 
The Airtex blanket may compress down to 1/8". Taking a closer at the fwd fuselage mount structure, I see where the mount pads are about 1/16" fwd of the tube structure. This would give a little space for the blanket to compress. Maybe it will be alright. The paint removal for grounding is a good point. Airtex photos attached. Thanks guys
 

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That looks pretty good. Is there a matching piece for the boot cowl?

Is the firewall new, or did you do something to recondition it?
 
One of the locals is having an ocd attack with the aid of a Cessna 150. This week's project is cabin insulation - I shall inquire.

Update: he is using 3M 4014. Apparently you cut it to fit, and it sticks where you put it. It also is very pricey - check Spruce prices.

I removed all the insulation in my Decathlon, and cannot tell the difference - except it is a lot easier to clean down there.

My buddy is doing a 15 year overhaul on the 150 - new engine, new wires, new avionics, new plastic interior pieces - a ground-up restoration. Should be ready for paint in 2026. He uses only the best materials.
 
I removed the insulation from my Decathlon too, and I like it better without. That factory stuff is vile when it starts to rot. The Devil's powder.

Unfortunately, the adhesive is still visible on the backside of the firewall and boot cowl. Removing it is way more time and effort than I want to sign up for, and it's kind of a glaring cosmetic issue. The new frame and floorboards look so fantastic together that I hate to spoil it. Just looking for something that looks decent and is easy to apply.
 
I just used acetone - wipe it on, adhesive wipes off, 45 year old sheet metal was shiny! I had the floorboards out, so it was really easy.

I take it back; it could have been Poly Fiber reducer. Either way, it came right off.
 
I tried multiple solvents on mine. Nothing made a dent. I'll give it another shot with MEK.

Regardless, if I could find a good product that looks decent and holds up better than the factory crap, I would go with that. Just too easy to install right now, when my firewall is sitting on a table.

What materials is the airtex blanket made of?

I am familiar with soundproofing products like 3M 4014. The problem with those products is weight. Deadening out sound is a matter of physics. It takes mass to absorb sound waves. The foam products marketed for sound proofing are very dense and heavy. I have a box of auto sound proofing foam that would just about cover a firewall, and it weighs several pounds.

Spruce has a product called Koolmat that looks interesting.
 
Big Ed said:
What materials is the airtex blanket made of?
Click to expand...

The Airtex insulation is a fiber like material with pleated foil on both sides. One of the foil sides is then glued to a vinyl sheet for interior display.
 

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Cool, thanks. Looks like a good product. Could you post some pics after you mount it to the FW and frame?
 
That's got a really nice look to it. Very neat.

Are you putting anything on the boot cowl?
 
Big Ed said:
Are you putting anything on the boot cowl?
Click to expand...

I haven't fabricated the boot cowl, yet. I may even forgo the boot cowl insulation. I have an obsession to keep the airplane as light as possible. The firewall blanket is more for summer time flying to keep the firewall heat out of the cabin. It gets up to 130' F behind the engine.
 
Any thing new on this firewall blanket, how’s it holding up, how did you cut holes for heat and did you seal the edges?
 
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