firewall to cowl seal?

[birddog486 21]

Whats everyone using to seal the gap between the cowl and firewall? I'm undecided on which route to take.

Pics are always a plus

Edited 5 Dec 2012 by birddog486

[Av8r3400 1179]

My flying Kitfox has an "envelope" style firewall insulation cover. The top of it overlaps the edge of the firewall and forms a baffle that keeps the two ares (mostly) sealed from one another.

I have not decided exactly how I will do my project plane. I am contemplating the use of a strip of flexible silicone engine baffling from Spruce or similar source.

[EDMO 1078]

My flying Kitfox has an "envelope" style firewall insulation cover. The top of it overlaps the edge of the firewall and forms a baffle that keeps the two ares (mostly) sealed from one another.

I have not decided exactly how I will do my project plane. I am contemplating the use of a strip of flexible silicone engine baffling from Spruce or similar source.

The silicone would be my choice - some older planes I have flown had felt there - others had the cowl riveted or screwed tightly to the firewall. Some booby in the FAA decided that since the Ercoupe aluminum cowl overlapped the firewall that a piece of stainless the shape of the rear of the cowling had to be put on the top rear of the firewall - under the aluminum skin of the fuselage - lots of pains that caused for the ones who didnt get it originally.

ED in MO

Edited 6 Dec 2012 by Ed In Missouri

[C5Engineer 1170]

My cowl blanket also overlaps. I use 1/2" weatherstripping between the cowl and windshield. Isn't perfect but pretty good.

[SuberAvid 617]

Attached pics of what I did for may boot cowl at the fire wall. I used a SS fire wall but made a flange of bent aluminum sheet to an angle and shaped it by crimping to follow the curve of the fire wall. I made it in 3 pieces and flush riveted them together with a backing plate, and riveted it to the fire wall to fit up against the cowl. I used firewall sound foam from AC Spruce in the inside of the firewall and the canvas antichafe between the fiberclass cowl and the aluminum flange.

[birddog486 21]

Thanks for the info gents, looks like I just need to make a decision and get it done.

[ChrisBolkan 130]

Bumping this thread.

How do those of you with two piece cowls seal the cowl to the firewall to protect from fire and keep air from the engine compartment from getting into the cockpit? Do you worry about fire with respect to this seal?

My MKIV used open cell foam attached to the cockpit side of the firewall to insulate, with a bit of overhang of the foam producing the seal. I was never a fan of this approach because while it sealed air well it offered no fire protection.

Photos are worth 1000 words!

Chris

 

[TJay 1041]

Super Avid I would like to see a pic of those seats, they look nice.

[birddog486 21]

Here's what I ended up doing.

 

Travis

[Av8r3400 1179]

That's a pretty good idea. 

If you look closely at the photo below, you can see the orange silicone baffling seal that I used.  (Kind of looks like fire sleeve.)

 

[tcj 150]

Mine is a lot like Birddog's.  It is regular black foam weather stripping.  I coated it with Red RTV which is fire resistant.  I smeared it on by dipping a gloved finger in alcohol.

[ChrisBolkan 130]

Thanks guys! Looks like a common theme is a stiffener riveted to the perimeter of the FW that also holds the trim. Except for av8r3400. Do you have a close up pic how you did yours? It is amazing to me how little there is in my builder's manual on how to accomplish this seal which seems pretty important!

Thanks again!

Chris

Edited 9 Dec 2015 by Chris Bolkan

[ChrisBolkan 130]

Travis do you have the part number of the trim you used and where you bought it?

[birddog486 21]

This is what I used. Its D-seal for RV's

 

Try this link, http://www.ebay.com/itm/D-Seal-Black-EPDM-with-pressure-sensitive-adhesive-RV-Slide-Out-price-per-foot-/181324176243?hash=item2a37c35b73:g:FbYAAOxyJX1S~SP0&vxp=mtr 

 

Travis

 

 

 

 

[Av8r3400 1179]

Just my opinion, but you should really consider using something that is fire retardant as a seal. 

I used the 3" silicone baffling seal because my cowling is so f'd up I needed to close a fairly good gap to the firewall. 

[EDMO 1078]

Super Avid I would like to see a pic of those seats, they look nice.

TJay,  I have the Cabellas boat seats like Suberavid has, except mine are red and white.   Look them up in the online catalog, but they also have a "Bargain Basement" or something where I got mine for half-price.    You cant use a seat over 16" wide, and they barely fit.

I agree with Larry about using the fireproof silicone baffling - It might keep the smoke and fire out until you can land and start pissing on your melting cowl...after you turn the gas off and the engine quits!

Seriously,  I think the most important part the firewall seal plays is to keep CO out of cockpit - hoping you never have a fire!

EDMO

Edited 10 Dec 2015 by EDMO

[TJay 1041]

 I looked they are nice but at 18 inches wide that may be a tight fit. I only have 33 inches at the floor under the seat. Are they heavy?

[EDMO 1078]

 I looked they are nice but at 18 inches wide that may be a tight fit. I only have 33 inches at the floor under the seat. Are they heavy?

Not 18 - Just 16 wide - their seats come in different widths - you have to check each style - I also got the high-backed.  about 7 lbs each for shipping - donno exactly what they weigh.

EdMO