The International Cessna^® 170 Association

Pulled the battery box to paint it with Acid Proof Paint this annual. From inside the cockpit, looking up while working with the battery box screws, I could see some daylight thru some cable penetrations thru the firewall! What is best to use, that is non aluminum corrosive, for sealing these openings?

ATS advertises Loctite Aviation Gasket Sealant that resists temperatures up to 400 degrees and is enert. Has anybody used that on the firewall openings and/or does it seem to be a good solution?

monkey dope.

I would like to thank everyone for all of the help and the terrific answers, now I know what to use on the firewall openings.

Sorry, Joe. The best thing to us is genuine thru-fittings and shields available from Aircraft Spruce and others.
If you truly wish to use "putty" I'd suggest GE High Temp sealant or zinc-rich putty (actually used mostly on Piper aircraft) available from Aviall.com .

PRC DeSoto PS700 - good up to 2000 F. your firewall will melt before this does.

this is what we use on the firewalls of all our stuff, it goes on like kind of a grainy paste and then hardens, usually black. 2 part stuff.

I see the newer Cessnas use some kind of grey stuff, maybe your local Cessna service center could look that up for you. we are one but I'm not home right now

HA wrote:

I see the newer Cessnas use some kind of grey stuff, maybe your local Cessna service center could look that up for you. we are one but I'm not home right now

The grey stuff is called monkey dope.

Thanks Guys! I've been to the local Cessna source, Van Bortels, and all of the aviation houses in the metroplex and was stared at like I was from Mars! No help, none of them have a clue as to what is used to seal around any openings not closed by fittings, shields, grommets, etc. I've seen really nice looking sealed areas on firewalls and it looked like some sort of putty. We looked thru stackes of their catalogs and had no luck. Sure would be nice to not be able to see daylight when inside looking out where all of those fumes hang out.

kloz wrote:monkey dope.

I tried like to hell to find some monkey dope, no luck. Then I found a monkey who had some, but he wouldn't give it up. Then I talked him out of some, but he wanted $200 an ounce for it! No way! We haggled a while, then a cop drove by with the siren going, and the monkey ran off.
Any other ideas?

Eric

Good thing that monkey doesn't sell hooker harnesses.

Monkey Dope. Is a putty like material. It comes in a flat strip about 1-1 1/2 in wide. It is rolled up with a paper material kind of like two way tape is rolled. It is grey in color always stays pliable (it will not harden) heat resistant, it is or in the past was used by a lot of auto body repair shops for seams etc. Also used where wires and cables go through firewalls. It is about the same texture as "Play Dough". It may have a "Tech" name, but all the shops Military and civilian, I ever worked in called it monkey dope.

Carl,

Monkey Dope! Here in the Mid-West it is also known as "Dum-Dum". In your list of uses you left out holding nuts or bolts in a socket when trying to start them in a hard to reach place.

Johneb

Joe, from the responses I am seeing those holes can be filled with a variety of materials, some probably better than others. What about using JB Weld? As you know it is a 2 part item and when cured is hard as steel. Fire sure isn't going to migrate to the cabin through it. It cures black. Don't know why I hadn't thought to use in on mine.

johneeb wrote:Carl,

Monkey Dope! Here in the Mid-West it is also known as "Dum-Dum". In your list of uses you left out holding nuts or bolts in a socket when trying to start them in a hard to reach place.

Johneb

Seems I do recall some guys calling it"Dum-Dum".
I found mine I have a little left. I took a photo but don't know how to post it.

Frank, I wouldn't recommend JB-Weld in that useage. The items that pass thru the firewall are expected replacement items, subject to vibration, and needful of a certain "cushion". The hard JB Weld would not allow for any of that.