Soundproofing

Walker · Post by **Walker** » Fri Jan 23, 2004 10:43 pm

This old girl is starting to get closed up. Does anybody care to share their opinion on what to put in and how to fasten it? I'm working over zinc chromate primer. My key concerns are corrosion prevention and weight savings. Respectfully, Luke Walker

Dave Clark · Post by **Dave Clark** » Sat Jan 24, 2004 12:09 am

Supersoundproofing ( http://www.soundproofing.org ) 1/2" put on with 3M 1300 if I remember right, bought from Spruce. It was easy to do, relatively light, and FAA approved. I put a layer on the inside of the firewall then contact cemented the rubber backed Airtex carpet over that which worked great. The firewall is a critical point. Now what I hear is the wind coming in the door seals as I've not gotten them done yet.

Post by **GAHorn** » Sat Jan 24, 2004 5:58 pm

The best stuff in my opinion, is the E-A-R Composite Daming Foam which is already backed with aluminum foil with adhesive already applied on the back. It meets FAR 25 fire resistance. Unfortunately it's expensive, Spruce Pn 09-00181 @ $75/sheet (27" X 48"). The entire cabin of my airplane was done with this stuff, fortunately there must be a lot extra of the stuff at the former owner's workplace.
A more economical material is Uniroyal Ensolite which is Pn 09-17574, a closed-cell foam, 1/4" thick, which is sold by the foot in 56" width, @ $5.95/ft. Install it with "Sticky Stuff Adhesive, in aerosol cans Pn09-274415 @ $7.85 per can.

Walker · Post by **Walker** » Sat Jan 24, 2004 10:16 pm

Thank you for the help! Is there any long term concern about trapping condensation? Should I fit the panels "short" to allow easy inspection? Thank you again, Luke Walker

dacker · Post by **dacker** » Sat Jan 24, 2004 11:33 pm

I just recently bought the 1/2" closed cell foam from Super Soundproofing, and insulation for the firewall (3 layers of foil). I have not installed it yet but it looks like some pretty nice stuff. It also came with the required paperwork to make it legal. It is not cheap, but it is not as expensive as the stuff George is talking about. I will be putting Selkirk interior panels on instead of the typical fabric panels. Maybe I will report the results in a couple of weeks when everything is installed. Dave, do you have any helpful advice on installing this insulation?
David

BloomerJohn · Post by **BloomerJohn** » Sun Jan 25, 2004 9:29 pm

Before you close it up or even before you apply insulation, treat all interior surfaces with Dynatrol AV 8 or AV 12. (refers to the thickness of the coating in mils) It is avail in spray cans about $25 ea. Two will cover the inside of your 170. It drys to a light gold tone and is absolutely inpervious to water, acids or srong bases. Spray the wing attach areas and inside the carrythrough spar with corrosion x. I used the foil sided material glued to the surface back to the baggage bulkhead. works great.

Dave Clark · Post by **Dave Clark** » Mon Jan 26, 2004 12:31 am

Luke and David

I made a quick set of templates out of printing plate aluminum for cutting out the material. I just ran a single edge razor around it. I'll loan the templates for the price of shipping. I made the fit quite snug to the longerons etc. My interior was zinc chromated and the adhesive did not seem to disturb it. Also the Supersoundproofing is closed cell so I wouldn't worry about condensation. The air has to get to the skins first anyway and I don't think it can.