Upholstery and sound proofing??

Greetings, I just had the pleasure of admiring at a flying RV-9 that I had helped put some rivets in. The builder chose to keep it simple and this included, no upholstery (except seats) and no sound-proofing. My question is: since we all wear headsets and some with ANR, is it worth the extra weight and complexity to install sound-deadning material. If so, how much is justified and how much is just extra weight? I hope some builders with flying RV's can shed some light on this as I'm sure some have gone "bare" and some have gone to the other extreme. I'm leaning toward the "buy a good ANR headset" and save the unnecessary weight, but I don't want to make a mistake regarding this issue.

Thanks,
Don Owens

Don,

Not to get too technical....however, was it a -9 you flew in or a -9A? The only reason I ask, is that if it is a -9 (taildragger), I'd like to see some photos! There are very few flying -9's out there as of right now. I only know of a handful (less than 4 or 5).? And to answer your interior question, well, I'm just not that far along yet to offer any good advice. The 3-4 RV's I have flown in were all "naked" inside, besides the seats.

Thanks!

There was a fairly detailed article on this topic a few months back in EAA Sport Aviation. The upshot was that you've got to use the right materials in the right way to get good results. I was surprised to read how much of a db reduction they got just by doing the firewall. They went into detail about which areas will get you the most bang for your buck (lb?) and also pointed out that making sure the materials fit really well is quite important. Think about how loud things get if you just barely pull an earseal away from your head while flying; the noise will fly right in through that little opening and pretty much negate the effect of the rest of the headset. My decision after reading up on it will be to definitely use something pretty agressive on the firewall and probably something on the floor under my feet as well. After that it'll be up to the headset.

Steve Zicree

Insulation weight

I too was curious about weight. For my RV-7A, I weighed the aircraft spruce 1/2" sound insulation foam I used. For the firewall, forward floors, sides from the NACA ducts forward, and top skin from the radios forward the weight was...

18 oz (by memory - for the exact amount I can check my log)

Suffice it to say, I think the weight was worth it (hell, it is forward of the CG and if anything I wish my O-360/Hartzell plane had a slightly more forward CG).

I have no other upholstery other than carpet on the baggage floor and seats.

We'll see how it works on Sunday.

Kevin

Don

I've got about 140 hours on my 9A in the last few months. I have seats and no other interior. I use Lightspeed 20XLC headsets. I've had several long days in the plane 6-8 hours at a time. I may one day put something on the floor but that's about it. I've flown at 10F up to 110F and the only comfort problem I had was the huge amount of cold air coming from under the seats. Aileron push rod boots took care of that. I've had quite a few pilots in my plane and most of them comment on how quite the plane is when they take the headsets off.

The point is, I don't have a fancy interior and don't plan on changing. The next plane will be done the same way. The only thing I would suggest is use a good quality paint on the interior if you plan on not putting a bunch of interior stuff in the plane. I used PPG Concept and it worked great, not a single chip after a year of dropping tools on it.

kevinh said:

For my RV-7A, I weighed the aircraft spruce 1/2" sound insulation foam I used. For the firewall, forward floors, sides from the NACA ducts forward, and top skin from the radios forward the weight was...

18 oz (by memory - for the exact amount I can check my log)

Click to expand...

thats really light.

has DynaMat come up in any sound deadening conversations? (I'm late to the party here...) The car audio guys swear by it.

Cool and quiet and less vibration!

http://www.dynamat.com/

Check out the link to Jay Leno's Garage - Watch the Video

The web site has specs, .45 lbs/ft^2 is not too bad (for the DYNAMAT XTREME).

Anyone try it?

PS Check out some of the other "Jay Leno's Garage" videos. Leno is well known for his large car & bike collection; he's a very knowledgeable collector. You can see what $27 mill/yr buys. Don't have a jealous bone in my body, good for him, at least he enjoys his wealth and can relate to it. His collection actually is an investment, at least that is what I'd tell the wife.

I Sound Proofed and Upholstered

I bought and installed the soundproofing and upholstery and carpeting from Becki Orndorf and the RV-6A is every bit as warm and quiet as the Archer II We used to own with the executive interior and soundproofing package. That means you should still wear a headset but taking it off for a little ear reflief during a full day of flying is not an unpleasant experience. We have the back side of the firewall insulated with aluminum foil backed thick black stuff (probably some kind of rubber product) with all of the seams covered with aluminum tape. Thick black foam padding is glued to the floor between the stringers and carpet is glued to that, covering the stringers. Upholstery is glued directly to the aluminum sidewalls back to the former mating with the wingspar and behind the seats. In the seat area the upholstery material is glued to thin white/yellow foam then glued to the aluminum side wall. Thick foam is glued to the arm rests and then material is glued over that. I had never done this before but with the Orndorf video it was a straight forward task. The glue was 3M Super 77 spray. 300+ hours no problems and no regrets.

Bob Axsom

What materials for firewall

szicree said:

....
My decision after reading up on it will be to definitely use something pretty agressive on the firewall and probably something on the floor under my feet as well. .......
Steve Zicree

Click to expand...

I like Steve's idea on being "aggressive" on the firewall (and probably on the floor).

So what materials are available... with 3/4 seeming to be the correct thickness for the firewall - which is probably around 9 to 10 sq. ft.

I'm using this ACS stuff on my Tiger, but not in the 3/4 thickness....

http://www.aircraftspruce.com/catalog/appages/soundproofinstall.php

But at 1.4 lbs/sq ft, it's heavy at 3/4 inch....

OOPS - UPDATE

It's 1.4 lbs/linear ft. - for 50 inches wide, that makes it 0.35 lbs/sq ft, not so bad....

Looking for ideas like Steve....

gil in Tucson

better, but...

I insulated my firewall and the floor area on my 7A with double layer sandwiches of fireproof insulation/aluminum foil as per the free handbook from ACS (a must have, IMHO). I also insulated the backside of the baggage bulkhead with the same material. I know just from installing it that it knocked down a lot of reverberation generated by crawling around the fuselage.

I have a set of Lightspeed 30-3G's and a Bose headset...both of them make the interior noise quiet enough to listen to satellite radio, etc. Maybe my ears are more sensitive than most, but it plain hurts to take those headsets off at cruise power...even with the insulation in place. As the soundproofing manual from ACS points out, much of the noise we hear comes through the canopy...and there isn't much we can do about that.

The other day I did a headset battery change in flight and was sure glad I had extras on board!!

I can't see why anyone would forego the few extra ounces of soundproofing insulation...there's a point where we get a little too fanatic over where to save weight IMHO.

The other side of the coin...

The wife...

After tens of thousands of dollars and countless vacant weekend and evenings, and the occassional bucking duty- I want the interior to be as comfortable and as 'rewarding' an experience as possible (ie. suck up).

The 9a is not acro, so while weight is always a concern, I like being married and I like flying- so (faux- those little nagas) leather interior, side panels, and front and back carpet from CAD.

I am not adding paint to the covered portions and will rely on the wash primer from the QB fuse to keep as much weight down as possible. The 6's and 7's that I've flown in are loud anyways even with the ANR headsets.

Has anyone looked into sound absorbing paint?

Bob Brown said:

As the soundproofing manual from ACS points out, much of the noise we hear comes through the canopy...and there isn't much we can do about that.

Click to expand...

Maybe there is, or maybe it's just a rumor... If you order a canopy from somewhere other than Van's, and you can have it made in a different thickness.
Does anyone here actually know someone that has a different thickness custom canopy? If so, what the $, weight, and CG penalty is to how much benefit?