What's new
Van's Air Force

Don't miss anything! Register now for full access to the definitive RV support community.

Sound proofing paint Noxudol 3101

CJT

CJT

Active Member
Has anyone experience with this material?

It helps in reducing engine vibrations to cockpit

Also has fire retardant prosperity

I flew Diamond DA 40 and was amazed at quiet, vibration free cabin comfort and did research and found a booklet on spruce website on How to soundproof aircraft

Non insulated RV 10 has db 95 on sound scale, with sound proofing it is likely to reduce to db70,

I am insulating my cabin with soundex Deluxe material but was wanting to apply Noxudol 3101

I don’t mind additional weight and expense, if it make my cabin vibration free and quiet

Will post my results once done
 
Last edited:
Thanks for updates

May be I misunderstood the reduction in decibels and quoted wrong figure

But my question remains, if any one has experience with soundproofing paint Noxudol 3101
 
Last edited:
Ask yourself two questions----weight, and flammability.

I suspect any paint that will attenuate sound is going to be kinda heavy.
 
Sound proofing

As mentioned earlier, I agree it is going to be heavy

The soundex insulation itself may increase weight by 50lbs

Both the paint and soundex are fire retardants

Effect of noise can be reduced by noise cancellation head sets but effect of vibrations on body can not be

Therefore the decision

Let me post my results once done

I wish some one who has used it, sends his views
 
CJT said:
Both the paint and soundex are fire retardants
Click to expand...

In general (definitions vary by standard), a material is considered fire resistant if it will self-extinguish in some specified time period after the heat source is removed. Note while in contact with the heat source, the material may burn merrily and still meet the standard.

Soundex presents a fine example. The vendor advertises compliance with FAR 23.853 and/or 25.853, both standards for fire resistant cabin materials. It's a reasonable standard for cabin sidewall insulation, upholstery, and carpet in locations where (1) the ignition source is not very powerful (the certification source is a Bunsen burner), and (2) the heat source can be easily removed.

Neither is true in the case of a red hot firewall. The heat energy is far, far greater, and it can't be readily removed.

This is Soundex firewall mat, circa 2008 or so, when placed against a stainless steel panel with a 25 sq in, 2000F flame (the FAA firewall standard) applied to the opposite side. I wouldn't want to be in the cabin with it.

P8310006.JPG


Coat a 16" x 18" 26 gauge stainless panel with 2mm of Noxudol 3100/3101 and send it here. Happy to check it.
 
Soundproofing Wars

I dug through hundreds of VAF posts looking for quantitative data on the effectiveness of soundproofing. I found agreement that the measured sound level of typical RV’s was in the 95 dB range but most of the insulation effect responses were something like: “much quieter” “significantly quieter” type of things. Anyone?
 
Soundproofing

Thanks for info Dan,

If i understood correct

Soundex should not be applied to firewall on either side

A question

Does the firewall not protect the fire spread to the cabin?
 
Thanks Mike

BTW

found a company named Silentium

They provide active noise cancellation in car called silentium quiet bubble technology https://youtu.be/lhgDIoQKVsE

This makes active noise cancellation in car interiors

Looks interesting concept
 
CJT said:
Thanks for info Dan,

If i understood correct

Soundex should not be applied to firewall on either side

A question

Does the firewall not protect the fire spread to the cabin?
Click to expand...

Looking at some of Dan’s tests, it would appear that the firewall can actually cause a cabin fire or smoke.
 
rocketman1988 said:
Looking at some of Dan’s tests, it would appear that the firewall can actually cause a cabin fire or smoke.
Click to expand...

On the plus side, that steel firewall prevents the fire from directly entering the cabin. On the minus side, it is a heat transfer mechanism. Metal conducts heat. The firewall is metal. If you heat one side of the firewall to 2,000F, the other side is going to be nearly that hot. So you don't want anything flammable or which produces gasses or smoke near the cabin side of the firewall.

This is why a fiberfrax blanked under a stainless shield is a good idea on the firewall. It'll greatly reduce the heat transfer into the cabin, hopefully buying you more time in the event of a fire in the engine compartment.
 
CJT said:
If i understood correct

Soundex should not be applied to firewall on either side
Click to expand...

It would be relatively harmless on the engine side, but perhaps impractical.

A question. Does the firewall not protect the fire spread to the cabin?
Click to expand...

The stainless steel firewall will effectively block flame. However, it will be hot enough to glow red. Any flammable material placed in contact with the red hot stainless, or placed too close, will ignite due to conducted or radiated energy.

Paint, glue, plastic fittings and lines, rubber or polymer insulation, and a host of other materials thus have the potential to be a fire transfer mechanism. Flame from the engine compartment did not penetrate the cabin, but poor builder choices resulted in open flame in the cabin.

I've heard a great many arguments discounting the seriousness of an engine compartment fire. Most refer to standard procedure, which is to turn off the fuel valve. Although entirely correct, such arguments don't consider time.

Assume a loose fitting at the fuel pump. The escaped fuel ignites. The engine is still running. What will be your first indication of fire? Smoke in the cabin? If so, the firewall is heating fast.

The clock is ticking.

How long will it take you to process the information (i.e. believe what your senses are telling you) and make the decision to shut down the engine? Would you hesitate? Will you look for a landing place first? Declare an emergency? Freeze and do nothing?

The clock is ticking.

Ok, you've decided to turn the fuel valve, as you're at 5000 feet over a 10,000 ft runway. How long will it take for the engine compartment fire to go out? Then how long to cool the red hot metal to something below the ignition temperature of a poor materials choice?

Here's reality...on the test rig, "firewall insulation" products meeting 23.853/25.853 typically ignite within 20 seconds of burner initiation, and they may burn for several minutes after the heat is removed. Even if they go out quickly, they tend to continue generating smoke.
 
Vern Dalman accident, NTSB LAX99LA063. Skilled pilot, fire in the pattern, on downwind.

On December 31, 1998, at 1151 hours Pacific standard time, an experimental Young Harmon Rocket II, N288M, was destroyed following an in-flight fire and hard landing at a private airstrip near Esparto, California. The commercial pilot/owner was operating the airplane under the provisions of 14 CFR Part 91. He and one passenger departed approximately 10 minutes before the mishap. The pilot was in serious condition after suffering burns over 1/3 of his body and succumbed to his injuries over a month after the accident; the passenger sustained minor injuries. Visual meteorological conditions prevailed for the local personal flight and no flight plan had been filed.

The pilot completed one flight and was taking another passenger up for a short flight around the area. On the downwind leg witnesses reported everything looked and sounded normal, and then they heard several pops, which they attributed to the engine being throttled back. One witness asked
the other if the airplane was on fire. The flames he thought he observed went away. They dismissed his observation as sun glare and turned away. When they looked at the airplane again on base leg, 2 to 3 feet of bright yellow/orange flame and a trace of black smoke emanated from the
cowling. On touchdown the airplane bounced, hit again, then skewed 20 degrees to the left. The left main landing gear collapsed outboard and the right main collapsed underneath the airplane. They gathered fire extinguishers and did not see the airplane come to a stop.

The passenger stated he saw light gray smoke in the cockpit and notified the pilot. The pilot secured the master switch and turned onto the base leg. At this point the passenger did not observe flames or feel any heat. As the airplane turned wings level onto final, thick black smoke that smelled like burning fiberglass or plastic filled the cockpit. After the airplane came to rest, he observed flames around the pilot and felt high heat. He yelled to the pilot to open the canopy, but the pilot responded he could not get it to open. Momentarily, the canopy opened halfway.

As the rescuers arrived, flames were still coming from under the cowling. The front cockpit was so filled with smoke that they could not see if the pilot was still in the airplane. The rescuers helped the rear passenger out, and then noticed the pilot on the side of the runway.
 
CJT said:
Has anyone experience with this material?

It helps in reducing engine vibrations to cockpit

Also has fire retardant prosperity

I flew Diamond DA 40 and was amazed at quiet, vibration free cabin comfort and did research and found a booklet on spruce website on How to soundproof aircraft

Non insulated RV 10 has db 95 on sound scale, with sound proofing it is likely to reduce to db70,

I am insulating my cabin with soundex Deluxe material but was wanting to apply Noxudol 3101

I don’t mind additional weight and expense, if it make my cabin vibration free and quiet

Will post my results once done
Click to expand...

Mike S said:
Log scale can be deceptive :confused:
Click to expand...


I'll call BS. I've stated here before; Sound Power Level doubles (or halves) ever three dB even when we humans can't perceive it. Look carefully at those claims and see if they are only talking about a very narrow frequency band, if there's a band rating like A, C, etc.

Get yourself some good quality, ANR headsets; ones that provide good protection without the electronics turned on. Then don't think seriously about this again.

Edit = We perceive noise doubling every 10dB as our ears aren't that great. Any noise attenuation you attempt is good for your hearing health (if unprotected otherwise; however, be prepared to be disappointed with the "comfort" results.
 
Last edited:
yep

I used some sound insulation in the cabin side walls, aft foot wells, and under the baggage area floor; it was a waste of time and effort.

Bose A20's or equivalent are all you need.
 
You must log in or register to reply here.
Back
Top