For the folks flying the RV-10 now...do you think sound proofing should be installed in the floor and side walls prior to installing the last panels?
We used supersoundproofing for our rv-10. We did all the side panels, floor and back of baggage bulkhead with 1/4 inch adhesive backed soundproofing. We used 1/2 inch adhesive backed for the cabin side of the firewall. Vic switched to this brand because it is moisture and fuel resistant. It can be purchased at a/c spruce or directly from the company http://www.soundproofing.org/. We purchase a 25 ft roll of the 1/4 inch and had 3-4 ft left. The company offers a discount on 25 ft rolls. You can purchase it with or without the adhesive backingThe adhesive backing makes it much easier to work with. It has a paper covering the adhesive so you can cut it to size, peel off the paper and stick it down.
I'm reviving an old thread.
This looks like a good solution for the floor and cabin sides. I was wondering what the long term verdict was on the product? How much of the 1/2" stuff do I need?
Is this the exact material being mentioned?
http://www.supersoundproofingsales....wide-w_PSA-per-foot/productinfo/09-42720-PSA/
Yup. ACS sells it.
Thanks, I wasn't sure if it was the same stuff.
I used it as the headliner base for my Tiger and it worked well and was easy to use. I glued Airtex headliner fabric directly to it with 3M spray adhesive. It is going well and remains stuck after 10 years in the AZ heat.
Is this the exact material being mentioned?
http://www.supersoundproofingsales....wide-w_PSA-per-foot/productinfo/09-42720-PSA/
Closed cell nitrile rubber foam.
When you install that class of material on the cabin side of a firewall, what you're really doing is creating a very effective fire transfer mechanism.
Given an engine compartment fire, the stainless steel firewall will get very hot. (The FAA standard is 2000F over a 25 sq in area.) A bare steel firewall will glow red like a toaster oven, and although it would make rudder pedal usage uncomfortable, it is survivable as long as the red hot metal doesn't ignite something on the cabin side.
Here we're talking about placing the material in direct contact with the stainless steel. The hot steel ignites the rubber foam. Here's what happens just a few seconds later:
The vendor will tell you the material meets FAA standards for flame resistance, specifically FAR 23.853 or 25.853. Here's the applicable paragraph from FAR23:
(ii) Floor covering, textiles (including draperies and upholstery), seat cushions, padding, decorative and nondecorative coated fabrics, leather, trays and galley furnishings, electrical conduit, thermal and acoustical insulation and insulation covering, air ducting, joint and edge covering, cargo compartment liners, insulation blankets, cargo covers and transparencies, molded and thermoformed parts, air ducting joints, and trim strips (decorative and chafing), that are constructed of materials not covered in paragraph (d)(3)(iv) of this section must be self extinguishing when tested vertically in accordance with the applicable portions of appendix F of this part or other approved equivalent methods. The average burn length may not exceed 8 inches and the average flame time after removal of the flame source may not exceed 15 seconds. Drippings from the test specimen may not continue to flame for more than an average of 5 seconds after falling.
Short summary? FAR 23.853 or 25.853 materials are allowed to be flammable. They just have to stop burning after the heat source is removed. Note that snuffing an engine compartment fire is not as easy as turning off the little burner specified in Appendix F.
The FAR conveniently ignored when selling such products for firewall application is "23.1182 Nacelle areas behind firewalls."
Components, lines, and fittings, except those subject to the provisions of ?23.1351(e), located behind the engine-compartment firewall must be constructed of such materials and located at such distances from the firewall that they will not suffer damage sufficient to endanger the airplane if a portion of the engine side of the firewall is subjected to a flame temperature of not less than 2000 ?F for 15 minutes.
We're not required to comply with the above FARs. You can legally insulate the firewall in your RV-10 with plastic explosive if you wish. In fact, as compared to nitrile rubber, it may even be a good idea. It would be a more pleasant way to go.
Ed,
It looks like you installed the heat shield mat underneath all bolted items through the firewall, including the engine mount? Or is the mat cut out in all those areas?
Which heat mat product did you use? Looks great!
Okay expert Dan, what's your thought on applying a product to the forward side of the fire wall in an attempt to dampen noise and add an extra layer of fire proofing?
In the context of normal operating temperatures, insulation on the front side is generally more effective than insulation on the cabin side. In the context of fire protection, it is vastly more effective.
Nothing a builder might install on the forward side of a firewall can do any great harm. The issues become merely practical; some overlays are better insulators than others under normal conditions, some offer better fire protection, and some are easier or harder to install.
BTW, you're new here, so it would pay to explore the search functions for additional information.
Thanks Dan. I've read your stuff on burn tests and was interested in how all of this tied in. Your input is valuable and appreciated.I think I will go Ed's route and put something on the engine side of the firewall and use the soundproofing mats for the floor and side panels.
Randy, be cautious about the forward floor and inside the tunnel. In the event of fire, it follows airflow, meaning out the cowl exit, heating the belly immediately aft of the firewall.
Some years back one of our RV-10 builders did in fact suffer a fuel fire and forced landing. He had insulated inside the tunnel with Thermozite, another product sold as "firewall insulation". It's actually polyester fiber (think recycled plastic bottles) and burns very well indeed. So, he got a double whammy; (1) the Thermozite caught fire inside the tunnel (he had to jettison a door to breath and see), and (2) because he had insulated the back side of the aluminum belly skin, it melted through very quickly. The only good news was that the now-floorless tunnel contained the burning Thermozite, so our man escaped after doing a great job stuffing it into a field.
I've seen people on this forum recommend sprayed urethane foam between the forward floor and belly skin....."Here's your sign!".
Thanks again Dan for this information. Can I ask what your recommendation is for how to accomplish the task of soundproofing while bolstering fire protection in the tunnel and the firewall?
Search is your friend; this discussion has been going on almost ten years.
Here's a pretty good thread:
http://www.vansairforce.com/community/showthread.php?t=131516
I have not studied sound control, just the flammability of the materials when applied to a firewall. I see no danger in applying whatever you wish inside the cabin, if restricted to sidewalls, roof, and floor aft of the spar.
The problem is finding consensus. The conflicting info given often leaves one more confused.
Welcome to the internets...
As the builder you ultimately have to make the decision of what you want to do. Asking a question on an open forum will often yield a ton of information that you will need to wade through towards your decision.
In the context of normal operating temperatures, insulation on the front side is generally more effective than insulation on the cabin side. In the context of fire protection, it is vastly more effective.
Nothing a builder might install on the forward side of a firewall can do any great harm. The issues become merely practical; some overlays are better insulators than others under normal conditions, some offer better fire protection, and some are easier or harder to install.
BTW, you're new here, so it would pay to explore the search functions for additional information.