After sanding on my rudder and still waiting for my shipment of wood I started to wonder how I could make my himax like a "real" airplane. I saw georges himax  and how he insulated his airplane cockpit but to me that looks a little heavy, then I thought 3/4" dow Styrofoam panels would fit awfully neat between those rs8 members. let me know your thoughts, I"m not necessarily trying to make legal weight but I do know a lighter airplane flys better. Mother Nature.  

Hi
First thought that comes to mind would be to check the flammability of the substance you are considering and the toxicity of the fumes when burned, ever the consideration in things that sometimes catch fire.
Kim Brown
New Hampshire

Quoted from kfb

Hi
First thought that comes to mind would be to check the flammability of the substance you are considering and the toxicity of the fumes when burned, ever the consideration in things that sometimes catch fire.
Kim Brown
New Hampshire

Wood and fabric burns alot faster than Styrofoam.

If you want insulation to keep your body warm wear a snowmobile suit.  

Noise cancelling headset deals with one issue; a hat and an extra pair of socks the other.  It is your feet that feel the cold first but most heat escapes through your head (I no longer have the insulation I used to have there,) so wear a suitable* hat.



* Currently out of stock.

I used 1/2 inch Al foil covered house insulating foam panels covered with truck bed liner. This gives the right thickness to fill between the members,  Very light weight and easy to do.
But there is more to it , I also replaced the sandwich engine mounts with Lord type and redesigned the muffler saddle mount which transfers all the vibration and noise directly into the fuselage , I did a it with the rubber muffler hang strap with no direct contact.
Between all this the noise and vibration was reduced significantly.

Thanks George.

George, those pictures impress me every time I see them  

What part number lord mount did you use George? I am very aware of the 277s high frequency vibration using samich mounts. I thought they  were made for just for cert "gov" airplanes.

This one
https://www.leadingedgeairfoils.com/lord-plate-mount-square.html

By the way , the foams for house insulating don't even burn anymore , at least not on their own they will self extinguish, unless it is surrounded with other burning stuff in which case they will burn up eventually.

Thanks George, I forgot all about leading edge airfoils.