Insulation & venting

I think I needed to ask others who have gone before me;
My neighbor and I are building an RV14A and it has gone very well and it is unbelievably fun though the process of building.

My question is, because we live in Colorado we needed to insulate the plane. We used SUPER SOUNDPROOFING 1/4" W/ ADHESIVE //Part #: 09-01244 from Aircraft Spruce. It has worked very well stuck to the inside of the outer skin as we built.

But then I have been thinking of the bulkhead in the rear. And the design of the bulkhead makes me wonder why they used a heavy corrugated shape for the rear cover? I figure it must be for weight because the bends allows for a thinner material. But then I had the thought maybe it is for pressure venting and therefore I should not seal up the rear for sound and cold air?

Hopefully someone would know.
Larry

It is a structural member. The corrugations add a lot of stiffness to the cover.
They do also provide a airflow path out of the cockpit.
Your thinking is correct... if air comes in (fresh air vents or heat), then air has to be able to go out somewhere.

Larry,

Keep in mind also, that it is NOT advisable to glue that super sound-proofing stuff (or anything else) to the cabin side of the stainless steel firewall. If the firewall gets hot enough, the sound proofing can give off toxic fumes and even ignite.

smoke, fire?

ppilotmike said:

Larry,

Keep in mind also, that it is NOT advisable to glue that super sound-proofing stuff (or anything else) to the cabin side of the stainless steel firewall. If the firewall gets hot enough, the sound proofing can give off toxic fumes and even ignite.

Click to expand...

Thanks Mike!!!
We have already stuck it to the back of the firewall mostly for sound proofing. You suggest taking it off? On the material I listed I made sure it was none flammable and aircraft approved. If you suggest / confirm removing it what would be a good sound proof measure or is it best left as steel?
I know you state above, I just want confirmation.
Thanks, Larry

larrys said:

Thanks Mike!!!
We have already stuck it to the back of the firewall mostly for sound proofing. You suggest taking it off? On the material I listed I made sure it was none flammable and aircraft approved. If you suggest / confirm removing it what would be a good sound proof measure or is it best left as steel?
I know you state above, I just want confirmation.
Thanks, Larry

Click to expand...

Search out firewall insulating posts by Dan Horton. You will learn everything you need to know!

Short version:

http://www.vansairforce.com/community/showpost.php?p=476353&postcount=20

not in my plane

DanH said:

Short version:

http://www.vansairforce.com/community/showpost.php?p=476353&postcount=20

Click to expand...

Wow, Thanks! It is now driven home what not to do. I am, as always grateful for VAF and members who know what they are doing.
thanks again, Larry