Cowl exit heat shield... when to rivet?

rmartingt · #1 08-13-2018, 01:34 PM

As of five minutes ago all of the riveting is finished and my fuselage is about ready to flip over. Before I flip this canoe, is there any reason I shouldn't go ahead and install the belly heat shield (as discussed in DanH's many firewall protection threads)? I have a 2x2 sheet of .008 stainless drilled up and I'm starting the prep work for installing it already.

I can't see anything it would interfere with so long as I don't rivet the line where the cowling hinge will attach. Anyone see something I'm missing?

Raymo · #2 08-13-2018, 01:54 PM

Like you said, jut the cowl hinge fitting. I purchased some for mine but haven't gotten around to installing it.

David Paule · #3 08-13-2018, 02:10 PM

That's the stage where I did mine on my RV-3B.

Since .008 isn't appropriate for a primary firewall, I decided that I'd use .020 titanium. I used 1/16" Fiberfrax under it as insulation. I used F.A.R. Part 23.1191 to learn what a firewall should be made of, and then got the cheapest titanium I could for that.

Now since this isn't considered a firewall, I suppose I could have used something thinner, such as your .008 stainless. I'm not criticizing your choice, just explaining mine. But there have been one or two reports of fires that melted the aluminum there, and on the RV-3B the pilot's feet rest directly on that belly skin, so I wanted something I had confidence in.

Dave

rmartingt · #4 08-13-2018, 02:26 PM

Yes, forgot to mention that it'll be backed by 1/16 ceramic fiber insulation.

jcarne · #5 08-13-2018, 02:44 PM

I just flipped my canoe and riveted my titanium 0.020 everywhere except for the cowl hinge line.

rmartingt · #6 08-15-2018, 11:51 AM

Looks like a consensus then!

I'll proceed with priming underneath and then I'll install it except for the cowl hinge line. I plan to seal the edges with proseal (to prevent moisture/oil intrusion and for corrosion protection) since it'll be on the outside.

On the firewall I'll be using the DanH method and I'll be welding up my own firewall passthroughs, as an excuse to use my welder and they're non-structural

Raymo · #7 08-15-2018, 02:03 PM

I suggest sealing with 3M Fire Barrier 2000.

rmartingt · #8 08-16-2018, 04:52 AM

Quote:

Originally Posted by Raymo

I suggest sealing with 3M Fire Barrier 2000.

I thought about it but was concerned about oil resistance and weatherproofness(?). However, some further research says it looks like it's actually pretty good for that sort of thing. I'll need another tube when I do the firewall blanket but it's not too bad ordered off of amazon.