Messydeer
Member
Hi!
I just finished installing insulation on the cool side. I had already put a fair amount of components on the hot side and I felt leaving it with the bare SS exposed would make for easier installation of anything later. So I used two 1/4" thick blankets of ceramic insulation 93315K51 and covered it with .002" tempered aluminum foil 9012K23. Those are the McMaster part numbers.
I believe Dan Harris had tested a similar installation, so I did little on my own. I did take a propane torch to the insulation and didn't get any smoking or anything. Things are a bit different than your typical RV. That's because this is a Sonex. I appreciate the RV community for allowing me to get help and share my experiences through this board.
I was hoping to attach some pics, but I don't see that as an option, except by entering a URL, which I don't think I want. So I guess you'll have to use your imagination. I thought this was like the aeroelectric board. So for now, I'll just describe what I did.
After sealing all the gaps with 3M Fire Barrier 2000, I cut the the first blanket to the width of the firewall, about 32" or so. The firewall height was ~25", so the 24" wide roll of RCF fit there just fine. The Sonex has a vertical 1/2" square tubing firewall stiffener in the center on the inside. I had thought of cutting two sections, but decided there wasn't anything bad about a 1/2" hump, so I simply covered over the top. The 2nd blanket went just like the first.
Next, I put on the aluminum foil. I had already put my two wire bundles through the firewall, so I just cut slits in the blankets and foil. It took two sections of foil to span the firewall and I simply overlapped them in the center.
I have two big holes in the firewall (cabin heat and nose gear steering push rod) plus smaller ones for the cables, fuel line, wire bundle support nutplates, and ground bus. I cutout the two big holes first. At first I was disappointed in how the aluminum went on. It was pretty easy to tear. And I quickly had to abandon my idea of having it look anything close to tight and flat.
The first major hurdle I came to was installing the fender washers. I first used 1/8" SS rivets, but they compressed down so far that the foil split. I used aluminum 1/8" rivets for the other 3 washers in the bottom half of the firewall spaced ~6" apart. I found that putting down a piece or two of aluminum tape over the foil area to be riveted before putting the washer on helped. There were two other washers I put in the upper firewall. For these, I went back to the SS rivets, but used spacers made of several #6 washers between the foil and firewall. If I had to do it over again, I'd try some SS 3/32" rivets, but I didn't want to make a separate ACS order and wait a week.
The biggest help in this process was the aluminum tape. I used Shurtape AF-973. Can't remember where I got it, but it's almost 2" wide and sticks really well. I taped all around the perimeter and around firewall penetrations. It is the exact color of the foil. This won't matter much later, since the inside of the firewall, except for the very bottom, will be forever dark since it's under the Sonex tank. It was really easy to tape around the nose gear pushrod and cabin heat openings.
So now I have a nicely insulated firewall. I only have the tank filler neck box to insulate, which I'll do from the outside after the engine is hung. Also may put a blanket or two on the floor and cover with 025 or 016.
Cheers,
Dan
I just finished installing insulation on the cool side. I had already put a fair amount of components on the hot side and I felt leaving it with the bare SS exposed would make for easier installation of anything later. So I used two 1/4" thick blankets of ceramic insulation 93315K51 and covered it with .002" tempered aluminum foil 9012K23. Those are the McMaster part numbers.
I believe Dan Harris had tested a similar installation, so I did little on my own. I did take a propane torch to the insulation and didn't get any smoking or anything. Things are a bit different than your typical RV. That's because this is a Sonex. I appreciate the RV community for allowing me to get help and share my experiences through this board.
I was hoping to attach some pics, but I don't see that as an option, except by entering a URL, which I don't think I want. So I guess you'll have to use your imagination. I thought this was like the aeroelectric board. So for now, I'll just describe what I did.
After sealing all the gaps with 3M Fire Barrier 2000, I cut the the first blanket to the width of the firewall, about 32" or so. The firewall height was ~25", so the 24" wide roll of RCF fit there just fine. The Sonex has a vertical 1/2" square tubing firewall stiffener in the center on the inside. I had thought of cutting two sections, but decided there wasn't anything bad about a 1/2" hump, so I simply covered over the top. The 2nd blanket went just like the first.
Next, I put on the aluminum foil. I had already put my two wire bundles through the firewall, so I just cut slits in the blankets and foil. It took two sections of foil to span the firewall and I simply overlapped them in the center.
I have two big holes in the firewall (cabin heat and nose gear steering push rod) plus smaller ones for the cables, fuel line, wire bundle support nutplates, and ground bus. I cutout the two big holes first. At first I was disappointed in how the aluminum went on. It was pretty easy to tear. And I quickly had to abandon my idea of having it look anything close to tight and flat.
The first major hurdle I came to was installing the fender washers. I first used 1/8" SS rivets, but they compressed down so far that the foil split. I used aluminum 1/8" rivets for the other 3 washers in the bottom half of the firewall spaced ~6" apart. I found that putting down a piece or two of aluminum tape over the foil area to be riveted before putting the washer on helped. There were two other washers I put in the upper firewall. For these, I went back to the SS rivets, but used spacers made of several #6 washers between the foil and firewall. If I had to do it over again, I'd try some SS 3/32" rivets, but I didn't want to make a separate ACS order and wait a week.
The biggest help in this process was the aluminum tape. I used Shurtape AF-973. Can't remember where I got it, but it's almost 2" wide and sticks really well. I taped all around the perimeter and around firewall penetrations. It is the exact color of the foil. This won't matter much later, since the inside of the firewall, except for the very bottom, will be forever dark since it's under the Sonex tank. It was really easy to tape around the nose gear pushrod and cabin heat openings.
So now I have a nicely insulated firewall. I only have the tank filler neck box to insulate, which I'll do from the outside after the engine is hung. Also may put a blanket or two on the floor and cover with 025 or 016.
Cheers,
Dan
