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Confusion/quetsions on Fiberfrax installation...

Reflex

Well Known Member
Thought I'd start a new thread instead of hijacking an old one....

After reading several threads/posts on adding a safety margin to the firewall, I've decided that this is one of the very few modifications I'd like to make on my RV-14. However, I'm still a bit confused. I'm planning on using Fiberfrax and Dan H's method on the firewall. Dan has been kind enough to give very detailed drawings of his method. However, I'm slow enough that I'm not quite understanding when or how to mount things to the firewall.

If we put the Fiberfrax and covering on first, it appears that items on the firewall would have a very "soft" mount. If we put items on the firewall before the Fiberfrax is installed, then we could/will have hot spots in the event of a fire. In a perfect world, I'd like to install install the Fiberfrax first and then mount everything to the firewall, I'm just afraid that they won't stay put. I've cheated and put Dan's pictures and a couple other examples below.

In what order do I install the items on the firewall, before or after Fiberfrax?

Drawings courtesy of a previous post from Dan H
Center%20Seam.jpg


Firewall%20Joint%20Caulking%20800w.jpg


Found this on Steevo's web site. It's an example of the type of items I'm wondering about.

0506171447.jpg
 
You do not want fiberfrax or foil tape under anything that requires a structural attachment like the engine mount. So:

1) Temporarily mount things on the firewall over a paper or cardboard template, mark the template to identify areas where you don't want the barrier. Remove the items, and make a barrier to to fit. Come back and attach the items later.

2) Mount all of the stuff, then cut and fit a barrier of fiberfrax and stainless to go around all of the items.

3) Whatever alternate method you can come up with. Hopefully better than the two I suggested. ;-)
 
In a perfect world, I'd like to install install the Fiberfrax first and then mount everything to the firewall, I'm just afraid that they won't stay put. ...In what order do I install the items on the firewall, before or after Fiberfrax?

What Kyle said, nothing under the motor mount attach points. As for the rest, none of it is critical. Lots of hours out there with accessories bolted down over foil and frax, but if it bothers you, do cutouts.
 
Dan,
I am hopefully getting my fiber and stainless foil on this weekend. Where they go around the motor mounts did you just put a fillet of the fire barrier compound around the mount so it holds down the foil around them?
 
Dan,
I am hopefully getting my fiber and stainless foil on this weekend. Where they go around the motor mounts did you just put a fillet of the fire barrier compound around the mount so it holds down the foil around them?

Yep. Fillet every foil edge, everywhere. Sealing is good, and at the practical level, you want the edges buried so they don't cut you.
 
I used razor knife to cut a slot out where parts were mounted. I poked a hole through the SS foil through the nut plates. I then opened up the holes and attached the part. I then traces around it with a sharpie, removed the item. I then cut a line down the center (about 2/3 the length) and then diagonal to the corners. opened up the hole and cut out the insulation. I then folded the sharp edge over to make sure the bolt holes were exposed and then bolted the part in place. At this point, the part holds the SS foil to the FW. Hopefully this is an acceptable method. Does this make sense?

I did get 1" SS tape and I have used that in places around things and I used it to join the two sheets of SS foil together down the middle.

I do have the insulation and SS behind the battery. this means that the battery "brace" can't screw in completely.

I was looking at your picture and I noticed that you have only 2 FW pass thru fittings (the one supplied by Van's). I know that you can put everything through those two points, I decided to put one in the upper section near just left of the center point (pilot side). I got it from ACS--they are very nice. I put all the wires through that pass thru, then I put only the push pull cable through the other two.

From what I understand, the cables are more likely to need being replaced. I figure that it would be much easier without the wires in the way.

Also, put on the forest of tabs on the FW before doing the insulation. Also figure out where to put the 60 amp fuse and shunt. I screwed that up, which led me to need to put in an oil air separator.

One last thing. That SS foil is supper sharp you should were cut resistant glove. I did not and ended up with several small stab wounds.
 
FW insulation

If the foil has any curve to it use to your advantage and install it curving toward the FW. Most of my FW items will bolt thru the foil and clamp it in place, but a couple will be mounted using 1/4? long bushings as spacers

Don Broussard
RV9 Rebuild in Progress
57 Pacer
 
Firewall near done

This is a photo of a 14A firewall with 1/8" fiberfrax and .005 Stainless Steel Shim stock. You can see what we did cutouts around and what is simply bolted through. The foil tape has not yet been applied and the Firebarrier 2000+ has not yet been applied. This firewall has a few extra mods so don't feel like your missing a bunch of components, but hopefully this helps you visualize. We used Stainless Steel blind rivets to hold everything together.

Firewall.jpg
 
Thanks Dan! Also seeing firewalls completed like this last pic are a great help. Thank you! Does anyone have a pic of how they covered the recess area in a 7 or 9 firewall?
 
Jon--

When I look at where you put things on your FW, it looks like you will have to have a new plan for the breather tube. Look at 49-02. The 60 amp fuse holder is in the way of the breather tube--the one next to the starter and master solenoids. I think that the shunt and the fuse holder are not in the way--the ones at the top center of the FW. I went out and looked at my set up, so I think that they are out of the way.

I screwed this up and put the shunt about 1/2" over too far and there was no easy way to put in the breather tube. I ended up having to put in an Anti-Splat Oil separator to circumvent this issue in my case.

I guess you could make a new breather tube that bypasses what is in the way. It would be way easier at this point to just move the fuse holder over closer to the solenoids at this point. I would strap in the breather tube now so you see how it goes. If you don't have one, then I can send you mine, since I won't bee needing it. Send me a PM if you are interested.

Where did you get the SS blind rivets?

cheers
ken
 
SS foil

Please post some details of SS foil. Part number, brand, thickness and where it can be purchased.
 
Just ordered from a place called "Quick Ship Metals"

They offered .002" STAINLESS FOIL on a 12" roll. got 20 feet for the RV-10 firewall so we'll see if things work out once it arrives. I'm sure there are a few other options out there.
 
Jon--

When I look at where you put things on your FW, it looks like you will have to have a new plan for the breather tube. Look at 49-02. The 60 amp fuse holder is in the way of the breather tube--the one next to the starter and master solenoids. I think that the shunt and the fuse holder are not in the way--the ones at the top center of the FW. I went out and looked at my set up, so I think that they are out of the way.

I screwed this up and put the shunt about 1/2" over too far and there was no easy way to put in the breather tube. I ended up having to put in an Anti-Splat Oil separator to circumvent this issue in my case.

I guess you could make a new breather tube that bypasses what is in the way. It would be way easier at this point to just move the fuse holder over closer to the solenoids at this point. I would strap in the breather tube now so you see how it goes. If you don't have one, then I can send you mine, since I won't bee needing it. Send me a PM if you are interested.

Where did you get the SS blind rivets?

cheers
ken

You are correct that my placement of the shunt would normally interfere with the breather tube. However, I am installing a half raven kit so the breather tube is coming from a completely different location (left side of the engine mount). I got the SS blind rivets from McMaster. They had some with an extra wide manufactured head so that I didn't need washers. Hope this helps.

In regards to the SS foil, I actually used .005" SS shim stock from McMaster. it came in a 2'x10' roll and was rather expensive, but it was more like a sheet of metal than foil. If you buy a roll find another builder who is also doing this since it only takes about 5' for a 14A firewall. The blind rivets also came in a 100 count box and I only used about 50. I ended up splitting the costs with another builder who used the other half of the material on his 14.
 
Just double checking....

Just double checking. The battery box on the RV-14 is riveted onti the firewall. OK to rivet though .002 stainless and .125 Fiberfrax to the firewall?

What Kyle said, nothing under the motor mount attach points. As for the rest, none of it is critical. Lots of hours out there with accessories bolted down over foil and frax, but if it bothers you, do cutouts.
__________________
Dan Horton
RV-8 SS
Barrett IO-390
 
I turned my TI foil so that the seam is horizontal. I liked the way it worked better that way with the recess. I'm not sure I did this the optimal way but it seemed to work pretty well.

First the insulation is adhered to the recess with some of the 3M high temp caulking. The the foil is folded over into the recess. I did make some templates for the side pieces out of poster board and then I cut pieces of foil to match them. I added flanges to those pieces so they could overlap.

I used a very simple home made brake to make the bends. I just clamped the foil to my bench with a piece of Al angle on the bend line. Then I used a block of wood and a rubber mallet to form the bends.

To finish it off I used some closed end blind SS rivets from McMaster to secure the foil where needed.
 

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Thanks Dan! Also seeing firewalls completed like this last pic are a great help. Thank you! Does anyone have a pic of how they covered the recess area in a 7 or 9 firewall?

I used a little heavier SS to cover the fiberflax (.010). I rolled the sides into the recess with a small return against the back of the recess, then fit a continues back piece, slipped up under the firewall cover and overlapped on the bottom.
 

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