C

Catbird

Well Known Member
Mel,

Step 4 on Page 22-03 states, "Smear a thin layer of fuel tank sealant on the top surface of the top flange of F-1201C Firewall Bottom. Cleco then rivet the F-1201B Firewall Shelf and F-1257 Rudder Pedal Support Channels to the Fwd Lwr Fuse Assembly per the callouts in Figure 2.

Now here's my question: If I'm building my RV-12 to E-LSA certification, am I required to use "fuel tank sealant" on the firewall? It seems to be a rather general term and does not specify a product or equivalent. There have been many threads in this forum on the subject of firewall sealants. The general opinion is that there are some really good heat resistant products out there that will out-perform "fuel tank sealant". Do we have any wiggle room here, staying within the confines of E-LSA?
 
Catbird said:
Now here's my question: If I'm building my RV-12 to E-LSA certification, am I required to use "fuel tank sealant" on the firewall? It seems to be a rather general term and does not specify a product or equivalent. There have been many threads in this forum on the subject of firewall sealants. The general opinion is that there are some really good heat resistant products out there that will out-perform "fuel tank sealant". Do we have any wiggle room here, staying within the confines of E-LSA?
Click to expand...

I can't speak for whether Mel would allow this type of deviation if he knew about it but consider this...
At this particular joint you are basically sealing two surfaces that are a net fit. You are not trying to seal a gap for fire, you are sealing a joint to prevent oil and other fluids from passing through. A thin coating of tank sealant is easy to do and does the job. I would guess you have never used the fire rated firewall sealant. I is very dry and viscous. It can not easily be spread thin. Your firewall parts would likely have a gap between them with a thick layer of the sealant caught between.

That is the reason tank sealant is specified at that joint.
 
Stick with the plans!

I agree with Scott. Use what the plans call out. If it's not a specific "brand" etc., I think it is certainly "implied" that you are to use the same sealant as for the fuel tank.
 
Fire resistant sealant?

Is there a product that not only has the properties of fuel tank sealant, but is also fire resistant? Is there something that sticks to aluminum as well as proseal, is flexible, seals against vapors and petroleum based liquids, and is fire resistant?
Joe
 
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