Aluminum Firewall Thickness

[BB2_Ed]

I know the Rule book in section 3.F States that the firewall must be Metal, and .060" thick.

I remember in a conversation with a tech inspector (can't remember who) that it should be .060" thick if Steel, or .095" thick if Aluminum?

Is this just good advice, or a rule? 

I cannot find any mention of it anywhere else in the rule book, and I  have also searched this forum for this answer.  Ready to order the new aluminum and would like to confirm the thickness requirement before I place my order.


Thanks. 

Ed Hillstrom

[Glen]

Go with the .095 Aluminum. Makes it stronger for mounting any other hardware etc. on. Also better protection

[RichFox]

3.F requires .060. Recomends .095. Up to you.

[Cajun Kid]

MY car has a 7/16 fibergalss firewall and I overlayed it with  form fitting, seamless 12 Guage  Aluminum Sheet  Metal. when I mic'd the  12 ga  sheet it only measure out to .081

I guess that is 33% thicker than the minimum .060 but less than the suggested .095

I then shot 3 coats of Lizard Skin Ceramic heat shielding on it (that stuff is good, not totaly fire proof but really resists heat and flame) also shot the Lizard skin in 3 coats on the entire floor and 2 coats on the doors, sides and roof.

Charles

[836dstr]

Sounds like you are very well protected, and legal. Good idea with lizzard skin on both sides!

[Glen]

NHRA just passed a rule that all funny cars be sprayed with a fire resistant coating on the underside of the bodies. Lots of fires lately have caused concern and it's a good rule. If you have a fiberglass or carbon fiber vehicle this might be worth looking into.

[Cajun Kid]

Glen,  That is also what I heard.  I did not spray the underside of my body, but I did spray the complete inside.

Let me tell you, I was sold on this Lizard Skin Ceramic when I saw the guy at the rod shop put a propane torch to the aluminum side of a sheet coated with 3 coats of this stuff, for a full minute he put the flame to it, then he put his bare hands against the coated side of the sheeting.. It was warm but not hot. I felt it and to my surprise it was not a trick it was warm but not hot...

A 2 gallon bucket of this stuff runs about $190  but it will coat the average car no problem,, I had enough to put two coats on the roof (more for heat insulation than fire up there).

Charles

[jl222]

  That Lizard Skin sounds good think i'll look into it, as our front end and hood is fiberglass.
  Any body know what the drag racers are using?

[maguromic]

On my roadster I am using aluminum coated fiberglasses cloth on the panels in areas where I think a fire may happen. Its all a guessing game that I don't want to prove.  I don't know who makes it though,  I got a roll of it from one of the shops at Indy.

[dwarner]

This makes sense for glass bodied cars if you watched Cruz Pedregon knock the body off his funny car recently when the fire was inside the car. When the body flew off it continued to burn but the chassis fire went out pretty quick.

DW

[Cajun Kid]

DW, that is exactly what I was thinking. any extra bit of heat or flame protection is a good idea.

Charles

[jdincau]

     I thought intumescent (expands when heated) paint was an NHRA reqirement for funny car bodies for some time now. We have fire retardant paint on the inside of the roadster body. It has been there for so long I forget who made it. I think Ken got it from a funny car owner he was crewing for.
Jim

[manta22]

While it may be legal, an aluminum firewall is not much protection from a sustained fire-- the melting point of AL is simply not that high. Mild steel is a far better proposition and a sheet of stainless steel wouldn't be bad, either. I scored a few sheets of Inconel on the surplus market for my firewall. It's used in jet engines so its heat resistance is well established.

[John Noonan]

While it may be legal, an aluminum firewall is not much protection from a sustained fire-- the melting point of AL is simply not that high. Mild steel is a far better proposition and a sheet of stainless steel wouldn't be bad, either. I scored a few sheets of Inconel on the surplus market for my firewall. It's used in jet engines so its heat resistance is well established.

The Proper thickness Aluminum firewall is fine.

J

[interested bystander]

Thanx, noonan. Methinx all were getting a bit OVERWORKED with the topic.

But, with that said, BUY  THE BEST SAFETY EQUIPMENT YOU CAN AFFORD, to CYA's (literally).

Ya don't want to make a chitlin of yerself!