[rebel-builders] Non-magnetic stainless firewall?

[Dick Wampach]

Alum is non magnetic and is much softer than any type of steel.

Almost all Stainless in totally non magnetic, Only a few have the very
slightest magnetic tendency, like 5% of that of hi carbon content steel.
Hi carbon content steel will almost grab your magnet when you get it close.

If I may suggest the regs for small Airplane Design, should be in part 23.
I do not think it is in part 43, or 91.
Advisory Circular AC 43-13- will contain a lot of usable data on how to
do things and it should be on your work bench. I consider it required
reference material.

Dick Wampach SR-108 N331RW



-----Original Message-----
From: mike.davis@dcsol.com [mailto:mike.davis@dcsol.com] On Behalf Of
schaumr@dcsol.com
Sent: Wednesday, August 04, 2010 6:26 AM
To: rebel-builders@dcsol.com
Subject: [rebel-builders] Non-magnetic stainless firewall?


Hang on.....an earlier message states that this type of stainless might be
non- magnetic.

I admit the color is slightly different from the surrounding aluminum, and I

would love to believe this is stainless. Maybe it wasn't that easy to file
after
all? How the heck do I tell?

Rob

Now I'm not so sure On 8/4/2010 4:28 AM, klehman@albedo.net wrote to
rebel-builders:

-> Curtis
->
-> Some of us riveted a thin flat sheet of stainless on the forward side
-> of
-> the aluminum. Actually makes for a stronger firewall with a little less
-> risk of damage I'm told.
->
-> I understand that fibrefrax cloth also meets the requirement. It and
-> the
-> glue is available from Spruce. I did not use it because I figured it had
-> to be covered with something else anyway to keep it from eventually
-> becoming saturated with oil.
->
-> I don't know why MAM considered aluminum acceptable for early kits.
->
-> Ken
->
->
-> Curtis Langholz wrote:
-> > Rob, Great topic for sure.... I purchased kit # 175r that had been
-> > in storage for a long time. When I purchased it I bought the
-> > upgraded manuals from MAM and got a tour of the factory plus talked
-> > to Daryl about my engine choice. He recomended the 3" shortening of
-> > the boot cowl which I did as well as the fload stiffeners and motor
-> > mount doublers. I was feeling really good now that it was
-> > complete.... I check the MAM bulletins regurlarly as well and there
-> > has not been any mention of the firewall being aluminum or
-> > stainless. It is very frustrating to have all this time putting it
-> > together to find out MAM was so cheap to use an aluminum firewall
-> > that is a safety hazard. Can anyone give me a suggestion of what I
-> > should do with it at this point? Although it is a setback in the
-> > building process, it does need to be addressed. Thanks for bringing
-> > up the question about the firewall material.
-> >
-> > Curtis
-> >
-> >




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[David A. Ricker]

Hi Rob

Here's a couple of thoughts:

1. You might find something on the web, like how aluminum & steel
react to certain chemicals. Eg. aluminum is treated with
sulphuric acid (and electrical current) to anodize it. Also
aluminum will take a gold colour when it is treated with
Alodine/Irridite chromic conversion coating (availible at your
local NAPA as a Dupont product. Look up the P/N first thought the
parts counter person may not know it by Alodine/Irridite)
2. You could drill a hole in the firewall (where you were going to
put something anyway....) and make sure you get a nice long spiral
drill chip from it. Do this also with a piece each of known
aluminum and stainless. Take the 3 samples and heat with a
propane torch and see how they react. The aluminum will melt
before the steel and the steel should take a nice cherry red then
yellow/white before melting. I believe the aluminum will just
melt with little colour change. I don't typically use the cutting
torch on aluminum!
3. Taste it! We all know what stainless tastes like from our
tableware and aluminum has a different distinctive taste/feel. Of
course you don't want to eat it, I don't remember but I think
there's some connection to Alzheimer's disease (With apologies to
anyone who has been touched by Alzheimer's...)

FWIW, I'm betting you have stainless, our Elite (583, mixed into the
Rebel S/N list) definitely has a stainless firewall.

Cheers

Dave
elite583.cjb.net



schaumr@dcsol.com wrote:

Hang on.....an earlier message states that this type of stainless might be non-
magnetic.

I admit the color is slightly different from the surrounding aluminum, and I
would love to believe this is stainless. Maybe it wasn't that easy to file after
all? How the heck do I tell?

Rob

Now I'm not so sure On 8/4/2010 4:28 AM,

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[David Jackson]

What about polish? Will stainless and aluminum polish up differently?

Date: Wed, 4 Aug 2010 12:07:58 -0300
From: daricker@ns.sympatico.ca
To: rebel-builders@dcsol.com
Subject: Re: [rebel-builders] Non-magnetic stainless firewall?

Hi Rob

Here's a couple of thoughts:

1. You might find something on the web, like how aluminum & steel
react to certain chemicals. Eg. aluminum is treated with
sulphuric acid (and electrical current) to anodize it. Also
aluminum will take a gold colour when it is treated with
Alodine/Irridite chromic conversion coating (availible at your
local NAPA as a Dupont product. Look up the P/N first thought the
parts counter person may not know it by Alodine/Irridite)
2. You could drill a hole in the firewall (where you were going to
put something anyway....) and make sure you get a nice long spiral
drill chip from it. Do this also with a piece each of known
aluminum and stainless. Take the 3 samples and heat with a
propane torch and see how they react. The aluminum will melt
before the steel and the steel should take a nice cherry red then
yellow/white before melting. I believe the aluminum will just
melt with little colour change. I don't typically use the cutting
torch on aluminum!
3. Taste it! We all know what stainless tastes like from our
tableware and aluminum has a different distinctive taste/feel. Of
course you don't want to eat it, I don't remember but I think
there's some connection to Alzheimer's disease (With apologies to
anyone who has been touched by Alzheimer's...)

FWIW, I'm betting you have stainless, our Elite (583, mixed into the
Rebel S/N list) definitely has a stainless firewall.

Cheers

Dave
elite583.cjb.net



schaumr@dcsol.com wrote:

Hang on.....an earlier message states that this type of stainless might be non-
magnetic.

I admit the color is slightly different from the surrounding aluminum, and I
would love to believe this is stainless. Maybe it wasn't that easy to file after
all? How the heck do I tell?

Rob

Now I'm not so sure On 8/4/2010 4:28 AM,

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[andrew Byers]

At work we use copper sulphate to test weather a material is ferrous or not, we normally use it on steel but this should work on stainless as well. I had a second look at kit 779's firewall which is still in the original wrapping under my bench, and there is no doubt that it is stainless. Copper sulphate will turn iron a copper colour when applied, we generally put some on a rag and brush it on, it doesn't take much.

Date: Wed, 4 Aug 2010 12:07:58 -0300
From: daricker@ns.sympatico.ca
To: rebel-builders@dcsol.com
Subject: Re: [rebel-builders] Non-magnetic stainless firewall?

Hi Rob

Here's a couple of thoughts:

1. You might find something on the web, like how aluminum & steel
react to certain chemicals. Eg. aluminum is treated with
sulphuric acid (and electrical current) to anodize it. Also
aluminum will take a gold colour when it is treated with
Alodine/Irridite chromic conversion coating (availible at your
local NAPA as a Dupont product. Look up the P/N first thought the
parts counter person may not know it by Alodine/Irridite)
2. You could drill a hole in the firewall (where you were going to
put something anyway....) and make sure you get a nice long spiral
drill chip from it. Do this also with a piece each of known
aluminum and stainless. Take the 3 samples and heat with a
propane torch and see how they react. The aluminum will melt
before the steel and the steel should take a nice cherry red then
yellow/white before melting. I believe the aluminum will just
melt with little colour change. I don't typically use the cutting
torch on aluminum!
3. Taste it! We all know what stainless tastes like from our
tableware and aluminum has a different distinctive taste/feel. Of
course you don't want to eat it, I don't remember but I think
there's some connection to Alzheimer's disease (With apologies to
anyone who has been touched by Alzheimer's...)

FWIW, I'm betting you have stainless, our Elite (583, mixed into the
Rebel S/N list) definitely has a stainless firewall.

Cheers

Dave
elite583.cjb.net



schaumr@dcsol.com wrote:

Hang on.....an earlier message states that this type of stainless might be non-
magnetic.

I admit the color is slightly different from the surrounding aluminum, and I
would love to believe this is stainless. Maybe it wasn't that easy to file after
all? How the heck do I tell?

Rob

Now I'm not so sure On 8/4/2010 4:28 AM,

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