Should I oil the firewall if I don't prime it?

This has surely been asked before, but I'm not finding it.

I'm building an RV-7A and have the firewall all final drilled and deburred, and the stiffeners, etc. primed/painted. The stainless steel firewall itself is neither primed nor painted. However, it was obviously wiped down with oil before I received it from Van's, presumably to help protect it from moisture.

It had collected dust over the years and I've cleaned off the "factory oil." I've decided not to prime the stainless steel firewall parts and that seems to be the consensus with most other builders too.

My question is: should I wipe it down with oil (or something oil-like) again? And if so, is there a recommended type? Should I apply it before riveting the stiffeners? (That would put oil against primer, so I'm not sure about that.)

Thanks in advance.

Nothing

It is stainless steel, and therefore will not corrode. If you oil it, the firewall will just collect more dust. I put a thin layer of insulation on engine side to help keep cockpit cooler in the summer.

Firewall will not corrode, leave it as is and it will be fine .

Any idea why the factory oils it?

smiller said:

Any idea why the factory oils it?

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Probably a by-product of when the big machines stamp them out of flat S/S sheet.

Oil is lubrication for punch press

Steel sheet and especially stainless steel are typically lubricated to minimize wear on the punch press tooling during manufacture. I don't know how this part is formed, but the lube could also be useful if a "'wiping" style forming die is used to form the flanges. Count wiping the oil off as part of your 50 % build quotient.

Kerry