Pitted Aluminum on Mirro Pressure Cooker

[rp2813]

I just picked up this vintage Mirro-Matic model 394 4-quart cooker at Salvation Army today for $5 and change.  It's complete and also had an instruction/recipe booklet for a later model.  It tested fine; reached 15# pressure quickly without any leaks.

 

This will replace my appx. 1970 avocado 4-quart model 404 Mirro that I'm afraid has become warped, as a new gasket did not  help with a significant leak near the handle.

 

As you can see from the picture, the lid has pits all over it.  I don't know what would have caused this, but is there any polishing compound that would at least diminish their appearance?

 

 

 

[austinado16]

Cool looking cooker.

Maybe try "Simichrome" metal polish (available at hardware stores) and see if that doesn't give you a nicer finish.[this post was last edited: 1/22/2011-00:23]

 

[maytagbear]

That looks like it has

 

been through a dishwasher, and if so, those spots should buff out  fairly easily.  Dishwasher detergents with chlorine do not get along with aluminum.

 

Simichrome, Wenol, Mother's....all reasonable polish choices, depends on what you can get locally.

 

 

Lawrence/Maytagbear

 

 

 

 

[toploader55]

Hi Ralph

I use Brillo on my Pressure Cookers.

When one was in storage for 20 + years, it was pitted like that. Elbow Grease and Brillo should get the pits off.

 

[austinado16]

I think brillo is going to be too aggressive for that smooth aluminum finish.

 

[rp2813]

Thanks Eddie.

 

The finish has definitely been scrubbed over the years.  It has plenty of swirly scratches from it that don't show up in the photo. 

 

I'll experiment with different polishes and pads to see what provides the best results.  I have Wenol handy so that will be my first attempt.  I'll have to go buy the auto polish and Brillo pads so will do that if necessary.  Maybe Brillo will end up doing the job and then I can follow up with a polish to make it really shine.

 

 

 

[rp2813]

Wenol gave the lid a nice deep shine, but the pitting didn't change.  It goes pretty deep.

 

I bought an identical cooker not long before I found this one, and while the pot seems more used, the lid is in better shape.  It has a chip in the bakelite handle, but I see that the handles are attached to the lid by a single screw.  I'll switch out the handles and the lids rather than pursue what may be an exercise in futility with the pitted one.

 

[iheartmaytag]

Pits

Could be caused by dishwasher, but I am more inclined to believe that they are caused by someone leaving it soaking in a sink for several days. It looks like long term water exposure, these should buff out.

 

[3beltwesty]

conflict that the fissures/pits need massive work; majority

My Aluminum stuff that went under salt water in Katrina has varied pits like your pressure cooker. Even items that were not flooded but on high shelves often got pits due to salt air and just having salt all over the place.

The odd thing is that these pits can be on the surface, or go very deep. ie like the salt sat in one place and burrowed deep.

The real question is how deep is the defect. I had some items that the defect went completely through; thus no amount of magic will remove the defect. This was in cast aluminum items and stuff that went under salt water.

Here I just experiment. If that defect one place is 0.03 deep in one spot; that is a lot of material to remove. If you use a fine compound; one gets a mirror like finish over 99.9 percent; and still has that deep fissure 0.01 to 0.03 deep.

Many folks in Katrina land just chucked their aluminum items, or replaced them and gave them to the thrift stores, salvation army etc.

The few aluminum items I saved look like you item or worse, many I tried scotch bright type pads, brillo pads, fine sand paper, electric erasing machine, elbow grease.

You have the conflict that the fissures/pits need massive work; but the majority needs only fine polishing. With a casting that defect can go to China, through the entire part's thickness.

 

[rp2813]

Yeah, the pits are deep and I'd have to really take down the surface to eliminate them and I think even then they would remain as dark spots that wouldn't take to a polishing.

 

I've opted to use the lid from a more used cooker.  It cleaned up nicely.