Cleaning carbon off of aluminum?

I have a couple of pizza shops (Way OT!) but metalworking DOES come into play!

We use aluminum pans for baking the pizzas in the oven and since we use butter on the edges of the pan-pizza pans they start accumulating carbon buildup after a year or so of use. Is there a way for my to remove this carbon short of sandblasting? It must be a food safe and leave the pans structurally intact, figure about 125-150 pans overall that I need to clean, then re-season.

Any ideas? Anyone in the Kirkland or Kent WA area with a sandblaster that wants to trade sandblasting time for pizzas? :)

-Dan

Reply to
Dan
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Normal sandblasting will leave a messed up aluminium surface full of tiny dents that will catch food the next time they are used. I know from years ago in the army when we cleaned a bunch of hotplates with the workshop sandblaster. They went back looking clean, but I pitty the next poor buggers that had to clean them.

They use crushed walnut shell blasting or similar for cleaning inside some aircraft engines, these would run just as happily through a normal $20 air sander and be easy to do at home if you wished.

Top of the range is using dry ice as the grit for blasting out ovens and cookwear on site and there is no residue other than the old carbon that has already been blown away. Totally food safe, and all you need is a compressor, a sandblaster attachment and a container of dry ice crystals.

Hope this helps, Peter

Reply to
Bushy Pete

"Bushy Pete" skrev i en meddelelse news:d23chh$299u$ snipped-for-privacy@bunyip2.cc.uq.edu.au...

I have tried this on some old packaging machines for food products.... This kicked some serious *ss and wasnt nearly as messy as sandblasting would have been.. The dry ice blasting didnt leave a scratch on the stainless steel surfaces, but it might damage the aluminum pans...

Normally I'd suggest ammonia or sodium hydroxide for this type of cleaning, but that would work too well on aluminum ( sodium hydroxide can corrode aluminum )

Another trick that might be worth looking into is liquid nitrogen... I have seen it used on food processing equipment.. Freeze the object to be cleaned and brush off the dirt...

Otoh.. I might be more cost effective just replacing the pans..

/peter

Reply to
Q

Bush Pete

How do you get the dry ice to size for blasting? I really like the concept, but dont visualize how the process works.

Jerry

Reply to
Jerry Martes

You either buy it that way, or buy specialized equipment that shaves blocks. It's an expensive process and it requires special tools to do it on a practical basis. I had a good application for it but soon decide that the media cost, etc. would eat us alive.

Reply to
ATP*

We use dry ice pellets for cleaning High Voltage ( 500KV) insulators and switch gear as well as generator windings. Talk to Seattle City Light they use the same process for their distribution equipment cleaning and they have a Co2 pelletizer. Co2 shavings do not work any where as well as the pellets.The nice thing about the pellets is it strikes with enough mass and mechanically dislodges the particulate and the vaporizes into a gas lifting the contaminate away from the surface.

Pete

Reply to
Pete

Any idea how much it costs for the pellets and how long you can blast? It looks like an ideal process, with the exception of the cost, which seems to limit its application. From time to time there is dry ice blasting equipment on ebay.

Reply to
ATP*

Contact a commercial blasting shop. Most will have some pretty fine media for powder coat work. I have seen the demonstration that uses baking soda to strip electric motors while they are running. Here is a site that talks about it.

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(top posted for your convenience) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Keep the whole world singing . . . . DanG (remove the sevens) snipped-for-privacy@7cox.net

Reply to
DanG

You buy the pellets by the pound . As for shelf life they deteriorate quickly . Your storage is critical.Don't plan to keep them for more than eight hours . It is very dependant on storage and humidity. Once they start clumping you are fighting a losing battle.

Pete

Reply to
Pete

If you have a good fire source and don't mind them being soft afterwards, you can anneal to 1000°F or so. Carbon burns right off. Don't overheat or it'll melt.

Tim

Reply to
Tim Williams

A Scotch Brite Abrasive wheel on a drill motor. I 'd suggest a corded 1/2" angle drill motor, over a cordless. Unfortunately a Makita DA4031 is coslty, but a fine tool. You will need to secure the pans with clamps, so they don't go airborne. Makita DA4031 1/2" Right Angle Drill Kit - $250.00 - Coastal Tool Makita, DA4031, 1/2" Angle Drill, 2-Sp, Rev, 10.0 amps - $324.00 - Rhinotoolshop Makita DA4031 1/2" Sidewinder Angle Drill - $329.95 - Tyler Tool Co.

You could try a propane torch and a 2 inch putty knife.

MAke a paste from cream of tartar and apply to the carbon, let set for

30 minutes, then soak the pans for 1 hour in HOT water, Repeat as needed.

Buy more pans and wash your pans daily.

The dry ice approach, might work if you place the dry ice in the pans and let them get cold, so the aluminum shrinks a few microns, and the carbon would lose grip, and flake off. Perhaps a pot of hot water after the pans have chilled for 10 minutes. There might be a way to dip the pans into liquid nitrogen, then into hot water, but I fear that may crack the pans. Of course you would have to send the pans out for that.

Lastly, I would try liquid oxygen, but that would cause the carbon to explode,a nd the aluminum to burn. Besides, you need some training before you handle the stuff. Also, if you get LOX on your skin, you burn like a newspaper.

BTW - When I was in the Navy, I spent 3-months in the chow hall, part of which I spent in the pot and pan scullery. On my second day, I threw a few pans out into the kitchen, and yelled at the FKCUing cooks to clean these G'damn pans, since they're the ones who baked this shit on there! It didn't work, I was back in the scullery scrubbing pots and pans.

:/

Reply to
Halcitron

An old trick for estimating the yield temperature of AL castings for welding is to turn up the acetylene on an oxy torch and smoke up the work piece.. Then preheat it with a cherryblossom until the carbon evaporates. The piece is ready to weld. After welding, keep the heat on the joint and slowly let it cool down. Burning off the carbon is a good option, if as the man said, you don't mind annealed pans. Bugs

Reply to
Bugs

I had a BOC Gases prototype CO2 snow blaster that I sold on Ebay a couple of years ago. It was a high purity stainless steel gun with a special hose that hooked directly to a special high purity CO2 cylinder with a dip tube. The liquid CO2 turned into snow as it left the nozzle at high velocity. It was designed for cleaning silicon wafers during chip fab. If you weren't interested in the high purity, you could do pretty much the same with an air blow gun and a high pressure hose to hook it to a CO2 cylinder. If you turned the cylinder upside down you wouldn't need one with a dip tube. Obviously the hose would need to be able to stand the full cylinder pressure, even very cold, but it might be an interesting experiment. Wear gloves and protect your eyes, particularly if the hose bursts!

-- Bob (Chief Pilot, White Knuckle Airways)

Reply to
Bob Chilcoat

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