Help with CFS Super Platter restoration project

[Chris Wehrman]

Hello everyone,

I've inherited the 5 deck CFS Supper Platter, that was used in the theater where I grew up, to use in my home screening room. I've learned the trade on this platter system and have maintained it till the end. Now I know there are far better platter systems out there that I could get, but this platter has sentimental value to it so I want to continue to use it. I've stripped it down completely. I'm replacing all the bearings in all the decks and rollers, replacing all the wiring and connectors. Replacing all the motors using the "strong motor rebuild instructions" in the tips section. The control plates have already been retro fitted with the AP3 control plates with the spindles bored out to accept the socket. I'll replace all the micro switches in them as well. The tree, arms and legs and any steel mounting parts will be sent off for sand blasting and power coating. It should look and operate like a brand new platter system when it's all done.

My question is, what to do with the decks. They are stainless steel with loads of stains, scratches and gouges in them. I've never worked with stainless steel so I attempted to search the forum archives about it but can't find anything that talks about what i'm trying to accomplish. I've read the Christie tips page about sanding platters but those are for aluminium platter decks so I don't think I would want to use sand paper on stainless steel, or should I? I've cleaned them with simple green, but I was thinking of sending them off to a shop to be buffed. Would this be a good idea? Wound this make them too slick? Should I just leave them alone? I want to get them in the best working state they can be.

Any Thoughts or suggestions would be greatly appreciated.

Thanks!

(Glad to see the Film Handlers Forum is still on line!)

Chris

[Sam Chavez]

Chris,

Seems to me you know what you are doing although spending serious money on this platter takes a lot of sentiment. I one restored Brenkert Enarcs complete with a new black cracke paint job and was never quite sure why I was doing it. Steel taper pins holding it all togther. So stainless steel decks that are badly stained? Not trying to be a smart ass, but are you sure on the metal? Also, may have a couple of new platter motors in my storage. You can have them if they are of use. Welcome to Film-Tech.

[Randy Stankey]

In the plating shop, we used to clean steels with hydrochloric acid. ( 5 molar - 20 Bé muriactic acid that you buy at Home Depot is approximately 10 molar so a 50/50 dilution with water should yield a 5M solution.)
The problem with that is that HCl cleans steel right down to the bare metal so it will rust/oxidize soon after. In the plating shop, cleaning down to the bare metal is a good thing to do before electroplating. In regular use, that's not a good thing to do unless you mean to do it. Also, acid will etch steel. Again, in plating, that's desirable to give the plated metal something to grab onto. In real life, you'll want to watch out. You should only keep the your parts in contact with the acid solution only for a minute or so.

You could also use sodium hydroxide. (8 to 10 oz. dry weight per gallon of water.) This will remove all organics and oils but not remove much oxidization.
Dip in the solution for a minute or two then rinse well with water before applying acid solution.

I'm just engaging in some geekery, here. Use your judgement before trying any of this.

Another thing you could try is "Barkeeper's Friend" brand scouring powder. The active ingredient in Barkeeper's Friend is oxcalic acid. It is great for removing dirt and baked on food from pots and pans. It makes stainless steel pots and pans look nice and shiny. I've used it for years and have never had a problem. It works well for copper and aluminum, too.

Also... No matter what you try, be sure to wear protective gear!
Apron, gloves, goggles and face mask.
Be sure to have a good supply of running water nearby in case of accidents. I've got permanent scars from messing with acid.
Hydrochloric acid also give off some nasty fumes. Be sure to work in a place with good cross ventilation. HCl gives off fumes simply from contact with air. The more humid, the worse the fumes. If those fumes come into contact with other substances, it could produce toxic gasses or vapors.
Better yet, do it outdoors if you do it at all.

If it was me, I'd try the Barkeeper's Friend first. If you elect to try the industrial methods, try them on an inconspicuous part that won't risk major damage before going ahead.

[Dave Macaulay]

I think a polished surface is undesirable. A surface with more friction will hold a film roll in place better... many here have had to deal with a thrown print and I assure you it isn't fun.
Sanding will ruin the platter finish though. Maybe 0000 steel wool? I would try a kitchen stainless steel cleaner and GumOut before using anything abrasive. They should remove stains at least.
You won't get scratched, dinged, bent platters back to factory fresh but they can look pretty good.
Stainless was and is expensive compared to aluminum or painted steel, confirm the metal used before taking drastic steps. I have worked with a CFS platter but don't remember much about it.

[Gordon McLeod]

Are you sure it is stainless steel if memory serves they were Dural a aircraft hardend aluminum The smooth ness of the decks was a issue with their bad habit of wrapping prints

[Randy Stankey]

If your platters are made of aluminum DO NOT use acid or lye in attempt to clean them!

HCl and NaOH will destroy anything made of aluminum on short order. At the concentrations I detailed above the damage might occur in less than a minute.

In this case, stick with kitchen cleansers like Barkeeper’s Friend.

No matter what method you try, I still recommend testing on an inconspicuous place where any potential damage won’t be noticed.

[Chris Wehrman]

Thanks Guys. I've double checked the metal and Gordon, you are correct, they are aluminium. These platter decks really aren't that bad I guess. They aren't bent or warped, just scratched and discolored in spots. Dave, I too am concerned about making the decks too slick, they are slick enough as they are right now. However, in over 10 years I have worked with this particular platter, it has never thrown a print. Other than vibration issues, they have served us well and very reliably over the years.

Now that I've confirmed they are aluminium, is there anything i can do to improve them other than cleaning? Randy, i'll try the Barkeepers Friend for the discoloration.

Thanks,
Chris

Here are some pictures of the platter decks...

[Randy Stankey]

Remember that BKF has an abrasive in it. Don't use a scouring pad until you have tested it, first. You don't want to scuff or scratch the surface any more than needed.
I have always used the traditional scouring powder but I also know that the company also makes different "soft" versions of the same product.
Just use a regular cloth like a dishcloth. If you need to get off difficult dirt or staining, I don't think you'll need anything more aggressive than a green ScotchBrite scouring pad.

It also depends on how you want the metal to look. Do you want that shiny, aircraft look or do you prefer a slightly dull, matte surface?
Personally, I'm okay with a matte surface but, if you want these to be showpieces, shiny might be better. Your choice.

When you clean aluminum, it will remove the surface oxidation on the metal. Aluminum is a self-passivizing metal. It builds up a layer of oxide on the surface that protects the metal, underneath, from further atmospheric corrosion. (Similar to the way copper turns green.) When you clean aluminum, you're taking that surface layer away. There won't be anything to protect the metal from staining or spotting until that passivation layer reforms.

I would clean the metal by whatever process you decide upon, rinse with clear water then dry really well. After that, I would put the platters in a clean, dry, moderately warm place and leave them alone for a few days, more or less. You'll want to keep them in a place where dirt or moisture won't get to them and potentially cause spotting or staining before the metal re-passivates.

[Gordon McLeod]

I would get some tape that has a gritty surface and run angled strips on the techs towards the centre as that stops some of the wrapping and throwing of prints that they were famous for doing. There use to be a thin masonite disk that was set on the decks with aneoba shaped ruff patchs on it to do the same thing back in the day