Protecting Ali Moulds

[ant...]

My aluminum moulds take ages to make, turning on the lathe, sanding & polishing, but if they dont get used for a few days they start to tarnish.

The release agent i use cannot be mixed with any other substance, the surface must be clean of wax, silicone, grease etc, yet this release agent itself doesnt act as a protective coating.  (Morbocote 220)

Can anyone suggest a protective coating which wont interfere with the release agent?

[Jasonb]

Could you get them annodized?

[Majorstrain]

Maybe vacuum bagging, like you use for food.
It's a bit left of field but it's an idea.

Good luck, let us know what you come up with.
Cheers,
Phil

[ant...]

Annodizing sounds ideal, but id like to know what the proper method is before I go ahead. 

Alloy moulds are very common in industry for casting, injection moulding etc, the ones ive seen have a very dark surface. But ive only come accross one site which offers a ceramic process similar to annodizing, they say their process is better because its less likely to crack and is more non-stick. This process will be way out of my price range though, so if i can find a local annodizing company, that seems the way to go.


Majorstrain: Im composites we use vacuum bagging to consolidate the material, but its amazing you should mention vacuum food bagging because i bought a system last month because my small moulds fit in food bags and they work out much cheaper.  But vacuum bagging my moulds after every use would be too expensive.  Thanks anyway

[Bernd]

Ant,

Here's a link to all you'd ever want to know on how anodize. http://www.focuser.com/atm/anodize/anodize.html

Bernd

[ant...]

Ah yes thats a brilliant link, thanks.

Ive found a kit on ebay for £55 too, but id rather find a local anodizing service, just because my garage is filled with lathe stuff, heat cupboard, vacuum systems, compressor, spray painting, tools, etc, etc, etc.  If im gonna add another service to my cluttered garage then it must be something i will use often 

[75Plus]

Check your industrial gases dealer about the availability of nitrogen. If you store the molds in an airtight container then purge the oxygen with nitrogen there will be no oxidation.  Nitrogen is inert and safe to have around the shop.

Joe

[ant...]

If you store the molds in an airtight container then purge the oxygen with nitrogen there will be no oxidation. 

Wow mate, thats definately a solution, if not a bit extreme 

What i was really looking for was to find what is officially used by most industrial manufacturers.

After doing some searching ive found a company offering ceramic coatings http://www.keronite.com/tooling_moulding.asp Probably too expensive though.

[ken572]

Ant,

If you have a good chrome plating shop close to your shop, they can put
a good smooth shiny hard chrome finish on aluminum for you.

Ken.

[rowbare]

Perhaps a Ziploc freezer bag with a couple of oxygen absorbers/hand warmers tossed in might do the trick. A heat-sealed mylar bag would certainly be better but if you use the moulds fairly often, the Ziplocs might work.

bob

[foozer]

Would Powder Coating be an option?

Robert