How to polish cox engine parts

Tumble or vibratory polishing would work. Check Rio Grand jewelry suppliers for equipment and media.

Tumbling is very touchy... too long and your back to square one. Tried it on some babe bee tanks.

Bernie,

If the problem was unpolished parts then all the colors you mentioned would be affected. I can see nothing special with green dye.

Seems to me that the lighter colors such as yellow (gold) would be more succeptible. I would get a second opinion.

Sounds more like a batch of green dye was poor.

Ron

Hi Bernie,

If they were the cast version, then yes they are very hard to anodize, but can be done with correct chemical. If it was the extruded cases and machined tanks, then yes tumble polish is the way to go.
You could try a lye bath and remove color, tumble and re-anodize, but it's iffy and time consuming...or do what Disc Golf manufactures do when Plastic discs golf discs get stamped wrong or have slight blemishes, sell them off as factory seconds, collectors items, etc., or maybe add some yellow parts and sell 'em as green and yellow Bees!

Mark ; I knew there was someone on here that was doing there on anodizing and had been brought up before // is there a place to get you started that don't cost a arm and a leg ? I have been wanting to try a hand at this but all I see is $$$$ Not cost effective ..... I agree with Ron that before I went to a lot of costly cleaning I would ck with the die manufactory / or maybe another shade of die for green . Getback

WingingIt74 wrote:Tumbling is very touchy... too long and your back to square one. Tried it on some babe bee tanks.

There are lots of variables. You cannot run aluminum and brass together. Media and solutions need chosen based on the material being polished. And all aluminum is not the same as Roger Schroeder found in his article in ECJ #175. But there are experts who sell supplies for a living such as Rio Grande and Kramer.
You are doing a large enough lot it would probably pay for you to some of them.

http://www.riogrande.com/
http://www.kramerindustriesonline.com/catalog.htm

The Anderson engines, Cub 049X and Firebaby firewall were all tumbled.

I am set up with good bench buffers ( 4", 6", and 10" buffs) and several Dremel versions. Tiny cox part take too long with Dremel method and just fly across the room on the bench machines. I now polish with walnut or corn cob and rouge additive in my Hornady Case Tumbler.

Not set up to anodize (YET) but the process looks simple and inexpensive for the small items I wish to do in the future. Based on my research I suspect a defective Dye and or contaminated parts. Polished parts should only effect the final finish. But if the polished parts are contaminated with finger oils, cigarette smoke, or other things like the fine mist off the plating tanks then blotchy finish is going to happen.

Nothing in my extensive reading on the subject suggests that Green is any different than any other color

Google is your friend, there are many sites aimed at the hobbyist for plating and anodizing including several that sell turn key starter setups for not too much $$$

Thanks for all the input gents.

We are trying to anodize extruded and machined alu parts. We only did 2 each in green and, at the same time, had sent down parts to be anodized in other colours; which turned out fine.

According to our anodizer, green does not "take" as well if the parts are not "perfect".

Having done more research, we will be sourcing a semi-local outfit that can tumble the parts.

Green and blotchy? Sounds like the Cox Green Frog high performance engine might sell. :-)

Have you tried electro polish before anodize? Your guy should be able to help with that.

We farm out the anodizing to a large commercial outfit and they don't polish, etc.

Electro polish is a plate process. Ask your plate guy. It is a common process used on aluminum and stainless.

No idea lol. However, they can't do any better unless we have them prepped by an outside source.

Well maybe they tried already. You could send them to Embee plating in Santa Ana Calif. They do beautiful work.

Our anodizer does great work as well but, when we send them parts with tool chipping, there is not much they can do.

schiada96 wrote:Well maybe they tried already. You could send them to Embee plating in Santa Ana Calif. They do beautiful work.

lol, i wonder if these people did the anodizing back-in-the-day?

I the trouble is the engine on page 7 of the tach race. I would bet that electo polish would fix the white spots on the crank case and the "hard" spots on the tank.

Does anyone here do their own abrasive blasting?  I'm thinking of procuring a small bench-top blasting cabinet and was wondering if any of youse out there have experience in doing this to Cox and other small engines.  Specifically I'm looking for a compare/contrast between glass bead and soda blasting.

Anyone ...?

Soda is safe, but it only removes paint and dirt, not much else. Motorcycle carburetors (cast light alloy) look like new after soda blasting.

With glass beads results vary depending on the pressure and bead quality, I have not done it myself but I have seen parts right after bead blasting. It does change the surface texture of aluminum a little, the surface looked rougher than what it was before. Might be a good preparation for paint.

I have sand-blasted some motorcycle cast aluminum parts, the surface became rough which was OK because I was going to paint them anyway. The paint stuck to the rough surface better than to the smooth original cast surface.

So, for what it's worth, I would start with soda, the rest depends on what kind of surface you are looking for.

For me COX parts are small enough to polish with a Dremel and paste

dinsdale , I have used bead blasting at were I work for several years and it is great stuff on larger parts / quick to strip . This was a contained unit . By larger I mean than Cox engines // If you were to use this you will want to flush with HOT water really good and blow out good to get the beads out of the engine . This stuff can ruin an engine in a matter of seconds if drawn into the combustion chamber while running . On the other hand I haven't heard of soda blasting ,so I looked up , here a guy made his own rig for cheap that is interesting http://www.garagenight.tv/diy-soda-blasting-build-your-own-rig-cheap/ And works quite well also no risk of destroying an engine . Eric

I forgot to mention earlier that water dissolves soda, so clean-up of the parts after blasting is easy, just rinse with some hot water. Hot water makes the parts hot, which in turn makes them dry faster. I like to dip or wipe aluminum parts with alcohol after cleaning, it'll take off all the water and possible grease residues. That way the natural oxidization of aluminum surface (which starts in minutes after pure ally is exposed to air) happens evenly and it seems that parts stay clean and shiny longer.