Chrome removal - How?

My 73 750 has extensive chrome flaking on the primary cover, along with the rocker and point cover. First question, is this factory? Second, how can I remove? I don't think I want to re-chrome, just polish. After looking at lots of pics, it seems most just polish the aluminum. Thoughts?
Thanks

I have tried removing chrome from steel and it is not easy. Probably best way for the home workshop is sanding. There are chemicals and electro-chemical ways to do it, but I'm not sure you want to do that in your backyard. I would take it to someone that knows what they are doing, you don't want to ruin the aluminum. I don't think Norton ever chromed any of the aluminum parts.

Dave
69S

Norton never chromed Al parts. Likely have to blast off chrome as any chemical or electrolysis method would dissolve the Al before the Chrome. There is one other possible way that might take off chrome in one step cheap all at once no damage to Al. Cryogenic tempering in standard nitrogen gas -300'F or another gas that gets down to ~ -400' F. The Al may contract so much more than the chrome it just flakes off in one sheet. This is an issue to cryo parts like heads with brass bushes or steel valve seats installed, they just get pinched right out with touching them. Ms Peel got her a new set of valve seats this way : (

Just got off phone to various cryo shops, mine included, none knew it it'd work.
Also chrome plate is so thin its flexible and i've crumpled a front chrome fender but the chrome didn't crack just separated off steel with a crumpled tin foil texture, so suspect abrasive force is only option.

I know Al is not ferric to more fully convert its crystals but I figured with that much thermal compaction it might work harden it a tad denser and stress relieve.

I talked to a guy at my local chrome shop some years back about removing the blistering chrome plate someone had done on a primary case. They said no way. I tried glass bead and wet sandblast [takes off anything] to no avail. Finally gave it a thick coat of powdercoat. Jim

Just went through this on a Triumph I'm working on. I simply bought used, unplated covers and had them polished. Cheaper and easier than getting the chrome stripped by a plater and I then sold the old chromed covers off.

I've heard chemical stripping or elctrolysis can cause pitting of the cast AL.

Thanks for the thoughts. Glad to hear the chrome is not factory as I'd prefer to keep it original. I did read/google a number of posts, not here, about removing chrome via various acid/water mixtures. I can confirm no success in experimenting with muriatic acid and water. I think the idea of looking for good used versus trying to remove the chrome may be the way to go -anyone here have extra's? I'll keep an eye on ebay.
Thanks

I've tried the muratic acid and other reverse electro plating and never had any luck with it. You may do best with new items. Caswell (which I tried to no avail, 1 part lye to 9 parts water, + side to de-plate item, - side to ss cathode, all the current it will take) has a method with lye (sodium hydroxide) and electricity, and then you have a bucket of solution with all kinds of heavy metals in it plus the lye will eat up the aluminum and with the electricity probably even faster.

Dave
69S

From my young years, we would put lye and water in a coke bottle, drop in pieces of aluminum foil then put a balloon over the bottle neck. The lye reacts with Al releasing hydrogen that fills the balloon. Cheap way to get balloons that float in air. Not a nice way to treat your good Al parts.

The usual way to remove old chromium plate is with sulphuric acid - battery acid.
As many wull have seen, any spilt from a bettery onto the exhaust system will remove it, almost instantly.

If the aluminium alloy is very reactive, it may dissolve before the chrome though.
As always, NEVER leave aluminium in acid or caustic unattended.

And remember that battery acid will eat clothes and flesh, so take care.
It also has the charming habit of getting stronger if left lying around, through evaporation, so cleanup or wash thoroughly any spills. And rinse off thoroughly anything in contact with acid.

Tipping the chrome residue down the drain is also a big no-no, find your nearest toxic waste depot and collection points.

Opethiselps.

I removed a crappy chrome job on a Pre-unit Triumph timing cover with a single edged razor blade and lots of elbow grease. Once I got a patch loose, the rest kind of just scraped off. I think that had lots of the really small bubbles in the chrome. It may have been a terrible job, don't know. It polished up quite nicely. It was the tach drive version of the timing cover, so I really wanted to save it.

I used the razor blade trick, along with a bunch of roloc discs and a 90 die grinder. Was work, but turned out good.