old chrome frame

[Rocket Racer]

I have the bones of a '55 A10 in the barn, but having had some repairs done to the frame it has become apparent that under all the crappy paint that peels off readily and the gunk and rust, the frame has at some point been chromed.

I was thinking of building a bike round this frame as I have 3 sets of '55 cases (although the road rocket ones are in my sidecar), but am interested in the simplest way of dealing with the old chrome. I'm wondering whether just a sand blast and an etch prime will do the job or if I need to get it dechromed.

The chrome is far from bright.
It still needs a tank steady fitting as well as the seat front bracket, so a bit of welding to be done too.

Any thoughts from the forum of dealing with old chrome on a frame and swing arm

 

[Goldy]

I would think that there are three options
1. Buy loads of emery cloth of different grades, get lots of patience and slowly emery cloth it all off.
2. Take it to a chrome plater or metal finisher and get them to dip it in the acid to strip it all off.
3. Talk to a shot or sand blaster to see if that process would remove it.
All the best with it.

[BSA_54A10]

Are you sure that is not nickel or zinc ?

A drop of hydrochloric acid will react quite strongly with zinc as will a strong caustic solution.
Neither of them will have much effect on the other two.

Look up commercial paint removers.
Most of them use a caustic dip to remove the old paint from timber and it will do the same your frame.

[Rocket Racer]

You raise a good point, one that had passed my mind as the finish is 1. not bright like chrome usually is & 2. hasnt shown signs of peeling or flaking anywhere.

I put some hydrochloric on it without any immediate response so doesnt appear to be zinc. Perhaps it is nickel?

I'll clean off the paint which shouldn't be too difficult, try and source a tank steady bracket, get the welding done then reconsider how carried away I'll get. Was hoping to not disturb the swing arm rubber bushings, but cant imagine them liking an acid bath.

Before noticing the plating, I had been thinking of initially building the rolling chassis with simply a primer coat... while I collect the various parts and mock assemble, so if the plating still has some integrity may even leave it while it takes shape. 

Are you sure that is not nickel or zinc ?

A drop of hydrochloric acid will react quite strongly with zinc as will a strong caustic solution.
Neither of them will have much effect on the other two.

Look up commercial paint removers.
Most of them use a caustic dip to remove the old paint from timber and it will do the same your frame.

[RichardL]

I like to use names when I can, and I found yours on an earlier post so...

Tim,

At first I thought the acid would likely have little or no affect on the silentbloc bushings. I believe the rubber in the bushes is probabaly butyl rubber and I found the following link that describes chemical resistance:  http://www.junta-polymers.com/JuntaPolymers-productdetail.cfm?c=BUTYL+RUBBER+SHEET+Elastomer+Sheeting&i=9&id=5 

It appears that if the acid is hot it can be a problem and if it is cold, probably not. You might be able to protect the rubbber with grease or wax, but there are better chemists here than I who can tell you if that is a good idea.

What I think is definitely not a good idea is to bake the swingarm in a powder coating oven. Tick tock, tick tock...standing by to be slapped if I am wrong.

Richard L.

[trevinoz]

Blasting should do the job, once the nickel starts to lift it may get under it remove it.
Probably a long and tedious job.
I have found that rust gets under nickel and it lifts fairly easily in these places but then you have to keep going to get it off the unrusted bits, if you don't then you have to do a lot of filling.
Looks like you will have to fabricate a new anti-roll rubber mount.
Trev.

[Rocket Racer]

All feedback appreciated gents!
I'm sure I've seen the frame brackets on flea bay in the past, but can't see any there at the moment.
Once I've got that and a front seat bracket welded on I suspect it may get a blasting or an emery cloth work over as a starting point.

cheers
Tim

Looks like you will have to fabricate a new anti-roll rubber mount.
Trev.

[BSA_54A10]

Acid baths are not a good idea as it will get past the silent blocks and sit in the swing arm slowly doing what water dose only more so.
I think you can guess the eventual result.
Caustic will kill the rubber
OTOH the silent blocks are 60 years old and they only had a 10 year service life from new.
If you can take the shocks off and the frame dose not istantly drop then they are past their use by date.

[spyke]

Can the platers not ' unplate it' , ie.reverse the electrical process and dump all your chrome/nickel onto some lump of metal in their tank?

[Rocket Racer]

Can the platers not ' unplate it' , ie.reverse the electrical process and dump all your chrome/nickel onto some lump of metal in their tank?

yes, that is the dechrome option I alluded to. I do wonder if its nickel as has been suggested, it seems to clean up fairly well with wet and dry, whereas chrome doesnt tend to.

A plater is not going to want to put a crappy dirty old frame in their baths, so it'll still need a thorough clean first to make it acceptable.

I'll quietly clean it up while I follow up redoing a tank anti sway bracket, then reconsider the dechrome.

[steve c]

as explained to me chrome is only a flash over nickel plate anyway, go to a chrome restoration specialist
I use ACF Howell in walsall ( ask for Graham) they will strip it, my experience of blasting chrome plate is it just ends up duller rather than removed ,
for triple plating surface is polished  then  copper plated  (if surface is pitted ) , then nickel plated then flash chromed and polished in some cases.
Most stuff remade is just flash nickel followed by flash chrome.( flash as in a thin coating)

regards

Steve

[Rocket Racer]

Steve, walsall's quite a trip for me, but thanks for the tip.
I do wonder if my frame may have been blasted already at some point as the plating under the paint is dull.
I've removed all the paint and while no show pony, is quite adequate for me to build a bike round and have some fun with .
Rummaging through the parts I've got, I can see someone loved chrome; chrome tool box/oil tank, primary chain case cover, timing cover, gearbox cover etc. All now peeling and looking like crap (apart from the oil tank).
Unlike most of the ancillaries though the frame plating is still remarkably sound and hardy - doesn't peel off.
I'm moving my attention to the front end, to get a workable rolling chassis together. All still just in mock up currently.
Thanks all
Tim