Mini Magazine – September 2019

Tech

MINI

WORKSHOP

5

1 2 3

6

4

The stripping process not only removes the

old plating, it also removes surface

corrosion. The undersides of bumpers will

not be polished, but need to be clean to

accept plate.

This overrider is now cleaned back to bare

steel and ready to move onto the next stage.

As Doug points out, left for long enough, the

stripping fluid would actually dissolve the

base metal, so timing is key.

The first tank contains sulphuric acid based

solution which strips the old plating. The

parts are submersed to ensure even removal

and the process is carefully monitored.

Almost there - the chrome has started to

dissolve showing the nickel underneath.

Doug checks the parts in the tank regularly

and they only stay in just long enough.

Most of the items coming through are large

and awkward so the tanks are built to

accommodate them. Here the bumpers are

lowered into stripping solution.

Doug discovers a small hole in the overrider. This will need to be sandblasted, welded and

ground back to a very high standard before it’s passed through to the polishers.

passed through to the polishing shop.

This is a lengthy process which starts

with coarse 80 grit bands to remove

pitting and imperfections, through 180,

240, and 320 grits and ends with the

metal polished to a high shine with a

sateen wheel and finally a brush, using

progressively finer compounds. Only

when the team are completely happy

with the results does the part go through

to be electro plated.

“It’s the nickel that’s the absolute key,”

explains Nick. “That’s what gives the

finish, and it’s that which shines through

the chrome. It spends an hour or so in

Lorraine, “but other than that,

everything is treated the same.”

The company is happy to sandblast

and repair steel components at the

customer’s request, and they’d much

prefer to handle this part of the job. “We

don’t like dealing with other people’s

repairs. The finish has to be f lawless or it

will show in the finished job. Silver

solder falls out in the stripping tank

anyway,” says Lorraine.

Each component follows the same

path through the workshop - old plating

is chemically stripped, parts are checked

and repaired as necessary, then they’re

the copper, then an hour in the nickel.

At every stage, the piece is checked, and

small imperfections can be improved or

removed by polishing.”

Perhaps the most surprising fact is

how little time the actual chroming

process takes. “Chrome builds at one

thou every 25 minutes,” Nick says.

Most parts will stay submerged in the

chromium bath for just over half an

hour, with progress closely monitored.

When they emerge, they’re covered in a

sulphurous yellow film. But after a quick

wash down, that incredible finish just

bounces through.

Tech

MINI

WORKSHOP

5

1 2 3

6

4

The stripping process not only removes the
old plating, it also removes surface
corrosion. The undersides of bumpers will
not be polished, but need to be clean to
accept plate.

This overrider is now cleaned back to bare
steel and ready to move onto the next stage.
As Doug points out, left for long enough, the
stripping fluid would actually dissolve the
base metal, so timing is key.

The first tank contains sulphuric acid based
solution which strips the old plating. The
parts are submersed to ensure even removal
and the process is carefully monitored.

Almost there - the chrome has started to

dissolve showing the nickel underneath.

Doug checks the parts in the tank regularly

and they only stay in just long enough.

Most of the items coming through are large

and awkward so the tanks are built to

accommodate them. Here the bumpers are

lowered into stripping solution.

Doug discovers a small hole in the overrider. This will need to be sandblasted, welded and

ground back to a very high standard before it’s passed through to the polishers.

passed through to the polishing shop.

This is a lengthy process which starts

with coarse 80 grit bands to remove

pitting and imperfections, through 180,

240, and 320 grits and ends with the

metal polished to a high shine with a

sateen wheel and finally a brush, using

progressively finer compounds. Only

when the team are completely happy

with the results does the part go through

to be electro plated.

“It’s the nickel that’s the absolute key,”

explains Nick. “That’s what gives the

finish, and it’s that which shines through

the chrome. It spends an hour or so in

Lorraine, “but other than that,
everything is treated the same.”
The company is happy to sandblast
and repair steel components at the
customer’s request, and they’d much
prefer to handle this part of the job. “We
don’t like dealing with other people’s
repairs. The finish has to be f lawless or it
will show in the finished job. Silver
solder falls out in the stripping tank
anyway,” says Lorraine.
Each component follows the same
path through the workshop - old plating
is chemically stripped, parts are checked
and repaired as necessary, then they’re

the copper, then an hour in the nickel.

At every stage, the piece is checked, and

small imperfections can be improved or

removed by polishing.”

Perhaps the most surprising fact is

how little time the actual chroming

process takes. “Chrome builds at one

thou every 25 minutes,” Nick says.

Most parts will stay submerged in the

chromium bath for just over half an

hour, with progress closely monitored.

When they emerge, they’re covered in a

sulphurous yellow film. But after a quick

wash down, that incredible finish just

bounces through.