I'm new to electroplating and was wondering if anyone could provide
some insight (and save me from reinventing the wheel) in the following
methods of electroplating an aluminium cylinder bore both for
protective reasons and also restoring a worn cylinder bore back to
spec. so don't need oversize pistons. This is for a homemade two-
stroke engine, see http://groups.yahoo.com/group/DIY_2S/ for more
information.

Cylinder Bore Protective Plating:
-Hard Anodizing, high silicon aluminium, easiest
-Electroless Nickel-Phosphorous/NiP: can do it in one step, hardness
close to chrome
-Nickel Cobalt: not sure if can get enough cobalt in nickel to be
useful?
-Nickel/Suspended Particles: trapping hard particles suspended in
solution into nickel plating
-Nitride: similar to how some metal tools are protected, not sure if
possible/practical
-Hard Chrome: tested and proven but an involved process

Plating Cylinder Bore Back to Spec., need thick deposit, these are
some metal I thought would be possible:
-copper
-nickel
-iron
-zinc
-tin: have heard of pistons being plated with tin for less friction

Brock

On Sat, 24 Mar 2012 10:57:03 -0700, durabol wrote:

I'm new to electroplating and was wondering if anyone could provide some
insight (and save me from reinventing the wheel) in the following
methods of electroplating an aluminium cylinder bore both for protective
reasons and also restoring a worn cylinder bore back to spec. so don't
need oversize pistons. This is for a homemade two- stroke engine, see
http://groups.yahoo.com/group/DIY_2S/ for more information.

Cylinder Bore Protective Plating:
-Hard Anodizing, high silicon aluminium, easiest -Electroless
Nickel-Phosphorous/NiP: can do it in one step, hardness close to chrome
-Nickel Cobalt: not sure if can get enough cobalt in nickel to be
useful?
-Nickel/Suspended Particles: trapping hard particles suspended in
solution into nickel plating
-Nitride: similar to how some metal tools are protected, not sure if
possible/practical
-Hard Chrome: tested and proven but an involved process

Plating Cylinder Bore Back to Spec., need thick deposit, these are some
metal I thought would be possible: -copper
-nickel
-iron
-zinc
-tin: have heard of pistons being plated with tin for less friction

How big of an engine? What's it for? Will you find joy when it finishes
first in a 1000 mile race, or when it manages to run once on a test stand?

I wouldn't think too hard about plating up a worn bore to save making
myself a piston, unless perhaps it's a miniature engine with a lapped
piston. You're probably better off making at least one part (cylinder
liner or piston) new and fitting everything up.

Consider that if the cylinder is so badly worn, the piston probably is,
too, which means that at the least you'd have to either plate the piston
up to size, too, or you'd have to turn it undersized which would require
that you plate all the more material onto your bore.

Does anyone still hard anodize cylinder bores? I know there was a brief
rage for it around 2000 or so with model airplane engines, but it seems
that everyone doing it went back to hard chrome or nickel.

Keep in mind that anodizing is not a plating process. The surface does
grow, because given the same amount of aluminum, aluminum oxide is bigger
than just aluminum -- but the anodizing penetrates into the parent
material as much as it grows out of it. The anodizing is way hard (it's
basically sapphire), but if it were such a hot-s**t way of doing it, why
isn't it still done by model airplane engine manufacturers?

Hard chrome is -- hard, and low friction.

Nickel is low friction, but I don't know if nickel-phosphorus is; I'd be
interested in how well it stands up (OS engines uses nickel plate on some
of its engines, but I'm not sure if it's nickel phosphorus, and I'm not
sure if it wears super well).

--
My liberal friends think I'm a conservative kook.
My conservative friends think I'm a liberal kook.
Why am I not happy that they have found common ground?

Tim Wescott, Communications, Control, Circuits & Software
http://www.wescottdesign.com

On 03/24/2012 12:05 PM, Tim Wescott wrote:
On Sat, 24 Mar 2012 10:57:03 -0700, durabol wrote:

I'm new to electroplating and was wondering if anyone could provide some
insight (and save me from reinventing the wheel) in the following
methods of electroplating an aluminium cylinder bore both for protective
reasons and also restoring a worn cylinder bore back to spec. so don't
need oversize pistons. This is for a homemade two- stroke engine, see
http://groups.yahoo.com/group/DIY_2S/ for more information.

Cylinder Bore Protective Plating:
-Hard Anodizing, high silicon aluminium, easiest -Electroless
Nickel-Phosphorous/NiP: can do it in one step, hardness close to chrome
-Nickel Cobalt: not sure if can get enough cobalt in nickel to be
useful?
-Nickel/Suspended Particles: trapping hard particles suspended in
solution into nickel plating
-Nitride: similar to how some metal tools are protected, not sure if
possible/practical
-Hard Chrome: tested and proven but an involved process

Plating Cylinder Bore Back to Spec., need thick deposit, these are some
metal I thought would be possible: -copper
-nickel
-iron
-zinc
-tin: have heard of pistons being plated with tin for less friction

How big of an engine? What's it for? Will you find joy when it finishes
first in a 1000 mile race, or when it manages to run once on a test stand?


Does anyone still hard anodize cylinder bores? I know there was a brief
rage for it around 2000 or so with model airplane engines, but it seems
that everyone doing it went back to hard chrome or nickel.

Keep in mind that anodizing is not a plating process. The surface does
grow, because given the same amount of aluminum, aluminum oxide is bigger
than just aluminum -- but the anodizing penetrates into the parent
material as much as it grows out of it. The anodizing is way hard (it's
basically sapphire), but if it were such a hot-s**t way of doing it, why
isn't it still done by model airplane engine manufacturers?

Maybe heat transfer is not so good? Insulators are not usually good heat
conductors. Some exceptions..diamond comes to mind.

Hard chrome is -- hard, and low friction.

Nickel is low friction, but I don't know if nickel-phosphorus is; I'd be
interested in how well it stands up (OS engines uses nickel plate on some
of its engines, but I'm not sure if it's nickel phosphorus, and I'm not
sure if it wears super well).

On Sun, 25 Mar 2012 13:26:37 -0700, Bill Martin wrote:

On 03/24/2012 12:05 PM, Tim Wescott wrote:
On Sat, 24 Mar 2012 10:57:03 -0700, durabol wrote:

I'm new to electroplating and was wondering if anyone could provide
some insight (and save me from reinventing the wheel) in the following
methods of electroplating an aluminium cylinder bore both for
protective reasons and also restoring a worn cylinder bore back to
spec. so don't need oversize pistons. This is for a homemade two-
stroke engine, see http://groups.yahoo.com/group/DIY_2S/ for more
information.

Cylinder Bore Protective Plating:
-Hard Anodizing, high silicon aluminium, easiest -Electroless
Nickel-Phosphorous/NiP: can do it in one step, hardness close to
chrome -Nickel Cobalt: not sure if can get enough cobalt in nickel to
be useful?
-Nickel/Suspended Particles: trapping hard particles suspended in
solution into nickel plating
-Nitride: similar to how some metal tools are protected, not sure if
possible/practical
-Hard Chrome: tested and proven but an involved process

Plating Cylinder Bore Back to Spec., need thick deposit, these are
some metal I thought would be possible: -copper -nickel
-iron
-zinc
-tin: have heard of pistons being plated with tin for less friction

How big of an engine? What's it for? Will you find joy when it
finishes first in a 1000 mile race, or when it manages to run once on a
test stand?


Does anyone still hard anodize cylinder bores? I know there was a
brief rage for it around 2000 or so with model airplane engines, but it
seems that everyone doing it went back to hard chrome or nickel.

Keep in mind that anodizing is not a plating process. The surface does
grow, because given the same amount of aluminum, aluminum oxide is
bigger than just aluminum -- but the anodizing penetrates into the
parent material as much as it grows out of it. The anodizing is way
hard (it's basically sapphire), but if it were such a hot-s**t way of
doing it, why isn't it still done by model airplane engine
manufacturers?

Maybe heat transfer is not so good? Insulators are not usually good heat
conductors. Some exceptions..diamond comes to mind.

It could be. Or maybe it doesn't stand up so well when you abuse the
engine. Or maybe it's because it was pioneered by a Russian company that
ended up having typical Russian QA problems (Norvel, now NV engines --
they got a reputation as being really good engines as long as you
stripped your brand new engine down to the component parts, washed off
all the chips left in the engine, and reassembled).

OS Engines, who is The Name in reliable mid-priced model airplane engines
these days, toyed with it but rapidly went back to nickel plated brass or
aluminum cylinder liners.

(The state of the art seems to be hard-chromed brass or aluminum liner,
and a high-silicon piston. Sometimes the brass or aluminum liner is
nickel plated. A normal engine, when cold, has a slightly too-tight fit
at TDC. As the engine heats, the cylinder liner expands ever so slightly
more than the piston, and the fit becomes perfect. If you adjust the
thing too lean and get a too-hot run, you get low power, excessive blow-
by, and when things cool down an undamaged engine. Most other piston/
liner combinations that have good wear qualities will let the piston
expand more than the cylinder, so at the end of that same really lean run
you'll have a galled piston or liner, or a loose piston/cylinder fit,
neither of which is a Good Thing).

--
Tim Wescott
Control system and signal processing consulting
www.wescottdesign.com

On Mar 24, 1:57*pm, durabol wrote:
I'm new to electroplating and was wondering if anyone could provide
some insight (and save me from reinventing the wheel) in the following
methods of electroplating an aluminium cylinder bore both for
protective reasons and also restoring a worn cylinder bore back to
spec. so don't need oversize pistons. This is for a homemade two-
stroke engine, seehttp://groups.yahoo.com/group/DIY_2S/for more
information.

Cylinder Bore Protective Plating:
-Hard Anodizing, high silicon aluminium, easiest
-Electroless Nickel-Phosphorous/NiP: can do it in one step, hardness
close to chrome
-Nickel Cobalt: not sure if can get enough cobalt in nickel to be
useful?
-Nickel/Suspended Particles: trapping hard particles suspended in
solution into nickel plating
-Nitride: similar to how some metal tools are protected, not sure if
possible/practical
-Hard Chrome: tested and proven but an involved process

Plating Cylinder Bore Back to Spec., need thick deposit, these are
some metal I thought would be possible:
-copper
-nickel
-iron
-zinc
-tin: have heard of pistons being plated with tin for less friction

Brock

I know one popular type for motorcycles is nikasil- 1000 cc engines
running 12K rpm. No idea if it's home-brew-able.

On Mar 24, 11:57*am, durabol wrote:
I'm new to electroplating and was wondering if anyone could provide
some insight (and save me from reinventing the wheel) in the following
methods of electroplating an aluminium cylinder bore both for
protective reasons and also restoring a worn cylinder bore back to
spec. so don't need oversize pistons. This is for a homemade two-
stroke engine, seehttp://groups.yahoo.com/group/DIY_2S/for more
information.

Cylinder Bore Protective Plating:
-Hard Anodizing, high silicon aluminium, easiest
-Electroless Nickel-Phosphorous/NiP: can do it in one step, hardness
close to chrome
-Nickel Cobalt: not sure if can get enough cobalt in nickel to be
useful?
-Nickel/Suspended Particles: trapping hard particles suspended in
solution into nickel plating
-Nitride: similar to how some metal tools are protected, not sure if
possible/practical
-Hard Chrome: tested and proven but an involved process

Plating Cylinder Bore Back to Spec., need thick deposit, these are
some metal I thought would be possible:
-copper
-nickel
-iron
-zinc
-tin: have heard of pistons being plated with tin for less friction

Brock

If you're doing a one-off, it'd be better to let somebody do the
plating for you. Plating aluminum and getting a good bond is tricky.
Not saying it couldn't be done at home, just that you'd probably end
up with an engine full of nickle flakes a few times before you got the
hang of the process. On any of the plating processes, the first item,
after polishing, is removal of the oxide film and keeping it removed
until the plating occurs. Poor prep=peeling plate.

Anodizing would be about the last thing I'd use for a surface I needed
low-friction sliding on. It's basically a glass-hard, very fine
abrasive surface.

Now if you're really going to get rolling in production, a removable
liner of some other metal would probably be the way to go. Wear out
the liner, put in a new one.

Stan