Old despatch riders trick - Much simpler and cheaper just cutting a section from an old inner tube and sliding it over the shock and cable tie the ends -
Painting a Spring?
- Thread starter Udders
- Start date
Old despatch riders trick - Much simpler and cheaper just cutting a section from an old inner tube and sliding it over the shock and cable tie the ends -
Myke Rocks
Registered user
Powdercoating and electroplating
Electroplating is a nono. First of all, the chrome will peel off with the flexing.
Secondly, electroplating changes the surface characteristics of the plated metal, and this will almost certainly result in fractures.
Powdercoating:
As already stated, the coating is sufficently flexible to cope with the bending stresses, but there is a suggestion that the heat treatment involved will change the temper of the spring.
Powder coating normally is cured are circa 160 to 180 degrees for around 15 minutes, and permitted to cool off naturally afterwards.
This is so far below the point at which spring tempering is done that it should not affect the spring characteristics.
Myke
Electroplating is a nono. First of all, the chrome will peel off with the flexing.
Secondly, electroplating changes the surface characteristics of the plated metal, and this will almost certainly result in fractures.
Powdercoating:
As already stated, the coating is sufficently flexible to cope with the bending stresses, but there is a suggestion that the heat treatment involved will change the temper of the spring.
Powder coating normally is cured are circa 160 to 180 degrees for around 15 minutes, and permitted to cool off naturally afterwards.
This is so far below the point at which spring tempering is done that it should not affect the spring characteristics.
Myke
two pages on how to paint a spring 
i'm so glad this is in the 1150 section
i'm so glad this is in the 1150 section
Just a question, I have a 1985 Harley FXR, which has twin shocks with chrome plated springs, now apart from a little surface rust, the chrome looks fine, and my mate has a 1927 rudge with chrome plated springs (ok seat springs) and they seem fine as well, what special process do they use so the chrome wont come off ?
Myke Rocks
Registered user
A good question!
I am only quoting the accepted wisdom.
When a metal product is chromed, the chrome is a very thin layer on top to provide the surface finish.
The metal - E.G. Steel, is first polished to the finish you require. If surface finish is poor, final finish will reflect this.
Next, for a Rolls Royce job, the item is copper plated.
(Often left out, but improves the final finish beyond measure)
Then it is nickel plated over this. The nickel provides an impervious layer above the copper which is close to chrome in colour.
The chrome is then applied as a final, very thin coating.
Chrome on it's own will have rust through it in days.
In a past life, I had the side panels off a Honda black bomber chromed.
Since the bike frame was away being painted, I left the panels in my bedroom for 4 weeks. When I unwrapped them, they were a mass of rust.
Shite plating by Lyness Brothers.
Regarding how the chrome does not come off when flexing:
I do not know, It is probably some modification of the nickel coating - very well done, and not available with normal platers.
I worked in electroplating for around 10 years, but we were mainly electroplating copper kettles, so I do not have all the answers.
Hard chrome is another kettle of fish. I have no knowledge of it.
Myke
I am only quoting the accepted wisdom.
When a metal product is chromed, the chrome is a very thin layer on top to provide the surface finish.
The metal - E.G. Steel, is first polished to the finish you require. If surface finish is poor, final finish will reflect this.
Next, for a Rolls Royce job, the item is copper plated.
(Often left out, but improves the final finish beyond measure)
Then it is nickel plated over this. The nickel provides an impervious layer above the copper which is close to chrome in colour.
The chrome is then applied as a final, very thin coating.
Chrome on it's own will have rust through it in days.
In a past life, I had the side panels off a Honda black bomber chromed.
Since the bike frame was away being painted, I left the panels in my bedroom for 4 weeks. When I unwrapped them, they were a mass of rust.
Shite plating by Lyness Brothers.
Regarding how the chrome does not come off when flexing:
I do not know, It is probably some modification of the nickel coating - very well done, and not available with normal platers.
I worked in electroplating for around 10 years, but we were mainly electroplating copper kettles, so I do not have all the answers.
Hard chrome is another kettle of fish. I have no knowledge of it.
Myke
Just as it says , hard chrome , a much more wear resistant finish which is what is found on the actual shock rod, or hydraulic rams on plant equipment etc.
As hard as it is it will still pit and score , especially if minute particles of grit get trapped between the rod and the scraper seal.
You can imagine a chrome plated shock rod wouldn't last 5 laps for the MotoX boys and so hard chrome is used in its place.
Hard chrome has an actual use whereas chrome plating is merely aesthetics.
CPL
Registered user
I have built many custom motorcycles using "show chromed" springs and have never experienced any problems. As previously noted, the electroplating process affects the surface layer of steel only as the current and chemical electrolytes used are there only to deposit either thin layers of nickel, followed by even thinner layers of chrome (in the case of bright chrome) or a single layer of "hard" chrome, (which is liable to flaking because it is brittle) and if you try to plate a steel tube you'll see that the inside wont plate as the current only flows around the outer skin.
As for the temperature and time quoted for powder coating... Just because the instructions say one thing, dont assume people will adhere to them... my local fella rarely runs his oven at below 150C and many small companies deliberately run to the upper range of the coating material's tollerance in order to make sure it's properly bonded so that they don't risk having to strip and re-do it if it's "not quite cooked".... Then the finished pieces normally exit directly to ambient temperature as the faster initial cooling tends to give a nicer surface finish..
As for the temperature and time quoted for powder coating... Just because the instructions say one thing, dont assume people will adhere to them... my local fella rarely runs his oven at below 150C and many small companies deliberately run to the upper range of the coating material's tollerance in order to make sure it's properly bonded so that they don't risk having to strip and re-do it if it's "not quite cooked".... Then the finished pieces normally exit directly to ambient temperature as the faster initial cooling tends to give a nicer surface finish..
Similar threads
