Jump to content



Help Support IntlWaters by donating using the link above.
Photo

Hard Industrial Chroming of Aluminum, Brass or Steel Cylinders


  • Please log in to reply
177 replies to this topic

#166 Jim Allen

Jim Allen

    National Racer

  • Members
  • PipPipPipPip
  • 1,360 posts

Posted 15 May 2018 - 03:04 PM

New heavy duty, flint glass, round, 6" OD X 7-3/4" high battery jars from Flinn Scientific at a cost of $50.00 each, including shipping will be used for the new chrome tanks. New holding, masking fixtures will be used to chrome steel, brass & aluminum cylinder ID's. New battery jar covers were machined to fit both the old & new type battery jars. More details to follow on how to reverse the current when etching steel cylinders before chroming.

 

Jim Allen



Attached Files



#167 Terry Keeley

Terry Keeley

    World Racer

  • Members
  • PipPipPipPipPip
  • 5,488 posts

Posted 17 May 2018 - 06:46 AM

Great system!  :)





#168 Brian Spitzer

Brian Spitzer

    Beginner Boater

  • Members
  • Pip
  • 192 posts

Posted 18 May 2018 - 12:49 PM

Jim,

What material do you use to machine the covers from?  



#169 Jim Allen

Jim Allen

    National Racer

  • Members
  • PipPipPipPip
  • 1,360 posts

Posted 18 May 2018 - 03:46 PM

Brian,

 

PVC can be used for any plastic part in the chrome tank. Brass parts should be made from #360 free machining brass. Alligator clips are Mueller 25C 75-amp types with 25C rubber insulators.

 

JA



#170 Brian Spitzer

Brian Spitzer

    Beginner Boater

  • Members
  • Pip
  • 192 posts

Posted 30 July 2018 - 06:58 AM

Jim,

From post 165, has a decision been made on releasing more information on the plating process?



#171 Terry Keeley

Terry Keeley

    World Racer

  • Members
  • PipPipPipPipPip
  • 5,488 posts

Posted 30 July 2018 - 09:18 AM

I looked up my notes from 20 years ago, I used the formula that's all over the net and what Caswell plating recommends:

 

https://www.caswellc...chrome-plating/

 

I used "Chromium Trioxide" crystals (UN1463), the sulphuric acid was 1.84 SG (98%+), plus distilled water.

 

Bath temp was 50C, current density was 2.5 A/sq in, about 10A for a 45 liner and 14 for a 67.

 

I might try to chrome some 67 cranks this winter in the area of the rear bearing to improve the fit.   :)


Edited by Terry Keeley, 30 July 2018 - 09:19 AM.


#172 Brian Spitzer

Brian Spitzer

    Beginner Boater

  • Members
  • Pip
  • 192 posts

Posted 30 July 2018 - 10:20 AM

Thank you Terry! A 25 Amp power supply should be more than sufficient?


Edited by Brian Spitzer, 30 July 2018 - 10:33 AM.


#173 Terry Keeley

Terry Keeley

    World Racer

  • Members
  • PipPipPipPipPip
  • 5,488 posts

Posted 30 July 2018 - 11:36 AM

Thank you Terry! A 25 Amp power supply should be more than sufficient?

 

 

Oh ya.  Be sure the parts are very (chemically) clean, I used a 15% sodium hydroxide solution for a 5 min soak.



#174 Jim Allen

Jim Allen

    National Racer

  • Members
  • PipPipPipPip
  • 1,360 posts

Posted 30 July 2018 - 11:42 AM

Brian,

 

The "SUCCESSFUL" hard industrial chroming of any type of brass alloy only requires a general physical cleaning & then a chemical cleaning in a strong alkaline solution. However, the "SUCCESSFUL" hard industrial chroming of aluminum is a very different situation! Aluminum alloys must be carefully cleaned physically with Dawn, a rotating brush & hot water. The cylinder is then "immediately" placed in three different chemical baths, for a specific measured amount of time for each bath. In between each bath, the cylinder is washed in hot running water. After the final immersion in the last bath, the cylinder is washed in hot running water & then it is "immediately" placed in it's chroming fixture. MISS ANY STEP IN THIS PROCEDURE & YOU WILL HAVE A PITTED, FLAKING OFF, NOT HARD, CHROME PLATE!

 

The typical basic Chromium Trioxide bath should be operating at 125 to 130* F. The bath's temperature & current density will affect the hardness of the chrome plate. A typical .45 size liner will run at 13.5 amps for 58 minutes providing the electrical contacts between the cylinder, the anode, the cathode & the power supply are "absolutely sound". This current & time will put on approximately .0015" of chrome per side. Any bad connection anywhere will generate unwanted heat & raise the necessary current density amount! The power supply should be as ripple free as possible. The power supply should have an adjustable current & voltage output. There should be a precision amp meter & volt meter between the power supply & the chrome bath. A typical basic chromium bath will plate approximately 200 cylinders.

 

As previously stated the necessary chemicals used for aluminum alloys are very corrosive & dangerous! The chrome tank emits very heavy fumes when in operation & it should be operated in a controlled environment. No decision has been made concerning the release of information about the chemicals being used.

 

Jim Allen

 

 



#175 Terry Keeley

Terry Keeley

    World Racer

  • Members
  • PipPipPipPipPip
  • 5,488 posts

Posted 30 July 2018 - 11:56 AM

Brian,

 

The "SUCCESSFUL" hard industrial chroming of any type of brass alloy only requires a general physical cleaning & then a chemical cleaning in a strong alkaline solution. However, the "SUCCESSFUL" hard industrial chroming of aluminum is a very different situation! Aluminum alloys must be carefully cleaned physically with Dawn, a rotating brush & hot water. The cylinder is then "immediately" placed in three different chemical baths, for a specific measured amount of time for each bath. In between each bath, the cylinder is washed in hot running water. After the final immersion in the last bath, the cylinder is washed in hot running water & then it is "immediately" placed in it's chroming fixture. MISS ANY STEP IN THIS PROCEDURE & YOU WILL HAVE A PITTED, FLAKING OFF, NOT HARD, CHROME PLATE!

 

The typical basic Chromium Trioxide bath should be operating at 125 to 130* F. The bath's temperature & current density will affect the hardness of the chrome plate. A typical .45 size liner will run at 13.5 amps for 58 minutes providing the electrical contacts between the cylinder, the anode, the cathode & the power supply are "absolutely sound". This current & time will put on approximately .0015" of chrome per side. Any bad connection anywhere will generate unwanted heat & raise the necessary current density amount! The power supply should be as ripple free as possible. The power supply should have an adjustable current & voltage output. There should be a precision amp meter & volt meter between the power supply & the chrome bath. A typical basic chromium bath will plate approximately 200 cylinders.

 

As previously stated the necessary chemicals used for aluminum alloys are very corrosive & dangerous! The chrome tank emits very heavy fumes when in operation & it should be operated in a controlled environment. No decision has been made concerning the release of information about the chemicals being used.

 

Jim Allen

 

 

 

I'm sure the process for successfully plating aluminum must have taken many, many hours to perfect.  Many other manufacturers have had problems with the plating on their aluminum liners and have gotten away from them, the weight advantage must be worth the effort in pylon racing tho.

 

I also successfully plated some cast iron liners for my buddies 1/4 scale V8 and that was much more difficult than chrome, brass is a breeze to plate!  :)



#176 Jim Allen

Jim Allen

    National Racer

  • Members
  • PipPipPipPip
  • 1,360 posts

Posted 30 July 2018 - 04:11 PM

Weight is not the only advantage when using the correct aluminum alloy for the cylinder. The 4032 aluminum alloy used for the cylinder, combined with the hard industrial chrome plate expands at a rate that is slightly larger than the RSP-444 piston alloy. This fact plus the correct amount of taper on the piston & in the liner make it impossible for the engine to seize, even when over leaned!

 

Jim Allen



#177 Rudy Formanek

Rudy Formanek

    Boater

  • Members
  • PipPip
  • 493 posts

Posted 13 August 2018 - 12:02 PM

Knew a guy that tried doing chrome plating in his garage (1980's). The fumes etched his wife's car's windshield. He almost got divorced over that. A hammer left on the workbench rusted badly. Ron Sheldon (1970's) used to do it in a separate out-building. He was building Supertiger G-40's for RC airplane F-1.


Edited by Rudy Formanek, 13 August 2018 - 12:04 PM.


#178 Jim Allen

Jim Allen

    National Racer

  • Members
  • PipPipPipPip
  • 1,360 posts

Posted 13 August 2018 - 04:05 PM

Rudy,

 

The fumes that come out of a typical 1 gallon size tank, operating at 130* F, will fill a 3 car size garage in several minutes. Anything that is made of steel or iron, even pieces that have been hardened, will be rusted in a matter of minutes. Any electrical circuit which is not in a sealed container will also be damaged. This is one reason we are reluctant to divulge what chemicals are to be used in chroming aluminums. 

 

JA