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Need to do zinc plating inside the pipe, what process to follow?

May 19, 2008

Dear All,

Hi we are the manufacturer of Agriculturer machinery i.e., Top link assembly. we are currently facing a problem regarding corrosion inside the pipe. is there any possibility to prevent the same?
Thanks,

Mahendra Singh
- Noida, UP, India

Plating on the inside of a pipe is NOT simple or easy or cheap. Consider using stainless steel. Possibly paint.

James Watts
- Navarre, Florida
May 20, 2008

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As James said, it's not easy or cheap, Mahendra. You need to get an anode inside the pipe; you need to run solution through the pipe; and you need to avoid the formation of gas pockets in the pipe during plating. If you can tell us the pipe size and shape, it may be possible to offer further advice. Good luck.

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
May 22, 2008

Hot dip galvanize will coat the inside of the pipe with a heavy layer of zinc. But zinc does not offer very good corrosion resistance. Alternatively High Phos electroless nickel will. G. Marrufo-Mexico

Guillermo Marrufo
Monterrey, NL, Mexico
May 23, 2008

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I would be much obliged if anybody could advise me for zinc electroplating interior of a tube with zinc

Mojtaba Farahani
unskilled plater - Tehran, Iran

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May 29, 2008

Dear Mahendra,

I have seen a plater who plate fuel pipe by using auxilary anode with Alkaline Non-Cyanide Zinc process.

But you need special design of the jigs that can carry (+) current and (-) current together, and contact point for busbar as well.

Please contact your chemicals supplier to help you for designing the jig,etc.

Understand that in Germany many good plating engineers that could help you.

Good luck.

Best regards,

Tony Chandra
- Jakarta, Indonesia
May 23, 2008

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June 26, 2008

The best way to coat the inside of pipes is through Sherardizing. 12 meter long pipes are done this way in Russia to a thickness of 100 microns in very large quantities.
Martin

Martin Straus
- Elk Grove Village, Illinois

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July 9, 2008

Dear Mr Mahendra,

People normally use an ordinary Mild Steel rod with rubber bushes as an internal anode in a chloride zinc plating bath. The rod ends are connected by PVC coated wire to the anode pipe to give the current. Midway during plating the Steel rod is shifted by six inches to plate the portion that is masked by the rubber bushes, hence the entire internal portion is plated without much difficulty.

You must bear in mind the following:

1. If your pipe Dia is 50 mm then you anode rod must be about 10 mm with rubber bushes of about 35 mm so as to allow solution movement.

2. You must run a filter continuously to agitate the solution and remove contamination.

3. The MS rods will dissolve horribly fast and build up iron contamination, hence heavy treatment with H2O2 on a daily basis is recommended.

4. If you can substitute the MS rod with Zinc wire it will be excellent. Or else use heavily zinc plated internal anode rods which you will be continuously plating in another tank on the side to avoid build up of iron and increase the life of your anode rods.

Wish you success in your venture.

Best wishes,

Khozem Vahaanwala
Saify Ind

Bengaluru, Karnataka, India