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Rust and Scale removal on metal casting like control valve body

I have problem to remove the scale and more rust (from the machined and casting material)in the phosphating method. If components are having heavy rust, we are doing sand blasting before phosphating. Large size (16" t0 24") bodies are phosphated by cold phosphating method. Even though we are doing in this method, we are able to remove the sacae in the body. for that we are doing buffing and grinding on the scale. I wish to rectify this problem to improve the quality and process.

Sudhandhira Babu
- Chennai, Tamil Nadu and India
2006

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Not sure where your rust problem is coming from. Before, after machining, or storage. Without that info., I can only suggest a controlled storage environment to reduce humidity.

AF Kenton
retired business owner - Hatboro, Pennsylvania
2006

I have the problem after the machining component phosphating. Already I have posted my problem description.

Sudhandhira babu M
- Chennai, India
2006

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Something just doesn't add up here. If you are blasting and then treating the surface as you say you are, there should be no rusting. If problem is occurring, I suggest you look into a new chemical supplier. Again, the best way for long storage is a controlled environment.

AF Kenton
retired business owner - Hatboro, Pennsylvania
2006