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Mask and de-mask solution

We are currently doing stripping for aluminide coating and wish to mask the uncoated area. we are looking for some maskants which can be removed easily after the stripping. Can anyone recommended an approach?

Chee Wong Siew
Aviation - Kuala Lumpur, Malaysia
2005

You forgot to say what method you are using for the stripping. Mechanical, chemical?

Guillermo Marrufo
Monterrey, NL, Mexico
2005

We are currently using a chemical stripper to strip off the aluminide coat but due to the some uncoated area, we need to look for a suitable mask to prevent chemical attacks.

Chee Wong Siew
Aviation - Kuala Lumpur, Malaysia
2005

O.K. What kind of chemicals are in your stripper, do you know? Organic acids, mineral acids, strong oxidizers or other compounds? This information is necessary to properly suggest.

Guillermo Marrufo
Monterrey, NL, Mexico
2005

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Well, we are using a mixture of nitric acid with ammonium Bi-Fluoride (the original product name is ASC-2N). This mixture of chemicals are very aggressive especially the temperature exceeding 90-100 deg F.

Chee Wong Siew
- Kuala Lumpur, Malaysia
2005

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First of two simultaneous responses --

We are using a mixture of nitric acid and ASC-2N (ammonium bi-fluoride) chemicals. We will dip the parts in this mixture for an hour at room temperature, 30 °C.

Chee Wong Siew
- Kuala Lumpur, Malaysia
2005

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Second of two simultaneous responses --

There are wax based stop-offs designed to withstand around 45 °C (120 °F) operating temp. You may try them. They are removed by petroleum based solvents. Otherwise there is a PVC tape that is self adhesive over itself that can be overlaped (no adhesive as it will not stand the mixture).

Guillermo Marrufo
Monterrey, NL, Mexico
2005

Are there any more kinds of maskants that can be burned off after use?

Chee Wong Siew
- Kuala Lumpur, Malaysia
2005

The best method is wax. e.g Cannings Clamca wax. It can be applied by melting in a domestic electric chip pan and applied by dipping. 3 dips are recommended for complete coverage. Sapura MARS is using this method in Klang, Malaysia.

John Dodgson
- Kuala Lumpur, Malaysia
November 13, 2008

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