MIL-DTL-5541 chemical conversion coating 2

[Tunalover]

The latest version of Subject standard defines two types of chemical: Type 1 and Type 2. These types determine if the chemical contains hexavalent chromium. The older version of the spec specified only classes of treatments: Class 1A and Class 3, for example, determine the thickness of the surface treatment.

What if one does not specify the Type of treatment and instead calls out only the Class of treatment? What Type of treatment is received by default? Or is the specification incomplete in that there is no default defined?

Tunalover

 

[coatingengineer]

Hi. How much corrosion protection do you need? The difference between hexavalent and trivalent chromium is night and day. Seems the specification is incomplete. However, ask for "Fred" or "Chris" at Luke Engineering:

http://www.lukeeng.com.

They will have the exact answer you need.

For more information on corrosion resistant coatings, I'm always glad to help:
<a href="

http://www.industrialcoatingsworld.com/Corrosion-Resistant-Coatings/index.html">Corrosion

Resistant Coatings</a>

Best wishes

William Gunnar

http://www.IndustrialCoatingsWorld.com

 

[Tunalover]

coatingengineer-
On paper the level of corrosion protection for a given Class is the same whether the Type is 1 or 2. The level of corrosion protection I need is simply to suppress oxidation at the surfaces of aluminums which is what this coating is supposed to do.


Tunalover

 

[coatingengineer]

Hi. With no Class specified, choose hexavalent chromium. On paper, both hexavalent and trivalent chromium require 168 hour salt spray. Though, for trivalent, unless conditions are near perfect, that is very difficult to attain.



William Gunnar

http://www.IndustrialCoatingsWorld.com

 

[rerig]

Per MIL-DTL-5541F, Pg 3, Para 3.1 "If no material type is specified type I shall be used. ..."

Rerig.