Alodine 600 vs. Alodine 1200

A. Eri:

You sent me scampering back to the archives on this one. Some facts first:

Alodine 1200S~ Powdered Material
Spray Application
Used 6.3 lbs./100 Gallons
Temp: 70-100 degrees F.
Time: 15 Sec. to 1 minute.
Color: Light Iridescent gold to Tan, depending on aluminum alloy.

Alodine 600~ Powdered Material
Spray or Immersion Application
Used: 12.5 lbs./100 Gallons
Also: 9.9 lbs./100 Gals.(Toner 22)
Toner not used to meet Class 3 of AMSC5541.
Color: Light Iridescent Gold to Tan, depending on aluminum alloy.

The differences seen are that the #600 can be applied by an immersion dip, while the #1200 is applied by spray. A toner is used with the #600 and not with the 1200S I hope this helps.

A. Eri,

Mr Budman is correct in his answer about the concentrations of both chemicals. But both can be used in Spray or Immersion applications. The primary difference in the two chemicals is the issue of coating weight. The Alodine 1200 will produce a heavier film than the 600 will. The Aerospace industry uses the 600 chemical on areas that require electrical bonding.

Thanks I hope this helps.

A. Hello,

The Alodine 600 resists corrosion. Alodine 1200, 1200S, 1201 shall be used where maximum corrosion protection is required for surfaces to be painted or left unpainted.

Alodine 600, 1000 shall be used for corrosion protection where low electrical resistance is required and the installation and assembly it must be accomplished within 24 hour limit.

Don't forget exposed electrically bonded assemblies or installations shall be sealed.

A. Yes, I have faced terrible paint adhesion issues when dealing with Alodine 1200S. Would you like to know more?

A. Hi Andre. letter 3369 includes an explanation which should answer that immediate question. But remember that these are not dictionary words or generic terms; they are Henkel trade names -- so they mean whatever Henkel decides they mean, and that could change! Good luck.

Regards,

Hi Vadivel.

You can contact Henkel to see what they say. For a number of reasons readers are often hesitant to respond to abstract questions; so please explain the details of your situation. Thanks!

Regards,

A. Hello folks!

Alodine 1200S can be replaced by 600 as far as I know.

Best Regards

A. Hi Roger. Alodine is a tradename for Henkel products and they are free to change the formulation, the operating parameters, or anything else at any time. Thus, although it can be interesting to get general impressions from users, we should not rely on years-old postings for operating parameters! Please request a current technical data sheet from Henkel. Good luck.

Regards,

Thank you for the feedback Ted. Best Regards.

A. All the other replies notwithstanding, I just got off the phone with Henkel Aerospace Technical Help as I had a drawing requirement of coating to the MIL-C-5541 spec with "Alodine 600 or equivalent". The chemistry difference between the two is that the 600 has some "complex cyanides" in it that the 1200/1200S doesn't - more environmentally unfriendly.

The 600 - in either Class 3 or 1A can be sprayed, dipped or brushed. The 1200 can be sprayed, dipped, or brushed in only Class 1 work - Class 3 work must be dipped.

From the standpoint of producing the corrosion protection or electrical conductivity properties, the products are "equivalent" if recommended process times are followed. The 600 takes longer to develop the desired properties than the 1200 does.

A. Hi Robert. There are other vendors of chromating solutions, such as Chemetall, Macdermid, Sur-Tec, and a number of others, but we don't recommend brands or sources (why?). Rather, I'll note that all of these vendors offers good chromate conversion chemistry.

Another thing to note, though, is that the Alodine 600 and Alodine 1200 mentioned on these pages are hexavalent and not RoHS-compatible. You may want to contact Henkel or another vendor about a more eco-friendly trivalent chromate product.

When you say Alodine 1200 is not doing what you want, odds are strong that the problem is inadequate pretreatment or process control rather than Alodine 1200 being a marginally performing product :-)

If you are not with a metal finishing company, the easiest path to a satisfactory finish may be to farm out the work; very few OEMs do their own chromate conversion coating these days. But the process sequence is usually mechanical treatment followed by non-etch alkaline cleaning, followed by etching and de-smutting before chromating. Different alloys may require different pretreatments. We have dozens of threads here about chromate conversion coatings on aluminum, including some with photographs.

Regards,

A. Hi again. If you're going to do it yourself, use a scrub brush [on eBay or Amazon] with pumice [on eBay or Amazon] and a little detergent for the cleaning (wear plastic/rubber gloves because a single finger print is a problem, then rinse and Alumiprep 33 [on eBay or Amazon], then rinse and Alodine [on eBay or Amazon], then rinse and dry (better to just drip dry in a hot dry room than overheat because above 140-160 °F can be a problem.)

Regards,

A. Hello Robert,
There's some bad news and good news about your conversion coating project:
Bad news first. Conversion coating on castings is always going to be a bit more of a challenge due to inherent properties of castings -- the alloys will have more Si, which inhibits effective coating. That's not to say it isn't done; we do it here all the time -- it's just uglier as a finished product, and won't be as resistant to salt spray corrosion for as many hours as an extrusion type alloy coated under the same conditions. That being said, your Alumiprep step is critical in minimizing this effect. The results are likely to look different on a casting vs. an extrusion.
But the good news is that as a preparation for paint, chromate conversion coatings are fantastic! In fact, this is one of their more common applications -- and the castings we do here are almost all destined for the paint booth. Paint will adhere better, and a small scratch won't be nearly as likely to turn into a peeling mess in a few years.
So even if you don't like the look of your finished conversion coating, consider it time well spent :)
Good luck with your restoration, that's gonna be great!

  Excellent posting, Rachel.

Regards,