Just got PPG CHEMFOS 2008, rinse? concentration?

[twistedneck]

I have a sample bag of PPG CHEMFOS 2008. It doesn't say a thing about how much water to add, concentration, etc.

The application guide states it should be daubed on a room temp.

In addition, it states to rinse off with CF 2008DEE and let sit for 20 seconds followed by a final rinse / dry.

What is CF 2008DEE?

Can i use tap water for the zinc phos and the rinse operations?

Thanks!

 

[swall]

Just a guess, but I would say that the "CF" stands for "chrome free" and the CF 2008DEE is some sort of sealer for the phosphate.

 

[twistedneck]

You are right swall! its just so new its not on the property sheet.. next question, do we need these sealers or are they just extra fluff?

Also, i don't have DI water handy for the rinse (or to mix with phosphate mix for that matter) - do i need? thinking tap water here.. but i can purchase distilled if it matters.

Also, this is listed at room temp to work fine, but most commercial phosphate tanks operate between 100 and 135F immersion. I could heat my part up slightly and do it that way, as i'm daubing on the phosphate and i doubt it would hold heat during rxn with metal.

 

[TVP]

twistedneck,

Can you provide some background on the purpose of this excercise? Is the intent to use this process to meet typical automotive requirements for a large number of parts? If so, then yes DI water is required and likely the phosphate should be heated. The sealer is definitely required if there will be any subsequent organic coating applied such as epoxy electrocoat.

 

[twistedneck]

Thanks for chiming in TVP.

This is not for large production, not automotive (home project). There will be an organic (non e-coat) epoxy type coating ristant to UV and Solvents.

Will distilled water work in place of DI for small test parts?

How does the conditioner improve the performance? I will ask my PPG contact for a sample, but i don't want to be annoying, can we purchase it in samples?

Thanks very much.

 

[TVP]

If this is for test parts, then distilled water should not be overly detrimental. Phosphates are very sensitive to surface conditions, which is why most high quality phosphates use a surface conditioner prior to deposition of the actual phosphate layer. With regards to the post-phosphate sealer, the non-chromium sealers are either organic polymers or inorganic compounds, with the exact function differing somewhat between the two. The organic polymers act as chelating agents to tie up metal ions. The inorganic salt type sealers deposit onto any of the incompletely covered surfaces left over from the phosphate bath. Either way, they can significantly improve corrosion resistance over phosphate-only pretreatment. SAE Technical Paper 820366 is a good reference on this. I would assume that PPG offers the sealer in a relatively small container (quart or gallon rather than barrels).

 

[twistedneck]

TVP, I'm such a dork. I didin't realize there was a bottle of liquid inside the sand bag! so i don't need to worry about concentration.

Now, after researching i realize the conditioner helps prevent rust after cleaning, it also removes residule from the caustic cleaning. I'd like to get a poor mans conditioner but i have no clue where to start.

The Sealer is seeming more and more important since it acutally fillis in gaps in the phosphate crystal structure and conditions the surface for paint.. I'll post links here if i can find them in small qty.

 

[CoryPad]

What is your expected duration between caustic cleaning and phosphate application? If it is short (which seems very likely), then you don't really need a conditioner. Just use a lot of water to rinse (preferably hot water since it will evaporate quickly).

Regards,

Cory

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.

 

[twistedneck]

CoryPad, I'm doing in by hand as fast as possible.. with a hand bottle and city water + distilled water rinse.

I have an insanely powerful cleaner for post blasting; MI Clean 100 by Hubbard Hall

http://www.hubbardhall.com/files/2002019.pdf

.

If i go straight from MI Clean tub to City water rinse, then to distilled water rinse and then while still wet, directly to dauber phosphate application.. I could follow on with the sealer as they recommend. My friend at PPG said a lot of companies are starting to get rid of the sealer, but he will try to get me a sample.

Sealer sounds like its the icing on the cake and i can't see getting rid of it. i bet the chrome is even better.

What are the pitfalls in this process? Thx.