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Need info on preparation chemicals for powdercoating

 

We are a small company that manufactures suspension items for the automotive industry. We have been powdercoating for the last 3 years but our quantity has been low enough that we just individually wipe our products down before powdercoating and manually hang each item into our oven. We have grown and now a typical day produces anywhere between 50-100 products that go through the coating process. We have a new facility being built to allow a larger production line and are semi-automating the line. I need to streamline the cleaning portion of our line and want to spray our products down instead of wiping them. What I need to know is what type of chemical can be sprayed on to the parts that will degrease the product, prep the surface, and dry fast without being a health hazard. Right now we glass bead each part and then wipe it down with lacquer thinner ⇦this on eBay or Amazon [affil links] Warning! highly flammable! . Any help with this would be greatly appreciated.

Brett Rockey
BMR Fabrication Inc. - Seffner, Florida

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First of two simultaneous responses --  

Brett,

For the highest quality, a zinc phosphate pretreatment would provide a foundation for the powder coat. The present production volume does not justify an in house system. It may be prudent to find a pretreatment company to process the parts.

A book like "Phosphating of Metals" ⇦[this on Amazon or AbeBooks affil links]by Werner Rausch is a good source for basic information. It is out of print; however, it may be found on the Internet.

Herb Ashley
- Smartt, TN (USA)

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Second of two simultaneous responses --  

Hi,

As your throughput is fairly low I suggest a single cabinet washer cabinet, multistage: Hi performance iron phosphate cleaner-coater, cold water rinse, hi performance hot final rinse, flash and air blast dry. The same chemical line-up in a conventional 3 stage spray plant in the UK on bead blasted suspension bars meets automotive performance specs (500+ hours salt spray).

Hope this helps,

Roger Bridger
- Croydon, UK

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Dear Sir,

The way I suggest is barrel dipping Iron Phosphating small line.

The stages are as follow:

a. Alkaline Cleaning: Hot solution for oil and buffing compounds removal .
b. Tap water Rinse
c. Rust removing and Pickling: Proprietary acidic solution based on Phosphoric Acid , detergents and Inhibitor.
d. Tap water rinse
e. Iron phosphate solution: Cold or Hot solution depending on the supplier .
f. Tap water rinse
g. Deionized water rinse or Acidic sealer rinse
h. Dry
i. Powder paint.

The process will be accomplished by using slow rotating drums where the parts will be in touch with the proper solutions and stages and will be ready to be paint. Drum size and rate of work will be designed by the line manufacturer depending on your work quantity now and rate of work growth(important).

Yehuda Blau
YB Plating Engineering and Quality - Haifa Israel