Powder Coating Questions & Answers

Just a friendly bump to the top.

Hi Y'all:

It has been some time since I checked the SCCoA Forum out. Nice new look.

Anyways, I am back on the job to answer your Powder Coating Questions. Play stump the Consultant.
 
Question #1 CArlisle?
Question #2 Best type of powdercoat for underhood?

Also any way to prevent oxidation of aluminum under teh powder?
 
Carlisle & Powder Reccomendation

1. The only way I will go to Carlisle is to trailer my car. I just is not worth the risk to drive that far and risk a road hazard incident that will take out my Coddington wheels. I decided this last year and it is especially applicable this year with the tough winter and all the potholes. I looked into buying an enclosed trailer, but have difficulty justifying it for a once a year use and can't figure where I would store it. I even looked at renting an open trailer, but this has issues as well. Having said that, I hope to possible find a resolution to my indecision soon.

2. Under-hood parts are normally coated using pure epoxy or epoxy-polyester hybrids, as they offer the best chemical resistance and are very tough coatings. Color selection is extensive in these formulas, except in clears and tinted clears. These coating have poor UV (sunlight) resistance and can chalk (loss of gloss) in direct sunlight in a couple of weeks. The chalk can be easily removed using a cleaner wax, compound, or even a dry cloth if it isn't too bad. However, this normally doe not present a problem for under-hoop and under-carriage (chassis) applications.

3. All metals oxidize when exposed to air (oxygen). Moisture and salt accelerate the time of occurrence and the degree of this oxidation. Coatings (powder or liquid paints) will slow this process, but not eliminate it entirely. Better coatings. like powder, will slow this process more than other coatings. Cleaning parts before coating will eliminate contaminants that will accelerate the oxidation process. Converting the metal surface using a pretreatment will enhance adhesion and significantly improve corrosion (oxidation) resistance. Aluminum is protected best with a chromate conversion pretreatment, but can also be converted using zirconium pretreatments.

If you want to get "real technical" look at the attached article.
 

Attachments

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nliberto@powder said:
1. The only way I will go to Carlisle is to trailer my car. I just is not worth the risk to drive that far and risk a road hazard incident that will take out my Coddington wheels. I decided this last year and it is especially applicable this year with the tough winter and all the potholes. I looked into buying an enclosed trailer, but have difficulty justifying it for a once a year use and can't figure where I would store it. I even looked at renting an open trailer, but this has issues as well. Having said that, I hope to possible find a resolution to my indecision soon.

2. Under-hood parts are normally coated using pure epoxy or epoxy-polyester hybrids, as they offer the best chemical resistance and are very tough coatings. Color selection is extensive in these formulas, except in clears and tinted clears. These coating have poor UV (sunlight) resistance and can chalk (loss of gloss) in direct sunlight in a couple of weeks. The chalk can be easily removed using a cleaner wax, compound, or even a dry cloth if it isn't too bad. However, this normally doe not present a problem for under-hoop and under-carriage (chassis) applications.

3. All metals oxidize when exposed to air (oxygen). Moisture and salt accelerate the time of occurrence and the degree of this oxidation. Coatings (powder or liquid paints) will slow this process, but not eliminate it entirely. Better coatings. like powder, will slow this process more than other coatings. Cleaning parts before coating will eliminate contaminants that will accelerate the oxidation process. Converting the metal surface using a pretreatment will enhance adhesion and significantly improve corrosion (oxidation) resistance. Aluminum is protected best with a chromate conversion pretreatment, but can also be converted using zirconium pretreatments.

If you want to get "real technical" look at the attached article.
Click to expand...

Ohh I am familiar with treatments of metals and why they corrode. Just wasnt sure what processes would be used with powdercoating and still get good adhesion. Had an issue with an intake or two after 10 plus years..Seems teh prep is better then some....But I douubt they use a pretreatment. Is there a particular product?
 
Powder Coating on Aluminum

Ten years!!! What do you want, "FOREVER"? :D

The best powder coating job on chromated aluminum (outdoor furniture) is warranted for 15 to 18 years. Skyscrapers use coatings (Kynar & Duranar) that can last 30 years when applied on aluminum with the same chromate pretreatments.

Chromate conversion coatings and zirconium conversion coating are sold by Pretreatment Chemical Suppliers like DuBois, Henkel, Chemetall, Coral, and about a dozen more. These guys sell directly to the Custom Coater (Job Shop) companies and OEMs. You will not be able to buy from them though. That is why Eastman has a selection of pretreatment chemicals for the hobby powder coater.

If you clean the surface really well and remove the oxides, you should get at the 10 years you experienced on aluminum and about half that on steel.
 
Ill have to check out eastwood. Its funny because I do alot of forensic work with curtain walls and failure of finishes. I always have you in mind if we ever need a coatinsg expert but it never comes to that:O)


nliberto@powder said:
Ten years!!! What do you want, "FOREVER"? :D

The best powder coating job on chromated aluminum (outdoor furniture) is warranted for 15 to 18 years. Skyscrapers use coatings (Kynar & Duranar) that can last 30 years when applied on aluminum with the same chromate pretreatments.

Chromate conversion coatings and zirconium conversion coating are sold by Pretreatment Chemical Suppliers like DuBois, Henkel, Chemetall, Coral, and about a dozen more. These guys sell directly to the Custom Coater (Job Shop) companies and OEMs. You will not be able to buy from them though. That is why Eastman has a selection of pretreatment chemicals for the hobby powder coater.

If you clean the surface really well and remove the oxides, you should get at the 10 years you experienced on aluminum and about half that on steel.
Click to expand...
 
XxSlowpokexX said:
Ill have to check out eastwood. Its funny because I do alot of forensic work with curtain walls and failure of finishes. I always have you in mind if we ever need a coatinsg expert but it never comes to that:O)
Click to expand...

Well there is always hope for the future. We can use the business!
 
Nick..Having a buddy who owns a PC shop give you a shout. Name is Keith. Hes new to it so he has some questions:O)
 
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