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Ted Mooney, P.E. RET
Pine Beach, NJ
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for Metal Finishing since 1989
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Testing of powder coated CRCA strip
Q. Hi,
Can somebody suggest what are the tests to be done on powdercoated CRCA strip which is used for making bells (e.g., salt spray, humidity, adhesion, etc.). I am not sure whether some tests are enough or all the tests needs to be done.
Product designer - Chennai, India
March 9, 2008
A. DEAR SIR,
please specify thickness of the strip and also let us know what type of machines you use for post forming.
- GURGAON, Haryana, INDIA
March 12, 2008
A. I think you are asking the wrong persons "what tests" are required to be carried out on the powder. This is the prerogative of your customer. If this information is not forthcoming, then a simple test for cure and adhesion would be more than satisfactory.
Terry HicklingBirmingham, United Kingdom
March 13, 2008
March 13, 2008
Thanks, Terry. I appreciate your advice on cure and adhesion, and I know what you are saying about the rest. But written between the lines may be the possibility that Cowkur's "customer" is the public, or that his customer is relying on the expertise of the coater for good product. This discussion about who is responsible for fitness of the finish has been on the site several times, with letter 34235, "Powder Coating Rusting Dispute" being a particularly interesting example of the conundrum :-)
When a shop is doing metal finishing for an aircraft manufacturer or a major automobile manufacturer, their job is basically to do what they are told. But in other cases they may be expected to be "the experts" with a proactive plan to insure that what they are providing will be satisfactory for the application. It is possible that Cowkur has some responsibility for coming up with a test protocol that extends beyond what his customer has asked for.
Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
Hi Ted, There are many questions to be asked: are they cow bells, doorbells, church bells, hand bells, alarm bells, etc. I cannot think of any circumstances where humidity or salt spray evaluation would be required. What is important is where the items are to be sited, exterior or internal locations. This will determine the choice of resin base and the pre-treatment if any. Next important factor -- is the powder fully cured, hence a cross hatch and bend test.
Terry HicklingBirmingham, United Kingdom
March 14, 2008
Hi Terry, Hi Ted,
Both of you are missing one thing.
The user was applying on the Metal Strips that are going to be used for bell, this is not the bell what Terry understood.
These coated strips are going to be used for fastening purpose of packagings, etc.
I believe what Mr. Singh is asking is the right question because for fastening post forming of the strips may rupture if the application DFT becomes high. Of course that would be supported by right curing of the powder.
Thanks,
- Margao , Goa , India.
July 28, 2008
Ed. note: We have many readers & contributors with your same name, Subir. Thanks for participating, but please use your full name so your postings are not assumed to be by those others named Subir or vice-versa :-)
Q. Dear Sir,
Can we do humidity test (test time 24 hours) on Powder coated CR sheet after water dip test (time 12 hours).
Regards,
- Jaipur, Rajasthan, India
December 30, 2014
A. Hi Sanjay. Of course you can; when it comes to testing, you can do anything you please :-)
But please present your situation because I don't understand where you're coming from or going to. Thanks!
Regards,
Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
January 2015
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