finishing.com -- The Home Page of the Finishing Industry
no_pop_no_spam
HomeFAQsBooksHelpWantedsForum letter 60408
Serious Education ... plus the most fun you can have in metal finishing.

Coating Adhesion on sanded vs. unsanded 1018 CR Steel


March 9, 2017

Q. Hey,
I work at a high end furniture shop, we patina all our visible surfaces, but for unseen we either spray with a black enamel plaint, or Dykem Opaque black.
I'm trying to establish metal prep procedures for parts and their corresponding coatings. I've been able to find all the surface prep requirements for our enamel paint, however Dykem seems to be seriously lacking in that area. The best I've gotten so far is "Apply to a surface that is clean, dry and free of oil and grease" from the Dykem technical data sheet. Will this alone provide us with a long lasting indoor finish on non seen parts?
My gut keeps telling me Sand it first. If that is the case is there any ASTM-like documentation stating this?
Also if this helps, its not on their MSDS oddly, but it does contain Nitro Cellulose.

Anthony Algieri
Metal Prep Supervisor - Philadelphia, Pennsylvania, USA


March 2017

A. Hi Anthony. Indoor furniture is a relatively easy application with regards to corrosion resistance, so sanded vs. unsanded vs. pretreated probably isn't a big issue. Still, painted steel ideally would be phosphated.

Assuming the steel will remain without phosphate pretreatment, an advantage of sanding the steel would be that it will remove some soils and oxidation products which might otherwise be on the surface, and which could interfere with adhesion.

Regards,

pic of Ted Mooney
Teds signature
Ted Mooney, P.E. RET
finishing.com
Pine Beach, New Jersey


March 26, 2017

A. Hi Anthony,
I completely agree with Mr. Mooney and very light sanding would likely improve adhesion if cleaned afterward properly. A sanded surface at a microscopic level has a far greater surface area compared to a smooth surface. A greater surface area means more places for the paint to stick and hang on to!

blake kneedler
Blake Kneedler
Feather Hollow Eng.
Stockton, California


ADD a Q or A to THIS thread START a NEW THREADView This Week's HOT TOPICS

Disclaimer: It is not possible to diagnose a finishing problem or the hazards of an operation via these pages. All information presented is for general reference and does not represent a professional opinion nor the policy of an author's employer. The internet is largely anonymous; some names may be fictitious and some recommendations may be deliberately harmful.

  If you need a product/service, please check these Directories:

JobshopsCapital Equip. & Install'nChemicals & Consumables Consult'g, Train'g, SoftwareEnvironmental ComplianceTesting Svcs. & DevicesUsed & Surplus


©1995-2017 finishing.com     -    Privacy Policy
How Google uses data when you visit this site.