6 Replies Latest reply on Sep 29, 2017 11:52 AM by David Matula

    material finish notes

    Steve Krause

      I am looking to see what others do when calling out on a fab drawing the powder coat finish on a metal part.  Where I work over the years we have done that in a few different ways.  We usually get good results from all the different ways but we want to standardize on a one set of notes for our powder coated finishes.

       

      We are an electronics company producing rack mounted equipment and peripherals.  We powder coat a lot of product a textured black and we screen graphics on the front and back panels.  Sometimes we use lexan overlays and labels.  Some production is done by local vendors in the US.  Other parts are done off shore in Asia.

       

      Our goal is to use notes that insure that all black metal parts have the same look. I believe we need to be calling out Color, Texture, and Gloss in the Finish section of the fab notes.

       

      But there is potentially more than one shade of "BLACK" for the color.

       

      There are different interpretations of "FINE TEXTURE".

       

      There are different interpretations of "LOW GLOSS".

       

      1) One approach we have used is to define our companies paint number as a company paint spec number.  For example we have our DPS059.  On the fab notes we say "FINISH PER DPS059".  The fab shop is given the definition of DPS059 in a our PLM system.  The name in our system is BLK FINE TEXTURE LOW-GLOS and attached to that item in the PLM system is the manufacturer Cardinal and the manufacturer's part number C241-BK303 with Cardinal's spec sheet that says "C241 - BK303  Polyester powder coating Semigloss hytex Black"

       

      I we know that every manufacturer isn't going to buy and use Cardinal when we ask them to powder coat the part but that note has usually gotten us what we want.  In some situations we have attached multiple manufacturers when we learned from the powder coater that they are using something equivalent and we have confirmed that it works from seeing their output.

       

      2) A long time ago we worked with color chips and had them available to pass to the vendors when we put on the fab notes something about matching to our paint chip.  Pretty subjective and time consuming.

       

      3) Lately we have also taken the approach of just putting in the fab drawing notes: FINISH: COLOR: BLACK TEXTURE: FINE TEXTURE GLOSS: 20% GLOSS PER ASTM D523 FIRST ARTICLE APPROVAL REQUIRED The first article approval can be problematic since it puts a delay in the process so sometimes we leave out that line. Using a percentage of gloss as measured per ASTM D523 seems to lock down the gloss nicely.

       

      But I don't know how to specify black since paint companies have multiple versions of black.

       

      Also is there a texture standard for powder coating?  I know there are plastic mold texture standards like from Mold Tek.  Are their powder coat standards for texture?

       

      What do you guys do?

        • Re: material finish notes
          David Matula

          I would look at the SSPC and ASTMA or even the AAMA specks for powder coating and come up with a coating specification separate from the drawing that would drive the coating for the parts.

          The speck should include all surface prep such as cleaning blasting...ect and the type of materials used to achieve the finish of the part that you are looking for...

          When creating the coating speck you specify colors by mfg and #...so if you have a black that is made by PFG. that you know that you want all you need to do is call out the mfg and then the # that makes that black...and it should match up....

           

          coating is another specialty all in its own best of luck.....

          • Re: material finish notes
            John Stoltzfus

            Here we would call out the Paint number and Manufacturer and add a note or equal... which like you say is subjective and for your information Black is the hardest color to match btw or so they say..

            • Re: material finish notes
              David Matula

              I prefer to leave all mention of any kind of paint....off the drawings that I make...I worked at a place where we where making the same product for different customers....and every customer had a different paint spec...and when it got around to calling out all that info on the drawing....there was no way I was going to make or revise a drawing for every paint scheme that came along....That is where we started to call out the paint speck on the work order...so if one guy wanted his product fire engine red and the other guy wanted the same thing canary yellow....I did not have to make new drawings for them and could concentrate on the next job that I had. 

               

              The bugger is in the details....blasting,  blasting media....types of paint...low voc...hi voc.  Primer color-thickness, mid coat color-thickness, to the final finish coat.  Then the inspections...to make sure everything went according to the speck.

              Some of the paint specks we would get from customers came in 6in binders...at times there where 2 or three of them.

                • Re: material finish notes
                  John Stoltzfus

                  For here if that were the case then I would add just a simple Project Folder as a reference - (Finish Spec see... )

                  • Re: material finish notes
                    Matt Peneguy

                    One big catch-all in those specs is to refer to the paint makers prep and application instructions, and specify a good paint system.  Regardless what I think or spec, I want the paint makers requirements followed.  So, in the hierarchy of our specifications we make sure that the paint makers requirements are followed over any specified conditions about surface prep., application instructions, etc. that we may list in our specifications.  But, we do also like to mention SSPC, minimum application requirements, etc.to make the Contractor aware of what we are expecting him to do...Sometimes our Contractors are not as thorough reading our plans and specs as we would like.