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    Painting Tips: sanding / primer / paint

    PAINTING TIPS:

    Sanding:

    How Does Sandpaper Work?
    --"Sandpaper works a lot like a saw, chisel, or any other cutting tool in your shop. The particles on sandpaper are made up from a number of sharp edges that cut the wood the same way a saw blade does. The only real difference is that sandpaper, unlike your saw, can’t be sharpened."

    --When sanding, start at a low grit sandpaper and work your way up to a finer grit. Doing this will get you the best surface possible.

    --When sanding plastics or doing body work, don't use lower than 220 grit. Low grit sandpapers will scratch and put grooves into the surface that will be extremely hard to get out.

    GRIT OPTIONS:

    (HEAVY GRIT)
    0-36______Extra Coarse
    40-50_____Coarse
    60-80_____Medium
    100-120___Fine
    150-220___Very Fine

    (FINE GRIT)
    240-360___Very Fine
    400-600___Extra Fine
    800-1200__Super Fine
    1500+_____Ultra Fine

    Select certain grit sandpaper to your advantage. Using every single grit available doesn't make the process faster.
    personal favorites: 80,120,220,320,600,800,1000

    --WET SANDING
    The term “wet sanding” is just that. The panel you are working on is lubricated with water as well as the paper itself. This method can be used between coats of paint, or on your final clearcoat. The most popular and common papers to use are 1500 and 2000 grit.

    Why would wet sanding be necessary?

    --"Sometimes during painting, dust or other particles will stick to the surface and create bumps in the paint. Wet sanding will remove all paint imperfections including scratches and blemishes."

    **READ** Wet sanding is only necessary if you want a perfect paintjob. If you follow all the steps in cleanliness and ventilation, wet sanding can be a waste of time.

    --------------------------------------------------------------------------

    Primer:

    Why should I use primer?

    --"Primer is a pre-coating put on materials before painting. Priming ensures better adhesion of paint to the surface, increases paint durability, and provides additional protection for the material being painted."

    --Priming is mandatory if painted material is not water resistant and will be exposed to the elements. Priming is also a good idea if a material is dirty and for some reason cannot be cleaned, or when painting light colors over existing dark colors. Primer and paint form a chemical reaction that allows the paint to adhere much better than if paint were used alone.

    PRIMER OPTIONS:

    Sandable primer / Universal primer, great for sanding. example: (great for painting anything; this primer sands very easily)
    Filler primer / Universal primer, used for porous materials. Ideal for wood and fiberglass. example: (definitely needed when using Bondo, this primer helps fill in scratches)
    Self-etching primer / Ideal for most plastic, fiberglass, bare steel, aluminum, and stainless steel materials. example: (great primer for any metal parts such as wheels)
    Primer sealer / Ideal for maximum corrosion resistance and bonding of basecoat colors. example: (great for keeping corrosion down)

    --------------------------------------------------------------------------

    Painting:

    How to get the best results.

    --Always read specific can instructions to achieve maximum results.

    --Paint in good weather only.
    • 55° to 75° F is ideal; 40 to 60% relative humidity is recommended
    • Avoid direct sunlight and hot, humid weather.

    --A smooth, even application is important. Follow these tips for success:
    • Use an even, side-to-side motion with each pass beginning and ending beyond the edge of the object.

    --Take your time!
    • Use 3 light coats vs. one thick coat.

    --Avoid over spraying!
    • Mask exposed areas with tape or drop cloths.

    --Ensure adequate ventilation!

    PAINT BRANDS:


    Dupli-Color
    Krylon
    Rust-Oleum


    personal favorite: Dupli-Color truck/van/suv

    **READ** When using primer and paint, use the same brand for all steps! This is a huge part in making sure your finish product turns out good. When you mix brands between primer, paint and clear coat; you could run the risk of getting cracks or blisters in your paint!
    Last edited by coletrain; 07-24-2008, 12:15 PM.

    #2
    A++++ for a very informative thread. Excellent write-up my friend.

    1993 Honda Accord LX 2004-2009
    1996 Honda Civic LX 2009-2012
    2012 Kia Optima LX 2012-2013
    2010 Honda Accord EX-L V6 2013-2018
    2007 Honda Fit Sport 2017-2017
    2018 Honda Accord EX-L 2.0T 2018-20XX






    Comment


      #3
      Originally posted by f22cb7lx
      A++++ for a very informative thread. Excellent write-up my friend.

      x2


      To see my car click here

      Bordeaux Red Crew #8

      Comment


        #4
        nice thanx

        Ride List
        1990 Accord dx coupe - my baby (dsm turbo set up in progress) http://www.cardomain.com/ride/3202853
        2005 Mazda 6s - daily driver http://www.cardomain.com/ride/3171724(totaled)
        newest 2006 mazdaspeed 6 http://www.cardomain.com/ride/4073987/2006-mazda-mazda6

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          #5
          I have a question.. I 'lost' a big spot of Paint on my hood because of high pressure washer :\ and I wanna know if I sand the big spot, prime it and paint it if i'm gonna see a very big difference of color between the original paint and the 'new' one ?!?!
          thx

          Comment


            #6
            i added it to the Thread Index in DIYs

            very nice thread, these are some good tips thatll help a first-time painter get things to come out lookin good.


            - 1993 Accord LX - White sedan (sold)
            - 1993 Accord EX - White sedan (wrecked)
            - 1991 Accord EX - White sedan (sold)
            - 1990 Accord EX - Grey sedan (sold)
            - 1993 Accord EX - White sedan (sold)
            - 1992 Accord EX - White coupe (sold)
            - 1993 Accord EX - Grey coupe (stolen)
            - 1993 Accord SE - Gold coupe (sold)
            Current cars:
            - 2005 Subaru Legacy GT Wagon - Daily driver
            - 2004 Chevrolet Express AWD - Camper conversion

            Comment


              #7
              Originally posted by croc-note
              I have a question.. I 'lost' a big spot of Paint on my hood because of high pressure washer :\ and I wanna know if I sand the big spot, prime it and paint it if i'm gonna see a very big difference of color between the original paint and the 'new' one ?!?!
              thx
              if you can get your paint code and get that paint, feather it onto your old paint and if your old paint isnt very oxidized they it shouldnt look too different i wouldnt think

              Comment


                #8
                Not bad, but i questioned your grit choices and descriptions until i googled it:

                http://www.woodzone.com/articles/sandpaper/index.htm

                now, the problem is, you changed the wording for grit choices to suit your needs. However advising anyone to use some of those grits in the way you mentioned can cause problems. I use 220 on body work, 400+ to prep the car for paint, 600+ to really feather in bodywork. 80-120 for removing small marks or imperfections will scar the car up more than you want and 150-180 before you paint will undoubtedly leave scratch marks that will show up in primer, ESPECIALLY rattle can primer as you're aluding to in this thread.

                CB7tuner.com Appearance Specialist - PM me with any bodywork questions

                Comment


                  #9
                  The tips can be used for a wide variety of materials. Everything I've mentioned I've applyed to: Wood, MDF, 10lb/20lb Foam, Metal, Bondo, Spackle, Spot Puddy.

                  You mentioned the grits seem a bit "extreme" but for people that don't know anything about sanding, if you work your way up in grits....you should have a nice surface every time.

                  SAND PAPER GRITS UPDATED!
                  Last edited by coletrain; 05-31-2007, 07:19 PM.

                  Comment


                    #10
                    cool

                    it is a good write up since i agree with alot of things you said. ESPECIALLY about using one brand for everything, a concept lost on many people. Although you mention rattle-can brands the same truth applies to bc/cc's as well. I just wanted to make sure no one tried to paint over a spot after using 80 grit since primer WILL bring out the sandpaper scars, then you'll get flooded with pms, like me lol.

                    Also, have you ever used Epoxy Primer? good for use on bare metal, provides great cohesion.

                    I applaud your effort in writing this DIY, since it's something i never got around to doing

                    CB7tuner.com Appearance Specialist - PM me with any bodywork questions

                    Comment


                      #11
                      running water in the paint booth ftw! (catch dust and the such)
                      I <3 G60.

                      0.5mm Oversized Stainless valves and bronze guides available. Pm me please.

                      Comment


                        #12
                        DUDE!!! i took your advise on the sanding. but i couldnt wet sand, (didnt know how to do it) anyways there was this circular core sander bit at o'reillys and i bought it for about 10$ because my sand paper got bumps like you mentioned, anyways i use the circular core sander bit on my hood just to try it out and it took about 30 seconds to get to the primer, well, obviously the primer wasnt too thick on the stock coat because about 2 seconds after sanding that area, the core sander went right to thru the primer and down to the bare metal, it looks clean now but i have a question, when i primer my car with like regular primer or primer sealer, will my coat of primer and/or paint look different since some of the primer is still on the car and a scratched up but smooth version of my stock coat of paint is on as well and some of the bare metal as mentioned? i guess what im asking is since i have so many paint and non paint layers on my cars hood, will the paint look uneven after i paint it???
                        1991 HONDA ACCORD LX (MY BABY) COLD AIR, FULL EXHAUST. COMIN UP: CIVIC SPOILER!

                        Comment


                          #13
                          super cool diy....great info very usefull thanx fellas!!!!



                          Heart and Brain Transplant fail I had to pull the plug

                          My new best FRIEND!!!

                          Comment


                            #14
                            Nice writeup. Now I've always wanted to ask this: will the use of heat (from heat gun or blow dryer) help with the curing process or is it unnecessary?

                            Comment


                              #15
                              Originally posted by lonski View Post
                              Nice writeup. Now I've always wanted to ask this: will the use of heat (from heat gun or blow dryer) help with the curing process or is it unnecessary?


                              if necessary.. you're better of using some spotlights and simulate an oven baked finish..

                              also, depends on the type of paint used..
                              read.. http://www.scottgrundfor.com/ideas/paint3.html
                              Last edited by casterX; 02-27-2009, 09:30 PM.

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