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Thread: Sand Paper grit general uses?

  1. #1
    Join Date
    Sep 2007
    orange county california

    Default Sand Paper grit general uses?

    I could have sworn there was a chart that Len made that shows all the different Grits and there general uses - does anyone know where I can find that?

    I have the Fenders and doors done, trim holes welded up, (finally figured out how to do my filler correctly - only took a gallon of filler that i ended up completly sanding off many many times on fender before i got the knack) thanks Len - your tips helped immensly, I also found that Evercoat z-grip sands very easily and seems to be more fluid like then the Rage that I was using at first - so I am sticking with the Z-grip i like it)

    I am using 2k PCL high fill Polyprimer - some areas are to the metal - but mostly covered in filler, I have read not to use etching primer over or under the filler... what should I do about these small areas - or do you think that the polyester primer will adhear to the metal well. I have 2 guns - one is a syphon feed with a 1.8 the other is a gravity feed with a 2.0 - i am sure the 2.0 will be the best one?

    how many coats is too many coats of primer - there will be alot of sanding involved to cover the old paint, the filler so I dont see where my feather edges are?

    how long is too long for Primer to be on the veh. - I am doing this in the garage - its not outside, but it wont be until after Christmas before I can afford it to be painted in color.

    another quicky:
    anyone got any ideas on a in line water seperator/filter that does not choke the air supply so much - got a small one from Lowes and it seems to choke about 35% of my air supply off im using it about 3 feet from the end of the hose?
    Last edited by cmalves1; 10-31-2007 at 02:53 PM.
    ~ There is no substitute for hard work. ~

  2. #2
    Join Date
    Nov 2005
    Rochester NY


    On this page found here Len explains some of the common sand paper grits and there is a link at the bottom to a conversion chart. Maybe that was what you were looking for?

    I've never heard of the Primer your using but found this on PCL's website and wonder if it's the same thing your using?

    If it is then according to that P-Sheet this stuff is a Polyester Primer-Surfacer and will stick to metal. Yes you don't want to use a Primer-Etch over body filler as it's only intended to be used over metal and what it does only works on metal.

    In your case you could just make sure the metal is clean and treated then shoot your primer over the entire area, filler and metal.

    Can't answer you on which one of the guns would be better. Generally for spraying Poly Primers, either tip size you have would be sufficient. I own 3 guns and all are Gravity Fed HVLP but I have heard of folks using the Siphon style guns for heavier materials as they tend to do a better job.

    You should use a Guide Coat when working with body fillers or anywhere else that requires feather edging. That way there will be no surprise's when you lay down the covering material.

    Piling on Primers or Paint isn't going to substitute for poor body work. You'll just be making work for yourself.

    As for how many coats, the P-Sheet will usually specify that but generally for Primers two or three medium wet coats is plenty.

    The P-Sheet for the material being sprayed will list different "windows" as to flash time between coats, time to dry, sand, topcoat, and re-coat with itself.

    The Primer can stay on indefinitely while your waiting to paint the car. It's what happens to it while your waiting to apply the paint which is of concern.

    Since your not going to be driving it, and it'll be stored indoors I would just wait a few days after the primer has dried then cover the area up with some plastic mill sheeting to keep any contaminates off.

    When you go to paint, you'll need to clean the panels (not with a wax grease remover) then scuff with 320/400 grit.

    Those cheapie water separators at the Big Box stores are junk. If you have a Autobody or a Industrial Supplier near you stop in and they should have them or you can get them from Len here at the store.

    Thoughts and comments expressed by me are mine based on my own experience and research and shared here freely. I am not a professional nor make any claim to be as such

  3. #3
    Join Date
    Nov 2005


    How did you find that page?

  4. #4
    Join Date
    Nov 2005


    From the Home Page hover over Paint Shop then Surface Prep then click on Materials.

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