pitting in primer

Discussion in 'Paint and Body' started by ryan greathouse, Nov 6, 2018.

  1. ryan greathouse

    ryan greathouse

    Messages:
    199
    Likes Received:
    48
    Joined:
    Mar 1, 2015
    Location:
    Oroville, CA
    I am sanding my primer and there is pitting. Even after I get all of the guide coat off there are still some pits. I have sanded down to the old paint in some places and it is frustrating. The picture shows the pitting as darker spots, with more sanding done at bottom.

    some say it is too dry, add more reducer, some say the tip is too small and should bump to 2.0 (google)

    Experienced painters please help.

    IMG_2491.jpg
     
  2. Splangy

    Splangy SILVER Star

    Messages:
    6,669
    Likes Received:
    1,093
    Joined:
    Aug 4, 2009
    Location:
    New Hampshire
    Could be either of those things or a combination. Either way, it didn’t lay down very smoothly. Be sure to use adequate lighting and watch it lay down carefully to ensure its going on wet and smoothly.

    By too dry, I usually think of too much air and not enough paint flow. It is possible, however that the wrong temp reduced was used (or not enough) and that it began flashing too quickly.

    Whatever the cause, it’s best to shoot a scrap test panel and watch how it lays down prior to shooting the car.

    Look at the bright side, this thing shiuld be straight as an arrow after blocking the second coat of primer!
     
  3. ryan greathouse

    ryan greathouse

    Messages:
    199
    Likes Received:
    48
    Joined:
    Mar 1, 2015
    Location:
    Oroville, CA
    ok, live and learn. I did test it out before hand and it looked great to me, but I didnt know what to look for i guess.

    I plan on sanding the whole thing with 320, then re-spraying after making sure I can produce a smooth coat. Thanks
     
    gregnash likes this.
  4. gregnash

    gregnash Anal Retentive Analyst SILVER Star

    Messages:
    9,202
    Likes Received:
    2,629
    Joined:
    Nov 4, 2011
    Location:
    Carson City, NV
    What tip are you using on your gun? Most info says that primers can be sprayed with a 1.4 to 2.0mm tip. When I was first messing around and trying I found that the 1.4mm tip on my cheap purple HF gun didn't like the DTM primer I was using (which a lot of people said the gun didn't like ANY primers) so I drilled it out to approximately a 1.8mm tip and it flowed great after that. Food for thought?
     
  5. ryan greathouse

    ryan greathouse

    Messages:
    199
    Likes Received:
    48
    Joined:
    Mar 1, 2015
    Location:
    Oroville, CA
    I am pretty sure it is the 1.4 tip, the kit came with a 2.0.

    Ok, just talked to the folks at the local paint shop and I am going to spot putty the really pitted spots and deep sctratches that still show, then go over with 1000 grit.
     
  6. Splangy

    Splangy SILVER Star

    Messages:
    6,669
    Likes Received:
    1,093
    Joined:
    Aug 4, 2009
    Location:
    New Hampshire
    What tip does the primer recommend? If it’s a high build surfacer, I bet it’s at least a 1.8 tip.

    1000 grit is way overkill and would take you forever to sand. I would stick with 600.
     
    Last edited: Nov 7, 2018 at 5:34 PM
    gregnash likes this.
  7. ryan greathouse

    ryan greathouse

    Messages:
    199
    Likes Received:
    48
    Joined:
    Mar 1, 2015
    Location:
    Oroville, CA
    I agree but the guy convinced me because (he said) the 1000 will cut the glaze down without knocking down the primer, any coarser and you will dig out the glaze
     
  8. gregnash

    gregnash Anal Retentive Analyst SILVER Star

    Messages:
    9,202
    Likes Received:
    2,629
    Joined:
    Nov 4, 2011
    Location:
    Carson City, NV
    If you are cutting through to original paint I would recommend throwing another layer of primer on there. Buy another quart an throw it down with the 2.0 tip and bet it lays down nicer like @Splangy said.
     
  9. Splangy

    Splangy SILVER Star

    Messages:
    6,669
    Likes Received:
    1,093
    Joined:
    Aug 4, 2009
    Location:
    New Hampshire
    I agree. Don't waste your time with putty when this is probably the best option.
     
  10. PAToyota

    PAToyota Keystone Cruisers SILVER Star

    Messages:
    1,565
    Likes Received:
    481
    Joined:
    Oct 4, 2009
    Location:
    South Central Pennsylvania
    You don't say what primer you're using, but I agree with the others to lay down another high-build primer coat and go from there.
     
  1. This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
    By continuing to use this site, you are consenting to our use of cookies.