Bondo / sanding / primer questions

Discussion in 'That'll Buff Right Out' started by MP, Mar 9, 2004.

  1. MP

    MP New Member

    Joined:
    Sep 10, 2002
    Messages:
    34,377
    Likes Received:
    0
    Location:
    Silicon Valley
    ok here is my situation. I'm doing a little prep work before my car is to be painted.

    basically after i've applied a thin layer of bondo, sanded to be very smooth (ie: finger running across it is hard to even tell the difference from the body to the bondo area.

    after i sand it / clean it i'll spray on a coat of primper and when it dries you can kinda see where the bondo is. It's a little hard to explain but there will be a circle or whatever shape the bondo is in. Looks kind of like an island? I've sanded it and sanded it (using 400 btw) and everytime i primer it, i keep seeing the island looking thing. I'm doing a feather technique, sanding outwards and it seems to be working VERY well. I've gotten the area so smooth is nuts. but the island looking thing remains

    will this show up after paint, or will all the layers of paint / clear coat get rid of it?

    different sand paper?
    different primper?
    could i be mixing the bondo/hardener wrong?

    ahh, i don't even know if it's something to worry about. When i run my fingers across it after it's primered you feel NOTHING, it's very consistant and smooth.

    any suggestions would be great. I'm trying to get my car prepped asap.
     
  2. a red heart

    a red heart Guest

    yes it will show up. you have to get it perfectly flush with the panel. if you can see it with the primer over the bondo it will show up a lot more when its painted.
     
  3. a red heart

    a red heart Guest

    you need to be using a sanding block
     
  4. a red heart

    a red heart Guest

    also make sure the primer is sanded down with at least 800 grit or scratches will appera on the paint. i fucked up my car really badly when I painted it. i now know all the mistakes :rofl:
     
  5. MP

    MP New Member

    Joined:
    Sep 10, 2002
    Messages:
    34,377
    Likes Received:
    0
    Location:
    Silicon Valley
    800?? wow, i was told to block sand my car w/ 400


    i'll keep working at it to get it perfect. Should I use a lighter sandpaper for sanding down the bondo? 400 still?
     
  6. gandhibrokemyskates

    gandhibrokemyskates slangin beer

    Joined:
    Jun 22, 2001
    Messages:
    28,157
    Likes Received:
    0
    Location:
    Houston
    I believe what you are getting is called Fish Eyes. I've prepped two cars i had, and I got fish eyes on the first car i did.
     
  7. MP

    MP New Member

    Joined:
    Sep 10, 2002
    Messages:
    34,377
    Likes Received:
    0
    Location:
    Silicon Valley
    yeah i guess that's what it's called.


    I guess i just have to spend more time on it to get it absoultly perfect.

    oh wells, better safe then sorry.
     
  8. a red heart

    a red heart Guest

    here is a good method.

    block sand the car, get it PERFECT from all angles, use 400 grit

    go over that area with isoprop alcohol or laquer thinner or whatever, just clean teh fuck out of hte surface

    shoot he primer

    sand the primer down so that it fills all the minor scratches in well... do this sanding with 600 grit or 800 grit.

    now use the laquer thinner again i cant remember fuck fuck fuck the shit you mix the paint with... just use that its really gassy smelling just clean the surface well or you will get fish eyes

    now spray your final primer coat... sand it with 600 or 800, spray paint... spray clear.. wetsand buff fun.
     
  9. MP

    MP New Member

    Joined:
    Sep 10, 2002
    Messages:
    34,377
    Likes Received:
    0
    Location:
    Silicon Valley
    -sand like crazy w/ 400 grit
    -clean it good
    -primer
    -sand w. 600 - 800 grit
    -clean again
    -primer again
    -sand again w/ 600 - 800 grit

    800 grit is rough enough for the paint to stick?

    thanks btw
     
  10. a red heart

    a red heart Guest

    600-800 is ideal from my experience
     
  11. MP

    MP New Member

    Joined:
    Sep 10, 2002
    Messages:
    34,377
    Likes Received:
    0
    Location:
    Silicon Valley
    i'll be working on it tomorrow :wiggle:

    thanks again
     

Share This Page