Page 1 of 3 123 LastLast
Results 1 to 10 of 25

Thread: Very Unique Bondo Problem! Paint Screwing it up?

  1. #1
    Clover Grayscale's Avatar
    Join Date
    May 2004
    Location
    Arkansas
    Posts
    1,549

    Very Unique Bondo Problem! Paint Screwing it up?

    Alright. I thought I had all my fabrication problems worked out, but I guess not. I bondo'd the dash you see in my avatar this summer, and then decided to do some work on my console, such as removing the ashtray and coinholders and putting in a touchpad and some buttons to control stuff. Anyways, I had a few problems at first with getting the bondo to dry hard. Turns out it was the bondo/hardener consistency. After getting that all worked out, I did all the shaping and made it look perfect. And the bondo was rock hard. I used the same exact paint stuff as last time, obviously to match.

    First I gave it two coats of Bulldog Adehsion Promoter. I was having adhesion problems when I very first started with bondoing, and the guy at this paint store gave me it. It worked good. I just put a couple of coats on over the bondo, then was able to spray paint right on over that.

    The spray Paint I used was Duplicolor Truck, Van, and SUV paint. It's not too bad, but I don't think it's made for plastics. Thats why I used the adhesion promoter. I put a coat of it on over the bulldog stuff.

    I also must say this: Before painting on the bondo there were areas where it looked more "slick". They were like rings, and they were a darker red than the rest of the bondo. When I painted on the console piece, after it dried the paint also looked smoother where the rings where. You will see these rings in the pictures.

    So after the paint had 20 minutes to dry, I naturally pushed my fingernail into it to see if it was pretty solid. My fingernail fell right in. And I could scrape the paint right off the bondo. For some very strange reason the paint actually made the bondo go soft, and allowed me to scrape it off really easy. I was angry and i ripped part of it off, because I was going to have to start over anyways and it would be easier to replace the wood and rebondo than to sand it all. Well when I got home to take pictures most of the places where I had sanded on were nice and hard again.

    So two problems: 1) What are the rings where it looks smooth and is really shiny? and 2) why did the bondo go soft? was it from the paint or the adhesion promotor?!?!

    Sorry for the extremely long post, but I think I had to explain all of this to get a good answer! I put up a bunch of pix also, just so you will get to see what all is going on with this.
    Attached Images Attached Images  
    CarPC install is starting to come along again...

  2. #2
    Clover Grayscale's Avatar
    Join Date
    May 2004
    Location
    Arkansas
    Posts
    1,549
    Here you see the bondo thats all crumbled from where I ripped part of the piece off. This is when it got hard again. Before you could kind of peel the bondo right off the wood because it got soft.
    Attached Images Attached Images  
    CarPC install is starting to come along again...

  3. #3
    Clover Grayscale's Avatar
    Join Date
    May 2004
    Location
    Arkansas
    Posts
    1,549
    Here is a surface shot where I just kind of scraped the paint and the bondo a bit to let you see how that looks
    Attached Images Attached Images  
    CarPC install is starting to come along again...

  4. #4
    Clover Grayscale's Avatar
    Join Date
    May 2004
    Location
    Arkansas
    Posts
    1,549
    Here is the adhesion promotor I used, and the paint I used. They were stored out in my garage in the cold (40-50), but I warmed them up by the furnace where I was working.

    I should note: I did my bondo work and my painting in a nice warm shop where it was about 65-70 degrees I'm sure
    Attached Images Attached Images  
    CarPC install is starting to come along again...

  5. #5
    Clover Grayscale's Avatar
    Join Date
    May 2004
    Location
    Arkansas
    Posts
    1,549
    Another close up of the bondo crumpled
    Attached Images Attached Images  
    CarPC install is starting to come along again...

  6. #6
    Clover Grayscale's Avatar
    Join Date
    May 2004
    Location
    Arkansas
    Posts
    1,549
    To give you a better idea of what i was working on:
    Attached Images Attached Images  
    CarPC install is starting to come along again...

  7. #7
    Clover Grayscale's Avatar
    Join Date
    May 2004
    Location
    Arkansas
    Posts
    1,549
    Just one more of the surface with the "smooth spots" and the darker spots...
    Attached Images Attached Images  
    CarPC install is starting to come along again...

  8. #8
    Maximum Bitrate Altimat's Avatar
    Join Date
    Oct 2003
    Location
    WI
    Posts
    764
    Did you use primer?

    Bondo is like a sponge. Primer looks the same way when its first applied over bondo. You need to repair that, use good commercial-grade body filler like evercoat, prime severla coats, sand, prime again, repeat until all the imperfections are filled. Let every primer application cure overnight at least. It should look perfect when you apply the last coat of primer. then sand with 600 and paint.
    I suspect the bulldog isn't recommended over bondo. Its made to soften whats underneath it. I wouldn't use it.
    Fabricator

  9. #9
    Newbie
    Join Date
    Mar 2004
    Location
    North Delta, BC
    Posts
    18
    Can't necessarily diagnose your exact problem, but here's my take on things:

    First of all, straight Bondo was the wrong product to use for this application. It has very little structural strength on its own, and should never be applied more than 1/8" think, and it looks like you've got almost a half inch layer on there.

    Second, the soft spots you saw could possibly have been from simply not mixing your bondo and hardener thoroughly enough. Might be from the adhesion promotor, might not be, but that would be my guess... (but next time don't use the bondo at all at that stage).

    Finally, as far as your paint goes, not all types of coatings will work together, so it could simply be a compatibility issue.

    Next time try this, use a fiberglass resin or bondo glass to cover the piece you're working with, then only regular bondo or a spot putty to fill in the low spots, minor imperfections, etc. Then when you're ready to paint, if you're going to be using that duplicolor paint again, stick with duplicolor primer. It's always best (but not imperative) to match your paint with your primer, plus the duplicolor primer will provide a nice base to spray over anyways.

    Best of luck to ya

  10. #10
    Clover Grayscale's Avatar
    Join Date
    May 2004
    Location
    Arkansas
    Posts
    1,549
    Ahhh...It's made to soften whats underneath it. Well that will definately cause that I guess . Ok, well the filler I have is pretty good. It's not bondo brand and it's not evercoat, I can't remember what its called but most of the shops around here use it aparently. Ok, so can you recommend what type of primer to get? I am kind of scared of them because my very first bondo job I used a laquer-based primer and it completely screwed up everything. So this will take like 3 nights just to get to be able to actually paint on it? If it looks great, then it will be worth it I guess! I'm getting a respirator first thing before next project! I accidentally inhaled after spraying bulldog a couple of times. That stuff is super strong. I can still feel the sort of burning sensation in my throat/lungs. I wonder if it made them soft?!
    CarPC install is starting to come along again...

Page 1 of 3 123 LastLast

Similar Threads

  1. Xenarc + Bondo + Paint + One night =
    By LESLIEx317537 in forum General Hardware Discussion
    Replies: 52
    Last Post: 02-14-2004, 04:03 AM
  2. A Unique Problem
    By hippie in forum Software & Software Development
    Replies: 4
    Last Post: 05-14-2001, 09:32 PM

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •