Collision Blast

Providing FREE Auto Body and Paint Training Videos

Collision Repair Training – How To Apply and Block Sand Body Filler or Bondo

by 9 Comments




 

SCROLL TO BOTTOM FOR VIDEOS, THE  STEP-BY-STEP PROCEDURE AND ADDITIONAL RESOURCES. HOOK US UP BY SHARING THIS WITH YOUR FRIENDS. CLICK THE FACEBOOK BUTTON TO THE RIGHT.

First of all, let me explain what the difference is between bondo and body filler. Well, there is not a difference. Bondo is just a brand name. You may be saying there is a difference, some spread easier that others and some sand easier. That is true too! How can it be the same and different? Well, Coca-Cola and Pepsi are both a pop, right? But they are different at the same time. Body fillers are the same way. Bondo is just a brand of body filler. However, it has became a trade name. The reason that I post this first is because I get a lot of question about this. So there you go, now you know.

In the first training video, I will demonstrate how to mix and apply body filler to a damaged area.




 

[youtube]http://www.youtube.com/watch?v=eygKDon4z7M[/youtube]

In the next video below I am demonstrating how to block sand body filler.  A common question that I get asked it how to sand body filler without it feeling lumpy or wavy.  There are a few things that will help you get a level surface.

The first thing is to cross sand.  I can not stress how important this is.  Sanding in only one direction allows your block to follow waves.   Kind of like a ship at sea….going with the motion.  However, we don’t want to follow patters, we want to level them.

The second little bit of advice it to level before smoothing.  I think that students have the objective is to get the body filler real smooth.  However, switching to finer grits too soon will lead to lumpy body filler work.  Make sure to have surface completely level before switching to finer grits.

[youtube]http://www.youtube.com/watch?v=cUj_jZIOfNg[/youtube]

Step-By-Step – 9 Step To Apply and Sand Body Filler

  1. •If the repair has been welded, mix and apply fiberglass filler to repair area.
  2. •Sand the filler with 36 grit.  There is no need to use a finer grit as body fill will be applied over the fiberglass.  All you need to level the glass filler.
  3. •Mix and apply body filler over the repair area.  Cover and extend body filler over fiberglass.  Do not extend the filler onto the paint surface.
  4. •Block sand (cross sand) the filler with 36 grit sandpaper.  (This step can be done before the filler is completely dry to reduce the amount of sanding required.)
  5. •Repeat step if there are still lows.
  6. •Allow to fully cure (15 to 20 minutes) and spray with guide coat.
  7. •Block sand (cross sand) with 80 grit sandpaper.  Sand just enough to remove guide coat.  If guide coat does not sand off in an area indicates a low and additional filler will be needed.
  8. •Optional: Either apply guide coat and block sand with 150 grit; Or, Apply a coat of finish glaze over entire repair area.  Remember, glaze can be applied over sanded paint too.
  9. •Finish filler or glaze by blocking with150 grit.