Hey guys, Tom Cornelius here, application engineer at 3M.
Today the topic is going to be body filler. We know there's a lot of different ways to mix and
spread body filler, but today we're going to focus on best practices as well as some tips and tricks.
Before we get going, it's important to remember to wear your proper PPE. You'll see today I'm wearing
safety glasses, protective gloves, as well as a respirator. Another thing to remember is that
this video is intended for professional settings such as a body shop or paint shop.
for more information on safety and warranty please see the link below.
Cleaning is foundational. We want to clean with soap and water as well as a solvent-based
wax and grease remover. We're going to apply the cleaning solvent to the panel.
We recommend a folded paper towel so we can switch to fresh new sides as we're cleaning.
Okay, now that we've cleaned our panel the first step is going to be sanding with 80 grit on a DA.
So the goal with the 80 grit is to sand 2 to 4 inches beyond the damaged area
down to bare metal. We want to make certain that we sand all the way down to bare metal.
We don't recommend applying body filler over aftermarket
paint systems or any aerosol e-coat product. We recommend clean, bare steel.
Once we've sanded 2 to 4 inches outside the damaged area, we need to come back and remove
the pitted paint at the center of the dent. We have a couple of different options for this.
We can use a Roloc or a file belt tool, or we can scratch it out with 80 grit by hand.
but today I'm going to be using the 3M File Belt tool which is a cool tip or trick for removing that paint.
Now that the sanding process is complete it's essential that we come back and re-clean the area.
So again we're going to fold a paper towel and we're going
to use a solvent-based wax and grease remover.
After we've thoroughly cleaned the surface it's important to apply the body filler
within 30 minutes if we're working with steel, or within an hour if we're working with aluminum
in order to avoid dust debris moisture and other contaminants forming on the surface.
With that, we can go ahead and mix our body filler.
So, only use 3M hardener when you're using 3M body filler. It's important to stick to the brand
that comes from each manufacturer. It's important to knead the hardener
before we apply it to the body filler.
A good ballpark is roughly a 3-inch amount of body filler.
This is probably an average size mix, so when we have roughly 3 inches
of body filler on our mixing board, the recommendation is going to be to apply
one bead of hardener across the diameter of the body filler as opposed to two lines or three lines or even four.
This is going to be a good ballpark estimate on achieving that 2% or 50:1.
So now that we've applied our hardener to our body filler we can go ahead and start mixing.
There's a variety of techniques when it comes to mixing filler.
But one of the most important is going to be to fold and flatten the body filler
as opposed to stirring the body filler, which can introduce air
and so i'll show that to you in the event that we were actually to stir the body filler you can see
now that when i go to spread it we've introduced lots of different air pockets into the mix
and that's why it's so important to fold and flatten.
Once the body filler is thoroughly, mixed before we go to apply the body filler to the substrate
we strongly recommend that you flatten the body filler across the mixing board
for a couple different reasons. One is going to be to force out any air that's in the filler
and secondly, it's going to extend the work time of the filler as well.
When we go to apply the body filler to the surface, we're going to begin
by applying what we call a tight coat.
What this does is it forces the material into the substrate to obtain adhesion as well as
make certain that we don't introduce too much air which could lead to pinholes
After we've applied our tight coat we can follow with our actual build coats.
During our building coat application, we're looking to stay within the bare metal area
and not extend our body filler out into the paint area.
Once we've spread both our tight coat as well as our build coat
We're ready to let this cure and come back and sand.
Okay, now that we've applied our body filler I'm going to move some items that we
no longer need off the bench to make more space.
So guys, one more thing on the body filler application. You'll notice that we applied
a single tight coat as well as a couple thin build coats. Our recommendation is
that we don't exceed 1/4 inch in any single application of body filler.
This is to avoid air entrapment as well as many other issues.
It's strongly recommended that you refer to your OEMrecommendations for more information
One more thing I want to talk about is the importance of using a mixing board when we're applying filler.
So as you can see we used a 3M mixing board as opposed to cardboard which we see which is super
common, or other substrates that we see body filler being mixed on and so the reason that we want to
avoid cardboard for example can be a number of different reasons. We don't know which contaminants
are on the cardboard. Oftentimes cardboard is coated with a wax, the fibers themselves
of the cardboard could transfer into the body filler and contaminate the mixture. It could also
transfer ink that may be printed on the cardboard, as well as the fact that most cardboard naturally
has indentations which it could begin to fold and lead to air entrapment in the body filler as well.
So these are important things to keep in mind.
Okay guys, that's it for today. Hope you enjoyed the video.
I know today we were just working on a test panel and not on an actual car
but hopefully, you found some valuable information or some tips and tricks. If you like this video
please feel free to comment below. You can share the video or definitely hit the subscribe button.
For additional content please check out the 3M Collision Repair Academy
Thank you, guys.