Hey guys! Tom Cornelius here, application engineer at 3M. Today we're going to focus
on repair mapping and how to avoid it when it comes to body filler and glaze application.
And so we know there's a lot of different ways to feather and sand body filler and glaze,
but today we're going to focus on best practices and tips and tricks to help avoid repair mapping.
So before we get started guys, please remember to wear the proper PPE. You'll see today
I'm wearing my safety glasses, respirator, I have earplugs, as well as protective gloves,
and another thing to remember is that this video is recommended for professional settings such as
a body shop or paint shop For more information on safety and warranty, please see the link below.
Okay guys let's get started. In front of me I have a panel that had previous damage or dented area.
We've prepped this, sanded it down to bare metal, applied our body filler, and we're ready to start
sanding. First thing we want to do before we begin sanding is apply our Dry Guide Coat. This is a 3M
Dry Guide Coat product. It's a powder as opposed to an aerosol or spray and this is going to weep
down into coarse grade sand scratches and help us fully refine and feather those sand scratches.
So the recommendation is just a medium amount of Dry Guide Coat applied to the body filler.
A few things about the Dry Guide Coat - when we compare it to an aerosol or a spray guide coat,
the powder is actually going to weep down deep into coarse grade inline sand scratches versus
an aerosol or liquid guide coat can actually just bridge over the top of the sand scratches.
Both products will work well for high spots or low spots but really what we're focused on
today is having the ability to refine coarse grade or inline sand scratches with the DA
and it's next to impossible to do that without the use of Dry Guide Coat.
Okay now we're ready to start sanding. Again we're going to start out by applying Dry Guide
Coat to the body filler and the first thing we're going to do is do an initial sand with 80 grit
on a DA. Today I'm using 3M Cubitron 2 80 and really we're just going to do a rough sand just
to knock down the body filler and knock down any spreader trails or edges that we might have.
We're not looking to sand obviously all the filler away with the 80 but just initial rough sand.
So now that we've done our initial rough sand with 80 grit on a DA,
we're going to reapply Dry Guide Coat and begin the blocking process.
On my block I have again 3M Cubitron 2 80 grit and with that we're ready to get started.
After we're finished blocking with 80 grit,
we're going to move to either a 150 or a 180 and continue sanding.
Again we're going to reapply Dry Guide Coat.
And today I've chosen 150 on the block and again this is the 3M Cubitron 2
150 product. And with that we'll begin sanding.
So guys we applied our body filler. We reapplied Dry Guide Coat. We rough sanded our body filler
with 80 grit on a DA. We reapplied Dry Guide Coat. We check block this with 80 followed by 150. One
thing I want to point out specifically, we want to be intentional to try not to sand or to extend our
inline block scratches any further out around the perimeter of the factory paint than we need to,
so we want to try to keep it as tight as possible and really control those inline sand scratches.
Inevitably they're going to extend into the outer perimeter around our repair,
so what we need to do before we move on to the glaze application, and this becomes extremely
critical, is come back and feather edge these sand scratches. So again we're going to reapply
Dry Guide Coat. We want to make certain to apply the Dry Guide Coat not only on the body filler
but especially around the outer perimeter where the sand scratches from the block have extended.
So now that we've applied our Dry Guide Coat we're going to use
180 on a DA. Today we're using our 3M Cubitron 2 180 and we want to use the DA to fully feather
edge and refine the outer perimeter where the sand scratches have extended into the paint.
So we know that different positions exist in regard to whether or not to now
apply the glaze out onto the paint edge or to keep it within the bare metal area, but
regardless we need to make certain before we move to that step that we fully refine all inline sand
scratches from the block with a DA, typically with a 180, before we move to the glaze application.
So before we move on to the glaze application we want to clean
this damaged area using a solvent based cleaner. We want to make certain that we don't apply the
cleaner directly to the body filler but instead we want to apply it to the paper towel.
One important thing to remember when cleaning body filler, as mentioned,
we don't want to apply the cleaning solvent directly to the body filler due to the fact that
body filler is going to absorb that cleaning agent just like a sponge and some of that material could
get trapped in the body filler. If this is your standard practice, our recommendation is that you
fore-splash any of the cleaning solvent off the filler. Meaning run dry air or a blower across
the body filler to make certain that we don't trap any of that cleaning solvent in the filler.
If the cleaning solvent is trapped in the filler and we begin the priming process too quickly,
the trapped solvent could lead to blistering or other failures in the body filler.
Okay guys as you can see we've finished the body filler sanding. We've taken the time to
fully feather out and refine the inline sand scratches that were on the outer perimeter and
the original paintwork and so at this point we're ready to move the glaze. When it comes time to
apply your glaze and sand your glaze, we want to apply all the same principles. Use Dry Guide Coat,
take the time to refine inline sand scratches before we move to primer. If you keep these
tips and tricks and best practices in mind we should be able to avoid repair mapping.
Alright guys that's all for today. Hopefully you enjoyed the video and you learned something.
Please feel free to comment in the section below. You can also share the video
or definitely hit the subscribe button. If you want to find more videos like this you can check
out our YouYube channel or visit 3M Collision Repair Academy, and we'll see you next time.