ASE Test Guide B2 Paint and Refinish Surface Prep Part 1


– Hey, YouTube viewers. This is Donny Smith, and
welcome to this video series that is designed to help
you passed the ASE exam. Now this video series is specifically for the paint refinish, and what we’re going to do is
we’ll go through the tasks, and give you the knowledge
to pass the test. What this is not, this is not really your prep test type book. It’s not just test questions. If you want that, there is a
link down in the description. You can get more information about that. What this is, this basically
goes through all the tasks that you will need to
know to pass the test. (car screeches) Now we’ve already talked about
safety in a previous video. This video, we’re going to concentrate on surface preparation, and the first task we’re
going to talk about is inspect, remove, store,
and replace exterior trim and components necessary for
proper surface preparation. Now, this is important steps
and I’ve seen it skipped or missed many times, maybe
not so much in the body shops as it would at a school, but it’s really just thinking about what you’re going to do. During repair plan or
whenever you’re thinking about the steps you’re going
to take to paint something, you kind of have to have the
end in mind before you start. And go ahead and get
the car ready to paint, you know, to prep instead of waiting to the last minute until
you have to do everything. For example, it talks about exterior trim. If there’s a molding that’s
going to have to come off or door handle, take it off before you ever do anything else. I mean, do that first. Get it ready. For example, I’ve seen moldings left on the car till right at the end, and then you’re trying to get it off, and then you have to go back and sand where the molding was at, or the door handle, you end
up scratching the door handle or belt molding, you
know something like that. So it’s a really good idea to go ahead and strip the car down
whenever you’re getting ready to prep, ready to sand, wash, whatever. Go ahead and get all
that stuff off of there, that way whenever you’re sanding, you’re not having to be so careful, trying to avoid scratching
an adjacent molding or anything like that. So, get everything off the car before you ever start
prepping the surface. Okay this next task is
another one often overlooked, but it can lead to many problems and that is soap and
water wash entire vehicle; use appropriate cleaner
to remove contaminants. Now, before you start sanding on the car, let’s say you got it
stripped-down ready to go and I see this a lot,
you just start sanding and you think I’m going to wash it before I get in the booth
so it’ll be cleaned. Well, that may be partially true, but whenever you’re
sending, you’re smearing around those silicones and
contaminants on the car. So, you want to get that off first before you start working on car, not only is this going to make sure you don’t have any
problems, like fish eyes or adhesion failure or things like that, washing the car first is
also going to save money, and that is because of being
able to wash car first, you’re getting rid of the waxes, the silicones, the contaminants, and that’s not going to
load your sandpaper as fast cause if you leave all those coatings, you sand just for a second, those contaminants load the sandpaper and you’re going through
a lot more sandpaper and taking longer, so
it’s taking more effort, costing you more money if you’re
not washing the car first. So, be sure and wash the
car with soap and water. Use an appropriate
cleaner, you know something like a wax and grease remover. Every paint brand has
their own version of it, but as long as it’s designed
to clean off silicones… Be sure and wash the
car with soap and water, wipe it down and then you
can start your prep work. Okay, the next task that
we’re going to look at is inspect and identify type of finish, surface condition and film thickness; develop and document
a plan for refinishing using a total product system. And again this is important to do and this talks about
developing your repair plan, making sure that you go through the steps before you start working on the car. For example, it talks
about type of finish. Is it lacquer? There’s not a lot of
that around these days, but there could be. Is it base clear? You have a tricoat coming? What is it that you’re having to do? You want to know that up front. The next thing is the film thickness. This is very important. They got the little magnetic gauges, that will work. They’re not as effective, but they got the digital gauges, as well. Now the digital gauges
has to be a metal surface, but go around and gauge your paint on the different panels that you’re going to be
prepping and painting because of it’s 10 mils or more, you may have to strip that
or partially strip it. Too much paint coatings
can cause adhesion problems It can cause your gaps. You keep putting more
coatings on your edges, and that might cause a problem
where you open the door and it knocks a chip off after
you painted the last time. That’s the last thing you
want, is to open the door and then knock a chip of paint off, you know things like that. So, if it’s over 10 mils you
may have to partially strip it. Now you don’t have to
completely strip it necessarily if the paint is in good condition, it’s not cracking, peeling
or anything like that, it’s just too thick, you can go with, this is what we do, there’s different methods of doing it, but we start out with 180
and we take it down just about to the desired mil thickness, six mils or whatever we’re
wanting to get it down to, and then we jump a hundred grit at a time. So we go from 180, well, then we go to 220. That’s what we use. That’s not quite a hundred grit. And we go around the entire
service that we went with 180 to minimize the 180 grit
scratches with 220 grit. And then once we do that, we go with 320. And then we go around
the entire car with 320 to minimize the 220 grit scratches. And then we jump a little bit from 320, and then we go to 500. And that’s not exactly a hundred grit, but it’s pretty close and we go over the
entire car with 500 grit. And 500 grit’s just going
to minimize the scratches, you know the 320 grit scratches, and then that’s what we paint on top of. We seal and paint on top of 500 scratches, now your paint system may
be a little bit different. Water-born more may require 600. Just kind of determine, read
your technical data sheet to find out what the sandpaper grade recommendation is to finish that out. Generally, four to six hundred is what generally is used for
final sanding before paint. And also you want to check
the surface condition. Is it cracking or peeling or is there any problems with that paint? A lot of times, problems
like that’s going to require you to strip it completely. Now, there’s different ways to strip, whether you’re allowed to
use chemical stripper or not. You can do use a DA sander. You can sand it all down with 80 grit, whatever is recommended,
however your SOP prefers. 36 or 80 is probably what
most shops are going to use if they if they sand it with a DA. If it’s one panel, you can have
it sanded down pretty fast. If you got access to some
type of media blaster… There’s different ways to do it, but if there’s a problem with that paint, you’re probably going to have to strip that down to the metal and then come back with whatever system
you use or different… You can use, there’s metal
treatment you can use or there’s self-etch primers
or there’s epoxy primers. Depending on your paint system,
they all vary a little bit, it’s going to determine
what method repair method that you take from there. Then it says develop and document a plan, and basically I just
called that a repair plan. And what that is, is
basically determining what all you need to do up front
before you start on it, and then that way, whenever
you start to do it, you’ll have a step-by-step process to make sure you don’t skip things, like remove that molding or to check the paint mil thickness. So you’ll know, do I need
to strip this down partially or do I just final sand it? That way you’ll know up front the steps that you need to take. It is my goal to keep these videos short, so that’s all were going
to cover in this video. Just give you little chunks at a time, let you absorb that, and then
you can watch the next video. Down below is a link
to the test prep books that I have, but also there’s
a link that will take you to all these videos if you’re wanting to go through more than
one video at a time and take you through the entire playlist. So be sure and check that out to go through the ones
that I’ve already uploaded and as they become available, they’ll also be put on the site, as well. Thanks for watching this video. I hope this helps, and good
luck with your ASE exam.