Spraying Primer – Avoid These Mistakes When Spraying Primer on a Car – DIY Auto Body and Paint


-Hey. This is Donnie Smith, and
welcome to this lesson on spraying primers. In the last video
in this series, we showed you how to mix
up some Epoxy Primer, now we’re going to
spray it on the car, and then we’re going to
mix up some primer-surfacer and apply that as well. First, before we start
to talk about spraying, I’d like to talk about
some of the mistakes, the common mistakes that I
see with spraying primers. And probably the biggest
mistake I’ve seen out there is trying to put too
much on, put it too wet, too many coats too soon. And that causes a
lot of problems. A lot of the problems
that you have in paint can come back to not
enough flash time or putting it on too thick. That’s why it’s important to
look at the technical data sheet, and find out exactly
what you’re supposed to do. And there’s technical data
information to the Epoxy and the primer-surfacer
at the end of this video for the ShopLine. Putting it on too thick, it
can cause a number of problems. But let’s talk about one of
the problems that can lead to. If you’ve ever seen
dry dirt or mud that’s dried and all the water
has evaporated out of it, it’s all cracked up, well,
you know, primers and paints, they do the same thing. If you put it on too thick,
too heavy, it’s going to dry, and if there’s a possibility
that some of these products can do that, and it could
actually crack on you and give you that cracked
look just like dried mud. Another thing that can
lead to is solvent popping. And what that is, is when
you apply it on too wet, the outside surface is
already kind of dried and what’s underneath can’t
escape, can’t evaporate. So you’ve got all those solvents
underneath and everything’s going evaporate sooner
or later, and what it does is, instead
evaporating the way it should, it later, after that
top film is dry, is it evaporates but it makes a
whole where that evaporates at. So there’s like a tiny
little pinhole in there. And sometimes those can
be very deep especially if it was the first coat of
primer or this is escaping at. And so it’s going to go
through all that surface and have a hole there. Another thing, if you put it on
too thick, too many coats too fast, it could shrink on you. So you might have it
sanded down, it looks good. And you paint it,
and it looks good. Then a couple days later,
even weeks later, that primer continues to shrink because
it couldn’t dry properly and then you see repair mapping
and sand scratch swelling from where you did
your body work. All those can be
eliminated if you’ll just follow the technical data sheet
and not put it on too thick. I know. Most of us are all the same. I mean, if a little
bit does good, we always think more is better. I mean, I’ve tried vitamins,
and well, I can’t really tell if that doing anything. Let’s try more. But just like with
medications, vitamins, more is not necessarily
better, and that’s the case in refinished products. So always read that
technical data sheet and follow the recommendations
because they’re there for a reason. Now, I know I mentioned allowing
it to flash the proper flash time, what’s the technical
data sheet say about that. Let me back up and tell you
exactly what flash time is. Flash time is the amount of time
it needs to dry between coats. So if you put a coat of
primer-surfacer down, and it says allow
to flash 5 minutes, you need to let that
sit for 5 minutes. Now, that is not an absolutely,
and let me tell you why. These technical data sheets
are written in a lab, in a testing environment. It’s usually 70 degrees. So when they do this, it
dries 5 minutes at 70 degrees Fahrenheit, and that’s the
amount of time it takes. Now, like today, out here
in my garage, it’s very hot. It might not take that long. It’s going to decrease the
amount of time it has to flash. And if it’s really cold, it’s
56 degrees in your shop, well, you’re going to increase
that time quite a bit. So always take into
account the temperature that that’s going to
affect that as well, but that’s a good starting point
is look at the technical data sheet, but remember
that’s at 70 degrees. So flash time is the
time in between coats. Now, the window is
how long you have before you can re-coat on top
of that without having to sand. For example, Epoxy
has a real long window of 72 hours, the one
I’m using anyway. Most of them do. So you have three days to come
back with your primer-surfacer or whatever you’re putting
on top of that to spray it. And during that time,
during those three days, you can spray right
on top of the Epoxy. It has a chemical bond,
a chemical adhesion, but if it goes longer than the
72 hours are to three days, you’re going to have to sand
that scuff it up lightly to give it a
mechanical adhesion. So when following the
steps in this video, we’re going to
spray the Epoxy on. We’re going to allow it to
dry the recommended time, then we’re going to come
straight on top of it with the
primer-surfacer, and then we’re going to allow it to dry. Then we’re going to block it out
and get it ready for painting. Again, if you want the
specifics, the technical data information on Epoxy,
on primer-surfacer, at the end of this video, there
will be some resources for you to click there where you
can get to those videos where I’ll go over the entire
technical data sheet for you. OK. Let’s get started. OK. We’ve got the primer mixed up. And the way this
works, you have to buy this adapter that
goes with the system. And you just push
this lid on here. And the nice thing about
this is, is when you’re done, you just take this off. You can throw the
lighter away, and then you just have your gun
to worry about cleaning. You don’t have to
keep a cup clean. What I’m going to do is wipe
this down with wax and greaser maybe one more time. Making sure that you are
working on a clean surface is an important part and
ensuring good adhesion and preventing problems like
fish eyes and things like that. We’ll let that flash off
for a little bit and dry. And then this is
the way we prime it. We just have an old tack rag. I wouldn’t necessarily
get a new one for it. So you can just slightly go
over it with the tack rag. Make sure some of
the dirt is off. Then also with
primer, you always want to make sure that
you do wear a proof respirator for
spraying, and you also want to be in an area like this,
in a prep station or a tank booth and that you
have your fans on. As you can see, we’ve
got our first coat on and it’s flashing off. Be sure and check
your procedure pages to see what the flash time
should be in between coats. And we’re going to go ahead
and put two coats of this Epoxy Primer on, the first coat we
went the full length of this, the second coat, we’re going
to come back a little bit and not go quite as far. And what that does
is allows a thinner build to be here so that you
don’t have a hard edge when you’re trying to
block sand this out. All right. We’ve got the gun clean
and now the washing down. We’ll go ahead and wipe
if off a little bit. And now we can get ready
to go ahead and put the primer-surfacer. In this particular
job, we’re going to use ShopLine, a JP202,
which is a primer-surfacer. And what that is used to
do is to fill the scratches and we block it out and
make a nice, smooth surface. So like I said, you always
want to be sure and look over your procedure pages. If you notice on this, it
shows that we put two coats on, so you might wait at least
30 minutes before applying your primer-surfacer. And you have up
to 72 hours, which is three days, to go ahead
and apply the surfacer. If you go longer than
three days or 72 hours, you’ll have to scuff
the surface to provide a mechanical adhesion rather
than the chemical adhesion. So we’re going to mix up
about the same amount. And if you look
over here on 202, and depending on
the products you’re using, wherever you
buy the products, be sure and ask for
these procedure pages so that you can look at
them, and it tells you how many coats should be
applied, the flash time, things like that. So here it shows that
you mix it 4 to 1, so it means 4 parts of JP202
to 1 part catalyst, which is 301 for this application. So we’re going to
mix this 4 to 1. So you look on here. Find the 4 to 1 and probably
we’ll just go 2 and 2, 2 parts here to the catalyst. So there’s our
primer-surfacer, catalyst in. It’s always a good idea to
be sure to put these lids on immediately, because this
catalyst is moisture sensitive, and you don’t want
that lid left open. Now, I can sit the Epoxy
Primer for the one that takes the induction time. This is primer-surfacer. There is no induction time
as soon as it’s mixed. Go on and spray it. Put your lid on. And you want to be sure and
always put this ring on. It has been left off before,
and without that, that lid is not going to stay on there. Put it on. Now, we’re ready to apply our
two coats of primer-surfacer. OK. As I mentioned, if we’ve
waited at least 30 minutes and not no longer than 72
hours, we can just come in, and we can spray
right over that. You can tack it if you want
to, but it is ready to spray, so we’re going to pick up our
paint gun, turn our fan on. OK. I just had a problem. I don’t know if
you saw it on film, but we had a drop that
dropped on the car, and I stopped to see
what the problem was. And what happened is
I had the liner here, and this will happen
if you’re not careful. And I popped this on and
wasn’t paying attention. And when I did, can
you focus in on that? I kind of caught the edge
of that and pushed it in. And this got kind of
pushed down in there just a little bit, which
didn’t make the seal. And then I put everything on. So make sure that this
does stay on top here. And that probably had I opened
the gun up and just put it back on top. Make sure. This doesn’t happen often,
but every once in a while if you’re not paying
attention, that will happen. So that was a mistake that
we can learn right here. Try to avoid that. OK. I went ahead and got the
first the first coat on. Let it dry for a little
bit, and then we’ll come back and put
our second coat on. Now, if you’ve been watching
my videos for a long time, you may realize these videos,
I shot a long time ago. However, listening to your
comments and your feedback, you really enjoyed
this series of videos. But there’s a lot of
complaints about them because the audio
wasn’t too good, and I tried to enhance that the
best I could, plus I’m putting in this intro and talking
about some of the question you had in the beginning
and ending of these videos. So hopefully, you
found that useful. Another question I got a lot
from this video from years ago is, what kind of primer
gun do I recommend? And there’s a lot of good
primer guns out there. You just need a
1.6 to 1.8 range. You know, it’s a
little bit bigger gun than what you’re going
to shoot base coat with. Base coat is going to
be like 1.3 to 1.4. And for primer,
I’d use 1.6 to 1.8. 3M makes some good primer guns. This is a DeVilbiss. They make some good ones. Me personally, I have started
using 3M’s Accuspray primer gun. Some people really liked
it, and some don’t. I’ve heard good
and bad about it. Me personally, I love the gun. It’s true that you don’t have
to have atomization quite as well as you do when
you’re shooting base coat or clear coat. But you still want a gun that
can spray it really nice. For example, in this
video, I showed you how to mask off and
back mask, but I mean, if you’ve got a small
spot in the fender, it’s possible that
you could just spray that fender and
maybe not even mask. What you’re going to do is,
you’re going to turn your gun. You’re going to fine tune
it to a smaller pattern, and then you’re going
to prime just that area. You’re going to keep that
repair area real small. And so you want a
primer gun that’s going to shoot good if
you need to do that, and a lot of times, that’s what
you may do rather than masking off the way we
did in this video. But if you’re a
beginner, I would recommend going ahead and taking
every precaution until you become comfortable enough to
know what your limits are. If you’re unsure, go
ahead and mask it off. Drop a piece of plastic
over the entire car just like we did
with this video, because it’s always better
to be safe than sorry just to save a few minutes. If you enjoyed this
video, I’d really appreciate it if you go
down below, give us a like, give us a thumbs up, and
be sure and tell others about this video. Thanks for watching, and
remember, if something’s worth doing, do your best and
have a blast doing it. Hey. Before you go anywhere,
be sure and check out some of our other
videos and playlists.

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