Hey, it’s Tony with another live stream. Today’s topic is A-Z Sandpaper Grit and Primer Steps To Repair a Panel + Auto Body Q&A TALK!
I’m going to draw out a car fender. Sorry, you’re probably not going to see it very well. Thanks for being patient with the bad lighting. Please watch the video as I show you how to fix a small dent.
In some of my videos, I would say to scuff the paint with 80-grit and put a filler on it. You can do that on a light dent if it’s is less than a quarter inch. You don’t have to go to metal. I tested it and the bondo will not crack.
However, if it’s deeper than a quarter inch, pushed in a bit where you need to weld and jack it out and, you would grind to metal, so as larger areas.
For smaller dents, we’re going to use a 16- grit on a grinder disc. I show you a lot of videos of it in the LearnAutoBodyAndPaint VIP Course.
After you grind your dent, you pull it put with whatever you are using or push it from the back. And then, 2- 3 inches in diameter around it, use an 80-grit and feather in the metal. This is going to give you an area to blend the filler. You can put the filler over 80-grit and it’s going to fill the dent and be all nice.
You let it dry, then use 80-grit to cut and shape. Go around out here a little bit. Go to 80-grit to shape it.
Sometimes if you’re doing a large body work area where you’re doing a lot of heavy filler, you can actually cut with 40-grit, then go to 80-grit. But, I like 80-grit. It’s a good overall grit.
I suggest you use 80-grit to shape it. Once it’s all shaped and got your panel the way you want it, it’s then your choice of whether you go down to 240-grit or 280-grit. I like to go down a little bit finer before I prime.
Some people are doing 80-grit over polyester primer. I just think it’s too much sand scratches to fill in. I would rather not fill in when it will take you 2-minutes to take it down to 240-grit or 280-grit from 80-grit.
With either the 240-grit or 280-grit, you want to go around this whole area. Basically, have the whole section primer-ready.
You can use a 2K primer which is thicker, or a polyester primer which is a lot thicker. With polyester primer, you can go over 150-grit or 80-grit. It’s too thick so you may need to use at least a 2.0 or2.2mm needle to spray it out of.
For little jobs like this, a 2K primer is fine. You want to lay it on 2 to 3 heavy coats. It fills everything up. Then, you let it dry.
After which, you can get a 360-grit on a DA, if you want to cheat. Then, cut it down and get it flat. Finish it off with 400-grit.
If you want to do it well and take time, you can do it by hand and block it out with 400-grit wet sand. Do crisscross movement with it. It will probably take you 15 minutes to do this spot.
If you see a little bit of imperfections, this is your time to spot fill with polyester putty. Put little dabs of filler on it. Let it dry and block it out again. You want to make sure to touch up primer your glaze putty spots.
Never directly paint over glaze putty. You have to paint over primer. With the glaze putty, especially on bigger areas, it can bleed through.
Hopefully, you liked this demo. I’ll show you more demos on a real car when I get back to my shop.
Question: I did a job recently over factory paint jobs. Sanded dry with 400-grit DA over certain spots. Then, wet sanded with 1500-grit. I came out with pitting. How do I make the surface perfect to prevent this? [18:44]
Why did you go to 1500-grit? I hope you didn’t paint over 1500-grit! That’s way too fine. You want to paint over 400-grit.
Question: When sanding really bad peeling clear coat, should I go down to metal or not? [19:15]
You don’t have to. Just sand to feather. If it goes down to the metal, that just means you have to primer that area. If you have a little bit of metal showing on different spots, just use a regular 2K primer to cover it.
The only time you want to use an epoxy primer is if you’re doing a whole metal fender or a whole hood, or a large metal work.
Then, you can sand that, put a 2K over that if you want to, block sand with 400-grit and finally paint it. I’ve painted right over epoxy. That’s not a problem.
Question: What causes clear coat to bubble? [21:24]
It could be improper mixtures or water in the line.
The best temperatures to paint is more likely from 75 to 85 degrees. Remember, the hotter it is, the slower reducer you should use. The cooler it is, the quicker hardener, activator or reducer you should use.
I show you a lot of these techniques in VIP, so go check out the LearnAutoBodyAndPaint VIP Course. If you haven’t, go download your FREE 85-Page Auto Body And Paint Manual. I cover everything you need to know about auto body work.
I’ll share with you all of the techniques in my years of experience in the industry. Thank you everyone for joining me tonight in this hotel room. Join me every Thursday at 9pm Eastern. Please Like, Share and Subscribe to my videos.
Talk soon! Cheers!
Tony
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