I am kinda new to the paint world, enamel, laquer, etc.. it's all sort of new to me. I understand the basics of the paint, but I don't understand the use of primer. When exactly is it time to get a can of primer and go to it? From what I have learned its when you have a smooth surface that paint wont really stick to, is that right?

And for that matter, if paint wont stick to it, why will primer. Should you primer everything, or just go with your gut?

I am sure some of you know some stuff that I don't, so I am all about learning.

 

http://www.hotrod.com/howto/hdrp_061...k_sanding.html

Read that^^ .Hot rod sites are great for painting tips/ tricks.

Primer is like a shield to the metel and does make the paint stick better, it also can be used to fill in imperfections with high built primers. I use primer on everything, I would never just use paint. And buy the primer from the same company/brand your getting the paint from. There are different primers for different materials too, depending on what your painting.

 

Paint will stick to paint if that paint is roughened up. Paint will NOT stick very well to bare metal, That's where primer comes in. Primer sticks well to metal AND paint, so it acts as a bond between both. The most expensive paint jobs are those that include sanding to bare metal, priming, painting, wet-sanding - lots and lots of labor and cost. The quickie paint jobs involve simply sanding the existing paint and spraying a fresh coat over it. For a bit more money, one or more clear coats are added. ALWAYS clear coat new paint - it protects against oxidation and resulting dulling effect.

 

i would sand it and then primer it. and oh yea, clear coat makes it shiny too. i used house of kolor clear coat on my si emblem and it worked really well. but that was just a small thing.

 

so for example, if i was just spary painting stuff at random, some spray on auto shop primer will do the trick, if its a bare metal thing?

If and when I get a new paint job I am sure I will go for the full work up, but I am curious as to if the auto store primer in a can type things would be worth the trouble. So far on some of my engine items, I have sanded and painted, without the use of primer, but I notice that alot of times the paint wont stick to certain areas and it takes more and more coats to finally fill the gaps and get a good solid coat. And if you primer anything under the hood, is there a high heat version I should use, or just standard stuff, with high heat enamel over it?

Thanks for the link btw, good reading.

 

Read the label to make sure the primer is for the material you are coating. Aluminum DEFINITELY needs a primer coat and I can't emphasize enough that the base material MUST be super-clean. Use acetone on aluminum or steel, but make sure it doesn't get on any plastic parts; it'll melt some types of plastic.
Yes, there are engine enamels for high-heat environments. Epoxy-based paints can take more heat than polyurethane paints, for instance.