Difference between primer & regular paint?

[David Nebenzahl]

This is a serious question, not a troll or a trick, as I really don't know the answer to this: what's the difference between primer and "regular" paint?

First of all, some ground rules: I'm hoping to get answers from someone who actually knows what they're talking about (any paint chemists out there? or at least someone familiar with the inside of the paint industry), rather than the usual speculation. Therefore, any answers from "hallerb" or "ransley" will be politely ignored.

If someone forced me to explain the difference, my answer would be something like, "Well, duuuh, I think primer has more solids or something; or it's made to stick better. Yeah, that's the ticket--it's stickier!" Obviously, no definitive understanding of really what primer is and why we're 'spozed to use it.

Extra credit for answers to the following:

o Actual differences between oil-based primer (which I intuitively consider to be better without really understanding why) and water-based (latex, acrylic, etc.) primer.

o Are there any paints made today which can be considered "self-priming" and which do not require primer?

The assumption is that we're talking about painting wood products here, not speciality paints like for metal or other materials.

Your explanation of this matter, which is kind of like the eternal debate over WD-40 (what it is and isn't and why it's no good for anything) will be greatly appreciated.

[ransley]

I painted professionaly for about 15 years with a crew of 10 but im no chemist and you dont want to hear what I know as fact.

[jack]

I painted professionaly for about 15 years with a crew of 10 but im no chemist and you dont want to hear what I know as fact.

-----------------------

Oh don't be so touchy. He isn't being a jerk, he just doesn't know any better.

[Roemax]

I painted professionaly for about 15 years with a crew of 10 but im no chemist and you dont want to hear what I know as fact.

[George]

Awfully demanding for someone who wants free information. For the degree of details and explanations you require I would suggest hiring a professional engineer who specializes in chemistry to give you professional advice.

[The Reverend Natural Light]

Well it's really quite simple.

The primer is formulated with a higher molecular density that causes the end chain atoms to move their valence electrons to the next orbital level which enhances the strength and number of chemical bonds, thereby increasing the coefficient of static cohesion by an order of magnitude.

Actually, I haven't the foggiest idea. When you find out, tell me why Gojo takes grease off hands but not metal. Probably the same thing only in reverse.

[David Nebenzahl]

On 6/19/2008 2:45 PM George spake thus:

So you don't think this would be useful information, especially here where many folks use paint and primer but don't necessarily know *why*?

I guess according to people like you, we should either 1) pay a professional to get information, 2) use Google, or 3) just STFU, eh? No need for Usenet in that case ...

[Roemax]

[pheeh.zero]

You can use a tinted primer...and you're done! Flat finish though. Acrylic floor and porch is self-priming (if I remember correctly) on wood and concrete.

[Frank]

I'm a chemist, but not a paint chemist, and got a kick out of your explanation. If you had left off the last paragraph, 99% of the group would not have been any wiser.

Actually the op was kind of lazy and could have googled up something like this:

Frank

[Phisherman]

Not a paint chemist, although I do have a college chemistry degree. Primer leaves an excellent surface which paint will adhere. If you could prepare a surface by some other means a primer may not be necessary. I'd prefer an oil-based primer over a water-based, unless the vapors is an issue. Some paints do not require a primer and usually will say so on the directions. Milk paint may be applied directly to bare wood. For other finishing paints on wood, use a wood primer. Skipping steps, especially preparation, leaves you with a less satisfactory job. Generally you can get good advise from a paint store.

[David Nebenzahl]

On 6/19/2008 3:49 PM Frank spake thus:

Not lazy; I just know better.

I'd sooner ask ransley or hallerb before consulting Wikipedia, the "encyclopedia" any high-school or junior-high idiot can (and does) edit. (Or, worse yet, become an "administrator".)

[S. Barker]

To be fair though....... Just because you've applied 75,000 gallons of paint doesn't necessairly mean you know the answer to the question. I could pump gas into cars for 55 years and still not know how the gasoline is made.

just a thought. Not trying to throw the gas (that i don't know how's made) on the fire.

s

[Norminn]

#2 would be a good choice........I did a search on 'paint chemistry primer binder pigment adhesion', and got 50,000 hits. There are online stores selling all the ingredients for making your own paint. They probably have information as well.

I've tried Joy, Palmolive, Ivory and Dove dishwashing liquids. Dove is best, IMO. I don't need to know why. I like alkyd semi-gloss paint for interior woodwork and doors. It is harder, more stain-resistant and easier to repaint. I don't need to know why. I've got a lot of other stuff to learn, and my time is limited. If I was looking for a scientific explanation of anything, it would not be on a newsgroup. There are lots of smart, experienced and helpful folks here, but it isn't alt.home,repair.science.chemistry :o) And when you rudely point out that certain parties will be "politely" ignored, well.........go suck a paintbrush.

[RLM]

0 50 100 ^ / / Applause meter

Well done!

[Joseph Meehan]

Read what it says on the can. The guys who make it know how to use it. That's all you really need to know.

[ransley]

Yes I know fully why, and it varies product to product and purpose needed, easily 15 fully different products off the top of my dumb head. I have been lately using 30 - 50 gal a day spray and roll, on 2 jobs at a time, all different work, commercial and residential, different substrate, base, prep, and topcoat, some are even needed a self prime.

[ransley]

Tough one, I know and you dont.

[ransley]

And what do you have against Hallerb, he is alot smarter than you Nebenumnuts

[Red Green]

RLM wrote in news:67GdnRGaNYuiacfVnZ2dnUVZ_h [e-mail]:

I liked it a lot!!! Now we are humorously rating The Reverend on his creativeness and entertanment ability. Gee, the old Gong Show comes to mind. Chuck Berris and The Unknown Comic with his "Chuckie! Chuckie! Chuckie!".