# Do I really need to prime before I paint? **URL:** \ **Category:** Factual Questions\ **Created:** [May 26, 2009, 9:36pm UTC](https://boards.straightdope.com/t/do-i-really-need-to-prime-before-i-paint/497736 "2009-05-26T21:36:59Z")\ **Posts on this page:** 7\ **Page:** 2
**Author:** ![gotpasswords](https://avatars.discourse-cdn.com/v4/letter/g/c57346/32.png) [@gotpasswords](https://boards.straightdope.com/u/gotpasswords)\ **Post date:** [December 29, 2020, 6:51pm UTC](https://boards.straightdope.com/t/do-i-really-need-to-prime-before-i-paint/497736/22 "2020-12-29T18:51:26Z")
I recently had a disaster with putting Behr Marquee eggshell over the same, but a different color. The new paint was fragile - I could rub my fingertips over it and scratch it off. Then at the freshly torn edge, I could start peeling. It was a very messy process of wire-brushing the new paint off (orange peel texture on the wall, so just flat sanding was out) then scrubbing it all down with liquid sander/deglosser, prime, then the new topcoat. I foolishly thought $45/gallon Marquee “paint and primer” would stick like glue to itself. Nope. ---
**Author:** ![jjakucyk](https://avatars.discourse-cdn.com/v4/letter/j/3d9bf3/32.png) [@jjakucyk](https://boards.straightdope.com/u/jjakucyk)\ **Post date:** [December 30, 2020, 5:06am UTC](https://boards.straightdope.com/t/do-i-really-need-to-prime-before-i-paint/497736/23 "2020-12-30T05:06:15Z")
> [@MonkeyMensch](#): > > Ex-pro checking in: Not a stupid question at all. **Keeper** mentioned it in the second post: you CAN tint it but you don’t want to use it as a finish coat. It comes out with a dead-flat finish, a really dead flat finish. But this finish is exactly what you want in a primer. Most of the bond in latex paints is mechanical, that is to say, it holds on the the microscopic roughness of the previous coat. Think of primer like glue, whether actual sticky adhesive or mechanical grabbiness. If left exposed as your finish it will get dirty in no time at all and you can’t clean it without ruining the (already lousy) finish. That’s why trim is painted with higher sheens like semi-gloss, and walls that get dirtier in kitchen, bathrooms, and high-traffic areas may bump up the sheen to eggshell or satin for easier cleaning. The only place you’d ever want a totally dead flat finish is on ceilings. Even in low-traffic areas like the master bedroom, study, or dining room you may want to bump up to a more “normal” flat or matte sheen on the walls so it doesn’t look unfinished. The glue analogy is one I got from a carpenter who said he never buys pre-primed doors or trim. They sit in dusty warehouses and the primer either get “clogged” like dirty tape or the mechanical roughness breaks down. This can happen in just a handful of weeks, so there’s basically no leeway in the schedule from production to packaging to shipping to delivery to installation to ready for painting. Even straight off the line the primer used is pretty cheap and may just be used to hide substandard wood and construction. So re-priming is usually necessary and negates any benefits and wastes the extra cost. ---
**Author:** ![race\_to\_the\_bottom](https://avatars.discourse-cdn.com/v4/letter/r/c4cdca/32.png) [@race\_to\_the\_bottom](https://boards.straightdope.com/u/race_to_the_bottom)\ **Post date:** [December 31, 2020, 12:24am UTC](https://boards.straightdope.com/t/do-i-really-need-to-prime-before-i-paint/497736/24 "2020-12-31T00:24:25Z")
I was using a roller to paint the outside of my stucco house, and the previous paint job peeled off and wrapped around the roller in sheets. ---
**Author:** ![Hatchie](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/hatchie/32/3983_2.png) [@Hatchie](https://boards.straightdope.com/u/Hatchie)\ **Post date:** [December 31, 2020, 5:02am UTC](https://boards.straightdope.com/t/do-i-really-need-to-prime-before-i-paint/497736/25 "2020-12-31T05:02:03Z")
I painted some bare wood outdoor chairs with latex primer - I figured this would seal the porousness so the final coat would have a nice finish. Then painted over it with gloss oil enamel. As soon as it got rained on, it started to peel, both the latex undercoating and the enamel top. I wish I’d gone ahead and just used the oil enamel; I’m guessing it wouldn’t look as nice but would resist the moisture more. ---
**Author:** ![LSLGuy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lslguy/32/5813_2.png) [@LSLGuy](https://boards.straightdope.com/u/LSLGuy)\ **Post date:** [January 1, 2021, 1:41am UTC](https://boards.straightdope.com/t/do-i-really-need-to-prime-before-i-paint/497736/26 "2021-01-01T01:41:59Z")
> [@md-2000](#): > > I painted some walls in my house now that they are 12 years old and have been “used”. Since I have the same paint, it doesn’t matter no primer. Is it a coincidence that you revived a 12-year old zombie to talk about your 12-year old paintjob on your walls? 😉 ---
**Author:** ![Biffster](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/biffster/32/339_2.png) [@Biffster](https://boards.straightdope.com/u/Biffster)\ **Post date:** [January 1, 2021, 1:44am UTC](https://boards.straightdope.com/t/do-i-really-need-to-prime-before-i-paint/497736/27 "2021-01-01T01:44:46Z")
We spent more on the expensive paint with a decent primer already mixed in. One coat pretty much did the job over existing paint, but we put two coats on to be safe. ---
**Author:** ![HoneyBadgerDC](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/honeybadgerdc/32/1033_2.png) [@HoneyBadgerDC](https://boards.straightdope.com/u/HoneyBadgerDC)\ **Post date:** [January 8, 2021, 5:05am UTC](https://boards.straightdope.com/t/do-i-really-need-to-prime-before-i-paint/497736/28 "2021-01-08T05:05:39Z")
I have had my garage doors and wood trim painted several times over the past 40 years, it has always peeled, last time I did it myself using a good self priming paint and after 5 years is still as good as new. [Previous page](https://boards.straightdope.com/t/do-i-really-need-to-prime-before-i-paint/497736.md?page=1)