I read somewhere that primer will absorb moisture and cause rust more quickly, is this true? I live in the dessert. So, if I bought a rex that had primered panels such as the hood and bumper, how long could I leave it that way? The appearance of the car is fine, just different color primer on hood versus the bumper. I wouldn't be able to paint it untill well into next year.

 

I'm not sure about absorbing moisture... that **** is pretty damn tough... Even paint stripper won't take it off.. I can't imagine water would soak into it. Sounds like a myth to me. I would imagine a properly primered car (prepped/sanded, wax/grease removered, and primered) would last indefinitely.

 

You'll need to scuff and shoot the primer again if it's left for more than a few days.

If primer absorbed moisture...... I'm just gonna stop there

 

Primer (and bondo type body filler also) is in most cases porous. That is how it holds (absorbes) paint. It thus holds water equilly as well and permanently in most cases. So dont leave something primerd that you dont want to rot away pretty quickly.

In MN here cars with primer on them almost always have rust and it is always in the primered areas.

You could just throw some flat or semi gloss black over those areas. It wont look any worse and will help hold the mosture out.

 

Primer is for adhesion & smoothing only.
It is not a weather coat.
Read the label.

 

Un-true. Do you think every vehicle restoration done is only in final primer for a day or so?

Certain primers (see high-speed, production primers such as sherwin williams P30 or BASF's DTM powerfill series) will become too dry to allow reducer to penetrate for a top coat after a few days, but those types of primers aren't suited for a complete vehicle anyways.

Actually, primer doesn't *absorb* paint into *pores*at all. Paint is adhered two ways, mechanically (sanding scratches) and chemically in which reducer penetrates the primer and brings a little paint/basecoat with it. When the reducer leaves, the paint is left slightly inside the primer due to reducer's penitration. Thats another reason to use proper speed reducer for the temperature you're spraying.

But to the OP's question, if the primer is of good quality - which you *really* can't tell unless you put it on since you need to know where it came from - then leaving it won't cause rust to form. That being said, if the work done UNDER the primer was no good, it'll rust whether or not you top coat.

 

primer is a base coat for you paint to stick. it will not protect the metal under it.

 

A guy at a body shop here in Sanford once told me that primer would soak up water. I don't really know if that is true or not, but he told me to prevent this you need to kind of lightly spray paint on top. You know not to completely coat the whole surface, but to leave it looking speckled so to speak. Never tried it so don't really know.

 

No it won't do as good of a job as a hard shell coating such as clear coat or any other urethane based top coat.

BUT

It wil - and DOES - protect the metal.

Example.

Look underneath your car for me, any car I don't care if its an FC or not. Now tell me, is there clear coat on the inner edges of the rocker panels?

NO!!!

Its epoxy primer! And guess what, it protects the metal!! Sure, the underside of your car may have rust on it, but thats not the point here. Now, for any hardcore's reading this let me say this. The primer under the car will be epoxy based, or as OEM's call it, e-coat. This is a harder material then a typical highbuild "primer". However the quality (as stated before and now QUALITY) highbuild's now-a-days are urethane based (not spray balm ****, and not old lacquer based either) and will provide protection more so then the old types - to a certain degree. Simply because as stated, they are NOT a hard shell coating and will "absorb" moisture. But only within itself - not to the material under it - which will dry and leave residue.

And secondly, the primer is not simply a medium for the paint to stick. Paint will stick to old paint just fine and old paint is not primer. Primer is used for - get this - SEALING METAL as well as a medium to further smooth body work (ie. fill 80/120/180 grit scratches) and to provide, yes, something for the paint to stick to. Its just not all it does.

Edit: To Jasons7:

That won't really do much of anything because you aren't sealing the primer. You're only dusting material on top. Same theory as using small umbrellas to cover the roof of your house - its not solid, its not sealed.

And primer won't absorb water. Not QUALITY primer. The spray balm **** you people buy at NAPA I have no comment on

 

cCLASSICAUTO explained it all in a simple and easy to read way and i will make it easier

--bondo -absorbs water

---primer- doesnt absorb water if you use AUTO+BODY PRIMER - now if you go rattle can happy with the dollar store crap that will absorb and if you have bare metal or bondo you are screwd

In a sentence- dont do anything to your car until you have 100% of the money to do the whole car, skimping out and doing half *** body work will cost you double of a decent paint job and QUIT PRIMERING YOUR CARS IT MAKES OTHER RX7S LOOK BAD BECAUSE THATS ,duh! the ricer thing to do!!!!

 

there is some really good info about painting here!

 

I got a car that's been in primer for a couple of years, sittin' out in the weather and that bitch is rock solid! Primer has held up better than some paintjobs I've seen!

 

aright guys, I'm thinking of flying out of state and buying this thing. He wants 2 grand. Here are the specs (a lot of this is copy/paste from seller email discussions):

""No problem, its a clear title, fender bender involved bumper mount, bumper, light, hood, and fender, all of which have been replaced, thats all.""

""the car has tags till Jan 08, im 100% sure will pass smog again. i did install the dual alternator pulley, made so that you can remove the smog pump one day, but smog pump is still installed and working properly. Alighnment is great, no pulling that i have notices, all front and rear end suspension are in great shape, bushings, balljoints, tie rods are in great shape. Shocks are original adjustable, still works properly, shocks are still firm.""

Pics:

 

Classic Auto - aight - my bad, you're right, you could go to sealer

Good primer will. A long term test of good primer would be rust creeping under it. If rust don't creep, good primer, if rust creeps, you bought ****. Good primer will protect the metal. <- That's a period by the way......

88rxn/a - Yes there is. Classic is putting in more time than I would to teach people. I'm lazy and sinical, I'd rather just point out when people are wrong and correct them. But Classic, you have to agree with me that if you let primer sit for a long time and went right to paint (color, basecoat, whatever ya wanna call it) You'll have adhesion issues. It should be resprayed with some sealer with the appropriate reducer so some of the base coat cal flow into it.

 

There's primer, and then there's primer/sealer...there is a difference...

 

The difference between the primer and the sealer that I use is the amount of reducer that's added. PPG DT-LF iirc. I am NOT a pro but I had one guiding and helping me through the repaint of my FC. He's beein doing it for ~30 years. Painting, for as much science as there is to it, it's not a "science" so you'll get alot of different opinions and this product is better than that product etc etc....

 

No I do agree with you for sure

However, its mostly due to contamination of the surface then an actual change that happens to the primer from being exposed to weather. Its always best and ideal to have each step exposed or left sit as little as possible. For example, Diamont base coat has an open coat time of 8 hours when used with base hardener. Would I in good mind apply the base, go home and sleep, then come back and apply the clear coat simply because I can wait up to 8 hours? Nah, coat it as soon as you can once its flashed off so nothing can contaminate the surface.

Same applies to primer, just in a much much broader way.

I know what you mean when it comes to opinions though, too many body men and painters like to be chemists. I let the chemists do the work......they give me a nice little technical manual to follow and if something goes wrong following the manual - its their problem

But I think we've covered the primer issue here.....

 

since we are on the primer convo.
do i use etch primer for the front bumper??
i have one of those Tii rubber tyoe wings to. what about that?? what kind of primer?? i am going to ask the people where i get my paint what to use for a primer and what to add in the paint but id like other opinions also.

 

classicauto, it seems like i can only trust you when it comes to body work. How can one properly prep a car for paint? I would like to learn to do it myself rather than let someone do it for me but i don't know if thats a good idea.

 

No. You will want to use the appropriate adhesion promoter on any areas that have bare plastic though. Each paint company has their own which will correspond to their own material. Etch primer is for treating bare metal before applying high-build.

Also, for the plastic bumpers (or any flexible plastics) you should be using a flex additive on ANY material applied to the bumper, as well as flexed fillers - not simple putty/bondo as it will not flex with the bumper material.

To be honest, the typ of plastic in the wing escapes me right now but I think its ridigd stuff........don't quote me on that though.

Here's the test though, snip a small piece of the plastic from an area where it isn't noticable (hard to do on the spoiler - easy on a bumper) and drop it in a cup of water. If it sinks - you don't need adhesion promotor. Best way to remember is:
If its a floater, use the promoter
Seems crude, but thats what you do. There's too many types of plastics out there to get into specifics and this test was taught to me at a Lord Fusor rigid/flexible plastic repair certification course in 2004, so if you've got questions, email them

To be completely honest, my opinion is biased because of the amount of disasters I see people create in their driveways and garage's. But my advice would be if you aren't entirely comfortable with it - leave it to the pros. There's still much you can do yourself to learn and save money along the way.

That being said, if you're the paitent type, you can probably make out alright. I'd recommend finding a shop in your area that you can get to know. Usually a lot of small shops will sell material to the odd guy (some sandpaper, primer etc) and you can usually pick their brains for some guidance and tips.

But I'd start by taking your car by a shop and having an estimate done. Not for an actual price (but hey, ya never know) but to squeeze out of the estimator what the condition of the car is. I.e. whether its had a few areas sprayed, find old filled/repaired areas, trouble spots etc. That will give you a good idea of where you need to strip, what you don't, etc. then go from there...

 

actually primer filler, primer etchers, and primer sealer.

For those with mis-conceptions (including some body/paint shop people that have answered in this thread):

Primer sealer forms a epoxy like bond and seals out everything. You could leave that on forever and nothing would happen except it is not stable in sun light and eventually would break down. This primer just dried looks shiny to satin in sheen.

Primer filler (as found in most spray cans or primer from Pep Boys or most auto parts places) has a huge amount of talc in it, and will absorb water. This is the absolute last thing you want to leave on the car and drive around in. It will absorb water, it will eventually cause pealing or other final paint issues, as well as will not protect from rust. However in a somewhat dry area of a shop, it could be left exposed for up to a week, but not if the vehicle is exposed to overnight outdoor moisture. This primer just dried is dull in sheen.

Both are sold as primers and both have their place, however some body shops only use one or the other and claim that their way is best.

Primer etchers are typically simular to primer sealers, however should always be used when painting bare metal.

 

Ahh its been moved. C'mon Icemark, looking at the thread title, you know this is FC specific

 

considering how many people i see with primered 240's rolling around... forever.

 

^ yeah thats the s13 way!!

 

^

"Car:
02 SPIRITR REPLICA
Gender:
MALE
Location:
HERE THAT SPOOLIN!!!"