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View Full Version : DIY primer job to stop rust. Help!



Doc_Supreme
04-18-2015, 12:52 PM
Ok guys, I need help. When I bought my 72 Cutlass Supreme it had already been stripped down to 95% bare metal. Somebody added new quarter panels and they have already been sanded to a glass smooth feel with the rest of the car. The body is remarkably straight. The only major imperfections are 2 dime sized rust holes in the passenger A-pillar (originally a vinyl roof car) and a dent on the lower passenger door.
I would add in pictures for reference BUT I cannot seem to get them to work on this site...

I want to get the car professionally painted but the nearest body shop that will do restoration work is 90 miles away & a 70 hour work week makes it difficult to shop around for estimates also Im pretty sure Im looking at a 4-5k paint job and that will take several months of saving before i can afford it.

The car has started to flash rust all over and I really want to sand the surface rust down and cover the whole car in primer for the time being but my option at the moment is an open shop and spray can primer. My question is what would you guys recommend for sanding down the light surface rust and Priming it?
Start with 320 grit-then-400-then prime?? SHould I wet sand bare metal?? I was thinking of using Rustoleum epoxy primer and then a coat(or 2?) of light colored sanding primer on top of that? I want to paint the car Red & a single stage paint job is all i can afford right now so I dont want to have really dark layers of primer on the car.

I have ZERO body work experience so any input/tips/tricks/advice on how to go about this and what products to use are appreciated. :help!:

dhutton
04-18-2015, 01:48 PM
I don't think you want rattle can primer under your paint. It will have to be sanded off once you get it to a body shop. I would be inclined to leave it as is until it gets to a body shop. Either that or spray a decent quality epoxy primer over it once you sand it down.

Don

Paraman1
04-18-2015, 02:15 PM
When I was looking to keep my El Camino from rusting away while saving for a paint job I got numerous suggestions to use an Epoxy Primer . It won't let contaminants or moisture through so you have plenty of time to save up . We used a 9 dollar paint gun from Harbor Freight to shoot it in a single car garage but be advised you will need to come up with some way to ventilate the garage without putting primer all over the neighborhood . If you watch just about any of the car shows you will notice that as soon as a car comes back from being stripped they will shoot it into an epoxy primer and then proceed . I shot mine in white just to see what the car would look like in that color .

Wall
04-18-2015, 02:31 PM
I agree epoxy primer is really the only way to go. You don't need an expensive gun, just a cheap harbor freight gun will do the trick. I actually used summit racing epoxy primer and it sprayed on really nice and is pretty tough. I primered a few spots a little while back then had to go back and sandblast later. When I was sand blasting I went over some of the epoxy and it just roughed it up, didn't even take it off. If I had stayed on it with the sandblaster it would have come off but not easy.

Spraying epoxy may seem like a pain to go through right now it is well worth it.

Doc_Supreme
04-18-2015, 05:40 PM
So the general consensus seems to be that it's worth it to get a spray gun vs rattle can and mix up a couple gallons of Epoxy primer if I'm going to attempt this. Do I need more then one quote of epoxy? Or anything on top of the epoxy?

What about sanding the surface rust off? Am I right in thinking to hit it with 320 grit and then 400? Do I need to wet sand?

I will have to do some online shopping tomorrow for the gun and the primer since there is nowhere local to get these supplies

dhutton
04-18-2015, 05:52 PM
I scuff with 80 grit on a DA for good adhesion. Southern Polyurethanes sells good epoxy for a fair price. Use two coats. One gallon of epoxy and one gallon of activator should get you there.

Www.southernpolyurethanes.com

Don

Paraman1
04-18-2015, 06:12 PM
I used 3/4 of a gallon of primer to do my entire El Camino with 2 coats on most of the car and 4 on the roof and hood . That includes the inside of the bed as well . I had 4 of the Harbor Freight guns sitting in the shop and just pulled one out and cleaned it up before using it . If I was to do it again I would buy the larger HF gun with the larger capacity pot on it just so I didn't have to spend so much time mixing waiting and filling the gun .

Jetfixr320
04-19-2015, 11:18 AM
Epoxy primer over spray can primer!

But, which ever company you choose to buy from. Make sure to look up the product tech sheets for what you will be using. Primers, fillers, seam sealer, paint, clears. all of it. Read them and follow what they say. So your not wasting $$.

I'm just a rookie at body and paint. I got a deal on Matrix paints, And I'm happy with the end product.

Dhutton recommended SPI, and I have heard good things about them. So I looked up the tech sheets. Here is a link to them. The epoxy primer starts on page 7. Under the mix section, it says 30 Minute induction is recommended. it means to mix the 2 parts then wait 30 minutes then stir again prior to pouring in your gun and shooting. Make sure you do that to prevent problems.
http://media.wix.com/ugd/8ced3e_08f93c6b5e0a442e923e061eac324437.pdf

Buy what you can afford, you can always sand it off later if need be.

And yes, you need to sand the car to bare metal again prior to spraying the epoxy.

Good Luck

67CamNKC
04-19-2015, 01:53 PM
Just curious, but has anyone tried the epoxy primer that Eastwood sells in an aerosol can that you puncture the button on the bottom of the can, shake and then spray? I got a couple when I needed to shoot a valance panel and seem to work out well. Just not sure how it compares when sitting for awhile. Might be expensive route for an entire car.

Shannon

Arrowhead
04-20-2015, 05:03 AM
I scuff with 80 grit on a DA for good adhesion. Southern Polyurethanes sells good epoxy for a fair price. Use two coats. One gallon of epoxy and one gallon of activator should get you there.

Www.southernpolyurethanes.com

Don


Listen to the man ^^^^^^

Matman3
04-23-2015, 04:21 AM
Don't forget to neutralize the rust first. Otherwise all this work and money will be for nothing. When I first read the post my impression was light surface rust with a few holes. But....if there are holes then it is most likely more than surface rust.

Use a good acid wash to neutralize the rust. The majority of the light rust will go away. Once this stage is done follow Don's recommendations, 80 grit with a day and thier good epoxy.

Also remember that primer is porus so water will seep through over extend periods.

dhutton
04-23-2015, 05:08 AM
Don't forget to neutralize the rust first. Otherwise all this work and money will be for nothing. When I first read the post my impression was light surface rust with a few holes. But....if there are holes then it is most likely more than surface rust.

Use a good acid wash to neutralize the rust. The majority of the light rust will go away. Once this stage is done follow Don's recommendations, 80 grit with a day and thier good epoxy.

Also remember that primer is porus so water will seep through over extend periods.

Do not apply SPI epoxy over an acid wash without checking with them. I am pretty sure they advise against it and it will fail.

Don

Matman3
04-23-2015, 07:16 AM
Why?

As with any acid wash you have to neutralize it by dilluting it with water and let dry for a couple hours. Obviously, before you spray, the normal routine of cleaning with wax and grease remover and tacking it off with a tack rag but all that would be spelled out in the instructions included with the products.

Arrowhead
04-24-2015, 04:56 AM
From SPI's epoxy tech sheet:

Precautions:

NEVER use SPI Epoxy over a Soda Blasted vehicle unless you call us first for proper neutralizing instructions.

NEVER use SPI Epoxy over Acid Etch/Wash Primers or Rust Converters. It will not work and we strongly suggest if you want to use a rust converter that you use the rust converters paint system instead of SPI.

Acid treatments should not be used unless you know the proper way to neutralize them, again call us first to be safe. Acid films can cause an adhesion loss.

We only recommend using Ospho’s acid treatment if you even need one.

If not handled properly the aforementioned issues can destroy a paint job and will result in an expensive mistake.

For bare metal or aluminum do NOT use any other cleaner except 700-1 for cleaning step number one and then 710-1 for cleaning step number two.

Matman3
04-24-2015, 08:10 AM
I stand corrected!
PPG was that last wash I used and they recommend epoxy once neutralization and drying is complete.

Thanks for looking up the data sheet. I wouldn't want anybody destroying their paint because of me.

Jetfixr320
04-25-2015, 11:13 AM
Also remember that primer is porus so water will seep through over extend periods.[/QUOTE]


I'm pretty sure this is only true of the Cheap primers in a can. Not Name brand 2k Epoxy primers.

dhutton
04-25-2015, 02:17 PM
I'm pretty sure this is only true of the Cheap primers in a can. Not Name brand 2k Epoxy primers.

X2. Two good coats of a quality 2 part epoxy will last indefinitely.

Don

dhutton
04-26-2015, 05:54 AM
This is interesting:

http://www.spiuserforum.com/forum/spi-company-products-updates/70776-spi-epoxy-torture-test

Don

minendrews68
05-21-2015, 04:34 PM
I use Metalok epoxy primer. i was cleaning a area with lacquer thinner and rubbing the rag over the primer, it didn't touch it. not saying it
wouldn't after a while but..

MonzaRacer
05-29-2015, 04:35 PM
From what I remember from the old car magazine articles, they were using(i believe, if I remember correctly) PPG DP series epoxy primers, even etching epoxing primers.
I know of several cars using just this process, the owners have kept the surfaces up, repaired panels and repainted. Moderate fading was found. But on one car we had to do some serious sanding to open the pores of the primer, we hotcit with adhesion promoter, re-epoxied the car and top coated.
So far we have seen no crazing or bubbles or other heavy film issues, so far.
Only one car had issues, but it was from internal rust eating metal away from paint, up until the owner touched it the car looked fine. The paint film was pretty firm and was fairly pliable and resilient. But with no metal to adhere too it just pushed in.
Car is now repaired and reprimed awaiting a choice of color.

Doc_Supreme
05-30-2015, 09:16 PM
Wow, first off, sorry i left this thread hanging for a month... went on vacation and was pretty busy catching up with work when i got back. Thank you to everyone for your imput. A couple days ago I took the car down to Dickinson for an estimate, now this car is straight and rust-free aside from a dime sized hole in the A-pillar. I think it is in great shape... the body shop however told me it would cost atleast $10,000 to paint it and said it would require over 100 hours of bodywork before they could even prep it for paint... I honestly think they were either out of their mind or didnt really want the extra work.

So, my plan of attack now is to get with one of the guys at work and move the car to his garage. He has quite a bit of restoration experience and is building a sweet Kustom 50 'Merc. We are going to tackle what little body work is left and then cover the car with some self etching primer and sanding primer and prep the car for paint. I also need to find a grille/left tail lamps/windshield/weatherstripping/ and rear window trim to finish the car out. I have not decided on whether I will paint it out here or take it back home in September and actually have a shop do it... but I have decided on GM Victory Red as the color as I find it a great shade of red and it will be very easy to touch up the inevitable rock chips and road rash out here. I will try to keep this thread updated to give other DIYers a reference and I will be starting my own build thread soon

indyjps
07-04-2015, 05:23 PM
Scrub it down with evaporust and scotchbrite, the label says it neutralizes with water, but I mix baking soda and water to be sure. Blow dry with air, laquer thinner to remove remnants, DA with 80 grit, wipe with wax degreaser, shoot primer.

I've been using PPG DP90LF, or PPG shopline PG377. I'll use SPI primer on my next project, wanna try their products.

Victory Red, I have a truck that color so I'm partial to it, check out SPI's red though. Really rich color, victory red can look orange at times. Your primer color will effect your ultimate topcoat color in the sun. Ask any painter who's had to color match red.

Have you decided what brand paint you're using?

dhutton
07-05-2015, 04:27 AM
Scrub it down with evaporust and scotchbrite, the label says it neutralizes with water, but I mix baking soda and water to be sure. Blow dry with air, laquer thinner to remove remnants, DA with 80 grit, wipe with wax degreaser, shoot primer.

I've been using PPG DP90LF, or PPG shopline PG377. I'll use SPI primer on my next project, wanna try their products.

Victory Red, I have a truck that color so I'm partial to it, check out SPI's red though. Really rich color, victory red can look orange at times. Your primer color will effect your ultimate topcoat color in the sun. Ask any painter who's had to color match red.

Have you decided what brand paint you're using?

I am pretty sure SPI says that their product cannot be applied to metal treated with products like Evaporust. There is only one that they recommend.

Don

indyjps
07-05-2015, 06:57 AM
Yep, neutralize the rust, whichever brand you decide on, neutralize the derusting product, clean the panel, then DA, then clean the panel and paint. When you DA the panel and clean with wax degreaser from the manufacturer of your paint products, you are sanding and cleaning any residue off and providing the appropriate surface for the primer to bite.

Biggest thing is to kill the surface rust completely before applying primer, just DA'ing won't get it all and will come back to haunt you.

minendrews68
07-05-2015, 09:51 AM
I did notice in a earlier post you said you would mix up a couple of gallons of epoxy primer, i don't know if you meant that literally or not but unless your going to use it all at once, do not mix it all up at once. It will set up in the can.