Is it ok to epoxy over a little surface rust?

[OxfordMotorSports]

You can try the rust convertor, but in my experience it will only come back and still grows underneath the cover-up. 

I would recommend that you use Oxi-Solve or Pickle-X (sp?).  This actually removes the rust (may take a few applications) and leaves a phosphate coating which promotes adhesion.  You apply the stuff on the bare metal and then, let it set for about 20-30 minutes.  Next, you rinse with water (yes water) and the water reacts with the chemicals to create a phosphate coating.  The same type coating that OEMs use to protect bare metal prior to paint.

Eastwood caries the Oxi-Solve product and you should (no, make that must) wear gloves during application.  The stuff will eat you up if you don't.  Here is a picture of my hood that we applied the Oxi-Solve to.  It left a great finish on that was ready for primer.

As Stefan noted, it is also a good idea to fully remove the rust by blasting.

Hope this helps...

I didn't mean to get UKCuda riled up. I was semi agreeing with his opinion and he is correct about the epoxy over the rust issue. Anything but a rust converter. The metal etch process you have brought to everyone's attention would make it complete.

Rust converters contain acids, tanins and polymers that convert rust into black oxide. Rust is actually Fe203 a form of iron oxide. So you want to remove the rust - not cover it up. Any type of metal etch, such as the product you used on your hood, will actually start removing rust deposits on contact. You can apply treatment after treatment and it will continue the rust REMOVAL process while etching the clean bare metal around it. It might not get it all but it's the most logical choice. The final product after washing with water is your best shot at keeping any underlying rust from reappearing. THEN I WOULD HIT IT WITH THE EPOXY PRIMER. In this case I would use PPG's DP series epoxy. It's my favorite epoxy over treated metal surfaces. On clean metal that's not metal etched I always use HOK KP2CF. Metal etches can cause adhesion problems with KP2CF as it is designed for application direct to metal. Both of these epoxies are brutal and I strongly recommend then.

I'm only voicing my opinion to save some of you a lot of headaches. Not to mention money and time wasted on worthless products.

Todd

 

[E-Body Products]

Yea, here is the epoxy primer applied after the oxi-solve was rinsed with water and allowed to properly dry.  We use PPG brand DP50-LF (Lead Free).

[OxfordMotorSports]

Yea, here is the epoxy primer applied after the oxi-solve was rinsed with water and allowed to properly dry.  We use PPG brand DP50-LF (Lead Free).

Really nice work Daniel. It's that straight forward and ANYONE on these forums could do the same. Some of my friends shoot the Omni epoxy because it's cheaper. Three days later they are still trying to wet sand the junk and wonder why their paper keeps loading up. Keep up the good work.

Todd

OMS

[OxfordMotorSports]

I wanted to revisit this rust topic with some additional new information. Before I start let me state that I do not believe in covering up rust. I always remove or blast it away.

A young man over at Ole Miss college brought over his 79 Jeep CJ7 with a request that I spray the entire body with 2 quarts of POR 15. The entire vehicle was stripped to bare metal and prepped with Metal Etch. Small rust spots were evident in several areas. He has very little money and sand blasting was not an option. I was very skeptical and shot the Jeep with the POR 15 two days ago. The result is a rock hard finish that I cannot scratch with my finger nail. The POR 15 appears to be a solid product. I'm going over it with two coats of PPG DP 90 Epoxy (White) and a medium Guide Coat in black. He's painting the Jeep himself in a small garage behind his house.

I'll keep an eye on the final product and see how it holds up. It's not something I will start using because I'm set up to blast. But for someone who can't get their vehicle blasted - the POR 15 seems to be a decent product. I would recommend going over it with epoxy either way.

Todd

OMS

NYC

[ChallengerHK]

I did a lot of my suspension components in POR 15, and while I think it's a good product, I don't think I'd recommend it for this use. My results were nowhere near rock hard. More like a thick, rubbery covering. I think that for that purpose I'd go with rhino lining.

[AMXguy]

No question full removal is best, but I agree it just isn't always a realistic option.  there are so many variables that have to be considered, how bad is the rust, where is the rust, is it where it will effect the paint job if it returns, will the car be subjected to the weather and on and on. some of the quality outfits now sell a rust killer glaze putty and primers too that might help I'm not sure.

 I'm on the west coast so rust is a minor issue in my cars, but I have used Wurth in a few small hard to get to spots and so far so good. Lets keep it in perspective I'm 48, it doesn't have to last 100 years or even 50, that will be someone elses problem.

[Topcat]

I've used Rust Bullet in areas like underneath the Dutchman panel and the glass channels. It is sandable. I don't think it's as hard as POR is to prep for paint.

[Kapteenikosmos]

I think that I'll add my spoon into this conversation too.

I've been using Por 15 products on my Challenger project during the last five years. Mostly it seems to work pretty good but on some parts I have had adhesion problems, even on sand blasted surfaces. It could be because of wrong painting temperature or something else, who knows. Still it seems to work great and I even painted the surface rusted inside c-pillars without any prep work other than degreasing mayby 3 years ago and the paint it still holding excellent and no bubling underneath it.

Something that I have noticed is that the silver colored por 15 (it has some aluminium dust in it) seems to hold much better on new metal than the typically used black por 15 and in a matter of fact the only adhesion problems I have had have has been with the black por 15.

As far as it goes for the rust removal, I have used sand blasting on bigger parts and both citric acid and phosphoric acid one smaller parts, depending on the part type. For example, for rusty bolts I do the following:

pour some phosphoric acid on stainless steel cup, drop the bolts in and heat the acid with heat blower so that it boils & stir the bolts from time to time. After mayby 5 mins or so and the rust is all gone and the bolts are covered with nice phosphate layer. After that good rinse with clean water and some heating with heat blower. Last thing I do is that I submerge the bolts in engine oil while they are still hot/warm and wipe the excessive oil off with a rag. Seems to hold pretty good against rusting, atleast sofar.

[OxfordMotorSports]

I did a lot of my suspension components in POR 15, and while I think it's a good product, I don't think I'd recommend it for this use. My results were nowhere near rock hard. More like a thick, rubbery covering. I think that for that purpose I'd go with rhino lining.

This is not rubbery at all. It's rock hard. It looks like powder coat. I've shot LINEX for years. Truck beds, axles etc. The POR 15 looks good like paint should. I'm just putting this out there as an alternative for those on a budget. I'm anti cover up rust. If you can't afford to remove it all - this is a option.

Todd

OMS

NYC

[ChallengerHK]

It's entirely possible that I didn't apply it properly. If it ever turns out that I can work on my car again, I'll post some results. I can say for certain, though, that when I was installing my new torsion bars, everywhere they grazed the mount the POR 15 came off in a thin little flexible strip.

[Kapteenikosmos]

It's entirely possible that I didn't apply it properly. If it ever turns out that I can work on my car again, I'll post some results. I can say for certain, though, that when I was installing my new torsion bars, everywhere they grazed the mount the POR 15 came off in a thin little flexible strip.

As I said above I have had similar problems with por 15 but only in couple of occasions. Must have something to do with the painting process because I have used similar surface prep on all surfaces and it isn't peeling of from everywhere. I will also have to agree with ChallengerHK that por 15 is flexible paint, more like rubberized coat. There is no way that you could get it chip off, it only peels off. By now I have probably painted something like 8 quarts of it and it has been the same all the time.

But still, according to my experience it is great stuff when it adheres correctly.

[dutch]

I have used a little por on my car but I can`t say I`m impressed.  I used it on the inside of the decklid, just poured in a lot and twisted it around till it came out of every hole... I think it still sits great in there...     but I used it in some other spots as well and the problem I see every time is the crossing of rust to bare metal... when it starts to peel it wont stop coming off. I used the grey stuff, I didn`t know there was any difference besides the color though.  I don`t see por being flexible either. Every paint has some flexibility but the fact it peels off in flakes has more to do with adhesion than it being flexible.

[elitecustombody]

I'd probably never use POR15 hearing many horror stories of this stuff coming off in big sheets,but I like Rust Bullet.POR does have a very hard glossy surface, I just got a 69 Firebird in trade and the previous owner used it on the interior floors,fingernail will not scratch it.

[OxfordMotorSports]

I have used a little por on my car but I can`t say I`m impressed.  I used it on the inside of the decklid, just poured in a lot and twisted it around till it came out of every hole... I think it still sits great in there...     but I used it in some other spots as well and the problem I see every time is the crossing of rust to bare metal... when it starts to peel it wont stop coming off. I used the grey stuff, I didn`t know there was any difference besides the color though.  I don`t see por being flexible either. Every paint has some flexibility but the fact it peels off in flakes has more to do with adhesion than it being flexible.

Taking another look at this kids Jeep and I would have to agree with just about everyone's comments and Dutch is just about dead on. Adhesion problems are a painters biggest nightmare and the POR 15 can be sketchy if not applied correctly. I don't know if I would trust it under a big $ paint job. On a frame, under a trunk lid or any other area not exposed to direct sun light the POR 15 would probably be ok if properly applied. The heating and cooling of the sun would scare me under the top coat of a panel exposed to the elements and direct sunlight. Shrinking and swelling would be a major concern with the possibility of adhesion problems somewhere down the road. Again, only if it were not properly applied.

Todd

OMS

NYC

[OxfordMotorSports]

The POR 15 sucks! One of my workers hit the Jeep today with 320# grit DA paper and a couple of very small spots rolled back. My guys aren't perfect but they etched and wiped the body down twice. I'm certain that these spots were not wiped to perfection and the POR 15 wouldn't adhere properly. PPG DP epoxy would have stuck like glue no matter what. I'm going to have one of my guys go over it again with 220# grit Monday. Then I'll hit it with two coats of DP 90 (white) and seal it good. I DO NOT RECOMMED THIS PRODUCT.  I will never use it again. The finish seems hard as nails. The adhesion is sketchy to say the least. 

Todd

OMS

NYC