Hey guys,

I need some help. Please help me. I see that this forum isn't as popular. I am trying to stop the rust on my 95 F150 quarter panels and I have tried epoxy primer without much luck. It worked a little bit, but not much. So, I want to sandblast down to the bare metal on my whole bed side. Then I was thinking of using POR15's metal prep and then using gray POR15 paint. This POR 15 would last for a few days for me to use bondo over it where I have some holes right? Then I was thinking of spraying on a primer. Is primer necessary for POR15. I don't think it is, but I bet the primer over the bondo would be needed. Then I want to paint my truck a metalic blue and then clear coat it. How does this sound for stopping the rust? I am having a problem keeping the rust gone while I have time to use the Bondo. It will get bubbles overnight. I just sprayed my truck with silver Rustoleum and still have very small bubbles. I used a can that had to be 5 yrs old. Only 8 oz and I sprayed my whole bed quarter panels and coated the lower Super Cab panels. Not bad, huh? I will post pics pretty soon. PLEASE HELP! I KEEP PAINTING AND THE RUST COMES BACK IN LITTLE BUBBLES!

 

Should be okay with the por15, just scratch it up before you apply the filler, and yes you will need a primer over the bondo prior to paint, I'm pretty sure you can use the por 15, not positive. I would use the epoxy primer over it, this would be beter for block sanding an scratches out. Another concideration is the back side, if you have holes, the backside will need to be sealed as well ,or your rust will return no matter what you do on the front. Good Luck

Mike

 

No, you can NOT use a regular primer over POR-15 after it's set. You can only use regular primer over it if you spray while the POR is still tacky. Otherwise, POR has it's own primer that sticks to POR-15.

Another option (and probably cheaper) would be to do your sandblasting to metal, treat the metal with something like Ospho or Por's Metal Ready, prime with an etching primer and then put an Epoxy primer on. This should give you enough weather protection until you're ready to do your bodywork.

It sounds like where you went wrong before was by just covering up the rust with epoxy. When using any primer/paint, other than something like POR or ZR, you have to get rid of the rust first.

 

Ah, did I mention that I used a grinder to grind away all the old rust? This rust is a pain. It's much easier to prevent it than to stop it. Here's my pics. Not too shabby, but not something I'd want to live with for very long. It looks good until you get up close.

Other pics are in my gallery. Please look if interested. The rust was really bad before I did any work on it. It doesn't look too great now, but it looks a little better than primer on the side. RUST IS EVIL!!!!!!!!!!!

 

Picture doesn't come up! Sorry guys.

 

An etching primer, that's just normal primer right? Well I won't have time to do bodywork if I use POR15 then and want to repaint over it. Are you sure I can't just sand the POR15 a bit and then prime? I read that POR15 is compatible with other paints.

 

I sanded my POR15 with 60 grit and then primed with rustoleum auto primer and then painted with the rustoleum paint. It seems to be holding. Ted

 

<cr>
Why don't you go to the POR15 site and ask them. They will be able to tell you about any issues you may run into.

Anytime you start mixing products, you can run into compatibility problems. That is one of the reasons the major paint companies have developed a 'system'. All the different products (primers, fillers, paint, & etc.) are designed to work together and don't react with each other.

I have used POR15 paint one time. After a few days, the POR15 started to come off in sheets. I contacted POR15. Guess what their answer was? You're right. Compatibility issues.

Guaranteed to Work
1) Clean and degrease.
2) Sand to clean metal
3) Treat with metal treatment such as Metal Ready
4) Apply epoxy primer (Seals in micro-rust and seals out water)
5) Do your filler work over the epoxy primer
6) Cover filler work with epoxy primer
7) Finish as desired

Personally, I don't use self-etch primer anymore. If you exceed your paint topcoat time, make sure you scratch it good before you apply any further paint. Like someone said, if you have rust-thru and don't fix it, its only a matter of time before the rust will appear in your new paint. Your paint job will only be as good as your base. There is no magic bullet to take care of all your problems.

 

Thanks for the help everybody! Did anyone look at my pictures? Not too bad for an 8oz can of $3 Rustoleum that's been around for years in our hutch drawer. The paint did go on nicely. It kind of has a cheap look up close and isn't really a close match to factoy silver paint, but it looks better then primer or rattle can spray. I was hoping the primer layers would fill in the areas that I used a grinder on, but it didn't. Maybe I could've sprayed on a high build filler primer.

Aekisu, you always really know what you are talking about so I will take your word on it. I did do pretty much everything you said except use the metal ready stuff. They don't have that at walmart and the closest auto body supply is far away from where I live, but I better make a trip down and see what I can find there. When you say to sand down to clean metal, is it a must for the metal to be perfectly clean? For example, I sanded down and it looked shiny and all, but in some spots there were little rust spots the size of a pencil lead. I got rid of them as much as I could. Some of those little spots got larger while sanding. How long will epoxy primer last without causing rust for me to do bodywork? Would it be worth it to spray on some cheap auto paint over the primer in a very light coat before putting on filler? It will probably take me two days to finish the filler work and I'm working outside where the humidity is high and where it seems to be raining about every other day! Northeast weather! I need to build a garage!

Thanks again for the help everyone. It's greatly appreciated. I am finding out that this rust is very hard to stop sometimes. Maybe that is why some body shops like to just put on new metal instead of fix old metal. It would be a lot easier to keep a non rusty vehicle from rusting. Wax every month, wash it often, keep it out of the salt in the winter, and use undercoating. Anyone know if those electronic rust stoppers work? I put one on my truck after I found out about all the rust. Didn't seem to stop the rusty rust, but I don't see any new stuff.

 

I just mentioned Metal Ready because that is what I use. Others make it. It basicly converts the rust to an inert compound. You might be able to find a similar product at somewhere like Home Depot.

It's important to get as much rust off as you can. Rust converter works mainly at the surface level. Putting rust converter on thick rust and then sanding, will reveal unconverted rust.

If you can't put your filler over epoxy, then it would be best to apply the filler to the bare metal. One trick I use to use before epoxy, was to spray rattle can lacquer primer over the bare steel. When it came time to apply the filler, I removed the lacquer primer with lacquer thinner. Lacquer primer will provide limited protection. Just don't expect it to ward off rain or car washings.

 

Well, I guess I'll be doing all of this again pretty soon. I will use the metal prep this time. Today, I noticed a big bubble in the paint. I popped it and a good amount of water squirted out. I am considering fixing it and selling it to get rid of the problem. It might just come back to haunt me and I mine as well get it off my hands. I don't want to do this though, probably won't, but it seems not to work with me. It wants to be a rust bucket.