Huy350Z Posted January 16, 2004 Share Posted January 16, 2004 Hi all, I just got the fenders and the cowl sandblasted. Now, I’m going to paint the inside with POR15, and the outside with a primer like PPG DP74LF=red. I have three questions: 1/Should I use the red primer (I’m going to paint the car red-orange), or another color (like gray or black)? 2/ Do I need to get a spray gun to spray the primer on, or can I just brush it on since I’m not going any bodywork on the car? 3/ If I need a spray gun, which one do you guys recommend? Thanks in advance for your inputs, Huy Quote Link to comment Share on other sites More sharing options...
Jason Jarvis Posted January 16, 2004 Share Posted January 16, 2004 I am sure many on here are far more knowledgeable on this than I and will speak up, but I'll start.... On the primer, I see that the DP74LF is an epoxy primer, which I am a big fan of, on bare metal though, I like a self etching primer under it, better adhesion and built in zinc chromate corrosion protection. I like an epoxy over that because the self etchings usually are not moisture resistant on thier own, but epoxy usually is. As far as the color, there are different schools of thought, one is the tintable / same color primer / paint, so that the paint covers better. Others like different color primers, so you can see where you have sprayed better. I'm the latter, but I don't do much anymore. As far as application, yes, you need a gun. The primers you are talking about will not apply well at all any other way, and you will never get a smooth coat of paint over a brushed on primer job. Remember, house paint covers mistakes and blemishes, car paint doesn't.... As far as a gun, get a cheap gravity fed HVLP, they require less air, and make less overspray. I bought one at Lowes for like $50 on clearance, it sprays pretty well....... Good luck ! I'm sure if I am out of date or just flat wrong someone else will correct me, one other thing, you will probably want a sealer over that primer, so that's another coat to think about. Jason Quote Link to comment Share on other sites More sharing options...
Jason Jarvis Posted January 16, 2004 Share Posted January 16, 2004 I knew someone more knowledgeable would speak up ! Thanks for the MAJOR correction. I do have a question on that though, I am obviously not familiar with this series of primer, but do you find that to be the rule, no epoxies over self etchings ? I have done it several times, with SW automotive and a second line brand. I think I remember at the time the recommended applications was SE, epoxy, sealer, base, clear, but my memory is pretty bad, and that was a few years back ! I do still have some parts that were SE'd then epoxied (not yet painted) and they have held up wonderfully, even stored outside under a tarp for a while... Jason Quote Link to comment Share on other sites More sharing options...
Metallicar Posted January 16, 2004 Share Posted January 16, 2004 Instead of a brush, I have used an"Ultra Fine" roller, found at Home Depot. They come in 2 sizes I think 3" & 6" long. Both are about 1 1/4" dia. No brush marks, or streaking left to deal with, which may fool the eyes into thinking that they are scratches. I called tech support about my intentions to do this, they said it is fine. They recommended I add about 10% more reducer to the mix. I have rolled the primer on the "hidden" pieces as well as on the top surfaces where I have been doing some body filler work. Areas I wanted to re-sand anyway. My project seems to be more protracted than I ever hoped. So many distractions from what I really want to spend my time on. By the way, the roller covers are cheaper (6 for 5$), than the cleaning material needed to clean the spray gun. As RacerX noted, much easier to clean up and cheaper too. Well, right there is what little knowledge of auto painting that I know. So far anyway. Quote Link to comment Share on other sites More sharing options...
Jason Jarvis Posted January 16, 2004 Share Posted January 16, 2004 OK, thanks. One thing I learned the hard way, never apply SE primers to anything other than bare metal ! If you have fiberglass parts, don't waste the primer on them. In hindsite it's obvious, but if you are in a "primer the car" mentality with materials in the gun...... The reason I really like(d) the epoxy over SE is that you have the rustproof qualities of the SE, and the epoxy is moisture proof. Quote Link to comment Share on other sites More sharing options...
Huy350Z Posted January 16, 2004 Author Share Posted January 16, 2004 Jason, RacerX, and Metallica Thanks so much for your advices. I'll be shopping for a cheap spray gun this weekend, and probably some gray primer from PPG. It's time to get the project rolling again. Thank you, Huy Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted January 17, 2004 Share Posted January 17, 2004 Does the ppg dplf primer adhere to por 15 coat? Or would i need to prep the surface? Quote Link to comment Share on other sites More sharing options...
Jason Jarvis Posted January 17, 2004 Share Posted January 17, 2004 Hi Jason' date=' Just to let you know that self etching primers do not have "rust-proofing properties". It basically is an "adhesion promoter" for ferrous metal and used when mechanical surface preparation is not done. SE primers are porous and will not prevent rust flash thus it needs to be topcoated. One more note: Do not ever use SE primers on fiberglass. The acid will be absorbed into the gelcoat/fiberglass only to surface once the car is painted and exposed in the sun - then it's blisters everywhere!!! Hope this helps. RacerX[/quote'] Hey, seems I must apologize if I mislead anyone, I seem to have ASSumed that the 2 products I have used are representative of the entire class of primers, this is not the case as RacerX has pointed out. I would like to point out that I am not crazy, I worked in an auto / paint store on and off for 5 years. This is the specific product I based my assumptions on... http://www.sherwin-automotive.com/products/show_product.cfm?product=4332&cat=115 This specific primer has worked great for me over sandblasted metal, it fills the irregularities of blasting as well as anything, and is self etching, and contains zinc chromate for rust prevention. I can attest it works well. The second product I have used in the past was a second line product, and I can't remember it at the moment, seems like it was a blue and white can. Recently I have tried DuPont VariPrime 615S, which is also an etching primer with zinc chromate, and is advertised as a corrosion inhibitor as well. I don't have much experience with it, but I am assured it is an excellent product for what I want. You are absolutely correct that se's will aborb moisture, which is why I mentioned I like an epoxy top coat, and not to use on fiberglass ! Again, I apologize for making an assumption, and readily admit I know nothing about the PPG product line, but there are a few products out there with the properties I mention. Jason Quote Link to comment Share on other sites More sharing options...
Jason Jarvis Posted January 18, 2004 Share Posted January 18, 2004 Jason' date=' Please - no need to apologize and I hope that my articulation on the board did not come across as criticism. [/quote'] No, we're fine, I'm never insulted by accurate information presented with good intentions ! I made an incorrect assumption based on limited experience and shared it with the world, which is why I apoligized, you just pointed it out. I actually appreciate it, I now know that not all self etching primers are rust inhibiting, and I may be saved from making a big mistake because of it. In the end others reading this thread may have learned that not all are, but there are some options. I just hate I made an assumtion and shared it as fact, Z car boards and lists in general are full of good accurate information, and not the bunch of BS that others often are, so I don't want to share inaccurate info, especially when I don't preface it that I'm not sure about it. Jason Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.