Primer question for you paint guys

[JoshStratton]

Last night I was looking at my fenders, which I primed at different times a few months ago. One of them is really glossy and thick looking...almost like orange peel, but not really orange peel. The other is light, kind of ruff and dull in shine. Are either of these close to the kind of texture you want with your primer? I used PPG DP90.

The reason I am asking is because it has been a while and I cannot remember what I did to get each coat. I am not too experienced with laying paint and want to figure out what the standard is for priming. If I have a good example then I will have something to shoot for, no pun intended.



Sorry, I do not have pics right now.

[Travis B]

Well since it is primer...technically it does not matter but it should have a dull shine and be pretty smooth

[astroracer]

The "look" after spraying is really unimportant with most primer applications. Most primers will be blocked sanded or scuffed in some way before topcoat so, what you are "shooting" for, is good adhesion to the base and a consistant film thickness.
Mark

[73z-6sp]

I agree, the finish of the primer really isnt that important. But..the more textured it is the more block sanding you may have to do so strive to always spray anything as best you can and you will be better off because of it. I mean, where else are you going to get the experience of spraying paint with out the fear of screwing up the final product. So I say shoot it as if you were spraying the topcoat.

Good luck!

[JoshStratton]

Thanks for the info guys! I thought I was being a little paranoid. I actually agree with your ideas on priming as if you are shooting the final.

In fact, that is why I went out and got an air compressor that will handle a really nice gun. I was using a 30 gallon compressor before and had to use a LVHP gun. I wasnt too crazy with the way they shoot. It was a great compressor for a lot of the other tools I needed it for, but I think I will be WAAYYYYYY more happier with painting with the new 80 gallon one I got. Any tips on good guns for pimers and BCCs?

73Z-6sp: Mind if I ask how you managed to get the insides of this cleaned before painting? http://home.earthlink.net/~roopdogg/18.jpg

[Travis B]

Sata makes nice stuff, along with Binks and Devilbiss(spelling).......

[J2speedandcustom]

Kuhlryde - what pressure are you shooting the primer? This will also affect the finish, and said before practice is key. Try shooting at 30 - 35psi at the gun, your compressor will probably have to be turned up to around 100 to get that kind of steady pressure at the gun.

On your primer descriptions it sounds like the first one was more wet "more paint" to get the heavy orange peel. The 2nd sounds more dry coated "not enough paint" like you didn't overlap enough or went to fast with the gun.

Good luck and have fun!

[73z-6sp]

73Z-6sp: Mind if I ask how you managed to get the insides of this cleaned before painting? http://home.earthlink.net/~roopdogg/18.jpg

Well, I was fortunate enough to have a new hood to work with on that one. I have done original hoods and it can be a PITA. I usually clean the heck out of it with some degreaser/bon-ami, then wet sand it, metal prep and condition, then spray on the primer/surfacer. It is much like painting anything else except you REALLY got to watch your fingers if you want to keep them intact!

[JoshStratton]

Kuhlryde - what pressure are you shooting the primer? This will also affect the finish, and said before practice is key. Try shooting at 30 - 35psi at the gun, your compressor will probably have to be turned up to around 100 to get that kind of steady pressure at the gun.

On your primer descriptions it sounds like the first one was more wet "more paint" to get the heavy orange peel. The 2nd sounds more dry coated "not enough paint" like you didn't overlap enough or went to fast with the gun.

Good luck and have fun!

Actually I think I was at 20-25psi at the gun. I was using a crappy cheap-o to lay down the primer and I wasnt getting much of a pattern....more of a small stream. I tried adjusting, but it didnt do much at all. That would account for the dry second fender. I am just glad I have a more powerful air compressor this time around....one more useful for painting.

[Duesey]

If you spray at different humidity levels and slight variances in mix ratio will yield the two different style finishes that your getting. Both are acceptable for primers. I've been using a sharpe finex for primers and it's the best bang for the money I've came across. I'm confident that with a smaller tip my sharpe primer gun would spray base/clear very good. May not be Sata quality but in a clearcoat that has been blocked and rubbed you couldn't tell what gun was used.

[JoshStratton]

I used to have a a Sharpe gun. I bought it VERY cheap as a remanufactured gun direct from the company. I used it once and then sold it. Maybe it is time I give them a call again.

[BRIAN]

You probably started with a clean gun and ended up with a closed up tip from spraying the primer causing the small pattern and dry type spray. By the way there are 2 hardeners for DPLF. go with the one that takes 20-30 min to activate. Better adhesion by far.

[JoshStratton]

That is probably very true. I tried to get it clean but I may have missed some stuff. Is it possible to clean a gun that hasnt been used in several months and might have dried primer in it? Or after a while is it pointless?

[myclone]

That is probably very true. I tried to get it clean but I may have missed some stuff. Is it possible to clean a gun that hasnt been used in several months and might have dried primer in it? Or after a while is it pointless?

Once a gun has been sitting that long with primer in it (or any sprayable material for that matter) its pretty tough to get it completely clean. You might try some acetone or methyline chloride (<REALLY nasty stuff) ans soak the metal parts of the gun but do NOT use it on plastics.

If you have access to a small ultra sonic cleaning unit (hint: ebay) then acetone and a bath in the US unit will clean it just like new.

Soaking the parts in pain stripper will work but yeesh its a PIA and messy not to mention lots of time making sure every single molocule of paint stripper is washed off before you can use it again.

[CAMAROBOY69]

If you use epoxy primer the finish will be quite shiny. Anything else I was going to say is already covered.

[Jim Nilsen]

When using DP90 epoxy you will have to remember that you have to paint over it within 72hrs 0r 7 days I can't remember which but you have to paint over it within a specified time period or you will have problems with the paint adhereing to it. If it goes past that period of time you have to sand the primer and reprime it.

I primed the car and other parts over a 2 week period of time and then block sanded them all to make sure everything was good. Then I primed the whole car and waited 24 hrs and then blocked the surface one more time and then shot the paint on the 3rd day. So far it looks great 2 yrs later and it really looks a lot better if you block it before you paint over it if it has orange peel. I practiced on a couple of parts and the orange peel will transfer to the paint and make it harder to colorsand without cutting through to the primer.

Goodluck and be patient while trying to go as fast as you can. Being patient and not messing things up takes practice. That damn hose will always somehow try to hit the car or a part if you aren't paying attention

Jim Nilsen

[JoshStratton]

LOL the hose thing I can definately attest to. I am actually doing one part at a time. Strip. Body work. Prime. Move on to the next piece. I am limited to a 2 car garage and cant do it all in stages. I am working on dismanteling the whole car now and will begin the main body work. Hopefully this Spring it will all be in primer and driving around looking like Adams! LOL

[StRacerDuke]

DP90 is not a primer! It's an epoxy sealer!

Big difference. I've used the stuff a few times and will not bother working with it again. Typically it's used to seal metal and body work if a car is going to sit for a while. What most paint suppliers don't tell you is it doesn't sand worth a crap. The only way I've found to use it and by happy is to strip a car, do all the body repairs and filler work, shoot DP90, let it flash for 20-40 minutes, then lay 2-3 heavy coats of Polyester (SP?) primer over it. You can then let it sit for a long time and come back to final blocking when ever you want. After final blocking I would recomind a medium sealer coat, let it flash for 20-30, then first coat of base, etc.

The DP90 doesn't sand very well at all and the adhesion sucks after it's been sitting for more than 72hrs. If it's been a week and you really care about the paint job I would sand it off and start again. It's not worth spending all that time and taking the risk of having a crapy paint job.

My suggestion: (I've painted a half dozen cars in our shop and throught trial and error figured out what works best for me)
Body work until it is almost perfect, DP90 w/ 30 minute flash, tack it, then 2 coats of evercoat G2 primer. Set aside and go to next panel. Make sure your using at least a 1.7 or higher tip with the primer because you don't want to dry spray it.

Come spring (or when ever you get around to it) you can guide coat and start loosing your finger prints. Guide coat, 220 paper, then 400, with re-priming if burn through.

Just my 2 cents. Hope this helps.

[tbair]

Dp-90 is a non sandable epoxy primer used to seal bare metal. Dupont changed there mix formula in the past 6-8 months. from 1to1 tp 2to1 if your using a gun with a tip smaller than 1.8 its not going to lay as smooth. but thats not a problem if you have a gravity feed gun bump you pressure up a bit to 40 psi with the trigger pulled if your still not happy with the way it looks. use a little less primer and a little more reducer to thin it out just a little. let it set for a couple of hours and use 1140s uro(Dupont) primer surfacer this is a high build primer that you use to block. if your doing the whole car use 1130 reducer not the 1135 it sets to quick,actavater is 1125. hope this helps,Tim

[Jim Nilsen]

I went out and looked at my records and I used the DP90 to seal my car and then used DP48LF white epoxy primer which is sandable according to the paint supplier I used. You don't have to sand it if you don't want to and in most cases they don't recommend that you do, but in my case since I was trying to save on paint and it was yellow ,they said as long as I painted over it in 72 hours hours it would be good.
Just so it is more clear as to what I did and why. It takes a considerable amount more of yellow to cover a car than most colors and to make sure it was going to be as bright as possible I used a white primer,grey primer will make yellow get a greenish tint to it if you block the color out and get too thin. So to keep the cost down and not have to buy any more paint than necessary and to get the look I wanted it is the only way the paint shop said I could probably get away with it. It worked out well and was a lot of work in a short period of time. You really have to kick butt and sand for hours to beat the deadline of 72 hrs. I waited for 24hrs to let the DP48 to setup or it is a pita to not tear instead of sand smooth but it can be done and the difference in the final paint is worth the effort. I used at least 1 gallon less in yellow paint and the color sanding was much easier from the experiment I did on the spare lower valance panel I had laying around.

So I hope this clears up some questions that may have come up about what I did.

Everyone that has seen my paint have been impressed about how it came out for being only the 3rd time I had ever painted a car.

It was a lot of work and I don't know if I would want to do it again but the thought of paying 6k for someone else to do it would probably scare me right back to the paint gun again and wearing my fingers out sanding and prepping.

Jim Nilsen