More Primer questions????

J

Jim

Member
I'm a little confused when to use differant primers.I know if your down to bare metal,epoxy seems the way to go,PPG says after you spray thiers,over thin and spray another coat for a sealer,HOK's epoxy doesn't need a sealer,Then you have etch primer for bare metal too,fill primer,primer/sealer,etc,etc.
If you can strip something small like a bike frame,tank,fenders,etc all at once,it would be easy to prime the whole thing in one shot but,as with my car project,I found out I don't have that option.When I'm replacing panels or metal,I have to prime the panel,grind the edge,weld it then prime the welds before it rusts on me.I'm useing Sherwinn Williams self etching primer in a spray can from my paint supplier but It's the same stuff sold in quarts and gallons.I just can't justify cleaning my gun for two minutes of spraying.I'll do my filler on top of this primer when I get the whole car stripped.What should be my next step after I'm done with the filler?Although it will be very,very thin,the layers are from bare metal,etch prime,filler,sand it,primer,sand it,glaze or fill primer,block sand it,base and FINALLY clear.I was dead set on useing epoxy for durability,Am I still going to get a long lasting job this way? I'm getting pressed for time but,I want to do it right the first time!
 
R

rex

New member
Hey buddy,been a while.I can't say about SW but here's my PPG way if it crosses over.The etch primer in the rattle can is good for small spots but not advised for large areas over the 2part stuff and it must be topcoated before anything-no bondo yet unless they say so.After the weld sites have been cleaned I sand the crap out of the primer or if it's raw metal I get it sanded 150 or courser and/or sandblasted clean.Then I epoxy it(green DP) and do all my work over it.You can etch prime first but it's not completely necessary.Do your mud and putty work over the epoxy and use 3 coats of a good 2part primer surfacer over the bodywork and any 'rough' areas. (I think SW is still using the urethane version of UltraFill and it's good-the lacquer version was the best of the laquer based I thought.The newer version of the urethane might have changed but when I used the first version you don't tape off an edge or get a run or sag in it.A sag will be full of tiny pinholes after it's blocked out and if you tape an edge and prime up to it that tapeline shows no matter what without going to steel.) Block them down with a finer grit than previously (like 180) and scuff the rest of the epoxy on the panel and put 3 more coats on the whole panel.A guide coat is cool now if you want.If you know the panel is straight sand it down in the paint prep stage.If you think there might be more work needed block the whole panel down with the same grit.If you find a few flaws fix them,if not reprime.Just remember when you block and hit metal to stop,if there's a low section next to it fill it,don't keep sanding to make the primer smooth.Once the whole thing is in the last coat of primer surfacer sand it all,primer seal it and start painting.
 
J

Jim

Member
Rex,Hows everything down south?I've been here but hadn't had much to say,just been reading.There are so many pro painters here now,the posts are getting quicker responces.Things are moving right along with the Chevelle,finally got the quarters on,Boy did that s**k!I still have a few welds under the trunk floor to do but they're there to stay.So far,the doors and fenders look good,very little work to do there.Don't know if you read my very last post on "laquer paint"but the dash and that came out great,matches well!

Let me get this straight,strip my self etch off with 150,green DP,do the filler work,primer surfacer,more filler work,primer surfacer(guide),block it,primer sealer,paint,clear.Sound good?So the surfacer is what I'll be useing to check my filler work?.Good,I thought I had to use the DP(epoxy)again.What's the dry time on the green DP?(before I can apply filler)I can get the garage up to 75 if needed.
I still haven't decided on a red yet,Chrysler has a very cool Inferno red pearl that looks awsome on the 02 and 03 PT Cruisers but,I still like thesolid red Stinkie used. I have plenty of time to figure that out later.Thanks again,Jim
 
R

rex

New member
Sounds like things are coming along great.You have it.If there's a heavy coat of the rattlecan etch primer 150 should knock it down quick,or if it's thin 180 will be fine.You don't necessarily have to take it all off but thin it down.Usually it needs to be sanded after it sits for a day or 2 anyway.Any hard to reach spots run a red scotchbrite over it,the put a wet coat of DP without reducer over it all.At 70 you can mud or whatever in 60 minutes but I like to let it sit for hours if not overnite.Wherever you'll mud or putty just run the red scuffy over the area.Sand and recoat the areas as necessary to straighten it out then use the 3 coats of surfacer.Try to get it all done and straight first because putty and bondo don't stick as well to the surfacer-the label usually says no but there is adhesion if you rough up the primer with 180 or 150,it's just not the best thing to do.I like to finish my mud or putty in 150 or 180 but on large areas like a full panel I usually stop at 120,prime and block real good with 150 and reprime,fill any new pinholes with putty and block with 180 and final prime.You can guidecoat anytime on your 3rd coat of primer to hilite the lows as you sand it,but if you have good eyes you'll see the slight difference in color between the sanded and unsanded.When you're happy and the primer is only covering 180 or finer scratches just final sand it in the grit of your choice,blow a coat of sealer primer on it and paint it within the sealer's timeframe.I think the solid red will look best even though those others are nice.
 
K

Kyle

Guest
Lemme jump in here and add another question. The PPG DP primer tech sheets say you can get away without shooting a sealer over it. Do you always shoot a sealer over it anyay, and if I was going to shoot HOK base/clear over the DP would you suggest an HOK, or a PPG sealer?
 
B

BonesFX

Guest
I use nothing but the PPG DP primer - I used to use the Etching Primer, but had a problem with it flaking off. I shoot on the DP after I thin it a bit, over or under my body work, then I'll sand it with 150 grit to get any wrinkles or whatever out so it's nice and smooth. I shoot some more DP - let dry - wet sand and then go to base - never had any problems with base staying on... --- Bones!~
 
J

Jim

Member
If I understand the tech sheets,you spray DP without thinner,then thin it and spray it as a sealer before paint.You don't have to use any other products,I just don't see how thinning it makes it a sealer though.So to answer your question Kyle,just thin the DP and use it as a sealer.
 
R

rex

New member
Hang on,DP works double duty.Over bare steel like a panel that was stripped or Jim's case a new 1/4 that's going to get worked I like a straight coat of DP as a base.Do your bodywork over it or if none's needed let it sit until the paint prep sanding.After everything's sanded for paint-whether it be a primer surfacer over bodywork or whatever,or the first coat of straight DP,or original paint-then you can reduce it down to be used as a sealer.I go 1/2-3/4 of a part of DTV 802 but you can use the DT reducer for the temp(the DT was found not to be 'compliant' but it's the original reducer)You can of course reduce it down instead of spraying it straight but the bare steel protection is reduced.As a sealer DP isn't bad for production work but it really is too soft and will still be moving around after you paint it.Don't get me wrong I've gotten beautiful jobs that still look great,but it does shrink over time.What I like to do is let the straight shot of DP cure a week while I'm doing bodywork and such,and when I finalsand my surfacer I sand the DP flat without breaking through and seal the whole thing in NCS 2004 grey or 2005 black.Great stuff and goes on like a coat of clear or singlestage,sets quick and doesn't shrink like DP over time.The drawbacks are it's 2 part so there's another hardner you'll 1/2 use and you better use it when you mix it because the pot life is only 1 hour.
 
J

Jim

Member
What is the technical name and number for the PPG green DP?Been to the tech sheets and can't find it.thanks!
 
K

Kyle

Guest
DP-40LF is the gray green epoxy primer, the tech sheet is form P-122, which is the tech sheet for all of the DP primers, regardless of color. You can find it here:
http://autobodydepot.net/images/DOCS/P-122.PDF

Rex, one more question-- have you used, and what do you think of HOK KO-Seal? Just wondering because it uses the same hardner as the clear I plan on using for my next project and it would be nice to not need another hardner for the NCS sealer you use.
 
R

rex

New member
I haven't used the Ko-Seal so I can't comment but I'm sure if Scott or EZRider can't tell you someone here has used it.If you're going the HOK system by all means use it if that's they're recomendation.I think DP is the epoxy but I must say it's drying characteristics are funky,for lack of a colorfull adjective.The NCS sealer will break you since you need 1/3 of what you'll buy and the hardner will be junk if you don't use it again soon.I like alot of things about HOK but haven't really needed them yet.I do need some pearls so I'll be getting a few jars soon.

Jim,the Green is DP40LF,I keep forgetting the LF(lead free).
 
K

Kyle

Guest
Originally posted by John Pierce:
Kyle;

Are you sure you aren't confusing KO-Seal with HOK's epoxy primer? The KO sealer uses reducer, not hardener....

KO-Seal Tech Sheet
Click to expand...
<font size="2" face="Arial, Verdana, Helvetica, sans-serif">D'oh! You are right!
I think I am going to go ahead and try using it over the DP. I get the feeling that the DP is a better primer than the HOK stuff, and I think the HOK sealer will work better than no sealer at all without the cost of the hardened NCS sealer. Everyone cross your fingers for me!
 
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