Painters step inside please
Thread Starter
Drifting
Joined: Dec 2001
Posts: 1,560
Likes: 4
From: Dallas Texas
Painters step inside please
I,m using PPG DP48LF epoxy primer what grit sandpapers should I work up to before shooting color ?I was going to go 220-400-600 then shoot color/clear
Thanks for any input you may have
Last edited by White 68; Jul 31, 2005 at 08:08 PM.
Thread Starter
Drifting
Joined: Dec 2001
Posts: 1,560
Likes: 4
From: Dallas Texas
I,m going to use the original paint code 972 Polar White ...I,ll paint the door jams before hanging the doors and see what the color looks like . Its not a NCRS car so if its not the look I want I may look at other whites.
I,m looking at the 17inch Coys wheel with gray centers or may go black centers...
I,m looking at the 17inch Coys wheel with gray centers or may go black centers...
Last edited by White 68; Jul 31, 2005 at 08:09 PM.
Instructor
Joined: Apr 2005
Posts: 205
Likes: 0
From: Northern Idaho
Im not quite sure what your intentions are here,dplf 402 is a catalyst for dp 90,dp40,ect.you dont use it as a primer surfacer,usualy use it to seal bare metal,then primer surfacer over that like ppg k36,then you start blocking with 180 grit ,working up to 600 grit,then bc/cc.Maybe be more specific,Darryl
Thread Starter
Drifting
Joined: Dec 2001
Posts: 1,560
Likes: 4
From: Dallas Texas
Originally Posted by stepinup
Im not quite sure what your intentions are here,dplf 402 is a catalyst for dp 90,dp40,ect.you dont use it as a primer surfacer,usualy use it to seal bare metal,then primer surfacer over that like ppg k36,then you start blocking with 180 grit ,working up to 600 grit,then bc/cc.Maybe be more specific,Darryl
Instructor
Joined: Apr 2005
Posts: 205
Likes: 0
From: Northern Idaho
Dp 90, 40, 48, ect. products usally are not used as primer/surfacer,they are used as sealers,they are too thin,blocking primers such as k36 are builder primers,just depends if you want to block your car to make the fiberglass look alittle straighter, white will not show the ins and outs as much as other colors, if you just want to seal your car,just start with the dp48, then go right to the color,1 hour after spraying the dp48 cat. with 402,.if you want to block the car,spray the dp 48 to seal,after 1 hour spray a couple of coats of(I spay 3) primer/sufacer, let dry,the longer the better so it will shrink,then use a durablock to block,I say this as the durablock will tend to be forgiving of the ins and outs of the fiberglass,block to 600,starting with 180,carefull not to block to far ,if you block past the sealer,reseal, then go to your color,how staright do you want your car? 
Last edited by stepinup; Jul 31, 2005 at 09:18 PM.
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Instructor
Joined: Mar 2002
Posts: 140
Likes: 1
From: east hampton ct
I have been told and my experience has been that sanding the high build primer with 320 grit will give much better chip resistance than using 600. This is due to a better mechanical bond with the rougher grit. I just finished spraying a 75 with white and you will not see any scratches or sanding marks with the 320 wet sand once the base is applied.
Instructor
Joined: Apr 2005
Posts: 205
Likes: 0
From: Northern Idaho
some paint companys want you to go to just 320 wet,such as house of kolor(valspar),but I have never finished at 320 .Yes you get a better mec. bond and this is important .But I have never had paint fall of a car at 600 wet.At 320 wet you stand a chance of sand scrathes,wont see them at first but give it some time as everything shrinks they will show(wont be seen on white as other colors).If you chose to go the 320 as finish just put enough clear on to be able to cut the scrathes out later.the weak link of any paint job is the primer/surfacer,what I mean by that is if a paint job done and preped right is going to chip from a rock ect.,It will chip in the layer of the primer/surfacer,not at the mec. bond between the primer/surfacer and basecoat,the reason why is the p/surfacer has talc in it,this is the weak link,the more on the substrate,the easier it will chip. 
Le Mans Master
Joined: Jul 2005
Posts: 5,752
Likes: 4
From: Austin Texas
We used to use a sealer, but it didn't make sense. The primer, if catalyzed, will seal out any bleed-thru. Since we switched to DuPont at my shop, they recommended that we don't use a sealer over primer-surfacer.
Instructor
Joined: Apr 2005
Posts: 205
Likes: 0
From: Northern Idaho
Originally Posted by big_G
We used to use a sealer, but it didn't make sense. The primer, if catalyzed, will seal out any bleed-thru. Since we switched to DuPont at my shop, they recommended that we don't use a sealer over primer-surfacer.
this is true 68 as long as you dont sand thru the p/s and sealer to fiberglass,Im sure that was understood,but wanted to make sure.When your blocking and start to see yourself going into the sealer,STOP!before you go through,this means your going to need a couple more coats of p/s.when your done,you should not be able to see anything but p/s.the reason why is after paint and everthing begins to shrink,it will shrink evenly,does that make sence?After I think Im blocked and ready for paint,I always use final prep. and a scotch brite with dawn soap and water,and scotch brite the whole surface that is going to be painted(corners,edges,bodylines)every inch ,this will ensure that the surface is grease/wax/ect free and will make sure you dont have problems like fisheyes, ect.
Melting Slicks
Joined: Mar 2004
Posts: 3,365
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From: Farmers Branch TX
Cruise-In VI Veteran
St. Jude Donor '09
Im going by memory here from a few years back, but PPG says you can use catalyzed K36 as a sealer as well, you can either reduce it and respray, or if you left enough material on the car after blocking, you can sand with 1000grit and they say it works as a sealer.
--Chris
--Chris
Drifting
Joined: Nov 2001
Posts: 1,469
Likes: 6
From: 68 427 4.11s Roadster
Another reason for a sealer is for a color sub base.
When I painted my boat the epoxy primer was yellow. The silver base took hell to cover it where a sealer would have supplied a better color to cover.
This is only important on some colors. Black would cover anything and maybe white would take more.
Yellow I understand to be the worst to cover and needs a better base color rather than more color to cover.
I still think if your going with white something else is needed. Even if its all white it should be pearl or flip flop. Maybe because I painted mine white with flip flop red?
Or metal flake or.......
But not just a solid overall color
When I painted my boat the epoxy primer was yellow. The silver base took hell to cover it where a sealer would have supplied a better color to cover.
This is only important on some colors. Black would cover anything and maybe white would take more.
Yellow I understand to be the worst to cover and needs a better base color rather than more color to cover.
I still think if your going with white something else is needed. Even if its all white it should be pearl or flip flop. Maybe because I painted mine white with flip flop red?
Or metal flake or.......
But not just a solid overall color
Melting Slicks
Joined: May 2001
Posts: 2,131
Likes: 4
From: May help you? You can sure as hell try!
320 or 400 are more than fine enough to prevent seeing sanding scratches under the paint. 600 is too fine IMO for a good bond between paint and primer. Another alternative is to use "Superfine" pads by 3M. They are basically foam sheets with the abrasive bonded to them. They conform to the curves of your Vette much nicer that sandpaper will. 3-4 of them will do your whole car.
Also, consider using Evercoat's slick sand as an alternative to K36. It has a very high fill quality and is much less expensive than K36. Most of your first block sanding is going to end up on the garage floor, anyway. After all the major imperfections are filled, seal with K36 or do a final block sanding with it before painting. Slick sand is a very high quality and effective product.
Also, consider using Evercoat's slick sand as an alternative to K36. It has a very high fill quality and is much less expensive than K36. Most of your first block sanding is going to end up on the garage floor, anyway. After all the major imperfections are filled, seal with K36 or do a final block sanding with it before painting. Slick sand is a very high quality and effective product.
Thread Starter
Drifting
Joined: Dec 2001
Posts: 1,560
Likes: 4
From: Dallas Texas
Ok Just got home from the paint shop and have PPG NCP271 to use as my primer/surfacer instead of the K36 ...They said its the same but dries faster ....
Also any Whites you would suggest instead of the original Polar White ?
I like the Diamond White which is on Escalades or is that too funky for a C3 year car ?
I have a pint of the polar white and will spray some with clear to see if thats what I want ...If not I,m up for suggestions white only as my car has the Bright blue interior
Also any Whites you would suggest instead of the original Polar White ?
I like the Diamond White which is on Escalades or is that too funky for a C3 year car ?
I have a pint of the polar white and will spray some with clear to see if thats what I want ...If not I,m up for suggestions white only as my car has the Bright blue interior
Instructor
Joined: Apr 2005
Posts: 205
Likes: 0
From: Northern Idaho
What do you think about ermine white with a blue pearl intercoat?the ermine is kind of a bone white,alittle easier on the eyes,and the blue wont really show that much until the sun hits it,even then it wont over power the white with the right amount of coats,here is a pic. of the ermine white on my old malibu click on thumbnail
Last edited by stepinup; Aug 3, 2005 at 12:05 AM.