I am ready to bc/cc my lower quarter on my wifes Camry. It has a few scratches down to the primer. Can I D/A the schatches (feather them) and wet sand with 400 and just apply base. or do I need to use surfacer first? I am going to blend it at the body line to the fuel tank door so should I back tape it at the body line? ie.. roll the tape back on itself? Or should I just blend without masking off the rest of the quarter at all? If I prime first should I prime all the way up to the tape/ body line?

Zach, Id apply some primer or atleast some sealer. That basecoat wont hide or fill that featheredge NO MATTER HOW GREAT YOU DA IT OUT.

It will leave behind a bullseye meaning you'll be able to see the featheredge.

If you prime or seal keep it as small as possibe no need to prime something that doesnt need any fill!! Just spray it over that featheredge and somewhat extending past.

If you use primer instead of sealer when you mask it off, use the bactape method. If you dont use that backtape method the primer will build up right on the tape leaving a ridge that can be hard to sand away. Backtaping will leave a soft edge that is SO much easier to sand.

If you just seal it NO need for masking as you apply your sealer then basecoat, no sanding between rounds.

By saying blend it at the body line are you talking just blending the color or the clear?

If you are just blending the color at the body line then spraying clear on the whole quarter then dont use any masking when spraying that basecoat.

I dont get to many imports in this part of my little world but I think that car has break point on the quarter before you hit the roof.
If it does have stopping point on the quarter then Id paint the WHOLE quarter. Apply your basecoat to achieve proper coverage and blend it into existing paint but dont basecoat the whole quarter. The come back and clear the whole quarter. That will provide the best repair method, blending the clear is asking for problems later down the road when that blend edge final shows itself and it will...Eric

Edit if you are in no hurry I can scan some blending diagrams from my PPG tech manual that show the proper place to blend and the procedure

Thanks Eric, I am going to Dx1791 the bare spots around the B pillar that I welded in and then K-38 it. I have to hit the rocker with SEM chip guard because the other side has it as well. I think I will shoot the base where I need coverage and then clear the whole quarter.
That 2042 rocks I don't even have to buff ie..no runs and the orange peal is not any worse than the factory clear on the other pannels ;)
My question is I know I will have to shoot base over anywhere I primmed, BUT do I base over any factory paint that I scuffed when I wet sanded and feathered the primmer edge? Then I can clear the whole pannel? IE.. Clear right over the factor clear that I didn't touch? I will of coarse do my DX330 wipe before I shoot over it and be careful as the clear over the old clear will have me of a tendency to run right?
By the way do you DX330 wipe the new fresh base before you clear over it?

Apply color until the repair areas are covered then lightly blend the color out until the repair areas are no longer visable, then clear the complete panel. Make sure the entire area to be cleared is scuffed properly with no gloss showing. Remove tail lamps, mlds etc-these can sometimes be tough to scuff around. With some of the fine metalics it is benificial to apply a coat of midcoat clear to the complete panel before doing the blend. Fine metalics and pearls can hang up on the scuff marks and it will show when the topcoat clear is applied. I try to keep the color concentrated to the repair areas until full coverage is obtained then blend out from there.

add to previous, when clearing over an original finish the clear does have a tendancy to run easier because it has nothing fresh to bite into. If you apply the midcoat clear this will act the same as applying basecoat giving the topcoat clear something to bite into, hope I helped, Bob graemlins/beers.gif

Thanks Bob, anybody know what the midcoat clear is that I use on PPG2042 clear I think it is 500 something but I can ask the jobber.

If you're using DBC base then you will need DBC500, DBU500 would be for DBU basecoat. This is handy stuff to have, works well for spraying test panels for checking color matches also.

As promised theres a pic of a the blending process. Its from Dupont PPG's is very hard to follow :(

http://www.chevelles.com/showroom/color_blending1.jpg

Step 1 shows the primer/sealer spot on the rear portion of the quarter. It says sand the primer with 400-600 grit and the reminder of quarter with 1200-1500 grit.
I dont use wet/dry paper anymore on a blend area, I use 800 grit on a da or a gray scuff and sanding paste(PPG # DX103).

The sanding paste is faster, more efficient and I believe leaves behind a better surface for the clear and color to stick too.

Step 2 shows appling the adhesion promotor. Dupont calls it an adhseion promotor PPG calls it color blender or "MIDCOAT CLEAR".
Apply your DBC500 over the ENTIRE panel. This will allow the basecoat to "melt" into the original finish making for sweet blend. Also as Bob mentioned it gives the clear something to bite too.

Step 3 shows appling basecoat. The first coat should only cover the primer/sealer. Each coat after step it out farther.

MY Step 4. After you have achieved coverage and ready for the final blend on the base, I like to come back and just spray my BLEND area with DBC500, no need to redo the entire panel just the area that will recieve that final blend.
I like to do this because the NEW coat of DBC500 really melts in the blend edge.

Step 5 shows appling clearcoat. This method is showing blending the clear, pay NO attention to that. PPG wants you to clear the entire panel, some companies only suggest appling the first coat of clear on the basecoat then shooting the second coat over the entire panel.

Hopefully this helps...Eric

Eric, your the man! I will print this and then get off my rear and back to the garage! :D

Eric,
On step 4 you say after you have achieved coverage and stepped out your base color you come back and hit the blend edge(ie..where primmer met the factory clear) with DBC 500 and then what?
go over it again with more base? If so how much?

Or, I think you mean you just proceed on to clearing the whole pannel, right?
I think I will clear the ENTIRE pannel twice is that how you do it?
Sorry to be such a perfectionist, just want to get it right the first time!

I would clear it twice, you've got the proceedure down. Sevt-chevelle definately explained it well. You won't have any problems if you stick to the guide and don't pile the color on to fast, cover the repair first and let it flash then gradually step the color out with light coats. I'm sure it will be a perfect blend. graemlins/thumbsup.gif

Zach, on that step 4 I like to spray one last coat of DBC500 on the area where the next extending coat of base will be.

Picture appling basecoat as looking at a shooting target, you know the type that has bigger and bigger circles. The bullseye would be the primer/sealer spot.

So you want to apply the dbc500 over that next bigger circle, this melts in the basecoat. Allow roughly a 2min flash after that last coat of DBC500 and apply that final blend coat of base.

Yes do clear the ENTIRE panel twice. The pic I posted shows blending the clear on a quarter with no break point. There you step out the clear, but thats a moot point on a different topic. Some manufactors recommend that the first coat of clear to be only applied over the areas that recieved base then apply the second coat over the entire panel.

But PPG WANTS any panel to be sprayed TWICE.

Thanks guys glad I asked smile.gif

Bob,Eric, I want to clear (if you'll pardon the pun) something up. I don't want to be anal, I just want something clear for everyone. I know what you mean, and you know what you mean, but I just have to clear it up.

What you are discribing as a "Mid coat clear" is not the usual discription of a mid coat clear. A mid coat clear by any discription I know (other than what PPG calls it here) is an appliction of some sort of "tinted" clear like pearl or candy OVER a base coat and then followed by a final clear coat.

What you are discribing is a "colorless" basecoat used for blending and is NOT even applied in the "Middle" thus not a "mid coat". It is applied BEFORE the base coat or blend. And is applied on the entire panel so the blend will "fall" on a wet surface and reduce metallic stacking in sand scratches. I know PPG has this "midcoat clear" that is the same thing.

Before there were specific products to do this you simply used a base coat mixing clear off the toner mixing bank. Added your basecoat reducer and sprayed it as a "colorless" basecoat.

I just wanted this to be clear so someone doesn't get the two mixed up.