question about using PPG DBC clear that has pearl

[kidkombo]

edit:the DBC base i chose has pearl...not the clear =P


hello, im new to this forum and had a question.

i have a car that im shooting in the garage. The color that im painting the car is dolphin gray from a 05 audi A4...

now to my question...

im using a PPG DBC base coat...i painted the entire car, bumpers and all on one night, then i stopped because it was getting really late.

it says in the 'pamphlet' that if the paint has sat for over 24 hours, it must be scuffed before you do anything to it, like clear or reshooting the base...

so, following the instructions, i scuffed the basecoat with a white scotchbrite. i can see the base's white pearl start emerging from the base that wasnt visible before.....

thinking that i had completely scuffed it evenly, i shot the fender with PPG 2021 clear. the ending result was really crappy, and i can see the dark spots on the base underneath the clear.


i was wondering if its possible to shoot the base, and then shoot the clear another day without having to scuff the surface because the entire base was even before i scuffed it.

i hope you all understand what im trying to say...if anyone has any insight on this topic please chime in. thank you for your time!! hope to hear from you soon.

toto

[Phil V]

It sounds to me like where you made your mistake was after the scuffing and before the clearcoat. What you should have done is sprayed more basecoat over the scuffed basecoat before you applied the clear. Did you use the DX hardener for the DBC ?

[kidkombo]

yeah...i didnt use hardener for the DBC base coat....

so are you saying that i have to reshoot the base coat before i clear if it after that 24 hour time frame?

also, there's no way i can shoot the base..and then a couple days later shoot the clear...? =(

[Dennis N. Schmidt]

Correct, Your options are:

1) You shoot the base then 30 minutes later shoot the clear over it.

OR

2) You shoot the base wait however many days you chose then scuff the old base then shoot more base over the old base then clear within 24 hours

OR

3) You're screwed.

[kidkombo]

haha looks like im screwed..thank you for answering my questions...

now i need to go buy another gallon =(

[68-chevyman]

If you did not use hardner in the DBC you can spray a coat of DBC 500 over un-sanded base coat the next day and the window will re-open.

[kidkombo]

^^is what is dbc500?

on a side note, the entire base of all the parts i shot were already scuffed with the white scotchbrite....the surface looks spotty where there are bright spots where the pearl has shown through....i dont know if you know what im trying to explain but it looks uneven.:mad:

[Phil V]

We have a pretty good idea of what you're trying to explain. And the same rules apply. DBC500 is an intercoat clear that is the same chemical makeup as the dbc basecoat you already applied. What he was telling you is that you can extend the 24 hour recoat window of the original DBC basecoat by another 24 hours by applying a coat of DBC500 intercoat clear. The same 24 hour recoat window will then apply to the DBC500.

The basecoat and the clearcoat were made to work with each other within a recoat time window (24 hours in this case). Depending on how far over that 24 hour time window you go and try to coat the base with clear you take a chance of the clear not properly adhering to the basecoat and if you wait way too long the clear can actually make the basecoat lift like paint stripper was applied. It shouldn't take a whole gallon of basecoat to recoat what you already painted with basecoat. A couple quarts of base should be way more than enough and you could probably get by with just one quart of new basecoat.

I do see a potential problem that hasn't been addressed so far. You stand a really good chance of the the border area between where you applied the clear and uncleared base to lift the base/clear in that blended area (thats assuming you didn't tape of the rest of the car and just clear only the complete fender). I personally use DBU base for a couple reasons. One is that the DBU along with its reactive reducer will eliminate any lifting problems like you may encounter with the unhardened DBC. The other reason I choose DBU base is that in most cases it is quite a bit less expensive than the DBC. I have also noticed that the DBC in many cases is has less paint pigments that its comparable color in DBU (meaning DBU will go considerably further than DBC). DBU covers better than DBC in many cases.