Hi there

I have posted a little bit before on a little project I have. A 87 Camaro Z28 that is going to get new paint very soon.

I am doing a little prep work before the painting.

How can I block sand something like my front bumper cover??...Or my ground effects??....I mean, everybody around here is talking about you must ONLY use sanding block when i am sanding...Not my fingers/hand.

I have primed my door-panels and it looked good. When I sanded over with block sanding there was some spot in the middle that didn't get scratches at all.... Something like this:



As you can see there are some dark grey spots on the middle of the line.
Here I used a sanding block with wetsanding 400grit paper.

Then I was confused on how could I get this sanded. So I just took some sanding paper 400grit in my hand. Wiped over this 10times with the wetsanding paper, and then it was smooth and the dark grey spots were gone.

Is this wrong method??...Am I doing something wrong for the painting??

Please help me, I have been working for MAAAAAANY days now on only the ground effects...

 

The f/x have a conture to them. Try using a dowel rod or pvc pipe and sand in a x pattern. Use a guide coat to help out.

 

you need a flexible board sander not a block sander.
http://www.eastwoodco.com/shopping/p...ProductID=1581

the term block sanding is a little too widely used what most people actually mean is you want the surface to remain flat, when you use your fingers and sandpaper it often "gouges" the metal, abs, fiberglass, etc. creating more work to get a smooth and straight painting surface. To do any countours or anything the sanding method must be adjusted. Tiresmokin gave you great advice, try experimenting with something that has a similar contour to get in all the tight spots and use either a guide coat which is normally a dry powder or use a black primer and sand until you don't notice any high or low spots. if there are high spots they should be taken down. which can be done with a hammer and a shrinking dolly. if there are low spots they can be raised with a hammer also. just try to get it as close as possible and then use a light body filler to smooth completely out. Hope this helps.

 

Okay..So I am actually doing it right then...I tried with a Pipe earlier today and it went very good...I am wet sanding with a 400grit paper..Is that Ok or what??....Should I go higher???

I have sprayed PPG D8022 that is a Surfacer on all of my ground effects.
And now I just have to sand them down so they are ready for painting.

If the old paint is coming through in some small spots is that any problem for the new coat of paint?...I guess as long as I have sanded the area it would be good???

 

No you want solid primer before painting, After spraying your primer sealer you dont sand until after your first or second base coat. But thats only how I would do it everyone has there own opinions.

 

ideally you want it down to bare metal or your base material for painting but it can the paint as long as it is still sticking but if you are going that far you may as well strip it all the way.

 

Ok....I apreciate all the help I get from you guys... I have heard about 100 different types of methods how to prepare a car, but basically they are all the same....

I was talking to the paint shop that sold me all the base coat, clear coat and Surfacer Filler. And they told me I don't needed anything else....

So my plans was only to sand over the whole car with 180-240grit paper.
Use this dry-guide-coat I bought from 3m to find every low and high spots that must be fixed with thicker materilal like bondo or something and after that spray this surfacer filler ALL over the entire car.....

Then I am ready for some wet-sanding ann all the rest of the car.
Now I am only practicing a little bit on my ground effects and my bumper covers... Since I haven't painted a car myself, I have made a deal with a paint shop the 26.May. So I need to be as good as finish with the prep-work before that day....This is NOT a show car either...Just my daily driver so I am only getting a new gloss on the painting....

 

Spraying is easy

 

hehe...What U mean by spraying???
To paint a car or to just spray the paint??....
I don't have any good place to spray the paint all over the car. It is best to do it in a booth i have heard because of all the Ventilation needs and of course the temperature.

The primer is no problem to spray in my garage cause it doesn't need this ventilation or the temperature to dry....AND primer is going to be sanded a little bit so it will be smooth and nicely