newbe questions...

[michael grady]

Hey guys..I'm retoring an old model t. New to all this painting stuff...practicing on a fender...

After media blasting the surface, I sprayed an ultra high fill urethane primer yesterday....just a couple questions:

Was I supposed to clean the surface with some sort of solvent prior to shooting the primer? What about sanding the surface prior to primer..is that a good idea?

How long should the primer dry before sanding, and what grit should I start with? I have an air driven random orbital sander...can you guys recomend a good paper? At this point, should I be using all wet and no dry paper?

And one last question..if I happen to sand a small spot through the primer down to bare metal, do I need to reprime that spot?

Thanks,

Michael

[Bob K]

My first question is for you. Was the high fill primer you sprayed a direct to metal primer or does it need a different primer applied first? Most do but a few are labeled direct to metal. If you don’t know then get the product sheet for the primer you have and see what is called for as suitable substrate. Most can be found on the internet.

The product sheet may also tell you that first you should degrease and sand and then degrease again before application, I’m betting it says to do that.

No problem if you need to remove what you did so far, you are doing a good thing by working the application bugs out on a fender before you go ahead and do the entire car and then find out step 1 was wrong.

Bob K

[michael grady]

Thanks Bob...I'll check it out and reply back tomorrow.

[michael grady]

Bob and all..

The primer I sprayed said it was direct metal...so that answers my first question!

The remaining questions are:

What about sanding the surface prior to primer..is that a good idea?
How long should the primer dry before sanding, and what grit should I start with?
I have an air driven random orbital sander...can you guys recomend a good paper?
At this point, should I be using all wet and no dry paper?

And one last question..if I happen to sand a small spot through the primer down to bare metal, do I need to reprime that spot?

Thanks for your help!

Michael

[williams772]

Bob and all..

The primer I sprayed said it was direct metal...so that answers my first question!

The remaining questions are:

What about sanding the surface prior to primer..is that a good idea?
How long should the primer dry before sanding, and what grit should I start with?
I have an air driven random orbital sander...can you guys recomend a good paper?
At this point, should I be using all wet and no dry paper?

And one last question..if I happen to sand a small spot through the primer down to bare metal, do I need to reprime that spot?

Thanks for your help!

Michael

yes it's good to sand a sandblasted surface before primer, usually 80 grit will work for this, feel the metal then sand a spot and feel the difference.
time to sand varies due to product, thickness, temp, etc. go by your product sheets but most of the time you can sand before it says, as long as it's not loading up your paper your good. I would start with 180 or 220 dry. Save the wet sanding for final prep before paint.
not that you can't get away with a small spot but it is always better to reprime sand-throughs. why take a chance on messing up all the work you've done over an extra step. this would be my approach, hope it helps.

[michael grady]

Thanks Bob...this has been helpful!