Block sand...

[chicago]

Posted this up in my build thread too, but was wondering...
Im doing a single stage paint job on my rig, and its a wheeler, not a show piece. All I need it to do is look decent and protect the steel essentially.

Is a block sand after primer necessary?
What is the block sand step gonna do, I mean what is the purpose of the block sand at this point?

Thanks for any input!

K

 

[Frankencruiser]

A block sand will get rid of the high and low spots that cause a wavy reflection in the paint. If you don't care what it looks like don't bother. It doesn't help with protection or paint adhesion at all. Just give it a little sanding to get rid of any overspray, clean it up, and shoot the topcoat.

 

[spdwaver]

As someone who has painted using the "good enough for the trail" mindset, I can attest to the necessity of sanding the primer coat. That is, if there is unevenness, lumps or any defect that would otherwise compromise the finish coat; the primer will define the appearance of the top coat.

Whatever you choose to do, don't assume that the top coat will 'cover up' any blemishes apparent in the base coat; rather, the top coat will enhance the appearance of any mistakes in the base coat.

 

[chicago]

Thanks for the replies gents!
So it will have nothing to do with the adhesion of the final paint and is strictly an esthetic step in the process?

I stripped the whole rig down to bare steel, and picked up some DTM primer that apparently is kinda thick stuff.

 

[jimd4x4]

Depending on how long between primer and paint. You may have to use a scotch brite to reopen the pores for paint adhesion. I think on my PPG epoxy primer I had 72 hours to top coat. Any longer and I needed to scuff the primer.

 

[chicago]

Depending on how long between primer and paint. You may have to use a scotch brite to reopen the pores for paint adhesion. I think on my PPG epoxy primer I had 72 hours to top coat. Any longer and I needed to scuff the primer.

Lol... This is gonna be sort of a rapid sequence paint job.
Plan is to primer and then paint hood, fenders, windshield bib, aprons and tailgate hopefully ( space permitting) all at once. Then, move the tub into the "booth" and shoot that.
I'm trying to save time more than anything. If it's overall, gonna be better to stop, block sand the showing surfaces, I will based on recommendations I get here and how the primer lays down.

Short story.... The pieces aren't gonna sit for too long. I'm itching to get this step done!!