Progression of sanding grits

A

amt

Member
Joined
Jul 16, 2013
Messages
379
I was wondering what progression of grits people use when finishing a project.  I am working on a built-in bench seating for my kitchen, and I am now in the painting process.  So far I have used 5" in P120 and P180.  I am getting to the point where I am going to need to sanding in between coats of paint, and some kind of sanding/polishing on the final coat.  The piece is made of mostly MDF and I am using a Sherwin Williams oil based paint.  Will I be OK jumping from 180 to 240, then 320?  Or is it imperative I not skip any grit levels at all?
 
amt said:
I was wondering what progression of grits people use when finishing a project.  I am working on a built-in bench seating for my kitchen, and I am now in the painting process.  So far I have used 5" in P120 and P180.  I am getting to the point where I am going to need to sanding in between coats of paint, and some kind of sanding/polishing on the final coat.  The piece is made of mostly MDF and I am using a Sherwin Williams oil based paint.  Will I be OK jumping from 180 to 240, then 320?  Or is it imperative I not skip any grit levels at all?
Click to expand...

I usually do cosmetic sanding (before priming) 80/100/120, depending whats going on for prep and what the substrate is. After that you can jump a little here and there, especially in paint grade. You might try sanding primer at 150. Sand after first coat at 220/240.

Also depends how many coats you are doing, which involves the discussion of application method (brush, roller, sprayer).

I would not recommend that you buff out after your final coat. There should be no need.
 
180-240-320 is not usually considered skipping any grits.  That would be a full sanding schedule.

The normal rule of thumb is to less-than-double the previous grit number with the next.

HTH

Dave
 
Seeing as you are now at the top coat stage, I'd hot it with 320 and see what it looks like. If I like it thats what I'd go with, if not I'd drop a grit at a time until I was. You can do all this prior to applying your second coat. With clear finishes my go to is 320 and up.

Tom
 
Definitely worth pointing out that clear and paint grade are entirely different beasts in sanding.

I was in the shop today with some cedar that I am sampling clear/stain grade for a client. Here is a situation where you really don't want to skip a grit. For fun, I sanded one finished sample out so I could reuse the piece. As much as anything, to see how low I would have to go to get rid of our product and start over. I ended up going 60/80/100/120/150 and got it about 98% swirl-less rather quickly.

I think when lower grit sanding (under 100) is involved in any situation, it is more important not to skip a grit. When you get up over 100, its usually not necessary to go 120/150/180/220/240, but it sure can be nice.

When sanding you are either opening or closing grain. Thats why product comes so much into play. If you have a product that can anchor in closed grain, you can do some pretty wild things.
 
Thanks everyone for the feedback.  This is my first time trying to paint a piece of furniture [nicely], and IMO it has been more challenging than the construction.  Since I have grits up to 180 already, then maybe I'll just get a 220 or 240 and see if that's all I need for a paint finish.
 
Make sure the paint is between coats sandable (new word), latex paint tends to gum up parer. Use Granat paper what ever you do.

Tom
 
You must log in or register to reply here.
Back
Top