Scotch brite or scuff pads vs sand paper between clear coats.

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danford1

First off I want to say Thank You to everyone that has helped me recently. I've had a lot of questions and received some detailed answers. Thank You.

I've been reading a lot and using the search feature but can't find what I'm looking for.
I read here and there about scotch brite or scuff pads. I read where the thinner pads by Norton or 3M that you get from automotive paint supply stores are better than hardware store thick stuff. OK I'm good with that.

My specific question has to do with using these between layers of clear to scuff up the surface. They would be WAY faster than sand paper. I saw a guy using a pad with a sanding block and was amazed how fast it scuffed the surface. He said it didn't clog up like sand paper and he used it dry to avoid a water mess.
What color scuff pad it equivalent to what grit sand paper?
I do some clear coating of piano parts for a local piano shop. I'll spray 3 coats UC let dry a day then scuff with 600 then 2 or 3 more coats UC. I then block it 800, 1500, 2000, buff and polish.The scuff pad would really speed up my "sanding" time between clear coats.
Please spew forth great gobs of info :)

Thanks again.

Danford1
 
AAE;n81652 said:
Pads won't eliminate orange peel like sand paper.
Click to expand...

Thank you, I understand that. I don't have much orange peel when I spray the UC correctly :)
I never used the pads and want to try them, just want some good info from experienced users before I buy them.
Do you like them?

Danford1
 
The red pads are about 180 to320 grit .Gray pads 500 -600 grit white pads a little finer maybe 1200 , brands vary and also pressure on the pads. this is just a estimate of the grit.
 
I'll have top go to Painters Supply and buy some.
I'm painting a car also.
I have a cowl vent leaf screen with a lot of vents that will need to be sanded. I think the pads will be much easier to use on it then a block and sand paper...
Thank you.

Danford1
 
The grey and maroon pads work fine for scuffing between clear sessions, just be careful on your edges if you are using the maroon pads. Dryblocking with 400 or 320 is also an option if you want to avoid the water.
 
scuff pads are good, they all have their purpose, but I believe a 600 grit piece of sandpaper stays 600 grit until it clogs up. Scotchbrite starts "around" 320 but definitely moves finer and finer as it wears down. That is really the only reason I would be against it between coats, because part of your scuff will be 320, part of it will be 600. Its really why they make you search to find out what grit they are supposed to represent.
 
Here's a chart.
Please note the different shades of gray. This is where people going to the hardware store get messed up.
ScotchBrite%20Chart.jpg
 
What's missing from this chart above is the 6448 grit specs. Some charts like this floating around on the web have the 6448 listed as green with a question mark (?) after it and the grit listed in the 600 range. Per 3M the color is dark gray and grit range is 400-600 so that fits into the missing grit value field above. I guess their green line of Scotch-Brite is more for home use cleaning pots and pans though I have used it when in a pinch scuffing door jambs around the hinges when I ran out of 8447.
 
sandpaper will knock the finish down and work out imperfections. scotchbrite will not. scotchbrites scratch or dull the surface only so the next layer of paint bonds...thats it. if you have a dust spec in you finish and you scotchbrite then you will still have that dust spec there when your done. for what your doing the scotchbrite sounds like a big waste of time. the whole point of clearing twice is so you can knock the clear flat after the first round so when you do the second clear it lays nice and slick. if you just scotchbrite the surface then your just piling on more clear on top of a surface thats not flat to begin with. i just fail to see what clearing twice in this instance is gaining you. you could save yourself a ton of work and just do 5 or so coats of clear in one shot and be done OR if you dod want to clear twice then clear at the end of the day then come in the next morning and clear again. no need for any scuffing at all.
 
It's pointless to use a scuff pad with Universal because you could really save time and effort by just spraying more on it the next morning without any prep at all. Universal is good that way, it has a fairly long open time.

The point of sanding between applications of clear is to remove texture. If you are not willing or able to spend the time to do that step properly (remove all visible orange peel) just skip it and hammer on some extra coats of clear, seriously.

The only place for a scuff pad in this type of process is to get into places that sandpaper can't once the sanding is done.
 
Thank you to all that have commented. That is good info. It makes more sense than what I had floating around in my head.
I'll continue to do what I have been doing. The end results have all looked great in the past.
Cheers.
Danford1
 
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