# Sanding Primer



## H2O Paint Chemist

After applying primer to moulding, trim, cabinetry or any other surface that requires primer, do you normally sand? Or, do you expect the primer to go on so smooth that you don't have to sand? I'm talking just a quick scuff with #220 before putting on the finish coat.


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## BrushJockey

Yes.


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## TheRogueBristle

I always sand primer on bare wood, as it raises the grain leaving a rough surface. It gives you the smoothness but also the sheen you are looking for. A semi over unsanded primer will look duller than over a sanded primer. Perhaps over metal you wouldn't have to sand, but I have always used DTM's?

And yes, just a quick, but thorough, once over with 220.


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## PatsPainting

Same here. In most cases the primer raises the grain of new wood. Also sand even on old painted surfaces as it seems to make the finish coat look nicer.

Pat


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## H2O Paint Chemist

TheRogueBristle said:


> I always sand primer on bare wood, as it raises the grain leaving a rough surface. It gives you the smoothness but also the sheen you are looking for. A semi over unsanded primer will look duller than over a sanded primer. Perhaps over metal you wouldn't have to sand, but I have always used DTM's?
> 
> And yes, just a quick, but thorough, once over with 220.


Do you also sand when priming over previously painted surfaces?


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## TheRogueBristle

Yes. Partially out of habit, but also if you you run hand across sanded versus unsanded primer, even over a previously painted surface, the sanded is smoother. I guess you could say it has become a matter of practice at this point.


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## robladd

H2O Paint Chemist said:


> After applying primer to moulding, trim, cabinetry or any other surface that requires primer, do you normally sand? Or, do you expect the primer to go on so smooth that you don't have to sand? I'm talking just a quick scuff with #220 before putting on the finish coat.


It all depends on the primer. For instance if I was finishing doors and jambs with Frazee Mirro
Glide and priming with Frazee Prime+Plus it would get a good thorough sanding.

But say I was finishing doors and jambs with Vista CareFree and using Vista AquaLac WB lacquer undercoater it would get more of a wipe
or quick sweep.


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## daArch

as stated, primer raises grain (or SHOULD) on new work. Sanding is necessary, or at least highly advisable.

On old work, it helps fill in less than level brush strokes. Sanding helps provide a baby butt smooth surface. This would be moot if priming over a good spray job.

it would be nice if more waterborne primers were as sandable as the good solvent primers.


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## Conley

I always sand and on raw mdf i do two coats of primer usually and sand both until smooth. I always expect primer to raise the grain and i always expect to sand.


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## ArcherThePainter

I have to confess.......I never use #220 sanding, I normally use #80,#120#180#, special case I use #400 on electric sander, but very rare.....


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## H2O Paint Chemist

ArcherThePainter said:


> I have to confess.......I never use #220 sanding, I normally use #80,#120#180#, special case I use #400 on electric sander, but very rare.....


Would you try #220 between coats or as a final scuff before topcoat? I've found that #220 is the best for these purposes.


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## Ole34

Use 120 a bit an it turns into 220 ........


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## caulktheline

I use special formula paint, primer, and sandpaper in one


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## StripandCaulk

As already noted..primer should raise the grain. Depending on what the application is how much primer/sanding i use varies. Always sand after primer coat.

For cabinetry and custom millwork. Sand, prime(2 coats depending on product/build), sand with 220 and up. sometimes as fine as 600 if its really high end, and im using a lacquer or varnish. Sand between coats of finish.

Doors and trim in a home..sand after primer coat. If im spraying finish..usually dont need to sand between coats after that.

I think alot of it depends on what type of job you are trying to do and what results you want.


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## Workaholic

On previously painted I scuff sand for adhesion.


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