Sandpaper is clogging while sanding in between coats.

[Witchboard]

Working on a restoration.  I sanded the cabinet down to the wood, made the repairs and primed it.  I'm using oil based primer with a foam roller to try and get the smoothest finish, however the foam roller still produced a slight orange peel effect.  After the primer dried, I went back and filled some more on the cabinet.  I started to sand in between coats for a second and my sandpaper clogs up almost immediately.  I've tried two different grits and it does the same thing.

The primer is Sherwin Williams and states that it dries to touch in 30 minutes and able to recoat in about an hour.  It's been almost 24 hours since I did this so it should be dry enough to sand.  The tempurature has been in the 70's during the day.  I was hoping to get the cabinet painted before it got too cold this fall.  Any insight on why this is happening and possible resolution to the problem?

[ChadTower]

Are you putting the coats on too thick?  Primer alone shouldn't be clogging up sandpaper unless you put it on like peanut butter.

[Witchboard]

Not that I'm aware.  It didn't run and I painted it upright, so it shouldn't be too thick.  I just made sure it was evenly covered.

[patrickl]

Maybe it's too cold for the paint to cure as fast as it would usually do?

[ChadTower]

He said 70s during the day... could it be really humid at night?  Around here right now it gets pretty cold at night and everything ends up soaked.

[Witchboard]

I suppose it's possible, but it's in my garage. When I tried sanding, it was well into the afternoon where no dew was present outside.  I'm going to give it a few more days to see if it makes a difference.  It doesn't help that rain is forcasted for tomorrow. 

[orion]

Could be something wrong with the primer. Is it old?

[orion]

Or it might not be mixed properly.

[Witchboard]

The primer and paint are both just a few days old, bought from Sherwin Williams.  I would hope they know what they are doing with paint... 

[orion]

The primer and paint are both just a few days old, bought from Sherwin Williams.  I would hope they know what they are doing with paint... 

Stranger things have happened. I'm guessing that it will dry completely in a few days, if not I would ask Sherwin Willams about it.

[ChadTower]

You sure it's not the filler that isn't drying properly?

[Witchboard]

The Bondo skim is drying fine.  I'm not even trying to sand where I've filled at the moment.  I tried it again a little last night and same issue.  It's going to get cold this week, maybe not even getting back into the 70's, so it looks like the project is going to the back burner once again, or I'll have to invest in some heaters.

[ChadTower]

Have you asked the guy who sold you the primer?

[Witchboard]

No.  I'll give them a call tonight and ask.

[system01]

I have this problem a lot, and I go through a ton of paper, but I dont care cos everything I touch comes out badass.

On a random-orbit sander I switched to the zirc-oxide discs and found they last much longer.  I was having the red/brown paper stick up pretty quickly on urethanes and other "sticky" stuff.  The extra initial cost made it worthwhile (for me) when I was only throwing 1/3 as many on the floor.  Might be worth a try.

Also, how coarse did you go on the grit?  Clogging happens more if youre too fine.

[JazBrown]

Hey guys,

As a painter maybe I can throw in my two cents here.

Something to keep in mind with most paints is that the "dry to touch time" and cure times are two different things. With oil based materials its often a good idea to wait at least 48 hours before you sand unless the label says differently. You can use additives like "japan dryer" to speed up the cure time. From what you describe it sounds like the material may be too thick thus making your coats thicker. Using an oil based thinner can be helpful there. Thinning the material will also help with the orange peel effect. When thinner the material will have a chance to "lie down" more.

In addition, this is a great material to use for priming. It dries incredibly fast and you can sand in about an hour. It's white and you can tint it to suit your needs. It's alcohol based as well so the smell isn't as bad as a lot of oil based primers. I highly recommend it.

http://www.zinsser.com/product_detail.asp?ProductID=10

Keep in mind that you will have to use alcohol to clean up with this stuff.

[JazBrown]

something else I forgot to add is that mdf is an incredibly absorbent material so if it is kept in a damp environment for an extended amount of time before it gets sealed it can soak up the moisture around it. So my suggestion if you live in a damp area and have bought some mdf for a project that you wont be getting around to right away is to go ahead and prime it. That way when you go to use it later it wont be like trying to paint a sponge. Not saying that this is whats going with you witch but it is possible.

Also, as a painter I can attest to the fact that those guys at paint stores are far from perfect. We have picked up improperly mixed materials on a number of occasions.

[orion]

Thinning the material will also help with the orange peel effect. When thinner the material will have a chance to "lie down" more.

Any advise to help keep sanding to a minimum sounds great to me.

[ghettodish]

Zinsser oil-based primers are quick-dry and sandable after 24 hours, from my experience. Sherwin Williams, Kelly-Moore, etc. (pro paint stores) sell oil primers that are not typically sanded after application.

Like JazBrown said, cure time is a major factor. Full curing time can take up to 6 months for some house primers!

Zinsser is sold at Home Depot and major paint stores. For oil-based get the Cover Stain and have it tinted to half the color of the top coat of paint (tinted gray for black paint, tinted pink for red paint, mint for green,etc)