Mudding-how do I know when I'm done?

Ok, finally got all the drywall up, and the first coat of mud is on there.. I sanded like a mother yesterday, ignoring most advice and using 150-220 grit on my random orbit sander, since like most amateurs, we put way too much mud on.
It really worked well and with the shop vac attached right to the dust port, there was hardly any dust hanging in the air.
The question I have is, how do I know how many coat I need to do? I hear 3, with the 3rd being a skim coat. Maybe some basics you could tell me like
How wide should I expect a tape joint to be feathered? How to determine if flat is flat enough? (i'm using a bright halogen on an angle to the wall to detect any shadows).
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Once you figure out the process, you'll not be doing any sanding. A very small amount of scraping, maybe. Unless you have a gore-tex filter, the shop-vac serves mainly to broadcast the very fine dust. Also, any sanding of the paper will telegraph through.
You need just as many coats as it takes to make joints flat enough. Actually, more is better, in that each coat is as thin as you can make it- dries much faster that way. With each coat, you use wider knife. When it's relatively flush with 12", it's done. IMHO. For where tapered edges of sheets meet. At butt joint, just as little as possible, so no bulge.
J
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Larry Bud wrote:

It is difficult to describe in words. I suggest you buy some paint and once you think it may be OK paint across some of the joints and let the paint dry. If you can see the joint, it time to get back to work.
Once you get the hang of it, there is little sanding needed. I usually use three coats, first with a mid small knife, next a wider knife and finally with a wide knife. I often end up going back a fourth time to correct some of the errors I make along the way. I am no way a pro, it takes me far longer than a pro to do the work, but the final results are better than some pros and not as good as others.
As for the skim coat. It is popular in some areas and not in others. If I had the ambition or the money to pay a pro to do it right I would do it. I like the look, but many people don't.
--
Joseph Meehan

Dia duit
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i did some side work with a drywall guy who was a real pro. he ran that knife like a master painter.
technique is learned from pratice, but patience is the key. do several very thin coats with progressively wider knifes. we hardly sanded at all, and he used his hands(not eyes) to feel if it was right.

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Joseph Meehan wrote:

I got a friend of mine that I pay to do this stuff. its more than worth the price as their job is immeasurably superior to mine. If you want to learn best to pay someone and just watch.
--
Thank you,



"Then said I, Wisdom [is] better than strength: nevertheless the poor
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Check to see if you have enough by taking your largest knife, (12") and stand it perpendicular to the wall so the edge of knife is where the mud has been placed. With adequate light, a quick glance from the shadow side, you'll be able to see very quickly where the high/low spots are.
One tip I picked up is to work with thinned mud. Many times it harder to control on the hawk and knife edge, but it flows off of the knife easier than straight out of the bucket. You'll have to experiment as to what works best for you.
I don't subscribe to the "NO-SANDING" thought rather, sand just enough to remove the obvious bumps and ridges. For what it's worth, if you plan on leaving the walls smooth, I'd stay clear of the mesh sandpaper, as it can cause more tiny ridges than the smooth paper will. If you texture, either will work, the mesh I believe is more aggressive. A poll sander works well, save your ROS for wood working. Like another poster mentioned, feeling with your hands will revel many details, where you need additional work/mud/sanding.
Here's a site that's has some good information: <http://www.drywallschool.com/protips.htm mostly free. I am not affiliated with the site, just found it interesting.
Good luck to ya!
Darwin
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wrote:

Once you have it where you think it's good enough go ahead & prime it. You can always touch it up afterwards.
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You're a brave individual!! :) Been there... Done that... My results stunk... Floating sheetrock, in my opinion, is an art and the only way to get it done right is have an artist do it. While it may cost more, I ALWAYS hire someone else to float it. It is sooooo much nicer and sooooooooo much easier for me!! In my experience, whatever I paid always turned out to be well worth the $$. In any event, though, I wish you well and hope your results turn out great!
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Luke, the guy I hire NEVER sands. Then the last thing he does is wipe it all down w/ a damp towel to smooth it all out. Looked so good, I never even painted the ceiling job he did for me!! And after the 1st and 2nd coat, it LOOKED LIKE CRAP! the guy's amazing, and worth every 1ct. of the $35/hr he charges!
I've since moved and not only do I have to start all over finding someone, I'll never find someone as good as Luke :-(
steve
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Yeah, that's the same with my guy - Cooper is his name. Never sands anything!! And even though I've tried, I cannot find even one area where you can see a joint, butt or otherwise. That's why I say it's an art. And while I'm not an admirer of fine art or artists, one who can float sheetrock without the need to sand at anytime sure has my admiration. $35/hour is well worth the investment...
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