# What determines "speed" of mud to use?



## Old Thomas (Nov 28, 2019)

Dry time indicates how long it is reasonably workable. If you are taking your time, get the longer time material.


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## MTN REMODEL LLC (Sep 11, 2010)

Strange in my line of work.... but I've never actually done a skim over.

But, I *THINK* you want to use regular green lid....not hot mud, especially considering you are new and slower and not under time constraints or a small job.

Hot mud dries harder and stronger but is more difficult to sand....which you will likely be doing,

I don't know if hot mud has better adhesive properties, which might be advantageous.

AGAIN......just my thoughts and not my advice.

We have some excxellent pro drywall experts which will hopefully be along soon for definitive advice.

Good luck


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## Marson (Jan 26, 2018)

The only reason to use hot mud is if you need the strength, for instance if you are using mesh tape or filling big holes, or if you want to put multiple coats on a project in the same day. Most pro tapers I know prefer to use pre mixed mud if they can.


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## ClarenceBauer (Mar 4, 2005)

The setting time is based on the amount of Limestone used in each type compound. The faster set has the most Limestone & the slower set has other binders included. If you were to mix your own setting compound using Plaster of Paris & added anything like a guaging plaster or even sand it will affect the set time.


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## mark sr (Jun 13, 2017)

While I'm partial to the 20 minute mud, I rarely use it for the last coat. Premixed j/c is easier to work with - especially when sanding.


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## huesmann (Aug 18, 2011)

The speed you use depends on the amount of skill you have, and the amount of time you can afford to have between work on it.


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## mx13 (Apr 8, 2007)

MTN REMODEL LLC said:


> But, I *THINK* you want to use regular green lid....not hot mud, especially considering you are new and slower and not under time constraints or a small job.


What are hot mud and green lid?

I bought a can of Zinsser Gardz Problem Surface Sealer to put over the damaged paper on the drywall. Good product?


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## MTN REMODEL LLC (Sep 11, 2010)

Gardz is excellent....

Green Lid is regular 5/gal premixed mud (with the green lid and not the finishing premix). Hot mud is the powder with ingrediants that you hand mix and has a speed set....called hot because of a faster set .....with the 20 or 90 etc estimate of it's workability time.....It will dry significantly faster than regular mud.

(I can't think of green lids regular name, and don't have a bucket outside to read it....but it's just regular mud...The green lid is a trade type reference of a maker...probably USG...can't remember that either.) But the guy ar HD or Lowes will understand.) Regular (green kid) also comes premixed in a smaller box instead of a bucket withourt any green kid.)

Sorry for the confusion


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## mark sr (Jun 13, 2017)

The green lid is all purpose mud, it has better adhesion properties than the lightweight [blue lid] mud. Another reason setting compounds are called hot mud is because of the heat they generate while setting.


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## mx13 (Apr 8, 2007)

MTN REMODEL LLC said:


> Sorry for the confusion


No worries! I should probably type "I am completely ignorant of every damned thing about this subject" in every post I make, but it gets tedious repeating that.
:wink2:


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## MTN REMODEL LLC (Sep 11, 2010)

mx13 said:


> No worries! I should probably type "I am completely ignorant of every damned thing about this subject" in every post I make, but it gets tedious repeating that.
> :wink2:


That's no problem...all good...

Not one of us was born knowing which end of the hammer to use.


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## mx13 (Apr 8, 2007)

Here's the top of the wall. There was a fill of something around the edge of the wallboard, which I'm chipping away. Do I need to tape this gap between the wall and the ceiling?


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## mx13 (Apr 8, 2007)

Looks like the green lid product is "USG Sheetrock" joint compound. 

Premixed does seem more convenient than measuring from a bag of dry product into a bucket every batch, then needing to clean the bucket. How many times can you go into a premixed product before it dries up and becomes unworkable? 

I'm actually doing two small rooms (an outer sink/vanity-only space with a full bath behind it). I've started on the outer room and I *think* I want to more-or-less finish it before I start on the full-bath area, so that's only about 65 or 70 square feet of wall space to cover in the outer phase. I should probably buy enough for that job only, if I get premixed.


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## mx13 (Apr 8, 2007)

Trying this again with the attachment that I forgot to add... :vs_shocked:

Here's the top of the wall. There was a fill-in of something around the edge of the wallboard, which I'm chipping away. It wasn't adhering to the wall very well. Do I need to tape this gap between the wall and the ceiling?

Paper tape in the corners of the wall is also not stuck down very well. At a few places the hardboard adhesive pulled a couple of inches of it free of the drywall, so I should probably scrape all that off and retape it, too?


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## mx13 (Apr 8, 2007)

I found a time-capsule behind the hardboard on the wall with the medicine cabinet and lamp. Took me a minute to realize that it was an excuse for the cutout around the electrical box. I wonder if he was leaving that note to himself or anticipating that someone else would tear off the hardboard some day?

Deciphering that sentence would make a good Captcha problem!


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## MTN REMODEL LLC (Sep 11, 2010)

mx13 said:


> Looks like the green lid product is "USG Sheetrock" joint compound.
> 
> Premixed does seem more convenient than measuring from a bag of dry product into a bucket every batch, then needing to clean the bucket. *How many times can you go into a premixed product before it dries up and becomes unworkable? *
> 
> I'm actually doing two small rooms (an outer sink/vanity-only space with a full bath behind it). I've started on the outer room and I *think* I want to more-or-less finish it before I start on the full-bath area, so that's only about 65 or 70 square feet of wall space to cover in the outer phase. I should probably buy enough for that job only, if I get premixed.



MX13.....Premix joint compound is relatively cheap......

The real trick is not allowing whatever product you are using from becoming contaminated by dried out flakes of the compound.

If working from a plastic bucket, cover it...either with the lid or a wet towel...while you are scoopimg compund into your pan. When done for the night....I like to wipe down the inside of the bucket with a spomge, and leave a puddle of fresh water on the existing compound to use tommorow,

The problem with the smaller boxes of compound ,,,is the plastic it's packed in which for me is virtually impossibe to clean and reuse without dried compound flaking into anything you are saveng for tommorow.

If I buy boxes, I expect to use the whole thing that day.

If you are worried about wasteing mud by using hot on anything but a small job...... you'll spend multiples of the cost of pre-mix in both time and water cleaning your pan and blades and mixing new hot...honest.


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## mark sr (Jun 13, 2017)

I haven't used box mud in a long time [not sold locally] but when I did I always transferred it to a 5 gallon bucket. Mud in a bucket can last a long time if you keep it closed, scrape the sides so that mud won't dry and don't put leftover mud back into the bucket. I've used the same bucket of j/c for months or longer. If I know I'm going to store the mud for an extended time period I'll try to level off what's in the bucket and cover it with a thin layer of water.


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## jeffnc (Apr 1, 2011)

Old Thomas said:


> Dry time indicates how long it is reasonably workable. If you are taking your time, get the longer time material.



First of all, I really wish people would stop calling this "dry time". It is NOT dry time. It's setting time. That's why these materials are called "setting" materials. It refers to the time it takes for the compound to set up hard. Most of it will normally still be wet when it's hard.


Not understanding this is probably the reason most people don't understand what mud to use in the first place.

To answer the OP's question, I see no reason to use setting compound in the first place, regardless of the time. You're just making things harder on yourself (pun intended). Setting compound is stronger than drying compound, but there's no need for that in this case.

Just go get regular premixed drying compound and then you have all the time you want to do it. Obviously once it's on the wall spread thin it will dry relatively quickly, but I don't think that's the working time you care about. At least you shouldn't.


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## jeffnc (Apr 1, 2011)

mx13 said:


> What are hot mud and green lid?



These are slang and misnomer terms, respectively. "Hot mud" means setting compound as opposed to drying compound. See my previous post. "Green lid" is an unfortunate term because it refers to the color of one brand only. For example, all of the pictures at the bottom are of "green lid" joint compound. What they are trying to say is "premixed drying joint compound".





mx13 said:


> I bought a can of Zinsser Gardz Problem Surface Sealer to put over the damaged paper on the drywall. Good product?



Perfect.


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## jeffnc (Apr 1, 2011)

mx13 said:


> I found a time-capsule behind the hardboard on the wall with the medicine cabinet and lamp. Took me a minute to realize that it was an excuse for the cutout around the electrical box. I wonder if he was leaving that note to himself or anticipating that someone else would tear off the hardboard some day?



Most likely it was a note to his boss or buddy who was going to be coming in behind him to install the lighting. He was just acknowledging why he didn't do as crisp as job as usual. Although I can do better than that with just a jab saw :wink2:


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## jeffnc (Apr 1, 2011)

MTN REMODEL LLC said:


> But the guy ar HD or Lowes will understand.) Regular (green kid) also comes premixed in a smaller box instead of a bucket withourt any green kid.)



OK, again, we need to distinguish between the types of compound. There is premixed, there is drying type, and there is setting type. They refer to different things. I don't know what box you're referring to, but almost always if it comes in a box that means it's a powder. If it's a powder then obviously it's not premixed.


Setting type compound needs to set to get hard. It also dries, but that's a different issue. Drying type compound needs to dry to get hard.


Both setting compound and drying compound come as a powder that you can mix yourself. Obviously only drying compound can come premixed. Setting compound can't be premixed or else it would be hard in the bucket by the time it leaves the factory. It would be wet for years in the bucket, but hard. Premixed can only be drying type compound. Powder can be either. The only reason I can think to use powder drying compound is that crews that do a lot of work can move a lot of that stuff much easier (it's way lighter). Also they can mix it to their own preferred thickness, especially if they want it thicker than it comes premixed. Not sure why you'd want that - it's pretty thick as it comes.


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## jeffnc (Apr 1, 2011)

mark sr said:


> I've used the same bucket of j/c for months or longer. If I know I'm going to store the mud for an extended time period I'll try to level off what's in the bucket and cover it with a thin layer of water.



That's all good advice. Additionally, it's a good idea to put a capful of bleach in there and mix it in. Oftentimes mold spores will start a colony in there and after a few weeks it will be a moldy mess.


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## mark sr (Jun 13, 2017)

While I've heard of adding bleach, I've never done so. If I open an old bucket of mud and find mold I toss it .... or at least scrape off the top [and toss it out] until I get to clean mud.


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## mx13 (Apr 8, 2007)

jeffnc said:


> I don't know what box you're referring to, but almost always if it comes in a box that means it's a powder.


If you look here, you'll see a 3.5 gallon box of premix. 

https://www.usg.com/content/usgcom/...nds/sheetrock-all-purpose-joint-compound.html

I saw a box like that yesterday at a paint store. I guess that's for people who don't want to accumulate a bunch of empty buckets? Boxes are cheaper to manufacture than buckets, and when stacked on a pallet there isn't nearly as much interstitial dead space that you get between the curved sides, so I guess it's cheaper to ship, too, on a per-pound basis, since more pounds would fit on a pallet. Maybe the savings is passed on to the buyer? And if you were cramming a lot of it into a work vehicle where space is tight, I think you could fit more in boxes.

Also, there may be a drop distance in which the corner of the box crushes but the bag inside doesn't burst, so the stuff would still be useable, when a bucket dropped the same distance would crack and ruin everything.


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## mark sr (Jun 13, 2017)

Not all areas sell box mud. I haven't seen any in so long I don't remember the pricing. All the setting compounds I've used came in bags.


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## mx13 (Apr 8, 2007)

jeffnc said:


> First of all, I really wish people would stop calling this "dry time". It is NOT dry time. It's setting time.


Yes, people fail to make the same distinction about epoxy. It's a little annoying, but more often than not, people know what's happening and just use the term sloppily, I hope.

Although, last night I was watching a video of a guy using a mixed compound (it showed him mixing it at the beginning) and after rolling some on the wall, he was talking about it "drying" as he was working (i.e. he was worried that it would dry too much) but then he went back into the bucket, so either he mixed more off camera or that really was a drying product made from powder. Not sure if I can immediately find that scene again, and he was in Canada so the products are slightly different.


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## mx13 (Apr 8, 2007)

jeffnc said:


> These are slang and misnomer terms, respectively. "Hot mud" means setting compound as opposed to drying compound. See my previous post. "Green lid" is an unfortunate term because it refers to the color of one brand only. For example, all of the pictures at the bottom are of "green lid" joint compound. What they are trying to say is "premixed drying joint compound".


For some reason I can't remember at the moment, I was thinking of using that USG Plus 3 instead of the actual green lid. Pro vs con?


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## Tom153 (Nov 10, 2016)

Initially I use the "green lid", premixed mud. Sticks well, has long enough work time for my slow and picky application. Sometimes I use the faster/lighter pre mix for finishing work, because it sets faster and sands easier.


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## mx13 (Apr 8, 2007)

I should add that I'm not averse to having two compounds. If I buy a $10 bag of setting type and only use 1/4 of it, I'm not going to cry! It is too bad that it's wasteful, but I just regret having to send most of it to the dump later.

When working on our other bathroom, I actually kinda enjoyed mixing up thinset mortar and grout, even if that and cleanup is a waste of time (and water).

When I took off the trim around the door frames, I found gaps up to 1/2" or so between the drywall and the frame. I was thinking of repairing those with this method.





Not because I have to, but because it seems like the right thing to do, just in case I want to change the door trim to something narrower or whatever. 

I was thinking I could use USG Silver Set for that and a first coat over the wall to level the torn paper and the thin bits of hardboard adhesive I didn't get off, then apply a premixed topping compound for easier sanding. How 'bout that idea?


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## jeffnc (Apr 1, 2011)

mx13 said:


> If you look here, you'll see a 3.5 gallon box of premix.
> 
> https://www.usg.com/content/usgcom/...nds/sheetrock-all-purpose-joint-compound.html
> 
> ...



I'd say you probably nailed it pretty well. Obviously there is a plastic bag in there. I've never seen those boxes in my area except with powder in them.


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## jeffnc (Apr 1, 2011)

mx13 said:


> Yes, people fail to make the same distinction about epoxy. It's a little annoying, but more often than not, people know what's happening and just use the term sloppily, I hope.



Yup, you would hope. In my experience, a lot of the people don't really understand what's happening though, which is why I get on the soapbox. Present company excluded of course 




mx13 said:


> Although, last night I was watching a video of a guy using a mixed compound (it showed him mixing it at the beginning) and after rolling some on the wall, he was talking about it "drying" as he was working (i.e. he was worried that it would dry too much) but then he went back into the bucket, so either he mixed more off camera or that really was a drying product made from powder. Not sure if I can immediately find that scene again, and he was in Canada so the products are slightly different.


Well I almost always mix my premixed compound, to get it smoother. So that might have been what he was doing. But even if it was setting compound, I actually think that's a pretty interesting side topic. For sure, some setting compound can dry before it has a chance to set. (The same thing can happen with things like thinset when tiling, etc.) I don't really know if it reaches full strength if it dries too quickly (we're talking about the very thin edges of where you apply it.) The thicker sections can't dry in the 20 or 45 minute set time. But I guess full strength isn't very important on the edges, it's mostly important where the tape and joint are.


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## jeffnc (Apr 1, 2011)

mx13 said:


> For some reason I can't remember at the moment, I was thinking of using that USG Plus 3 instead of the actual green lid. Pro vs con?



I think if you listen to the company, it's better in every way. In real life, it's a lighter weight compound, and according to the laws of physics that's going to be a lighter weight finished compound as well. Easier to sand, easier to get scratches in, not as strong with the first embedded tape coat. I guess if it's strong enough, then using something stronger doesn't help. I suppose it's a matter of risk - maybe there is 10% more chance the joints will crack in the future, I don't know. A lighter compound is more fun to carry, I can tell you that much. Personally I might use standard for the first coat, then this stuff for the next 2 coats. But I don't think it makes for a harder finish and harder wall.


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## mx13 (Apr 8, 2007)

mx13 said:


> I was thinking I could use USG Silver Set for that and a first coat over the wall to level the torn paper and the thin bits of hardboard adhesive I didn't get off, then apply a premixed topping compound for easier sanding. How 'bout that idea?


Looks like again I'm not describing this very well. I mentioned the Plus 3 above in case I just go with one all-purpose compound. But maybe I should do it right (?) and use a setting compound to fix the edges and set the corner tape, then finish with something easier to sand. 

I haven't really made this choice yet. I don't have to choose for a couple of days if I decide to tear out the dubious ceiling material first (see my other thread).


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## jeffnc (Apr 1, 2011)

I don't see any reason to use any setting compound at all. All Purpose all the way around is fine. The main reasons to use setting compound are if you're on a schedule and have to get this done in one calendar day, or if you need extra strength for some reason. Neither apply.


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