HOW TO COAT DRYWALL( BUTT JOINTS)

hello and welcome to Vancouver carpenter today I'm going to be teaching you how to coat a butt joint so a butt joint is where the two four foot ends of the drywall meet and after you tape it it creates a humped joint that you need to float out really wide to be able to hide it so what you're going to need is a 10 or a 12 inch knife I have a 12 inch knife here I'm actually a trowel guy but because I know most people watching this are going to be using knives I will struggle along with you with this giant oversized tool so I have a pan with some all-purpose mud in it you can use all-purpose or topping for this and I have it thinned down to fairly loose it'll fall out of this if I don't hold it right now I need it fairly loose because using a knife this big is not easy on the hands or wrists and when you've done this for as long as I have you kind of got carpal tunnel so first it's a really good idea to check the butt joint to see what it means so what I mean by that is you put your knife on the joint to see how much fill it needs now this one isn't rocking very much so it doesn't need very much fill let's check the bottom oh this is an easy one it's too easy this one's almost flat well that demonstrates why'd you check it this one doesn't need much so we'll do this one real quick and then we'll find another one that's bigger wider it needs more Fanning so this little one doesn't require much and this is going to be treated basically like a flat joint anyway I'm going to start from just above the flat and now I'm going to feather the edge feather the edge so that was an easy one let's find a harder one okay so this one is a lot more like your typical butt to it so as you can see it rocks which means it needs a pretty good fill on either side out comes the very particular job of coding this thing and I'm very specific about how I like to do these so I'm gonna go one foot wide on each side of this joint because it's not a huge one it doesn't need to go three feet wide this will be settled in a two foot joint so I got plenty of material there you start from the top and go down and I take it right into the flat boy these knives are huge I don't know how people I don't know how people use these things all day instead of a trowel okay now comes the very important first step and this is where you have to bend your knife onto the wall so I'm putting tons of pressure on the right-hand side and I'm going to feather the edge and same with the left feather the edge so now I've feathered both edges and I'm going to again pass down here not putting so much pressure on the edge that one was just a gentle pass to push the material into the middle of the joint and I'm going to do one more on this side just a gentle pass so now what I have done is you can see this lift off line not this line that's a piece of crud hitchhiker traveling in my mind you can see this lift off line down the center of the joint that's good but we're not done yet now that I've got most of the material all in the center of the joint I'm going to do one more pass directly down the middle with this and that is exactly where I'm gonna leave it and I know it's not gonna be that easy for you but eventually maybe you'll be able to get the idea behind this now let me explain why that's so important okay I know it's a bit hard to see but here is one lift off and here's your other lift off and they are both on the other side of the joint the joint is right down the middle and the reason I want this is this is the biggest point of shrinkage they're in there that is where there's the most material and I want these lines these are my lift off lines that I'm just gonna sand off on my next coat so it's a big broad flat surface down the center of the tape and then I've got my liftoffs on either side of the tape now why is that important why am i fussing so much about exactly where those liftoffs are the reason is it is easy to hide tape if I left the lift off in the middle of the joint I will create a hump like a speed bump in the wall so the reason that I have the lift offs on either side and I use the 12-inch knife down the center is I create a broad flat surface when you are making a butt joint you are trying to make a long rolling undulation it's one thing to hide tape it is another to hide the joint I have gone into too many houses where I have seen speed bumps all over the wall I can't see the tape but I can see every single joint so on the next step when we sand it and coat it one more time you'll see how it creates a long broad rolling undulation on the wall instead of a speed bump that is obviously visible as soon as the shadow gets cast across it so I always like to sand my butt joints in between coats and I've got some pretty aggressive hundred grit here on a nice flat pad and if you remember I've got one lift off here and one lift off here and I want to create a nice broad flat space right here so I'm gonna sand down my lift ups and I'm also gonna send sort of like this to try and flatten this area out even more and if you start standing and you see the tape you've gone too far stop and my lift and then I'm gonna stand this middle even flatter so now when I go like this it feels pretty good what you're trying to do with your first coat is you're trying to create the form of the wall so I left enough material on there that I could sand it even flatter so now this is actually the shape that it's always going to be when I add my next coat it's going to be fairly thin and all that does is fill in all the scratches all the porosity and all the little inconsistencies they were left behind my final coat is going to wind up real smooth so the key there is that I put enough material on that I can sand this down and have a nice flat base and that way I can guarantee that I'm gonna do it in two coats over top of tape so now it's time to do the final coat on the but join --tz-- and for this one I'm going to be using a twelve inch knife and one thing I should have mentioned but I haven't yet is you should look down the blade of your knife and you will notice that the corners of it Bend a certain way for example this one curves this way and you should always have it so the curve is against the wall and the reason is the edges are bent up a little bit so that they don't go out when you're going down if you use it the wrong way you'll be leaving grooves and lines in your mind every time flip it around and it should work that problem out for a final coat I like my mud fairly thin makes it a lot easier and so I'm just gonna coat the whole thing over again and then wiping it off fairly smooth right now I'm just putting material on snow pretty pic right down going right down into the flat putting extra material where it's needed I haven't gone all the way up to the top yet I focused on just getting the material onto the wall first and I'm going to keep making sure that I don't have any empty spots okay now I'm gonna take a little bit and go right up into the corner right up into the corner okay now clean my bead off feather my edge now I'm gonna do my finishing passes and I'm gonna start keeping my knife like this this is exaggerated but that's the idea is that I'm keeping the pressure this way as I work this way you hear that you've made I've got a line here I need to go over it again one line right there okay let's take a look at that so my edge is nicely feathered there's really nothing there to sand I went right up into the top corner I cleaned off this edge and I've tried to leave about one millimeter of material on roughly so I'm not wiping it off so much that I'm compressing the mite together what I'm doing is leaving a thin film leftover so there's enough material on there for a nice sanding coat and that I don't sand back down into the previous work if you wipe it off too tight you're gonna be sanding into your previous work and you're gonna start getting all kinds of weird shadows and ridges you want to have just enough on there for a nice sanding coat and now I'm gonna show you guys one other little secret trick you can do haha homeowners I think you're gonna like this one gather your edges right away so I actually do that quite a lot and the reason is I have major neck and shoulder problems from doing like this for the last eight years of my life and I find using the roller to apply the mud only on the final coat you can't do it on the first coat because you can't apply it thick enough I do that on the final coat and it can really take a load off my shoulder and it's actually pretty darn fast too so I do this on my final coat when I'm skimming out coal ceilings or whole walls it's a bit messy and tricky at first I made it look easy you guys are probably gonna get massive blobs on the floor when you first try it but with a little practice it gets pretty easy so I don't usually do that trick on everything on corner beads or on flats usually but on large broad surfaces with a lot of area to cover it works pretty nice so the final thing to do is to sand and I like to use a foam back sandpaper if you can find any for my final coat this helps take away any of the scratches you're gonna get while you're sanding and remember don't sand straight up and down never send it this way or it'll flip over but I send in a slightly diagonal motion about maybe about 10 to 20 degree tilt and I send like that and that stops it from getting lines when you're sanding and it's also not so angled that it'll flip so anyways I hope with those tips you're able to get some really nicely finished but joints thanks for watching

Channel: Vancouver Carpenter

Views: 920,193

Rating: 4.9268994 out of 5

Keywords: drywall, coat, butt, joint, float, finish, taping, mudding, sanding, flat, perfect, easy, best, fast, DIY, home, owner, repair, patch, finishing

Id: t015fPsTsZw

Length: 14min 11sec (851 seconds)

Published: Sun Dec 31 2017