Plaster vs Joint Compound what's the Difference

hi everybody I'm Liev seating drill and today well I'm in a home-improvement store and I'm standing in the aisle where you can find joint compound so as you can see there are a lot of choices and it can be really confusing if you don't know exactly what it is you're looking at so today's video is all about joint compound and plaster and I'm gonna let you in on a few things you may not know [Music] [Applause] [Music] so here's the thing there's a lot of confusion about joint compound right we've got premix joint compound that's air dried then we have joint compound that isn't premix it comes in a powder you mix it it's setting type it's called a hot mix sets up very quickly then we have plaster and plaster and joint compound are worlds apart I don't want to tell you why okay what I have here is I have this is a piece of drywall and on the drywall I have three dabs of material this right here this is plaster the center is premix joint compound and this one right here is the setting type joint compound so first let's talk about J compound and why it's different than plaster well here's the thing with J compound it is a mixture of a lot of different materials glue being one of them and it's that glue that helps joint compound stick to the surface you apply it to so there's glue with it right and that helps it stick to the wall but here's the thing there's a lot of other stuff in it too it's like a real recipe there's clay and have you ever noticed how joint compound that is very very creamy the pre-mixed kine is because there is an ingredient like clay that adds to the creaminess so this is premix joint compound and one of the big pluses is its air dried now why is that a big plus well it gives you the time that you need to do the job and it doesn't matter how large the project is if you're doing an entire wall or ceiling or a whole room guess what you're not racing against the clock with pre-mixed joint compound now there are other things that are big benefits with pre-mixed what they are is its sands really easily now half a piece of sanding screen here and we're gonna sand this down suicide knocked those ridges down and it was effortless so the next advantage is also can be a disadvantage and that is premix joint compound is water-soluble so I've got a ridge right here I'm gonna apply water to this joint compound and what's gonna happen is it's gonna reactivate it all right so what's good about this the fact that it's water-soluble is it allows you to water trowel it if you make a mistake once it sets up you can take ridges out or you can move a piece of tape that didn't lay flat like you wanted it to you can take the ridges right out look at that so the downside is its water soluble right so you may not want to use it in an area that there's a lot of humidity or there's a lot of moisture so that brings us to this this is the setting type joint compound now it too has some advantages and disadvantages the big advantage that people like about setting tight joint compound is it sets very quickly so if you're working on a small job if you can finish it quickly whereas if you're using air dried joint compound it takes hours and hours and sometimes overnight to dry a setting type joint compound tends to be a little more moisture resistant so if you're going to tape a bathroom this is the product that you want to use now the downside is that it doesn't sand as well as the pre-mixed it's sandable but it is an effortless now let me show you how it sands so that brings us to plaster and plaster well it's been around a long time centuries it's one of the oldest trades the Egyptians plaster the Italians plastered you know those fresco paintings done on plaster so it's been around a long time now if you own a house that has plaster walls chances are you're using joint compound to make repairs to cracks and indentations and all like that then you're taking sandpaper and you're sanding down the joint compound now if you notice you don't sand the plaster walls away and the reason for that is plaster is a rock and you can't sand a rock okay so I've got that same sanding screen but I want to say this this is a little fresh because I applied this yesterday and plaster does retain water for a little bit notice how there's nothing clogging the pores so plaster sticks to a surface for a few reasons number one suction number two a mechanical bond where the plaster Keys itself two wooden lath or metal lath so the third is a chemical bond where you apply a bonding agent to an old already existing plaster wall and you want to skim that wall out with a new plaster and that helps the two bond now the other thing about a plaster is its water resistant and it's hard it's got a hard shell to it it can take a lot of abuse where joint compound not so much now plaster is really superior when it comes to water as well so I'm gonna let this down and I want you to watch this remember what the joint compound was able to manipulate it watch there's really nothing there watch no so you don't see a scratch no I'm gonna do the same to the joint compound look at that look and look at how easy so plaster is superior it's got longevity on its side you've got cathedrals you've got castles you've got buildings with walls that have been intact for centuries and you're not gonna get that with joint compound so hopefully I answered a few questions right about joint compound and plaster and why it's not the same this is Leah say you can do this see you next time

Channel: seejanedrill

Views: 363,881

Rating: 4.9482989 out of 5

Keywords: seejanedrill, see jane drill, leah, how-to, how to, plaster, plastering, joint compound, all-purpose, setting-type, pre-mixed, gypsum, silica, what is joint compound, what is plaster, lime, how to plaster, skim coat, taping drywall, drywall, plaster walls, sheetrock, sheet rock, plaster info, compound, sand, finish, finishing, walls, ceilings, bathroom, gaging, gauging, skills, techniques, info, plaster history, plaster ceilings, texture, sand finish, plaster finish, repair plaster, repair walls

Id: CoF5F9AuZ98

Length: 7min 17sec (437 seconds)

Published: Thu Nov 17 2016