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Knife Size

 
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Old 02-15-2014, 12:56 PM   #1
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Knife Size


What size knives do you use for taping and finishing? How far do you bring your inside corners out?

Is there a set specification? I looked it up and could only find the finish levels.
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Old 02-15-2014, 02:44 PM   #2
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Re: Knife Size


It depends on how I am taping and methods will vary wildly from person to person. If it is a large job and I am using a banjo I will use an 8" knife for wiping flats/butts and a roller and 2.5" or 3" flusher for inside corners. I will then use a 3.5" flusher for finish coat. I use a hawk,trowel and 6" knife for everything else.

If it is a small job and I am taping by hand I use a 6" for everything. Hawk,trowel and 6" for all finish coats. When coating angles by hand I use a 6" but a 4" would be adequate.

The set spec is how it looks when it is painted.

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Old 02-15-2014, 03:13 PM   #3
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Re: Knife Size


Most of what I do, have done, is remodeling and small scale commercial. No machines/boxes. Generally push for a level 4-5 finish in three passes and minimal touch-up. So the methods have become oriented toward filling cliffs and canyons. Uneven sheets and surfaces, blending into existing ... blah blah blah and so on & so forth.

2" & 4" Knife, for those BS spots where a 6" won't fit. Rare to use on new construction.

6" for inside corners (corner knife occasionally - whole other topic LOL) and paper on butts. All inside corners are skimmed with the 6" as well as screw holes initially. Will often 2-3 coat with what ever knife is in my hands. Long pass vertical build up over all in a row and then a good wipe.

8-10" knives for filling flats (mesh) and corner bead. Few reason over a 6", they hold more mud per swipe, can get a rounded build up on the tapers (closer to flush/flat sooner), gets a longer feather going sooner, and with corners avoid the high angles back to the flat. As a finish carpenter I CURSE corner bead.

12" all skims in the field.

A bit unconventional, but for remodeling it has become the best way to conserve movement by me.
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Old 02-15-2014, 04:25 PM   #4
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Re: Knife Size


4" for tape coat and all nail spotting
6" for inside corners
8" for bed coat factory seams and butts (one pass on either side, about 14" wide) and 2 passes on corner bead
10" for top coat on factory seams
12" for top coat on butts (one pass on either side, about 20-22" wide)

1", 2", 3" for the occasional inside corner next to a door window jamb

No taping machines or any of that crap
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Old 02-15-2014, 05:45 PM   #5
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Re: Knife Size


Ask a thousand finishers this question, and you will get a thousand different answers. I learned a certain way from some great hand tool finishers, and have combined some of my own methods into my teachings.

My basic handtool finishing:

Taping inside corners: 4"
Taping flats and butts 6"
Spotting screws: 6"
Flats bed coat: 10"
Flats Skim coat: 12"
Butts bed coat: 10"
Butts Skim: 12"
Bead bed coat: 8"
Bead skim coat" 10"

I don't knock any banjo or finishing tool. I would use them for production work in a heartbeat. The problem isn't the banjo, or other tool.....it's the person using them that makes the difference.
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Old 02-15-2014, 05:49 PM   #6
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Re: Knife Size


Quote:
Originally Posted by Texas Wax View Post
Most of what I do, have done, is remodeling and small scale commercial. No machines/boxes. Generally push for a level 4-5 finish in three passes and minimal touch-up. So the methods have become oriented toward filling cliffs and canyons. Uneven sheets and surfaces, blending into existing ... blah blah blah and so on & so forth.

2" & 4" Knife, for those BS spots where a 6" won't fit. Rare to use on new construction.

6" for inside corners (corner knife occasionally - whole other topic LOL) and paper on butts. All inside corners are skimmed with the 6" as well as screw holes initially. Will often 2-3 coat with what ever knife is in my hands. Long pass vertical build up over all in a row and then a good wipe.

8-10" knives for filling flats (mesh) and corner bead. Few reason over a 6", they hold more mud per swipe, can get a rounded build up on the tapers (closer to flush/flat sooner), gets a longer feather going sooner, and with corners avoid the high angles back to the flat. As a finish carpenter I CURSE corner bead.

12" all skims in the field.

A bit unconventional, but for remodeling it has become the best way to conserve movement by me.
Sounds like you do a lot of tie in work. I do as well.
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Old 02-15-2014, 06:15 PM   #7
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Re: Knife Size


Is an 8" over kill for insides? I started using it a few jobs ago and like it better because of how far out the flats and butts are from the corner. I feel like I get a better finish with less work.
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Old 02-15-2014, 07:14 PM   #8
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Re: Knife Size


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Originally Posted by Dan_Watson View Post
Is an 8" over kill for insides? I started using it a few jobs ago and like it better because of how far out the flats and butts are from the corner. I feel like I get a better finish with less work.

Sounds like you don't trust the 4". Pulling angles with a 4" can be frustrating for new or ocassional finishers. Most of the time... I see new finishers trying to spread too much mud over too short a distance and then they have to keep messing with until it's uneven, huge lap marks, or have huge ridges (handles) on the outside edge of the work. They also struggle with directing finger pressure to create a feather on the outside of the knife. The purpose of mudding over the tape.....(is to hide the edge of the tape). You don't need it a 1/4" thick. When I am sanding my work, I often see exposed tape right at the crease where I folded the tape. I dont worry about it unless I see the edge of the tape with it. The foundation of any finishing job is taping. If your tape is tucked properly..... (not wavy, bulging, or sucked into holes)

Try using the 4" again with slight finger pressure on the outside of the blade. With a little pratice, you will see that the knife will direct the mud towards the corner/angle with little mud left on the outside. Try using lighter pressure overall as well.

Hope this helps.
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Old 02-15-2014, 07:21 PM   #9
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Re: Knife Size


Quote:
Originally Posted by D.E.P.S. View Post
Sounds like you don't trust the 4". Pulling angles with a 4" can be frustrating for new or ocassional finishers. Most of the time... I see new finishers trying to spread too much mud over too short a distance and then they have to keep messing with until it's uneven, huge lap marks, or have huge ridges (handles) on the outside edge of the work. They also struggle with directing finger pressure to create a feather on the outside of the knife. The purpose of mudding over the tape.....(is to hide the edge of the tape). You don't need it a 1/4" thick. When I am sanding my work, I often see exposed tape right at the crease where I folded the tape. I dont worry about it unless I see the edge of the tape with it. The foundation of any finishing job is taping. If your tape is tucked properly..... (not wavy, bulging, or sucked into holes)

Try using the 4" again with slight finger pressure on the outside of the blade. With a little pratice, you will see that the knife will direct the mud towards the corner/angle with little mud left on the outside. Try using lighter pressure overall as well.

Hope this helps.
4"? No way. I was using a 6" like most, but changed it up.

I'm not putting a 1/4" of mud on. Just covering the tape and bringing the feathered edge out 8" instead of 6". If anything I can make the mud less thick while still covering the edge since my long point is farther out.
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Old 02-15-2014, 07:36 PM   #10
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Re: Knife Size


Inside corners 4", 6" or corner trowel (usually 4 or corner trowel)
Butts and flats 8"
upper angles 4" or 6"

Sometimes I'll do everything with a 6", but it isn't ideal to do it this way.
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Old 02-15-2014, 07:45 PM   #11
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Re: Knife Size


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Originally Posted by Dan_Watson View Post
4"? No way. I was using a 6" like most, but changed it up.

I'm not putting a 1/4" of mud on. Just covering the tape and bringing the feathered edge out 8" instead of 6". If anything I can make the mud less thick while still covering the edge since my long point is farther out.
I don't know any finisher that uses a 6" either. 5".... a couple. A 8" would get you laughed off any jobsite as soon as the foreman popped his head into the room. A 6" & 8" require a lot more effort and slows you down. It doesn't give a better product.
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Old 02-15-2014, 07:59 PM   #12
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Re: Knife Size


Wider knife means better feather edge right?
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Old 02-15-2014, 08:08 PM   #13
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Re: Knife Size


Quote:
Originally Posted by D.E.P.S. View Post
I don't know any finisher that uses a 6" either. 5".... a couple. A 8" would get you laughed off any jobsite as soon as the foreman popped his head into the room. A 6" & 8" require a lot more effort and slows you down. It doesn't give a better product.
Good thing I don't have to worry about a foreman...

The lack of a better end result in your opinion is what I was looking for.
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Old 02-15-2014, 08:12 PM   #14
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Re: Knife Size


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Originally Posted by tyb525 View Post
Wider knife means better feather edge right?
If it takes 6" or 8" knife to kill a edge of tape that is less that 1/64 of and inch, then your technique is seriously flawed. Bedding in tape has alot more to do with killing the edges......than actually covering the tape itself.........providing that the tape was put on correctly.
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Old 02-15-2014, 08:16 PM   #15
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Re: Knife Size


Quote:
Originally Posted by tyb525 View Post
Wider knife means better feather edge right?
Wider feather edge, not necessarily better.
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Old 02-15-2014, 08:20 PM   #16
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Re: Knife Size


Quote:
Originally Posted by Dan_Watson View Post
Good thing I don't have to worry about a foreman...

The lack of a better end result in your opinion is what I was looking for.
Just try it Dan, it might take some practice, but you will see better speed, less mud usage, less sanding, and excellent results. My first drywall employer put me in small closets for my first week until I learned the 4". I didn't see the logic in it until I saw other new people who were trying to learn finishing. They screwed up every angle, and pissed off the crew when it came to sanding day. It was always the big fuss.

Tip: get the most flexible 4" 5" and 6" knife you can get your hands on. A flexible blade is much easier to work with while developing feel. HYDE knives are my favorate. Wallboard flexibles are more like HYDE's stiff.......avoid them.

Last edited by D.E.P.S.; 02-15-2014 at 08:30 PM.
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Old 02-15-2014, 09:06 PM   #17
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Re: Knife Size


Hi Dan
The fact of the matter is there are alot of us out here that don't tape for a living but we do it occassonaly and at those times we may do it a lot. For us we might not find the way that a guy thats does it every day works for us.
To me I will do what ever it takes to get the finish I am looking for, if it means a 12 in the corners than so be it. Like I said I don't do it every day. Don't listen to the so called pro's as they do more taping in a day than you will do in a year. Find your style and go with it
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Old 02-15-2014, 09:20 PM   #18
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Re: Knife Size


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Hi Dan
The fact of the matter is there are alot of us out here that don't tape for a living but we do it occassonaly and at those times we may do it a lot. For us we might not find the way that a guy thats does it every day works for us.
To me I will do what ever it takes to get the finish I am looking for, if it means a 12 in the corners than so be it. Like I said I don't do it every day. Don't listen to the so called pro's as they do more taping in a day than you will do in a year. Find your style and go with it
The original question was in regards to what knifes were used to obtain satisfactory results....... was it not?

My original follow up said that he would get a thousand different answers.

The OP came back saying that a 4" knife................was no way!

This "so called" Pro was trying to give him the most efficient answer.

That is what we are all here for............is it not?

Sanding sucks.......... you wanna sand 6" 8" and 12" inch corners?

Go for it!
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Old 02-15-2014, 09:31 PM   #19
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Re: Knife Size


Quote:
Originally Posted by Dan_Watson View Post
Is an 8" over kill for insides? I started using it a few jobs ago and like it better because of how far out the flats and butts are from the corner. I feel like I get a better finish with less work.
Could be considered as such. So much depends upon on clean you bed the tape and set up the fill/feather. Properly set tape in the corner, all you need is a 4" knife and you'll have real good corners. Most of the time I'm sloppin' the mud on with my 6" knife because it holds more mud. When you apply it 90 degrees from how you smooth it out, in the corners. Larger jobs I'll use a wisk broom cut to fit in the corner to slip the mud in. Either way I've gotten used to the 5-6" knives for corners. With help around the little knives always disappear anyway LOL


Quote:
Originally Posted by D.E.P.S.
Sounds like you do a lot of tie in work. I do as well
Yes Sir
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Old 02-15-2014, 09:36 PM   #20
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Re: Knife Size


Oh and I'll add....

I avoid using the idiot stick to compensate for poor taping skills. A quick light sanding at the end is all that should be required. Focus on a few stray snots and final feathering

(Idiot stick is sanding pole)

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