What type of square do you use?

[Kody]

Hi fellas,
I need to buy a new square to be used for building the joinery for my T/D. It will also be used for other jobs so I want something that is accurate and won't go all out of shape when used for a hammer....... Uh, skip this last comment!
So what do you fellas use? Do you use a carpenters square, an adjustable square, a bevel square or a round square. I used to have some very nice engineers squares but they grew arms and legs when I left them back here in Aust. after I moved to the US.

I thought I would get another couple of engineers squares, a 4" and an 8". I had a beautiful 2 1/2" engineers square (Moore and Wright) that I used for all my toolmaking and gunsmithing but it too, ran away from home. NOT HAPPY, JAN!!
I have seen some carpenters squares in Bunnings but I'm less than not impressed by them. A bevel square is only good for setting up angles and transferring them to other parts etc. An adjustable square is never accurate enough for what I do when using it at 90 degrees and I have yet to find a round square (or a use for it.)
So what do you all use for your super accurate all purpose precision square and how big is it / them?

Kody

The term "NOT HAPPY, JAN!" is a unique, truly full on Australian phrase. It depicts extreme anger and dissapointment. It came from an advertisement that all Aussies loved.
We also use another statement that again, is unique to us, "You're terrible Muriel". This came from the film "Muriel's Wedding" and became famous in our Ockerisms. And NO, you have to watch the film to see what it means.

[asianflava]

Depends on what I'm doing. I usually use a Snap-On combination square or a carpenters speed square. If I'm working with big sheets, I use a drywall square. I have a regular carpenters square, but I don't use it much.

[NathanL]

Whatever works for what I am doing. I have probably 50 of those plastic speed squares which are nice because you can screw them down to whatever you need on both sides and it's a square and a jig at the same time. Plus because they are plastic you can cut the corner out if you need it to fit around something like a piece of trim or whatever.

Outside of those I have a large collection of every other kind as well. I have found drywall squares to be the least accurate of them all, but accurate enough to break down a panel but if you measure out on the 4' side normally it's tilted at least a 1/4" one way or the other - sometimes more.

[Corwin C]

I use a high quality carpenter's rafter square, a somewhat inexpensive combination square, and a couple of aluminum triangular speed squares (one is about 12" on the hypotenuse, the other is about 8"). BTW my experience is that the plastic speed squares distort with changes in temperature and aren't accurate enough for anything but rough work. For panels/sheets I have a 4 1/2' and a 10' straight edge and Irwin quick grip clamps. If you are comfortable with geometry, a good tape measure is priceless to setup very accurate angles. I also regularly use calipers for small measurements, and a trammel and dividers and to layout curves and circles.

My planned build profile will have several ellipses and I'm working on a jig that will draw an accurate ellipse up to 48" x 96". It could also be adjusted to draw ellipsoid curves between angles that are not at 90°.

[halfdome, Danny]

I have an assortment of squares, nothing fancy is needed.
A few framing squares, 6" combination squares and a couple 12" combination squares.
I periodically test the framing squares by tracing a square line on a sheet of plywood then flipping it over and trace on top of the line to see if they line up, like in this video.
If they don't line up it's out of square.
You can adjust out the of square problem by hitting the inside corner or outside corner with a hammer and nail set.
You'll have to figure out which way to bring it into square.
It takes a learned knack so do it gently and keep checking for squareness.
Danny

[CarlLaFong]

I have a boatload of squares. I find I use my Starret combo and my large and small framing squares the most often. High quality, ultra precise, lab calibrated squares are nice, I suppose, but the ultimate question is, can you cut, accurately, to the line that you've scribed? If you have a line that is += .0001 inch to square and you freehand it with a Skilsaw, what was the point? I'm lucky enough to have a heavy, high quality combination machine with a large sliding table. I can cut up a sheet of plywood to within a gnat's whisker of square. You can also use the good ol' Pythagoreun Theorem or, as we called it in the field, three, four , five. When I cut multiple dados, I make a one time square from a couple of plywood strips. It is as accurate as you make it.

[grantstew8]

For some of the bigger square I use a tape measure and use a 3,4,5 triangle or multiples of 3,4,5. It's a handy saint check
http://www.examiner.com/article/an-interesting-mathematical-curiosity
I also use diagonals to check squares. If you cut a slot in the tab of the tape measure it makes it easier to measure diagonals as it "hooks" on to a sharp corner better. If the diagonals are the same length it's square.

[Breytie]

I don't think a single square can do all. I have a selection of squares from great big 3' roofer's squares through combo and speed squares, down to 4" engineering types and even some drafting and a T-square thrown in.
I always use the biggest one that will fit, it's easier and more accurate.
The measuring tape and 345 rule can definitely save your butt, the day and a lot of material.
Buy them as you need and can afford them. Check them for square regularly or whenever dropped or abused.

[prohandyman]

If you are building a camper then you are using alot of big material, 4', 8', etc. and just as a long level gives you a better overall chance of true level, a big square allows for a more exact line to follow. iMHO, you cannot beat one of these large aluminum typically used in drywall work. The long axis makes for very accurate measurements and marks ,and still can be used for smaller work.

[jstrubberg]

I use a drywall square and an old, large (24 inches on a side) carpenters square given to me by my father.

For me, the most important part of any square is making sure it's actually square!

http://www.newwoodworker.com/fxfrmsqr.html


So easy, but most folks never check...

[bobhenry]

Go ahead and laugh your butts off.......

I often use a full or 1/2 sheet of plywood as a large square. When I framed the caboose the frame and deck was never leveled and I worked using a large letter "L" cut out of a full sheet of osb. I left about 15" on one side and the bottom. Yep it looked just like a giant steel rafter square. I set all the studs keeping them 90 degrees front to rear and side to side. When I reached the end of the 19'11" run I was out 1/4 inch measured at top, bottom ,and center. The bow was in the center so I simply nailed on a ratchet strap and pulled it into line before sheathing that section. Just like Dan said a longer level is more accurate and so I use a jumbo size square.

[grantstew8]

Go ahead and laugh your butts off.......

I often use a full or 1/2 sheet of plywood as a large square. When I framed the caboose the frame and deck was never leveled and I worked using a large letter "L" cut out of a full sheet of osb. I left about 15" on one side and the bottom. Yep it looked just like a giant steel rafter square. I set all the studs keeping them 90 degrees front to rear and side to side. When I reached the end of the 19'11" run I was out 1/4 inch measured at top, bottom ,and center. The bow was in the center so I simply nailed on a ratchet strap and pulled it into line before sheathing that section. Just like Dan said a longer level is more accurate and so I use a jumbo size square.

When making SIPS panels from OSB we would trim the panels square, depending on the supplier the OSB can be out be quite a lot.
The European Standard EN 315:2000 for plywood gives tolerances for length and width of -+ 3.5mm. It is possible the US standard are tighter.
I've seen some quality craftsmanship where 7mm (just over 1/4") over 8' would make a difference for them.
It's going to be square enough for what I'm building

[Kody]

Many thanks for all the info from you guys, it's much appreciated. I will be buying some engineers squares, a 4 inch and an 8 inch to use for my build. I have run the router along the sides to square up the floor and trim the overhangs to the finished size. There is a 1/16 inch taper and the floor measures 60 inches at the rear and 59 15/16ths in the front. The length of the floor is 10". I checked the squareness at the rear using 3,4,5 as 36, 48, 60 inches respectively. The amount out of square at the back on both sides is no more than 1/32" or even less, so I am very pleased with the trimming. I have yet to sharpen the router cutter after machining the steel frame with it. (see my build thread for machining RHS with a router). I will be buying the 1/2" ply (more likely to be 12mm - NHJ!) as soon as I can get back to town. The biggest job to do first will be to clean the garage so I can use my super accurate 7' x 3' benches.
I like to draw a line on the timber with the square so I can align it quicker and very accurately on the drop saw. I can actually cut and then trim off as little as 0.010" or even as little as 0.005" from the end of the timber framing. This is why I need an accurate square and then the trimming in such small increments is very easy to do. However, for this grade of work, I need a new saw blade. When you have a high quality drop saw, never sell it short in its performance, I love mine.

Kody

* NHJ - Not Happy Jan!

[Bob Hammond]

Generally for chassis and bodywork, I think that a high quality tape measure, a 49-100" straightedge for layout guiding a handheld saw, and a 12" orange plastic Speedsquare, and a standard framing square would serve most needs . This would probably work for the cabinetwork too.

I do have an 8 foot Starrett layout rule (16ths & 100ths) as a 'shop standard' to check new tape measures. I've found that most known brands (Stanley, Lufkin, etc) are pretty good indeed these days. But the Chinese have a very elastic notion of an inch.

I've been intrigued by the CH Hanson Pivot Square, but I think I could only justify buying the plastic version.

If money is no object or if you have true lust for fine tools, then go to Bridge City Toolworks.

[Miriam C.]

I still use a framing square but for most things, especially if I am gonna hit it I use a plastic throw away! I really couldn't get mine in square due to a dip in the frame. I skirted between square and level... then I hit it. Doing the same with the repairs on the Green lantern. I am thinking these things sag a bit out of whack...