How Do i determine the length of wood to use ?

If you are following the instructions above you will be stapling the cloth to the front of the frame so you should build the frame to the dimensions of your BOC, namely 58"x100". This allows for a 2" border all around giving a finished screen size of 110" diagonally (96"x 54") as you show above. If you opt for a 3" or 4" border it will extend beyond the dimensions of the frame by 1" or 2" respectively. This is useful if you want to install led rope lighting if you want a backlit "frame".

I made a 2.35:1 screen, 121 inches wide, about 51" tall. I used two vertical braces spaced evenly apart so I ended up cutting 4 vertical pieces all the same height (in this case 51 less the thickness of my board). I used 1x4 pine. Took awhile to find decent pieces that weren't warped or twisted.

The way I am doing it is like this: Say I want a 106" screen. The dimensions are 92.5 X 52. I want to put a 2" border on all sides. What I do is add 2 to both 92.5 and 52. So the frame should be 94.5 X 54. Then when the border goes on, the dimensions will be perfect.

Yes....but subtract 1/2" all around,(93.5 x 54 ) so that the overlaid Trim barely protrudes out / over the edges of the underlying fame. You don't want too be able to see the raw edge of the Frame sitting next to the Finished Trim.

People who want 1.5" -2" Trim overhang for recessed Strip Lighting adjust accordingly.

That's the way to do it.

However, in most Home Depots, at the "Trim" Cut Table, they usually have one of those inexpensive yellow Miter Box Guides and a Saw so you can do those needed cuts yourself without having to buy a Miter Box Kit for just one needed application. If you don't see them, ask them (...a Manager...) "why isn't it here?" It's pretty much a universally provided tool at ALL Home Depot5s for the DIY'er to use

I bet you just didn't know to look for it, and unfortunately, unless you get helped by a truly "Clue-full" Associate, such availability can...and does go unnoticed. Me? I'd take the Sticks back and use their provided box rather than shell out another $10-12.00 for the Miter Kit.

BTW, a good reason to do those cuts at the store is that if you screw up, you can always get another piece and try again.

Well that's some real .........well ya know what it is. I frequent HDs across the US regularly, and I'll tell you, that is the exception to the rule.

In any case, Miter Corners are what you really want.....Butt Ends are not sturdy or self supporting enough, even with a overlaid Bracer. Certainly $15.00 is not just a handful of change, but to get a Frame made right, it's also a lot less than many put out using other materials and hardware.

To my reasoning, despite being disappointed by my Local Store being so "Skinh-Flinty", I'd go ahead and get the Miter Box Set and give it a try....and if by some crazy chance your not happy with it after say....8 cuts or so...you can take it back. (pay cash....just in case...)

Disregard everything above if you have a friend who owns a Miter Saw. And if you do.........................

.................why didn't ya say so !!!

It is possible to use screws but if you used a hardwood frame, you will have to predrill the holes, which is a pain. If you use heavy duty staples they can just be hammered itno the wood.

Carpet tacks also work well.

The only screw to consider is a Truss head Screw, one that has a very flat, broad head.

http://www.plumbersurplus.com/Prod/Blum-Inc-612TH-Wood-Screws-with-Phillips-Truss-Head-100-Count/224248/Cat/100

However when you tighten them down, you'll have to be very observant so as to not allow the Screw head to twist the BOC. This entails doing the final tightening by hand....slowly.

I use Staples and those type screws, the former to get things in place, and the latter to do the majority of the attachment during the tightening.

I would not ever use a nail or a tack simply because it's very hard to hold a Fastener and Hammer it in while also trying to hold a piece of material very taunt.

Yuk. Use a Pan Head Wood Screw at least...not a Beveled Head Screw.

Any screw that has a Coarse Thread and a Broad Flat head would be preferable.

The Washer idea is a good one (...but adds to the unwieldiness of having extra hardware...) because it will prevent the "grab & twist' effect on the Black Out Cloth

Truss head screws are often called "Washer-head Screws" because they look like a Washer has been added to a very Flat headed screw.

Ask the Man @ Home Depot for "Sharp point Truss Head Screws" If they have them in 3/4" lengths your Golden. Lowes also carries them....in some locations.

Eliminating the need to have two-piece fasteners can be a big advantage, but as stated above, a separate washer can be good in this instance.
Edited by MississippiMan - 1/10/13 at 8:38am

Pan Head screws are a very standard product. Just look in the Wood Screw section and read the labels. Get a Phillips Drive type, and the smallest Washers that will accept the size screw you choose.

Those will work.

I disagree regarding the strength of miter corners vs butt ends. Miter joints look nice (which you won't see when it's BOC stretched over the frame). Neither are sturdy or self supporting for squat. That's why you use bracing. Now if they were splines, half miters, lock miters you might have a point but that's not what you were telling him to do. And none of those miters are going to be nearly as strong as a glued 12inch piece of plywood on each corner.
Edited by Warlan - 1/10/13 at 10:47am

You need to go back to Corner Framing 101.

But first, I don't think you can point to a single instance where anyone, myself most importantly, ever suggested that a Frame under tension that uses Miter Joints did not still need adequate bracing at the Corners and at any actual Butt" joint.

I'm not even sure why you'd imply that.

But as far as a Miter joint's penchant for having better strength, the top and bottom corners of a Miter distribute stress equally and in different directions when such stree is applied. A Butt joint has the bottom inside edge act like a lever to lift the opposite corner up and away if stress is applied. That is why such unions are prone to springing loose with a minimum amount of applied pressure.

Now absolutely, the addition of bracing serves to mitigate such detriment loosening. Obviously, braces on the Butt unions in vertical (Center" supports are necessary. It would be crazy to expect any such Butt Frame to accept any degree of tension, lateral or diagonal, and maintain a true dimension for long. But combining Miter Joints AND Bracing is an exercise in ideally supporting such structures.

Not of course, if someone found it impossible to do Miters because he was afraid of cutting wood using a inexpensive Miter Box guide (improbable) and had a store pre-cut all his sticks, then using "L"s and "T"s could in the least acco0mplish something akin to a satisfactory Frame. I don't dispute that. But the validity and superiority of a Miter Joint has been proven for....say, about a couple Thousand years on now, so arguing that it is not better to use whenever possible is just so......well, it's not to be argued.

In my Tutorial on constructing Black Velvet Wrapped Trim, I show examples of both Miter and Butt joined Trim. Done right...and with precise measuring and assembly, the Black Velvet will effectively hide the straight Horizontal line a Butt joint creates....pretty well. But NOT as nicely as a Mitered joint does...if also done with precision.

But we are not talking about unsupported Trim, are we?

Because if you set them to the depth needed to really allow the Screws to pinion the material so it will not pull out, you can risk having the leading point of the screw create a bulge / split on the opposite side of a 3/4" thick piece of wood. The point of the screw, when it is self-tapping it's hole, tends to push material ahead of it, displacing the material. With a 3/4" screw into 3/4" material, there simply isn't enough room for the displaced material (wood) to go, even with a thin Cut Washer in play. You don't want a bunch of "warts" on the front of your Trim, do ya?

Using 5/8" screws carefully, and using a smaller diameter screw (...you can't pre-drill the holes unfortunately...)should be ok. And if your using a Washer, all the more so.