cabinet project will wood work?

[Cr0nJ0b]

I have a cabinet project that I'm starting and I'm just not sure what material to use. I would really like to do this in wood, since I have the tools and can do it without help, but I'm not sure that wood would be strong enough.

The basic idea is this. I have an open cabinet 54"(W) x 56"(H) x 29"(D). I want to build a door to cover the opening, so a 54" x 56" door.

Here's the tough part, I want to hand a plasma on the outside of the door, so it has to handle the torque from the materials as well as about 90lbs of plasma TV.

My initial thought was to use a hard wood (oak?) 2 x 4 with like 6 door hinges on the right side. Then build a frame with 2 x 2 (oak or hardwood) around the edges. I would have across beam in the middle and diagonal from the top right to center left and center right to lower left. Sort of like 2 "Z"s on top of each other.

The whole door would move as one piece.

I thought about putting some 1/2" plywood on the back for more strength, but think that will add too much weight.

My worry is that with the weight of the material and the 90lbs of TV, that wood is just not the way to go...but again, if it's possible, it's my preference. My guess was the material weight might be 100 lbs.

The alternative would be to have the frame build our of 2" steel pipe and secure it on all sites, like a door and casing all from steel... I would build the wood on top of the steel to match the other cabinets.

thoughts?

 

[wuliheron]

Supporting a hundred pounds isn't exactly a lot to ask for and doesn't require 2" steel pipe which will support an elephant. At most a door like that should require steel angle supports at the joints.

 

[Cr0nJ0b]

that's what i was thinking, but every time i've asked someone from a hardware store they cringe and say that it's too much weight...I'm with you...it should be easy for strong wood with good support.

By the way, I'm trying to decide if it would be better to have the cross beams go from top left (the free side) to bottom right, or top right to left. I'm not a physics guy, but the thought is that the stress is pushing down from the top right corner, or that you are holding up the bottom left, as it were. I'm sure i'm not saying this right.

I'm getting closer to just investing in some wood and making it work.

 

[edro]

Are you going to bolt it to the wall from the inside?

 

[wuliheron]

that's what i was thinking, but every time i've asked someone from a hardware store they cringe and say that it's too much weight...I'm with you...it should be easy for strong wood with good support.

Its the joints and hinges you have to worry about rather then how much weight the wood itself can support. Once a single joint works free the whole thing will fall apart and the torque on the hinges can rip the screws right out. An industrial strength piano hinge (strip hinge) will spread the weight over the entire door jamb and a flat square steel frame is enough to make sure the door joints don't work free.

Half inch ply across the entire back will likely ruin the door as the wood expands and contracts.

 

[Murloc]

putting a TV screen on a door sounds wrong in so many ways.
Just wait until you slam the door inadvertedly because you didn't except that much momentum, or you smash the TV on the wall.

 

[Cr0nJ0b]

As for Hinges I was thinking of 6-8 door hinges (4"), I didn't really think about the piano hinge, since it just looked so small.

The whole thing will be screwed into the inside cabinet wall. I was envisioning 4 x 1" screws per hinge, so about 24 - 32 total screws in the inside cabinet all.

The idea of having metal supports and the corners is a good one, and really easy. I also thought about putting corner triangles of plywood on each of the corners.

The door shouldn't slam. I would put some kind of mechanism maybe with a piston or something to keep if from moving too fast. And I don't know how I would "smash the TV on the wall" since the TV will be on the door...I'm really more concerned about it pulling out of the inside cabinet wall.

The metal frame idea is a good one, but if I go to the trouble of getting the metal for the frame, I would just go all the way and get the whole door built.

 

[wuliheron]

As for Hinges I was thinking of 6-8 door hinges (4"), I didn't really think about the piano hinge, since it just looked so small.

The whole thing will be screwed into the inside cabinet wall. I was envisioning 4 x 1" screws per hinge, so about 24 - 32 total screws in the inside cabinet all.

The idea of having metal supports and the corners is a good one, and really easy. I also thought about putting corner triangles of plywood on each of the corners.

If you don't line up all those hinges perfectly the door won't open and close. Hence, the suggestion of a piano hinge which come in all different sizes. Spreading the torque out over a larger area also means the piano hinge doesn't have to be nearly as strong because any one spot on it never has to deal with a lot of strain. Its not called a piano hinge for nothing. Hinges like this are used to hold the heaviest grand piano lids for a reason.

For the corner joints you can also use recessed nuts and bolts or other hardware that can just be tightened if it ever wiggles free. Most carpenters don't think in terms of fancy hardware, but I used to build custom jigs.

 

[EarthwormJim]

I would make it out of nice baltic birch plywood sheets, not solid hardwood boards, and use dovetails for the corner joints. This will keep the weight down too. The alternating grain boards are very strong.

What you're asking is pretty minimal as far as loading. Speaker cabinets (like Marshall half stacks) are made from birch plywood, they see tons of abuse and loading without issue.

You can use framing inside of the cabinet (probably a good idea to prevent warping over time and support the corners), however it doesn't have to be metal, wood framing would be fine.


Will you be anchoring the cabinet to a wall? If it's empty and you open the door with a 90lb TV on it, you might have tipping issues.

 

[Cr0nJ0b]

I would make it out of nice baltic birch plywood sheets, not solid hardwood boards, and use dovetails for the corner joints. This will keep the weight down too. The alternating grain boards are very strong.

What you're asking is pretty minimal as far as loading. Speaker cabinets (like Marshall half stacks) are made from birch plywood, they see tons of abuse and loading without issue.

You can use framing inside of the cabinet (probably a good idea to prevent warping over time and support the corners), however it doesn't have to be metal, wood framing would be fine.


Will you be anchoring the cabinet to a wall? If it's empty and you open the door with a 90lb TV on it, you might have tipping issues.

The cabinet covers the whole wall, so it's securely anchored.

I talked to a lumber guy today and he suggested Kiln dried Douglas Fir. I figured I would mortise the top and bottom pieces...and now I'm starting to think I might use 2x4" instead of 2x2", with a diagonal brace (bottom left to top right), with Angle Irons on the edges and maybe some plywood triangles covering the corners. As I think about it, I would probably do the triangle or the angle iron, but not both. He also warned about using too many screws...basically weakening the corners.

I'm also back to using regular door hinges. I don't think it will be too difficult to line them up and I can buy them fairly cheap at the lumber yard. I heard the point about the piano hinge, but I just like the door hinge a little better.

 

[Fayd]

The cabinet covers the whole wall, so it's securely anchored.

I talked to a lumber guy today and he suggested Kiln dried Douglas Fir. I figured I would mortise the top and bottom pieces...and now I'm starting to think I might use 2x4" instead of 2x2", with a diagonal brace (bottom left to top right), with Angle Irons on the edges and maybe some plywood triangles covering the corners. As I think about it, I would probably do the triangle or the angle iron, but not both. He also warned about using too many screws...basically weakening the corners.

I'm also back to using regular door hinges. I don't think it will be too difficult to line them up and I can buy them fairly cheap at the lumber yard. I heard the point about the piano hinge, but I just like the door hinge a little better.

kiln dried douglas fir is standard what you get when you buy dried 2x4's for framing/construction. it's not a finish wood. it's a crappy wood.

i highly suggest you not use it for this. 2x4 of fir vs 2x4 of oak, the oak's gonna be several times stronger in shear/compression... probably even tortion. look up the average specs of the various woods if you're curious.

the thing is, as others have said, 90 lbs isn't a lot of weight. especially not to wood. so something like a 2x2 frame will *easily* support it granted that you use quality wood.

i'm not sure i'd use plywood in this case, but that's because i'm all about solid woods. i would use plywood as the face, and secure it every 8 inches or so around the cabinet with 2" long screws to spread the weight all over the cabinet face. but the door should *easily* be able to handle the weight.

 

[Cr0nJ0b]

kiln dried douglas fir is standard what you get when you buy dried 2x4's for framing/construction. it's not a finish wood. it's a crappy wood.

i highly suggest you not use it for this. 2x4 of fir vs 2x4 of oak, the oak's gonna be several times stronger in shear/compression... probably even tortion. look up the average specs of the various woods if you're curious.

the thing is, as others have said, 90 lbs isn't a lot of weight. especially not to wood. so something like a 2x2 frame will *easily* support it granted that you use quality wood.

i'm not sure i'd use plywood in this case, but that's because i'm all about solid woods. i would use plywood as the face, and secure it every 8 inches or so around the cabinet with 2" long screws to spread the weight all over the cabinet face. but the door should *easily* be able to handle the weight.

That's what I plan to build.

I decided on fir, for ease of use and I'm sure it will be strong enough....and light enough. I'm using 2x3" for the frame and 2 x 2" for the braces.

I'm using metal corner braces and metal "T" straps for the cross beams. They don't need to hold a lot, but I don't want them pulling forward.

The whole bottom half will be 1/2" finished plywood on which I'll do any cutouts and molding.

I have 5 x 4" ball bearing door hinges for the right side, which I will cut in to the wood to make flush.

Lastly, I'm going to try to mortise the cross beams for added strength...

wish me luck.