MDF construction advice needed

[RobertMP]

I'm planning on starting on a corner TV stand unit soon. It will need to be dragged out now and then whilst setting up or plugging in things etc so I'd like it to be pretty rigid and stay that way. It will have glider type feet and be on carpet so It shouldn't need excessive force to move it.

I'm thinking of buying a sheet of 12mm oak veneered MDF to make most of it. Top and bottom I was thinking of gluing 6mm plain MDF to the undersides to make those 18mm thick. All the edges will be trimmed with oak and the top and bottom trims profiled to match small tables I made as my first ever project.

Question is am I considering the right materials for the job and what is the best way to join MDF panels together?

A few pictures of the design so far...

Have not bought the big screen yet. That will be the reward for finishing this project

The big black box is a media centre computer

Front centre surround speaker is in a drawer (with cloth face) where other things like spare remote controls can be dropped in with it.

The funny blocks on the back of the amp etc is just allowing space for wires and plugs.

There will also be various holes in some panels to allow air flow and cable routes.

Oh and ignore the colour - I just used the beech texture from drawing my sideboard as it was easy!

Thanks in advance for any suggestions

 

[Newbie_Neil]

Hi Robert

It will need to be dragged out now and then whilst setting up or plugging in things etc so I'd like it to be pretty rigid and stay that way.

Is it possible to wall mount the screen? That would take a lot of weight out of the equation.

Question is am I considering the right materials for the job and what is the best way to join MDF panels together?

I would recommend the Kreg pocket hole jig and glue.

Cheers
Neil

 

[RobertMP]

Can't wall mount as it is across a corner and don't think I'd want to even if the hardware for that is available.

Just been looking at the kreg site and the video explaining the system. I can see that working and being quite easy to do. All those pockets may be inside and not visible on the finished item but the look of them on inside faces seems distinctly unattractive. Something to consider. Thanks.

 

[Gary]

If you don't want to see any fixings on the inside then go with biscuits or invest in the Festool Domino.

 

[Sawdust]

Robert,

I'd biscuit joint the whole lot. That way the joints are strong and invisible.

MDF is terrible for sagging and as your design doesn't allow for a solid back to keep it all rigid I think you will need to support the base, either with some solid wood or by putting a foot in the middle.

I would be tempted to leave a bit more space above the amplifier. If it's anything like mine it will get hot and a bit of air circulation space above it would be a good idea.

Cheers
Mike

 

[RobertMP]

I could do biscuits. I have a biscuit slot cutter for the router that would do edge slots. Guess I could get a 4mm cutter for slotting on faces - assuming router bits come that small.

Hadn't considered sagging. Extra feet are not a problem.

I was planning on vent holes in the base panel under the amp and an air route through the shelf - just didn't draw anything to show it. It has been working fine in a restricted space for a couple of years now so I don't think it will be a problem. It never gets turned up anyway - 105W/channel x 7 might upset the rest of the street

 

[Paul Chapman]

I could do biscuits. I have a biscuit slot cutter for the router that would do edge slots. Guess I could get a 4mm cutter for slotting on faces - assuming router bits come that small.

Will that work? While a biscuit slot cutter in a router will be OK for the edges, won't the body of the router get in the way when trying to cut slots in the centre of a panel :? :?

Cheers :wink:

Paul

 

[Newbie_Neil]

All those pockets may be inside and not visible on the finished item but the look of them on inside faces seems distinctly unattractive.

Have a look at their plugs.

Cheers,
Neil

 

[RobertMP]

Re the router I meant two different cutters. I have a trend biscuit slot cutting bit for edges and was thinking of a standard round cutter but small for plunging and cutting a groove hand held to a guide.

I do like the pocket hole idea as it looks easy and I did see those plugs but they are for 3/4" thick + material it says. Then there is the problem of flush finishing to a veneered surface if it could work on thinner stock.

 

[tim]

I think that there will be no sagging of the top given the vertical supports in your design. What i am curious about is why you have shaped the unit to fit the corner yet your units protrude past these edges. Why don't you make the unit a bit bigger?

Cheers

Tim

 

[RobertMP]

Because the width ties up with the start of a bay window to the right and allows access to a socket and gas fire tap on the right

 

[Slim]

Rigidity will be increase considerably if you use 18mm veneered MDF all round. It will also mean you don't have to faff about laminating extra pieces on.

I would use pocket hole screws, but I would also use a housing joint and glue to give it extra strength.

 

[Gaz_XB9R]

Wall mount like this would do the trick and is what I've got holding my 42" panasonic.

http://www.avrabbit.com/product-Premier-am3-bk-plasma-wall-mount-584.html

That and a concealed support shelf for the 5.1 centre speaker directly above the screen works a treat.

 

[RobertMP]

Rigidity will be increase considerably if you use 18mm veneered MDF all round. It will also mean you don't have to faff about laminating extra pieces on.

I would use pocket hole screws, but I would also use a housing joint and glue to give it extra strength.

18mm is a possibility. For some reason I just liked the thinner verticals and I don't want to buy 2 sheets!

And what is a housing joint?

While I think of it....Silvermans in Basildon is where I bought the veneered MDF for my sideboard. I noticed they don't have their own web site now and the only contact is through a Timbmet national number. Anyone know if I can still just turn up and buy at the counter. Might be out that way tomorrow.

 

[jasonB]

I would go with biscuits and either carcase screws or pocket screws depending on what will be seen on each joint.

As has been said it will be easier to make it all from 19mm veneered board , there is a risk of 6mm & 13mm cupping.

A 4mm straight bit combined with your slot cutter will be fine fot "T" joints, thats what I used when I started out.

Jason

 

[Slim]

And what is a housing joint?

Sorry Robert. You may know it as a dado.

Imagine that the piece with the trench is your top or bottom. You could use this for the internal, front to back verticals.

 

[RobertMP]

That is what I would have guessed it was - and what I may have tried if I hadn't asked the question here. Was worried about the veneer getting damaged doing it though.

 

[woodbloke]

Robert - lots of excellent advice so far, my input on this one. I too would use biscuits for the whole construction and would use 18mm mdf, suitably supported to prevent sagging. The sagulator will give you some indication of how much the mdf will bow under load and that would be one of my main concerns with building a piece of this sort. I assume that you haven't got a dedicated biscuit jointer so if funds can be spared (nwtS) this might be an excellent opportunity to invest in one. I used to have one of those biscuit cutters that go into a router...once you have a decent biscuiter you'll never use it again (or at least I haven't) - Rob

 

[RobertMP]

Just got back with an 8x4 of 3/4 inch (so even thicker than 18mm I was prepared for) veneered MDF - and it is heavy! Used to handle sheet steel that weight all the time when I was working. Seems a lot heavier now. Anyway it is off the roof of the car and in the garage. Better get on and do something with it now.

Silvermans still has the trade counter butt there is a big 'For Sale' sign on the main warehouse. I did ask and was told they are downsizing not going.

I bought another sheet of 6mm beech veneered board too while I was there for making more items to compliment the sideboard. The two 8x4 boards came to £80 inc vat - which was about what I was expecting.

 

[BradNaylor]

Just got back with an 8x4 of 3/4 inch (so even thicker than 18mm I was prepared for) veneered MDF - and it is heavy! Used to handle sheet steel that weight all the time when I was working. Seems a lot heavier now.

I too have noticed this phenominum.

Sheets of MDF have definitely got heavier over the last 20 years. Have they changed the compostion, or is the earth's gravitational pull getting progressively stronger?

This would also explain why my bathroom scales suggest that I am three stones heavier than I was ten years ago.

I think we should be told! :lol: