MDF shelf unit conundrum

[milkman]

Hi, I'm in the process of building myself some of these. They are pretty pricey and hopefully I can make something that will fit better in the room we have and with veneered board options.

I dont actually know how this is constructed. i dont think they'd be very forthcoming if i asked!
I'm making a mk1 so I can figure it out. As far as I can tell its 15mm shelves and 9mm uprights, MDF.
The shelves are slotted into grooves on the back board and fixed from the back.
The uprights are where I've hit a wall. They need to be positively fixed to both the back board and shelves but are so thin they delaminates when I try to screw them. 3.5mm screws were thinnest i could find while keeping a good length.

Does anyone have and ideas on how I might achieve this?. Don't want to go thicker as it would spoil the look and also I'm thinking if they can do tis I should be able to as well!

How you can give some ideas. Thanks very much as always.

Mark

 

[Sheffield Tony]

Ho ho ho. Obviously they must use very expensive fixings. If I've found the right one, just over 1 metre square H102½xW102½xD22cm, reduced to £594 from £699.

I would imagine the shelves are grooved for the uprights, and glued. By not having any of the uprights in line, there is enough thickness in the shelf for a groove on either top or bottom. As well as plenty of upright dividers, the back will help to avoid sag.

 

[transatlantic]

The uprights don't look grooved in to me, so I would guess it's just some really thin metal dowel.

 

[Racers]

Screwing into the end of MDF is as you have found is problematic, you will need to drill pilot holes of the right size to avoid it splitting.
I personally would use dowels or biscuits for the dividers.

Pete

 

[sunnybob]

I would glue it and then use panel pins from the back. being EXTREMELY careful measuring so a pin doesnt miss an upright and poke through.
If you must use screws then a 3.5 mm screw could still work fine with a 2.5 mm pilot hole, thus stopping the mdf from splitting.

 

[rafezetter]

I would glue it and then use panel pins from the back. being EXTREMELY careful measuring so a pin doesnt miss an upright and poke through.
If you must use screws then a 3.5 mm screw could still work fine with a 2.5 mm pilot hole, thus stopping the mdf from splitting.

A good way to do this with irregular spaced shelves is to clamp the back panel to the front, facing forward (so the back of the panel is against the front of the unit) and draw lines either side of the shelves / uprights. Clamp it to the back and nail between the lines.

Steve Maskery's usual trick for screwing into endgrain MDF is to glue in a reasonable sized wood dowel (6mm would suffice for a 3.5mm screw) and then screw into that. I've used this for MDF and chipboard and it works really well.

 

[RobinBHM]

Commercially made they would probably have grooved routed with a CNC. Say 6mm grooves x 4 deep then the uprights are machined like long tenon to fit the groove width.

If you have shaker style kitchen door cutters then that could be done, or even with 2 groovers mounted on an arbor in a router.



The shelves could be routed with a slot jig and a guide bush. If you used a 6mm or 8mm bit and made the slot slightly wider than the guide bush you could end up with the correct width for the uprights. Usually 9mm mdf is pretty accurate in size and a groove of about 9.3mm works fine -certainly for shaker door panels.

If your jig has battens screwed on front and back then it can be slid along the shelf to machine at any position and stay square.

I think you will struggle trying to screw them in place. it will be very difficult to avoid splitting and positioning will be an issue.

 

[Skeety]

If I were to make that i'd either use 4mm Dominos (as mentioned above) and glue for the uprights and 5 or 6mm Dominos into the back panel and screw through from the rear with pilot holes also using glue.

Jon.

 

[Jake]

I would do it with grooves in the shelves and back (stopped ones on the shelves) and the top, bottom and back edge of the upright dividers and use 3mm ply loose tongues so after the carcasse is all glued up, you can put the tongues into the pre-prepared grooves and slide the upright in from the front (with glue). That way all dividers can go in after carcasse glue-up which will save a lot of stress IME.

 

[milkman]

Wow thanks very much everyone and so quick too!
Good to know I'm not nuts for even attempting this.
Sheffield Tony yes the fixings are expensive : ) I assume the shelves are made in or at least imported from Denmark hence the price.
Thanks for the ideas folks. There's plenty to be digesting here but will keep this page updated with progress.
A quick look at the installation instruction download reveals that the shelves are indeed fixing through the back so that much is clear!
Slot jig. Yes it took me a while to rout the grooves in the back panel so having a dedicated jig would be a good way to go. I've got four to make so its worth jigging up as much as possible.
Loose tongues nice one I can see that working very well!
Thanks all once again very helpful

 

[Jake]

Boconcept is like Ikea on US private equity steroids. We were looking for sofas recently and went into one - all very plushly presented and very slick looking, and we were on the surfacepretty impressed by one sofa - very smart and actually quite comfortable too, at least in the sit down and test for a few minutes sense. I looked it up afterwards and found a feature about the making of it, and how basically the structure was a skin of hardboard (described as masonite no doubt to obscure things for a European audience) over mdf or maybe ply formers. All for a quoted price of c£5k for a 3 seater sofa (I am sure there a good discount could have been had on that, but still). I concluded showroom appearance was the main design goal.

Which gives you an opportunity to do better.

 

[milkman]

I'm with you there Jake. I like the design but those prices are crazy. I'm going to be making a few to fill out a wall so i think I really can do better!