Help Please, joining MDF for a childs bed

[marku]

Hi

I'm not sure this is the correct part of the forum for this question,

I am planning a bed for my son with a castle theme, although I have built some MDF built in cupboards this is slightly different because of the size I would like to be able to construct it in the workshop and then take it down paint and reassemble in his bedroom.

So basically I could do with some advice on the best way to join the main corners, I was thinking of using biscuits without glue and then screwing into the MDF but I don't think it will take a screw very well.

Any suggestions on how to make this flat pack would be great.

The rendered image is just a sketch to get planning permission from the boss, the plain drawing is for construction, it is where the end meets the back etc I am struggling with. I don't want to do any more to the drawing until I have worked out how to join the corners.

Thanks

Mark

 

[Myfordman]

Cross Dowel and matching screws work well.
MDF is such cr4p that no fixing screwing into the short fibres will last

 

[Mar_mite]

What about aluminium angle on the insides? You could drill and countersink plenty of holes for screws and paint it up the same colours as the mdf. Great design. Make sure you give us all a WIP.

 

[Mr T]

Hi
You could use minifix housings and metal dowels to pull the parts together for assembly http://www.hafele.co.uk/shop/c/cabinet-fittings/minifix-housings/8226 but you would also need glue and biscuits.

Like the design.

Chris

 

[blackrodd]

2"x 2", arris saw, corner to corner then glue and screw to either both or just screw 1 side? HTH.
Regards Rodders

 

[marku]

Thanks for the help, I was thinking of using battens glued to one and screwed to the other but was trying to avoid it at the top where the mattress will be, so a combination of this and cross dowels may be the answer.

Can you buy a tool, jig for the cross dowels had a look on google but can't see anything.

Mark

 

[heatherw]

We sell a lot of kids furniture which is made commercially, the beds are nearly always joined with cross dowels and screws as Myfordman says. Generally there are two 8 or 10mm wooden dowels (not glued), one on either side of the cross dowel joints. These stop twisting and also provide a surprising amount of additional strength

Minifix joints are often used when joining large panels in a right angle, also interspersed with unglued 8mm dowels. A high bed such as the one in your design never relies solely on minifix joints.

It's worth adding that the structural parts of these beds tend to be made of 30mm melamine faced chipboard, with decorative infills in 16 or 18mm. I don't know what the equivalent for strength is in MDF, but I suspect at least 22mm.

This set of bunks for instance is all made in 30mm melamine chipboard except for the back board and the drawers, which are 16mm. The upper and lower bed rails are joined with cross dowels and the back is joined to the sides with minifix joints and wooden dowels. It is supplied flat packed and can be disassembled if necessary.

 

[petermillard]

So basically I could do with some advice on the best way to join the main corners, I was thinking of using biscuits without glue and then screwing into the MDF but I don't think it will take a screw very well.

Any suggestions on how to make this flat pack would be great...

Fun project. MDF takes screws just fine - there's a few of us on here who'd be in real trouble if it didn't - but you must use decent MR MDF, and appropriate screws; carcass screws, MDF screws, confirmat screws, whatever's right.

Will the bed need to be broken down again once its in situ, or just for the convenience of assembly in the bedroom? If it needs to be flat-packed more then once, then use flat-pack fixings e.g. cross dowels and /or minifix / confirmat screws. If it's a more-or-less permanent fixture once it's assembled, then dominos/biscuits/dowels for alignment and glue/screws for mechanical strength.

I've only use cross dowels a couple of times and made my own jig for alignment.

HTH Pete

 

[SteveF]

make it out of real wood

and pass it down the family

 

[marku]

Thanks for the advice, I have ordered some cross dowels from screw fix today and I will make up a jig for them. I want to be able to take it to bits so when we have finished with it we could let someone else have it.

It would be nice to build it out of real wood but we are going to paint it and MDF will be cheaper and quicker to build,

I am still working on the drawings but hope to start cutting the wood this weekend, I don't usually draw things in much detail but this job will be quicker with proper cutting lists.

Thanks

Mark