folding MDF?

[BrokenBiker]

Is it possible to put a right angle bend in 6mm MDF without damaging it?

I am planning a little unit for under the bathroom sink that will incorporate a bin and some shelves and maybe a small cupboard.

I have a fair bit of 6mm MDF that is going spare but it is too thin to drill and screw, or nail, and I have trialed some wood glues on it and they don't seem to hold up well as it is only the edges being glued so only 6mm of contact area.

if it can be bent to give a right angle i could pretty much make it all without having to make too many cuts and it would have a lot more strength

if it cant be bent i will have to settle for conti board or ply and screw it together

 

[Sean]

no.

 

[bigegg]

You'll have to put a glue block inside - just a piece 1in square would be enough to provide enough a glue surface.

Glued butt joints don't work on MDF as the edges of the board soak up the glue.

 

[BrokenBiker]

thought i might have to use a block of some sorts. suppose it would be cheaper than buying enough ply to do it.

cheers guys

 

[brianblock]

I have folded MDF hundreds of times, although thicker stuff (18mm).
The secret is to router a v groove on the inside of the fold line (almost through) then masking tape to reinforce the fold apply glue to the groove, fold and clamp (or tape) at 90° until set up.
can't see any reason why this wouldn't work on 6mm, but i would imagine it would be harder to get the groove the right dept as opposed to 18mm.

 

[bigegg]

It breaks like cardboard if you try to do that with thin stuff.
MDF has a hard, smooth outer, which gradually becomes less dense towards the centre - not a huge amount of variation, but some.
With the thinner stuff, you don't get the less dense centre to support the outer as it bends, so it snaps.

If you *do* try this method, seal the cut edges with PVA first, allow to dry, then put more glue on to hold the joint.
The first application stops the second from being absorbed by the MDF

Actually - a thought occurs.
MDF is not the best choice in a bathroom, any way.
It absorbs moisture like a sponge, especially through the cut edges, but even through the surface.
Unless it's actually tempered hardboard which you are using (practically the same at this thickness, but waterproof

 

[BrokenBiker]

well, I ended up using ply. 15mm thick and just cut the panels, screwed them together. came out ok. nothing to write home about but does the job.

as for the steam, its not much of a problem. I have a closed shower unit and a very good (industrial) extraction fan that sucks all the steam (and the towels) out quite quickly.

plus its been painted all round so should hold up well