Flush Hinges with MDF cupboards

[Alexc]

Hi all,

I woke up one morning, just a short year before turning 40, and thought it was about time I picked up a craft and put my empty garage to good use.

So off I went and got me some tools and some MDF boards and some looks of pity from the tradesmen behind the counter (oh look at the desk jockey go, with his tender hands and his middle-life crisis. Couldn't he just get a sportscar or an extramarital affair like everyone else?) and started making my first ever project. This was to be a set of cabinets for the utility room, as so often seems to be the case.

These were to be made out of:

- 18mm MDF for the carcass and shelves.
- 12mm board + 6mm trim = 18mm shaker style doors.
- Flush hinges for the doors to be inset.

So far, I am happy with the result and I have learned from my mistakes by measuring twice and cutting thrice.

But there is one thing I cannot find the solution to. How to fit "flush" hinges and have the door face actually fit flush. Everything I find online says you do not need mortices with flush hinges but my door panel's face is refusing to sit flush with the frame. It is still inset and fits nicely all round, but its face is not flush to the frame. I initially used straight flush which i replaced as I did not feel comfortable with the screws' "bite" on the edge of the MDF board. With those, the door face was sitting flush. Now that i am using cranked ones (for the added screw to bit on the inside face) I am having this issue. The doors are sticking out by a lot. Do doors need to be thinner than the frame? Do I have to dig the frame-side part of the knuckle into the MDF? Will it still turn if I do?

Any help would be much appreciated.


Many Thanks

 

[AndyT]

Welcome to the forum - I like your style!

As you know, pictures will make sense of this and get some sensible answers.
Unfortunately, all forum sites are prey to spam bots so need defensive settings to stop them being plastered with dodgy adverts.

Round here, that means you can't post off-site links (such as links to externally hosted pictures) until you have made three posts. You can upload image files to the site as attachments, but only if they are small - below 256kb.

There's a guide to posting images in the Announcements section at the top of each sub forum.

So try uploading here, or post some more about yourself or your project, then have another go.

 

[Alexc]

Thanks Andy! I managed to edit the original and added some images

 

[AndyT]

Looking at your pictures, I think the problem is that those hinges will only work with a particular thickness of boards. They might be meant for melamine faced chipboard which I think would be 21-22mm - is the error consistently about 3 or 4 mm?

 

[Alexc]

The issue will only become worse if the door thickness increases. You are right in observing that the "excess" is consistent around the 3-4mm mark (edit: I measured since and it's actually 5mm).

As I fitted them, the only way this door face would sit flush is if it was 15mm thick or under, which makes for a very thin door

The other two options that I can see are:

1. Mortice the inside face so the cranked part of the hinge can be embedded into it, making the door sit further in the cupboard.

2. Cut a chunk out of the frame so the knuckle beds itself in rather than sit flush.

Something tells me though that these are hacks that one should not have to do a) with MDF and b) with this type of hinge.

I did look around for hinges with a larger cranked side but they all seem to be the same. The only thing that changes is the height and width, never the "depth". Almost as if all doors must be 15mm thick.

 

[Doug71]

A bit harder to fit but get yourself some of these, will make a much better job.

https://www.trade-hinges.co.uk/soft-clo ... et-3-p.asp

 

[Sgian Dubh]

… As I fitted them, the only way this door face would sit flush is if it was 15mm thick or under, which makes for a very thin door

It looks to me as if you've bought hinges for doors up to 10 mm thick.

I did look around for hinges with a larger cranked side but they all seem to be the same.

They're not all the same. Below is an image from the Hafele website of a cranked flush hinge to carry inset doors up to 16 mm thick. You state your doors are currently configured to finish up at 18 mm thick, so you might need to change them to finish thinner.

Similar hinges are available from Ironmongery Direct at this URL: https://www.ironmongerydirect.co.uk/sea ... hinge&fi=p

Alternatively, you could go the route Doug71 suggested and consider use of a concealed cup hinge. Slainte.

 

[Yojevol]

I made this cupboard/shelf unit about 3 years ago. The 18mm MDF doors are flush fitting and are hung on ordinary steel butt hinges. The hinge sides of the doors were strengthened with hardwood lippings to take the hinge screws. The unit is made of 28mm MDF so I had plenty of meat to screw into.

Brian

 

[Alexc]

Thanks for all the suggestions! Got a lot of options here.

Doug : I did consider these but we really wanted the butt-hinge look on the outside. Plus, it feels like I'm cheating

Sgian: Will teach me to only shop from big name physical DIY stores. Should had looked at specialist websites. They actually bother to post a schematic.

Yojevol: 28mm MDF looks great. I will definitely be going down that road in the future. I did consider using lippings (now i know what they are called) but for some reason didn't do it. I thought it was just some crazy idea I came up with in my head that nobody else would actually apply in real life. P.S. are these shelves of yours spray painted? They are very shiny!

I have now cut the corner off the edge of the frame to a depth slightly less than the knuckle so I can recess the hinge into it. It was like chiseling thermafleece but after some PVAing and two-part wood filling and sanding it is starting to look decent.

The edge of cut area follows the hinge quite decently now. And the door is flush.

What I take from all this is that for best results, I need to ensure I get the right size hinge for the door.

 

[Richard S]

You’ve got the wrong hinges, cranked style like you have are for overlay doors not inset. Inset doors require the type that screws only in to the edge. You mentioned you tried these and didn’t like the way the fixed in to the edge of your door and this is exactly why this type of hinge is so poor a solution for MDT doors. If you continue to use this type of hinge I would advise using very fine (3mm) screws, drill pilot holes and add a drop of super glue to the hole before inserting the screw. I’m afraid these hinges are not a good option but I think you have discovered that all by your self.
Good luck
Richard

 

[Steve Maskery]

Look on it all as a great learning exercise, we all started somewhere.

As regards screwing into the edge of MDF, first of all try to source MRMDF (it's Moisture Resistant). It's a lot friendlier to work with, less woolly and it finishes better as a result. Then when you have good material, mark where you intend to insert your screws and drill a 6mm hole on the back face, about 10mm from the edge. You don't need to go right through. Glue in a dowel and trim it flush. Then when you screw into the edge you are actually biting into solid wood rather than MDF.

I use that technique every time I need to screw into the edge and it's never let me down yet.

Good luck

Steve

 

[AES]

I have a LOT less experience than Steve, but FWIW, drilling a blind hole and inserting a dowel (even a cheapo soft wood dowel) is definitely the way to go in both MDF and chipboard carcasses.

P.S. If you get hard wood dowel (I often find finch Beech dowel in the DIY stores here) don't forget the pilot hole first. Actually, that's true for softwood too.

 

[Sgian Dubh]

You’ve got the wrong hinges, cranked style like you have are for overlay doors not inset. Richard

I disagree Richard. He has the single cranked hinge for inset doors, but bought the ones that work for thinner panels, roughly 10 -12 mm thick. He needs hinges that take a thicker door, e.g., 16 -18 mm.

Overlay doors attached with that style of hinge require a double cranked hinge like the one available from this link: https://www.nico.co.uk/product/double-cranked-hinge/ There's a double crank on the leaf that attaches to the cabinet side, as well as a single crank in the leaf that attaches to the door.

Interestingly, I notice that Ironmongery Direct incorrectly describe the type I showed in an earlier post as "Ideal choice for lay over doors". I suspect that's just an error on their part - I guess it's written by people that don't regularly use hardware. Slainte.

Another example below from: https://www.blum.org.uk

 

[Richard S]

I bow to your greater knowledge, however i have only ever seen that style of hinge used in an overlay configuration and I’m struggling to see how it could be used in an inset application.

 

[Sgian Dubh]

I bow to your greater knowledge, however i have only ever seen that style of hinge used in an overlay configuration and I’m struggling to see how it could be used in an inset application.

Hi Richard. The type below, a Hafele hinge I linked to earlier is for the inset application, which is what Alexc is aiming for and is the type he purchased, but for doors thinner than the ones he's made, hence his problems with the door sticking out beyond the carcase sides.

As you rightly point out, the double cranked hinge illustrated (both the Nico Manufacturing and the Blum hinge) in my last post is for the overlay application. Slainte.

 

[Richard S]

Thanks for clarifying that, my main experience of these hinges is with a national boat builder who insists on using the type the op used but in an overlay configuration. Very poor application, consistently splits the edges of the mdf carcasses. The hardwood overlay doors physically fair a little better but still a very inelegant solution.
Richard

 

[Sgian Dubh]

Thanks for clarifying that, my main experience of these hinges is with a national boat builder who insists on using the type the op used but in an overlay configuration. Very poor application, consistently splits the edges of the mdf carcasses. The hardwood overlay doors physically fair a little better but still a very inelegant solution. Richard

Maybe you could persuade the boat builder to consider using the double cranked hinge instead. They'll get 180º opening for a start as opposed to only 90º opening using the single cranked hinge, which I assume they're fitting with the straight leaf attached to the front of edge of the carcase - a bit of a strange way to fit the hinge I think, especially if they're working with sheet goods liable to delaminate when you screw into the edge.

On the other hand, perhaps I've misunderstood the way they're using the hinge? Slainte.

 

[Alexc]

More feedback and engagement that I would have ever hoped for.

You are are too kind.

Love the dowel technique! That would have solved a lot of my problems if I knew about it from the start.

I could even have used normal butt hinges, which come in nicer designs. Would that I knew, would that I knew.

All in all, the left door is now fitted and I'm happy with it, albeit my morticing skills leave much to be desired.

The right door now is in need of a double cranked (not double-cranked, rather 2 single cranks), with cranks facing the opposite way. Not sure they even make these. I have attached a diagram to show what I mean. Maybe I should simply use a non-cranked butt with dowels.

 

[AES]

Just as a P.S. to Steve Maskery's point about dowel reinforcing where screws are to go into chipboard or MDF carcases - the holes do not have to be blind of course. Where carcass thickness is thin, and especially when the sides are to be painted (or covered, e.g. by an alcove) the dowel holes can go all the way through, then cut off flush, then filled & painted as required. Especially if in chipboard, drill the holes from the INSIDE, as any chip out (which is almost inevitable with the carpy old SH chipboard I use for workshop cupboards, etc) will end up on the OUTSIDE of the carcass, therefore much easier to fill/paint neatly (or hide)!

 

[Richard S]

Boatbuilder fits hinge with cranked side against edge and outer face of carcase and flat side fixed directly to the inner face of the door stile. It’s rubbish but they’ve been doing it for ever and unfortunately I doubt they will change.