Specialist hinges?

[JohnW2]

Repaired a hatch like that , the weight of the hatch together will it not quite being supported when opened ripped the hinge screws out .

Yes, that is one of my concerns, but really applies no matter what arrangement of hinges one adopts.

My thought is not to attached the hinges with screws but, rather, with nuts and bolts, with a metal plate on 'the other side'. There would then be no risk of 'screws ripping out', but still some appreciably forces which would be trying to 'rip the wood apart' - and, although the 'frame is very substantial, the end side of the lid is only about 19/20mm thick. I'm not sure what I can do about that. Even if I reinforced all of the end of the lid of metal, that would probably merely move the problem to a tendency to 'rip apart' the joints between end and sides of the lid! ... take that approach to its ultimate conclusion and I would end up with a metal lid!

I'm still thinking - and am glad to see that others, are also doing so on my behalf

Kind Regards, John

 

[JohnW2]

.... (you'll need a hinge that opens further than 180 degrees, I'm sure it's easy to find up to 270, which will be more than enough)

I forgot to add .... standard butt hinges will usually open up to just under 270°. However, unless I'm missing some better configuration, for the lid to be able to open by "just over 180° " would require the hinge to open "just over 270" (since 90° of the hinge movement is already 'used up' when the lid is closed - unless one tried screwing the hinge to the edge of the lid, which would be very iffy) - but, whilst standard butt hinges cannot quite do that, as I said,I imagine that I could 'bend' one enough to get what I needed.

Having said that, there is a 'Plan D' (or is it 'Plan Z'? ) in my mind at present. In contrast with standard butt hinges, 'Parliament Hinges' generally can open to a bit more than 270°. Ironically, if just used 'as they come', such hinges would usually create a much greater 'pivot offset' than I want/need - but I am toying (and experimenting) with ways of modifying one in a manner that might achieve what I wanted (and, as with the 'storm-proof' ones, maybe without the need for the angle strip'). Watch this space!

Kind Regards, John

 

[JohnW2]

OK, it didn't take too long - "Plan D/Z" has now been investigated.

I found several 4" Parliament Hinges in a dusty corner of my cellar (see first pair of pics below. I initially thought they were solid brass, but it transpires that they are actually brass plated/coated steel. There are pretty 'solid' and I had to get one extremely hot before I could bend it in the fashion I wanted, but I eventually more-or-less succeeded (see second row of pics).

The remainder pf the photos are of a full-size mock-up of the relevant parts. It seems to work as I want, and certainly gives me far more than enough "opening of lid beyond 180° " than I need (in fact, potentially a full 270° or so).. As mentioned before, I would plan to put a metal plate on the inside of the lid to prevent the bolt heads ripping through, and I would also make some extra holes in the part of the hinge leaf attached to the lid which currently has no holes. I could put an 'angle strip' (or something) below the 'horizontal' part of the bent hinge if I felt more support was necessary, but I'm not at all sure that will be needed.

[ I would point out that since what I've been drawing and mocking-up is a slight simplification of the actual situation, since it overlooks the frame of the lid, but I don't think that alters anything about the hinging ]

Any thoughts about what I have done? More to the point, have I overlooked any fundamental flaws in what I've done?

Kind Regards, John

 

[robinbanks]

However, unless I'm missing some better configuration, for the lid to be able to open by "just over 180° " would require the hinge to open "just over 270" (since 90° of the hinge movement is already 'used up' when the lid is closed

If the lid opens through 190 degrees then the hinge opens through 190 degrees. The whole exercise is about arranging things so that there is no "used up" range and the range of movement of the hinge is matched to the range of movement of the lid

Create the triangular block described in blue and attach the hinge to the green face such that when the lid is open the hinge looks like the black rendering (I.e.the hinge is closed). The range of movement of the hinge and lid are now matched.

When the lid is as open as can be the hinge is closed as can be and vice versa

Lid closed, hinge open, same colour scheme:

have I overlooked any fundamental flaws in what I've done?

Resistance to corrosion? When you said steel, are they stainless?

 

[JohnW2]

If the lid opens through 190 degrees then the hinge opens through 190 degrees. The whole exercise is about arranging things so that there is no "used up" range

Yes, but as I explained, if one takes your 'angle strip+butt hinge' approach, then, unless one attached the hinge to the 'edge' of the lid (which would be very iffy), then there would inevitably be 90° (of the hinges total travel) "used up" even when the lid were closed - unless, that is, you have perhaps thought of a way of doing it that I have overlooked?

Kind Regards, John

 

[robinbanks]

I think you're misunderstanding. See the edits to the post above

 

[JohnW2]

If the lid opens through 190 degrees then the hinge opens through 190 degrees.

Yes, obviously.

The whole exercise is about arranging things so that there is no "used up" range and the range of movement of the hinge is matched to the range of movement of the lid.

Indeed but, as I said, in terms of how I had interpreted (seemingly wrongly) your previous suggestion of the "angled strip + butt hinge" approach, I could not think of a way of avoiding that "used up" part of the range - I thought you were talking about a bit of standard 90° angle, with one (vertical) face attached to the frame and the other (horizontal) face attached to one leaf of the butt hinge - which would then be 90° open even when the lid was closed. However ....

Create the triangular block described in blue and attach the hinge to the green face such that when the lid is open the hinge looks like the black rendering. The range of movement of the hinge and lid are now matched. When the lid is as open as can be the hinge is closed as can be and vice versa

... yes, with such a situation 'created', I agree it would work, without any "used-up" range - and that was a sort of approach I had not considered.

Anyway, what about the Plan D/Z which I recently presented - do you see any major problems with that?

Resistance to corrosion? When you said steel, are they stainless?

Nope, as I said, I initially thought it was solid brass, but beneath the brass coat is non-stainless steel, which would obviously need some protection. Having said that, I know for sure that the (very non-stainless steel!) hinge which has only very recently failed has been there for at least 50 years, and quite possibly for the whole 135 years of the house'existence - so I strongly suspect that even a non-proptected non-stainless steel one would probably last longer than me

Kind Regards, John

 

[JohnW2]

I think you're misunderstanding. See the edits to the post above

As you will realise, I hadn't seen those edits (which weren't then there) when I replied - but I have now seen them, and have just replied

Kind Regards, John

 

[robinbanks]

Anyway, what about the Plan D/Z which I recently presented - do you see any major problems with that?

I think it works fine; main concern is that the hinge pins don't corrode to become stiff/seized meaning that opening the lid will place exceptional load (a levering force) on the fixings. Well made internal hinges have close tolerances on the pin, so they don't wobble/rattle, whereas the likes of gate hinges are usually incredibly loose.

It doesn't hence take much for an internal door hinge to rust up and seize (especially if it is seldom opened), whereas a gate hinge can be rusted to buggery but still swings ok

To this end it may well be that making the hinge more loose (open the loops a bit) will be beneficial..

 

[JohnW2]

I think it works fine; .....

Thanks. I'm pleased to hear that you don't think that there is anything fundamentally wrong (wouldn't be the first time ) with that approach. However, I wonder if you feel that either of the approaches is in some way 'superior' and/or without as many potential problems?

main concern is that the hinge pins don't corrode to become stiff/seized meaning that opening the lid will place exceptional load (a levering force) on the fixings. Well made internal hinges have close tolerances on the pin, so they don't wobble/rattle, whereas the likes of gate hinges are usually incredibly loose. It doesn't hence take much for an internal door hinge to rust up and seize (especially if it is seldom opened), whereas a gate hinge can be rusted to buggery but still swings ok

Yes, all valid points, especially in my case since not only is the hinge relatively 'exposed to the elements' but the hatch is only very occasionally opened. However, this issue presumably applies to any hinges used in any configuration.

To this end it may well be that making the hinge more loose (open the loops a bit) will be beneficial..

It may be that I'm benefitting from the fact that the hinges I found here (which I presume are 'electrobrass') may have been relatively 'cheap and nasty' (I've had them for years, and can't remember where they came from or why I bought them!) since, unlike standard butt hinges (even the cheapest ones), they have a significant amount of 'wobble', even though they have never been used.

The other option (for 'my approach') would presumably be to get and use stainless steel parliament hinges, if I could find one of an appropriate shape and size (it was purely fortuitous that the ones I had were ';just about right'!) - there are certainly a good few around. My only uncertainty is to whether SS might be even more difficult to bend (as I said, what I have, presumably mild steel' was difficult enough!) - do you have any idea about that (I don't recall ever trying to bend SS!)?

Thanks for your continuing valuable input. A 'new pair of eyes' so often sees things that one has not seen oneself, despite a long period of 'looking'

Kind Regards, John

 

[robinbanks]

My only uncertainty is to whether SS might be even more difficult to bend

I believe it depends, to some extent, on the grade as to how malleable it is but I expect common stainless hinges would be a grade that bends relatively easily (my internal hinges are stainless and I've bent some just by screwing them in)

That said, if you use a triangular mount you don't need to bend them, so it's always possible to change tactic

I think in essence both approaches are approximately equal; it would take around the same amount of time to bend a hinge as rip a triangle through my table saw/circ saw so neither is particularly more arduous an approach

If your lid is particularly heavy, you might want to consider moving the bend away from the screw fixing holes some; the closer you put it the more "powerful a crowbar" you create, leverage-wise, for exerting pull-out force on the screws, which could work the hinge loose

Also worth noting, use the same metal for fixings as the hinges are made of if you can. Using dissimilar metals in general promotes corrosion between the two in the presence of water (galvanic corrosion)

 

[JohnW2]

I believe it depends, to some extent, on the grade as to how malleable it is but I expect common stainless hinges would be a grade that bends relatively easily (my internal hinges are stainless and I've bent some just by screwing them in)

Thanks. I was very surprised by how difficult it was to bend my (I assume mild steel) hinge. It's only about 2.2 mm thick, but when I put it in a vice and started hitting it with a hammer, it was not even slightly interested, even when I hit it as hard as I could - and it was only when I heated to it "dull red" temp that I was able to bend it at all. I suppose it theoretically now needs tempering, but it certainly does not show any inclination to 'unbend'!

That said, if you use a triangular mount you don't need to bend them, so it's always possible to change tactic I think in essence both approaches are approximately equal; it would take around the same amount of time to bend a hinge as rip a triangle through my table saw/circ saw so neither is particularly more arduous an approach

In that sense, your approach would probably be 'quicker', although that's a trivial consideration. It would probably only take about 30 secs to set up the table saw, then 2 seconds to do the sawing, but my bending took at least 10-15 minutes!

I have to say that, although I couldn't initially work out why, my 'intuition' was telling me that there was something 'less than ideal' about your approach (in comparison with mine), but I think I now realise what was concerning my intuition! With your 'wooden triangle' approach, the 'fixed' leaf of the hinge is angled somewhat 'downwards'. That means that when the lid is in it's 'upright' position (90° open), the entire weight of the lid is trying, to some extent, to rip out the screws attaching that fixed leaf (another reason for using nuts/bolts!) - whereas with my approach, in that situation all of the forces trying to 'rip things out' are perpendicular to the screws/bolts.

'If your lid is particularly heavy, you might want to consider moving the bend away from the screw fixing holes some; the closer you put it the more "powerful a crowbar" you create, leverage-wise, for exerting pull-out force on the screws, which could work the hinge loose

Interesting thought, to which I'll give some consideration - although there's not much scope (at least, with that particular hinge) to move the bend very far.

Also worth noting, use the same metal for fixings as the hinges are made of if you can. Using dissimilar metals in general promotes corrosion between the two in the presence of water (galvanic corrosion)

Indeed- that consideration is always there, particularly when things are in 'exposed' locations.

I would almost certainly think of using stainless steel screws or bolts, and I was about to write that I didn't imagine that would be much of an issue with a (presumably) mild steel hinges. However, I made the mistake of 'having a quick check' and, in terms of what I have found so far, it seems that the electrochemical potential of something called "Steels" is much higher (750 mV or so higher) than that of SS, which would suggest that the mild steel would be at significant risk of 'attack'. Zinc, chromium and cadmium (the common 'coatings' of steel fasteners) are much closer to 'steels' in terms of ec-potential. However, I may be misunderstanding some of this.

Kind Regards, John

 

[robinbanks]

That means that when the lid is in it's 'upright' position (90° open), the entire weight of the lid is trying, to some extent, to rip out the screws attaching that fixed leaf (another reason for using nuts/bolts!) - whereas with my approach, in that situation all of the forces trying to 'rip things out' are perpendicular to the screws/bolts.

I don't think you're thinking about things correctly there. I assert that it's worse for your hinge setup, as your hinge is essentially a pry bar pulling the screws out by that perpendicular force, whereas mine is an angle, meaning the force splits into a parallel and perpendicular component

In essence if the hinge were a vertical line, all the downforce would be shear, if the hinge were a perfect L all the downforce would be pullout, but being an angle it is split between shear and pullout.

Yours is all pullout

I'm not particularly concerned that either approach will result in a failure, so long as the bend in yours isn't too close to the screw holes. The closer it gets, the more the hinge is a force multiplier because it's moving the fulcrum closer to the fixings. You'd likely find that if the bend were right at the screw holes there would be nearly nothing you could do to stop the hinge rocking or working loose; the more of a landing zone you have beneath the screw heads the better the screws can hold the hinge steady

 

[martygturner]

Add a couple of gas struts and you would not need to go flat to the roof.

 

[JohnW2]

I don't think you're thinking about things correctly there........... Yours is all pullout ..... I'm not particularly concerned that either approach will result in a failure, so long as the bend in yours isn't too close to the screw holes. The closer it gets, the more the hinge is a force multiplier because it's moving the fulcrum closer to the fixings. You'd likely find that if the bend were right at the screw holes there would be nearly nothing you could do to stop the hinge rocking or working loose; the more of a landing zone you have beneath the screw heads the better the screws can hold the hinge steady

OK. I need to think a bit more about this, but a few immediate observations :

1... As I said, and as is apparent from the photos, with the hinges I've been using, there is little scope to appreciably increase the distance from bend to 'screw holes'.
2... Whilst the 'pulling out" (or just 'loosening"), could well be an issue with screws, with nuts/bolts (and a metal plate on 'the other side') through the ~2" thick side of the frame, I can't see that happening - so, if anything 'happened', it would presumably be bending (or, ultimately, possibly fracture) of the hinge?
3... If I understand correctly, the issue you are really highlighting is the size of the hinge - in particular, the distance between the hinge's pin and it's fixing ('screw') holes - and that would seem to apply, conceptually, to both our methods (being slightly less of an issue with your approach, since your 'triangle' means that the fixed leaf of your hinge is 'not quite vertical'). Are you therefore suggesting that, with my approach, I should perhaps be using different ('bigger') hinge (maybe a cut-down version of some sort of 'Tee' hinge?) that would/could have some fixing holes much further from the hinge pin - something like I show in the piccie below?

Kind Regards, John