Lock and latch for a thin (1") oak framed door on a boat?

[Peterthegardener]

I am restoring an old river boat. The previous owner fitted a standard 2" thick domestic door to the main cabin, but there is not enough room to open a 24" door because of a floor step so the door is divided into 2 parts which means I get 20" usable opening when both leaves are open. I am hoping to replace both parts with a single leaf 21" wide and 1" thick and so gain valuable layout space on board. I have some oak which is chunky enough to plane/thickness to 1" x 3.5" from this I plan to make a door from 2 stiles and a top, bottom and middle rail all morticed together and pegged. I intend to fit panels of 1/2" exterior plywood into the top and bottom spaces.

This sounds to me as though it will be sturdy enough, but perhaps more the experienced will tell me otherwise?

What I am unsure about is how to lock the door. It will open outwards. Although I could perhaps cut another mortice and fit a standard lock it would leave me very little material on either side of the lock case. Do I fit cover plates over this to strengthen the door? Alternatively I could fit some sort of rim lock, but most of these are designed for inwards opening and many of them seem to specify thicker doors as well. There are some specialist locks designed to fit to a single sheet of plywood for marine use, but these all seem to cost over £100 and I'm not sure that they would work with my 'thicker' door?

What I am aiming for is moderate security for no more than about £50...... is that possible with this set up?

 

[oakfield]

How about fitting a rim dead lock. This could be fitted inside an outwards opening door and used for the security aspect. You would then need some sort of latch/catch for everyday use.

 

[jdeacon]

For rim latch locks, you could consider the Yale 84/85 (small 40mm backsets) or 88/89 (normal 60mm backsets) series. They don't ask much of the door's fabric as they are in large part held in place by bolts that go through the locks back plate and grab the cylinder; the lock then fixes to its backplate via a couple of hooks and a couple of modest machine screws. (And there are a couple of small wood screws for the plate to help prevent a twist attack but are not a major part of keeping the lock in place.)

And they have reversible latch bolts for outward opening doors. The 84 and 88 don't double lock. The 85 and 89 double lock; meaning that turning the key "the wrong way" locks the bolt (and the inside handle as well, and thus are a poor choice if you might not spot that someone is still inside). Also available to go with them are long strike plates which can help the bolt get to the keep without knackering any wood it has to get past.

 

[Peterthegardener]

Thank you both for these suggestions.

Jdeacon, my uncertainty is that Yale specify a minimum door thickness of 38mm for their 1109 cylinder. Admittedly this looks to be overkill, but the cylinder does measure 29mm from the back face of the front, so I am still not going to fit this in a 25mm door am I?

Can I get round this (sic) with a thick brass escutcheon? Or do I need to attach a bit more oak about 1/2" thick?

Please keep the suggestions coming

 

[jdeacon]

Yes, a nice thick brass escutcheon, or "rose", would go a long way towards taking up the excess. The modern 1109 rose is a bit of pressed uselessness, but older ones were solid, and really old ones were pretty thick. Failing lucking upon an antique solid rose, there's always a cylinder pull if aesthetics permit; or a pull and a rose.

I've just measured up an 1109 with the supplied pressed rose in an 88 (which has a teensy bit more room than an 89) and an inch would just suffice. With a pull or a thick rose you might even have a sixteenth to spare. (The extra space comes from the 2mm that the 88/89 back plate adds.)

 

[Ed Bray]

Why not use a couple of stainless steel (316 grade) locking hasp/clasps. I had a couple on my boat for security and they worked well. If a thief really wants to get in, they will, you really are just trying to keep out the opportunists, this is especially so with portable battery kit like reciprocating saws and similar which someone who really wants to get in will use.