loose tongue & groove question

[thetyreman]

I've been thinking about using a tongue in two grooves as opposed to a tongue and groove, for the back of a cabinet, partly because it's much easier and less time consuming using hand tools.

do you glue up the tongue? and should you leave a gap on each side? I've not seen much information about these methods because from what I've seen the tongue and groove joint took over, I'm curious to know more about it,

regards,

Tyreman.

 

[Jacob]

Backs of trad cabinets often crudely finished with low grade material sometimes not planed. Saves time and money, never seen anyway.
Boards often plain butted, t&g, half lapped with rebates etc. Your loose tongue would be fine but you'd have to fix it at some point so it doesn't drop out at the bottom. Few dabs of glue in the slot on one side? but not both - you need the movement in case of shrinkage

 

[Argus]

To my reasoning, once the thing is assembled it's six of one...

If you are trying to replicate T&G boarding without a T&G plane, then secure the loose tongue spline with a few dobs of glue, but leave the junction between two boards free where the spline sits in the next board's groove, allowing about 2% space for expansion if it's soft wood that's reasonably dry. But there's room for a little experimentation. Don't raunch them all up tight! Doing it this way is basically the same as dedicated T&G.
(I used to put a cut-up business card or a postcard, edge-on between the meeting edge of the two to get a space). It's best, in my opinion, to leave all the boards free to 'float' all round in a retaining groove.

It is possible to still get wooden T&G planes, either come-and-go single planes, dedicated pairs from the same maker or a metal swivel-base type.... but I'm not sure how much you're prepared to spend, so if it's just a few boards and you have a plough plane, then a spline joint is the way to go. Obviously (sorry to bring it up!) always work from your face side to get a level surface when it is all joined up.

Good luck!

 

[Andy Kev.]

I'm surprised that you say it's time consuming using hand tools. I've made up T & G a number of times using the appropriate blades on the Veritas small plough plane and it's a relatively quick and painless job. (I realise that isn't much help if you haven't got that plane.)

 

[Argus]

Thinking about thetyreman's question a bit further, a thought occurs.

If you make your own T&G boards by grooving both sides of a board with a plough-plane, and spot-gluing a spline into one of the grooves, you'll want a good sliding (not too tight) fit at this point.

Initially, the spline will be sized to give a good fit on the glued section. The next step is to marry the spline edge into the next board and to do this the exposed spline needs to be a slightly slack sliding fit into the groove - this is to allow the union to expand-shrink and to move over time.

To achieve this, it will be necessary to either take some shavings off one side of the exposed spline with a small rebate or shoulder plane or a shaving or two off the side of the ploughed groove. (obviously working on the same side each time).

So, the job gets a little more complex....... but not overly so.

Good luck.

 

[Woody2Shoes]

A simpler profile - which needs no glue at all - would simply be half lap (with a simple rebate on diametrically opposite corners) - with or without a decorative bead. e.g. something like this, but with a suitable gap between boards: Profiled Cladding | Buy Air Dried Oak Half Lap Cladding Online | UK Sleepers

 

[Jacob]

A simpler profile - which needs no glue at all - would simply be half lap (with a simple rebate on diametrically opposite corners) - with or without a decorative bead. e.g. something like this, but with a suitable gap between boards: Profiled Cladding | Buy Air Dried Oak Half Lap Cladding Online | UK Sleepers

Seen quite often on backs of old furniture, even good quality stuff. Usually thin boards finishing 10mm ish sometimes less.

 

[Argus]

Seen quite often on backs of old furniture, even good quality stuff. Usually thin boards finishing 10mm ish sometimes less.

Agreed - half-laps are well established, simple to do, often used...... done it myself a lot of times.

I suppose that for some reason, (aesthetics, perhaps?) the OP wanted T&G or the T&G effect................. we don't know the pysical size of the piece.
Maybe he'll tell us.

.

 

[Jacob]

I suppose it's not a joint you'd expect until you have spent time pulling apart enough bits of old furniture. It's a crude joint but easy and quite good enough for the backs, out of sight.
Older stuff can be amazingly rough - hacked with adzes, axes, - scrub planes if you are lucky. Owners of a french piece I saw thought the back had been scratched by bears! It was in a wild part of the country though.

 

[Woody2Shoes]

Agreed - half-laps are well established, simple to do, often used...... done it myself a lot of times.

I suppose that for some reason, (aesthetics, perhaps?) the OP wanted T&G or the T&G effect................. we don't know the pysical size of the piece.
Maybe he'll tell us.

.

You can use the half-lap option on any size of board. You can also make it look indistinguishable from t and g with suitable mouldings. I simulated t&gv on my kitchen cabinets using this technique, with a simple 45 degree bevel added to both sides.