Dowels

[sxlalan]

All

As my first foray into woodworking I am trying to make a cot for my soon-to-arrive daughter. This is not intended to be a family heirloom etc, just something fairly simple but enjoyable to make. I’ve based the design on a cot in a local nursery store that basically consists of a pine frame (painted) with a natural beech surround at the top. The ends of the cot are a simple panel system like a large kitchen cupboard door, i.e. 2 vertical pine boards, 2 horizontal pine boards and a panel of ply in between. My question is, what is the best way for a NOVICE woodworker to join the horizontal and vertical boards together (stiles and rails?)? Would dowels be strong enough or am I better to bite-the-bullet and give mortise and tennon a go? I have bought a router (T5) and made a table for it so a M&T should be theoretically doable.

If I go for dowels, how long should the dowels be and how thick? The pine is 60mm wide by 21mm thick and will be joined on its narrow (21mm) edge. Also, is the type of dowel important, i.e. would the common beech dowel do or should I try and find pine?

The same question applies for M&T. If that is the preferred option, how deep should the mortise be and how thick the tennon?

Finally, on a different tack, when inserting the ply panel, should I cut the grooves that it will sit in so that it has a bit of room to move or will a snug fit (both depth and width) be OK?

Thanks very much

Alan

 

[RogerS]

Alan, as a relative newcomer to woodworking as well (I know..I post too much when I should be whittling!) what I've learned so far is..

that you'll get much, much more satisfaction out of making the joints M&T...dowelling to me seems a bit, well, not exactly 'true' woodworking. But make a few trial M&T's first using your table.

M&T dimensions..the books I've read say make the tenon 1/3 the width of the rail/stile...but when using the 'rat to do them, the pragmatic approach is to use a router cutter that is close to this figure ...as it means the mortice can be done in one pass...

Mortice depth I would guess at around 30mm maybe...but there are folks out there who have more experience and knowledge than me for this kind of info. Any deeper then you may be limited with the available depth of cut with your router/table combo.

If you go down the dowel route then my gut feel is it doesn't matter what material...

Re -width/depth of groove...again, based on my limited experience/reading....plywood is more stable than 'natural wood' and so I would be inclined to give it some 'breathing space'.

And apologies to grandma but if you're going to paint it then I think you need 'child friendly' paint.

And if you've got a digital camera then take some WIP shots to show us!

 

[Steve Maskery]

Alan,
Dowels are not a good solution. They have very little face grain contact and are difficult to get accurate without a relatively expensive drill jig.

60mm is a bit narrow for using biscuits, so for a beginner I would unhesitatingly recommend LOOSE TENONS. Use an 8mm cutter for 21mm stock. The ends of the rails can be shot cleanly before jointing, so you dont have to worry about getting the shoulders the same on both sides. Loos tenons are just as strong as M&T and are much easier to get right.

There is a mortising jig on my website which fits over the jaws of my vice, and I use it all the time. Have a look at that (doesn't work with Firefox at the mo - sorry F-users).

Best of luck with it, lets see some pics afterwards!
Cheers Steve

 

[sxlalan]

Thanks for the replies gents! If I go down the loose tenon 'route', am I still looking at a depth of about 30mm? This may be deeper than I can cut with my current setup so I may be looking for a new bit. How wide should the tenons be in 60mm, about 40mm (ie 8mm thick, 40 mm wide and 60mm or so long - 30 mm into each mortise)?

Steve, sorry to be dim but what do you mean by

The ends of the rails can be shot cleanly before jointing, so you dont have to worry about getting the shoulders the same on both sides.

Cheers (and I'll start snaping a few pics)

Alan

 

[Steve Maskery]

Alan
1. 30mm long into each component should do fine, assuming the joints themselves are fitting properly.

2. One of the difficulties in cutting "proper" tenons by hand is making sure the shoulders are the same all the way round. At least it is for me, When you glue up you find that one side closes before the other, and you are left with a gap.

With a loos tenon, you can make sure the two parts mate cleanly all the way round before you glue up. The ends of the rail can be shot with a plane on a shooting board to get them square, and you are half-way there.

Cheers
Steve

 

[RogerS]

Mmmm....loose tenons aka square dowels :wink:

I agree with Steve..if...you are making them for the first time by hand but Alan is keen to use his router and table, I think.

I was faced with a similar question when I made my first piece of furniture. I will never forget how chuffed I felt when the tenons that I'd made using my router table slotted in perfectly to the mortices...with no gaps.

I recently ended up using loose tenons on my garden gate...simply because I had to ... as I'd messed up the dimensions when I bought the timber to make the stiles/rails. I got nowhere near the same amount of satisfaction.

Cheers

Roger

 

[ydb1md]

If you're talking joining the verticals and horizontals on the headboard and footboard, you could use M&T or dowels. Personally, I'd also consider a bridle or a half lap joint. They're a little easier to make and as as strong (or stronger in this instance) than the M&T joint -- definitely stronger than dowels.

If you're talking about the joint between the bed rails and the head/foot boards, definitely use some bed bolts with some loose dowels or a M&T joint. bed bolts: http://www.leevalley.com/hardware/page.aspx?c=2&p=40445&cat=3,40842,41269&ap=1

 

[sxlalan]

Yes it's the headboard/footboard vertical/horizontals that I'm looking at. I had already decided on bolts for the headboard to rail joints but was having trouble finding any so thanks for the link!

Thanks for the support and suggestions all, I think I will have a play with both loose and fixed tenons before making a final choice!

One final question, what sort of depth should the groove for the central panel be (i.e. the groove in the rails/stiles that the panel slots in to)?

Thanks

Alan

 

[ydb1md]

One final question, what sort of depth should the groove for the central panel be (i.e. the groove in the rails/stiles that the panel slots in to)?

I usually make mine 3/8ths deep but they can be anywhere from 1/4 to 3/8ths.

 

[devonwoody]

to sxlalan

The vertical bars of a cot I myself would not want to be of a rectangular dimension..

Round bars are in my opinion safer, less likely to have a sharp edge or a sharp edge to appear with wear if this should happen.

This is my experience of 45 years ago. You will be surprised at the things little girls get upto as they grow older!!! Take seriously and facetiously.

 

[sxlalan]

thanks again.

The verical bars along the sides of the cot will be round. All other timbers will be passed along a roundover bit to remove any sharp edges!

I suspect I have a lot to learn re little girls in the next year or two!!

Alan