Dowelling Jig - advice please

[Deems]

I am thinking of buying a dowelling jig for a project ( boot storage box) that will involve 90 degree corner joints and internal shelves. I have a biscuit jointer but was wondering whether a dowelling joint will make stronger joints?

The main issue here is that the person who wants the box will wish sit on it whilst changing boots. (I guess it might be feasible to strengthen the top of the box with a thickish strop of wood fixed underneath the top and running the length of the top, but am toying with the idea of using dowels for greater strength)

What experience do others have of dowelling jigs? I need 100% accuracy and think I will struggle with the cheaper hand held devices. I’ve looked online at the Jessem (the expensive one, costs about £150 from Peter Sefton’s site) and the Milescraft Joint Pro( costs about £100 from Rutlands) Both look good but are not cheap, so I want to know if anyone else has any experience of either of these tools?

Thanks in anticipation

 

[AndyT]

The best way to make a strong box is to dovetail the corners.

This sounds like a fairly utilitarian project, so it could be an ideal chance to have a go. The joints don't have to be perfect to be incredibly strong.

And assuming you already have a saw and a chisel, you don't need to spend a lot of money on new tools.

 

[That would work]

No, dowels will not be stronger for that, in fact biscuits can be better because they swell due to using water based adhesive. Given this I definately wouldn't be thinking of buying a dowelling jig... if you use dowels it's pretty easy to make your own jig according to what you are doing.

 

[maznaz]

You can use the joint genie and some 10mm dowels for a super strong and accurate joint. You can look online at the merits of various joint types by googling for the dowelmax joint tests.

 

[TheTiddles]

I think you have the wrong thinking, or, well, very common thinking that’s not out of place, but wrong from a design perspective.

If you are having to make a really strong joint to take a load, you’ve probably designed it wrong as the joints are usually much weaker than the parent material, for instance, if you had two vertical sides and then a top between them like a shelf in a bookcase, to take the load of a person sitting on it you’d need a chuffing strong joint as it would be in bending, shear and tension, so dovetails would be a good choice for this bad situation.

If the same piece the person sat on was across the top of both verticals like a lid, a couple of screws through the top into the sides would suffice as the joint is substantially in compression with a bit of shear from the top bending. If you then put some rails under the top to minimise the bending, you wouldn’t even need the screws, see what I mean?

As for 100% accuracy, I wish you well. Good design doesn’t need super accuracy or precision, if you plan around it, you should be able to avoid the need in many cases and that’s partly what I like in design, something that looks perfect and sharp but has actually got a design that accommodated errors all the way through so in the end the result looks flawless.

Aidan

 

[Trainee neophyte]

I made something similar last year and used loose tenons (big dowels, in other words). The strength is all in having the lid sit on top of the sides, as Mr Tiddles explains so much more eruditely than I could.

If I was doing it again, I would be attempting my first dovetails, because the box I made (more of a bench, but definitely a box) is 2 metres long, and as it lives outside the amount of movement in the wood is impressive. Making it out of scaffold boards hasn't helped, but it is holding together so far. Lots of shearing forces across the plane of the joint as it expands and contracts - dowels might be a bit on the small side. I don't have any festool kit, but made my own floating tenons and used a router for the mortises - (I had only just learned about loose tenons, so thought I would have a bash).

 

[Eric The Viking]

I have one large toolchest, that mostly holds my plane collection (in the house, in the winter). But it first had a hard life as a cable chest* for the BBC, and I got it when it was "retired" (thrown out).

So the box was strong but utilitarian - good quality ply - and the volume was about what I wanted, but it needed trays. I got as far as making a whole one, way back in the early 1980s. Recently I had a careful look at the tray, as I couldn't work out how it had survived - full of heavy tools., thumped in and out of the chest regularly, etc.

To my surprise (for I had quite forgotten), I found that I had done dovetails. They look completely horrible - nothing fits, they aren't even trimmed off very neatly, and being softwood, they are splintery and, well, just nasty. But they have survived: they aren't loose, and there is still a lot of weight on that tray.

So my vote is for dovetails too! ;-)

E.

*It held short but heavy interconnecting cables for outside broadcast equipment, so got lugged around all over the place. It's a delightful batttleship grey, too, probably in heavy lead paint!

 

[Spectric]

Hi

If you want dowels then the Dowelmax is really accurate and easy to use and will be stronger than biscuits which are great for alignment but not strength. You could also look at lock mitre bits for the router, both Wealdon tools and Infinity sell these. If it was something fancy then Dovetails do look pretty but can be time consuming unless you have a jig or Woodrat.