Thread: dovetail vs biscuit joins

Is this a real question?

If you glue, biscuit, add corner blocks, and screws! there would be no timber left?

Strength would be about the same. but for appearance...

Originally Posted by Lumber Bunker

Is this a real question?
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no - this is a spurious question posted to display my ignorance

I'd back the dovetail. It has its own intrinsic mechanical strength because of its shape. Also, a biscuited joint will always involve either one end grain or two mitre grain, which are not terribly strong by themselves. biscuits will make them stronger, and they are probably strong enough for most practical purposes, but I'd back the dovetails every time.

Originally Posted by old_picker

no - this is a spurious question posted to display my ignorance

Sorry old picker, thought it might be a troll. As most people on the forum here will back dovetails everyday.
Seeing your number of posts, I thought that by now you would've read countless dovetail threads...

Dovetails would be the very strong (more than strong enough) for the purposes of a draw. (i.e force applied in only one plane.)
They are not great at resisting the diagonal forces that they can get if you drop them on a corner. Are biscuits stronger I would think so but again more than strong enough for a draw.

The glued/screwed corner block probably be the strongest?

i have built many speaker cabs using dovetails
i see others building them with biscuit joinery

i have two new projects to build and am toying with the idea of avoiding the fiddley DT jig setup / and the inevitable tidy up after glueup

biscuits seem a little more straight forward but at the end of the job bicuits and cleats is probably more work and a trickier glue up - i don't want to drive screws or brads externally

Fine Wood Working have done a number of articles comparing biscuits to other joining systems. Have a look through their site and you should find it. IIRC biscuits were initially used for lining up components not for strengthening joints.

Picker, the screws go from the inside

Kreg (pocket hole) screw would be my choice over buscuits. For a speaker cabinet you can position them inside as said and if you really care you can plug them. Faster than biscuits cheaper to buy the tool. I'm not sure which is quicker per joint but with the pocket screw you make a joint then move right on, no waiting for glue to dry.

If people are going to see the dovetails they are truely pretty and you can get as fancy as you want with them. If you want a quick easy joint to hold two pieces of timber together the pocket screw will be strong enough.

BTW Timbecon have theirs on sale this week but the kreg junior is good value and carbatec are cheap for the screws, assuming they are in stock. $60 for the jig, an f clamp, a pistol drill, screws are $6/100 for the normal ones about $8 for the blue outdoor ones.

2c.

If you have a router table, dovetails are dead easy to do with a Gifkins dovetail jig.

Such a jig will cost around $300 but they are terrific.

I used such jig to make this little stool out of 19 mm thick pine last week. The top corners are dovetailed and are very strong



..Click for large view - Uploaded with Skitch



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nice looking job there mate
i went through the gifkins vs liegh jig process a few years ago and opted ffor the leigh
i found it to be pretty good but tearout can be a problem and setup is a bit fiddly
makes it easy for a novice like me to cut reasonable DT's - there is a fair deal of skill in using it properly

never thought much more about the gifkins setup agter getting the leigh
how do you find it??

Originally Posted by old_picker

never thought much more about the gifkins setup agter getting the leigh
how do you find it??

If you already have a Leigh, there would be little point in getting a Gifkins but I find the Gifkins to be an absolute delight in using for general box making. There is nothing fancy or very adjustable in the jigs but they are so very simple to use.


I have only recently upgraded mine with an extra template to handle the larger thickness of wood such as the 19 mm stuff. I have previously made lots of boxes in 10 mm and 12 mm thickness materials and it is pretty well idiot proof for that sort of work.


Click for large view - Uploaded with Skitch


So much so that I just automatically get it out of its box at any time that I think of making any sort of box like structure or right angled joint. This is especially so where accuracy of the right angle and strength of the joint is required such as in workshop jigs. eg the pine box structure that forms the basic platform of the mortising jig shown below. In that case, I have strengthened the basic box structure with the orthogonally placed merbau box structure (also dovetailed) which also serves as carrying handles for the jig.


Click for large view - Uploaded with Skitch


Anyway, the point is that the dovetails are exceptionally easily and accurately cut with the Gifkins' jig. It is, of course, critical that the wood is cut accurately square prior to dovetailing but that would be the case for all dovetail jigs.


I occasionally also use it for plywood such as on putting sides on a bait board on my boat...


Click for large view - Uploaded with Skitch



I also have a biscuit cutter but it gets very little use. Mostly I use it for alignment of boards being edge glued for, say, a panel.



Obviously, I am a big fan of the Gifkins' jigs.


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mmm those joints look very good
thanks for your informative post
i am always after a simple easy approach and the gifkins setup does sound attractive
if i had more disposables would love to give it a burl
my jobs however are mostly 19mm with lengths of anything up up to 650mm 700mm
wondering whether the gifkins is right for that scale of work

The Gifkins can handle those lengths OK and longer with a bit of care. It is the widths that are its limitation.

The standard jig will do widths of up to 310 mm but they do have a new "Jumbo" jig that does widths to 480 mm.


However, if you have a Leigh, you already have a pretty good tool for the job.



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