Simple Dowelmax questions

[Brian Penning]

1. Basically, the more dowels one can fit in the joint the stronger the joint will be?

2. Using the longer 2" dowels makes a stronger joint than the 1½" dowels?

[J. Z. Guest]

1. Yes, unless you make the walls too thin in the process

2. Yes, just like making a longer tenon.

That said, I bought a couple hundred 2" dowels and discovered that they are too long for many applications. I recommend splitting your dowel order up between 1-1/2" (the standard size), and 2". If you get the 1/4" kit, get some 3/4" long 1/4" diameter dowels for use with 1/2" thick stock.

[Jim Lindsay]

1. Basically, the more dowels one can fit in the joint the stronger the joint will be?

2. Using the longer 2" dowels makes a stronger joint than the 1½" dowels?

Brian, the answer to question 1. is almost certainly - yes. With a 4 or 5 dowel installation on a 1" x 4" our test results indicated a joint failure at 890 and 910 lbs. per square inch respectively. Using fewer dowels would undoubtedly have reduced these failure pressures. With Dowelmax, I usually recommend 2 for a 1" x 2", 4 for a 1" x 4", 6 for a 1" x 6" etc. etc. Reducing to 9 for a 1" x 12".

In answer to question 2. The 2" dowels are stronger than the 1 1/2" dowels. I think there are only two ways a dowel joint can fail, by shear or dowel pull-out. In most cases, with a multiple dowel strength test, the wood failed horizontally with the grain and seldom did the dowels pull out.

I am quite sure that 1 1/2" dowels in a multiple application provide tremendous strength, suitable for most pieces of furniture. I would however use the 2" dowels (if possible) on a chair rail, a bed, or an outside door.

I am happy to try to answer any questions, so please feel free to ask away.

Jim Lindsay, Dowelmax

[J. Z. Guest]

From reading these posts, it seems that lots of folks who like Dowelmax also like Kreg Jigs.

Have you done any tests on DM strength vs. pocket screw joinery?

It seems to me that pocket screw joinery would be nearly as strong and in some situations, may have the advantage of bending the screws and having a slow joint failure rather than a single, snapping joint failure.

Pocket screws have their weaknesses, of course.

Thanks for your posts here, they are much appreciated. I like that Dowelmax is a "Ma 'n Pa Company" in which the owners still talk directly to their clients.