# Sliding dovetail and Wood movement



## v8extra (Aug 6, 2010)

Hello hello hello beloved friends and wood addicts!

I am planning to build a nice INTERIOR coffee table out of IPE hardwood flooring (5" x 3/4" planks).

So for that table, in order to connect all the planks together to make the top, I am planning to make sliding dovetails.

My first question is (dovetail form):

What do you think about the size of the tail of that dovetail considering the wood type and so forth. I am planing to make the tail part 1/4" long, the short end of the tail will also be 1/4" wide and the widest part will be 3/8" (the tails are 14 degree). Please consider that I am linking 3/4" planks together and that I dont want to use the preexisting groove in the flooring planks.

Does that make sense.

My second question is (implication of making a sliding dovetail with two wood pieces with perpendicular grain orientations):

I am planning to create a sliding dovetail were the female part (the table leg) has grain that are perpendicular to the male part (table top), if the top expand, the leg grain will not. Do that pose a significant risk? I hope not, the reason been that my actual tail will be quite small (3/8 on the widest part of the tail).

Would you suggest me to keep that sliding dovetail tight or not?

My third question is :

What are the dimension at which I should really start considering wood movement considering that I will be working with IPE.

I have a Sketchup plan that I can provide if needed (sorry for my english)

Thanks a lot!

Sébastien


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## beckerswoodworks (Dec 26, 2009)

I'm not sure I understand the 1st question but if I do then why not use the preexisting grooves? I don't think you'll gain much of anything by using dovetails.

If you join wood that's perpendicular then there is always risk of that the peices will expand differently but if one piece, like the table leg, is only a couple of inches then you shouldn't have a problem, it won't expand enough.

The sketchup plan would help understand exactly what you're doing.


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## v8extra (Aug 6, 2010)

Can I send you directly the sketch…

The reason why I need to cut the planks is first because they are too wide, secondly the side corner of the planks have been slightly cut and I want a flush top, and third I guess that by using sliding dove tail they will stay well together and will not split apart.

S"


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## a1Jim (Aug 9, 2008)

It would be good if you can post your drawings. From your description It sounds like your putting the female part on the wrong piece.
As to having a cross grain situation that's one of the reasons why you should use a sliding dovetail. just don't glue it together except for a small section usually on the front of the case so it can have wood movement towards the back.
as to fit. it should be a fit that's not loose but can slide together without pounding it together.


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