Limits To Figure 8 Tabletop Fasteners?

[Mark R Webster]

I am currently building an extending dining table with two main halves 3' x 2' and 2 leaves 3'x 12". I was considering using Figure 8 tabletop fasteners to attach the main halves to the apron. I was wondering if the 24" of end grain (main panels) was too much distance for this type of fastener. I am aware of trimming the corners of each mortice to allow for the fasteners to swing. I noticed on another site that someone felt that 18" was the max for these. Any thoughts? Thanks

[Andrew Pitonyak]

replying so that I can subscribe...

Had not occurred to me that there might be limits. Why are there limits? Is it because the wood movement is too great?

I purchased some (if I remember correctly), but have not used them. For what I have built, I was always able to screw the top to the base with no problem.

As for 18", I think that I have seen these on "kitchen tables", pretty sure those were well over 18". Am I misunderstanding the question?

[Mark R Webster]

No you're not misunderstanding the question. I think the 18" was mentioned in reference to the wood movement being too great for the pivot limits of the fasteners. I have not used the figure 8s and have not checked the charts for how much cherry could move over the 2' panels. I am just asking for the opinions of those who have. :)
This is where I saw the 18 inch comment, note under the "Figure-8 fasteners" paragraph: http://www.woodcraftmagazine.com/posts.php?id=212

[Andy Giddings]

Mark, as always it depends. If your lumber is acclimatized to your workshop and your shop is similar to the eventual location of the piece, I wouldn't have thought you are going to see extreme movement unless the environment changes significantly. I've used figure 8's for years and never had an issue with larger pieces than the link mentions.

You could try figure 8's, check them every now and again to see if there is an issue then take action. It's not like they are a permanently glued joint

[Mark R Webster]

Great! Thanks Andy :)

[Hoang N Nguyen]

I use these http://www.rockler.com/table-top-fasteners and cut the slot with a biscuit cutter. It allows me about 2" of movement. If you make the slot continuous, there's no limit to how much it can move.

[Mark R Webster]

Hi Hoang thanks for the input!!