Figure 8's for table tops

[DavidF]

I watched David Marks make a nice table yesterday in cherry with a solid top with leaf inlay. My query is over his use of figure 8's to hold the top. A shot showed the fasteners fitted to the all the aprons - 2 on each long side and two on each short side. He then screwed the top to all of them. I have never used these things and may be missing something, but wouldn't the long side ones restrict the movement that the end ones allow by pivoting. Surely as the top expands or contracts then it would exert either a straight pull or push on the fasteners and they would stop the movement?

 

[DaveO]

In my experience there is a little longitudinal slop in the holes that will allow for movement, while still holding down tight. And I also think that you get a little wooble room from the figure 8's twisting. I prefer the "Z" clips myself because you can adjust the amount of movement that they will compensate for.
My $.02, Dave

 

[DavidF]

Looking at the pics, the screws that hold them seem to be in countersunk holes so certainly not a lot of movement and this table top looked like 20" wide so could expect to experience a fair bit of movement.

 

[Joe Scharle]

I find them a lot in old pieces and have used them myself. However, I haven't seen them locally in a long time. Lee Valley hardware catalog has them for one.

 

[McRabbet]

I could see them as being effective if they were oriented at 45 degrees to the apron to allow for movement -- And I would reverse the angle on the opposite side so the top would not skew if it moves. I agree with DaveO -- either Z-clips or their wooden equivalent moving in a slot are more forgiving.

Rob

 

[michaelgarner]

never have used them, anyone have a link showing them?

 

[cpowell]

Michael, here's a link. I also prefer z clips.

http://www.highlandwoodworking.com/index.asp?PageAction=VIEWPROD&ProdID=6801

Chuck

 

[michaelgarner]

thanks bro,,

 

[DavidF]

I could see them as being effective if they were oriented at 45 degrees to the apron to allow for movement -- And I would reverse the angle on the opposite side so the top would not skew if it moves. I agree with DaveO -- either Z-clips or their wooden equivalent moving in a slot are more forgiving.

Rob

I agree totally. This seems to be one of those cases where the thought was good, but the execution poor, unfortunately, there are no pics on the DIYNET.com showing the view in question, but all the fasteners were at right angles to the aprons.

 

[michaelgarner]

wish I could watch shows like that over here!! I will have to invest int TEVO or something when I get back. Be blessed

 

[DavidF]

wish I could watch shows like that over here!! I will have to invest int TEVO or something when I get back. Be blessed

TIVO Rocks!!! TV would be unbearable without it.

 

[michaelgarner]

LoL,,guess I should spell it rigth if im going to talk about it huh?,,lol

 

[Howard Acheson]

If that is what he did, then it is not correct. On the end pieces the movement is along the skirt and on the side pieces the movement is into and out of the skirt. Therefore, the side piece should be installed so then lay on top of the skirt--in slight depressions the depth of the thickness of the figure 8--when the top is in it's neutral position. To do this you need to install the side figure 8's first, move the tabletop so the figure 8's are parallel to the skirt and then install the end figure 8's.

You need to keep in mind the direction that the wood will move. Installing the figure 8's on the sides the same way they are installed on the ends will not accomplish what it intended.

BTW, I am not a fan of figure 8's. They are not a very secure way of attaching a top. They are particularly vulnerable if you attempt to lift the item by its top. I prefer shop-made wooden buttons or elongated holes in glued on supports.

I watched David Marks make a nice table yesterday in cherry with a solid top with leaf inlay. My query is over his use of figure 8's to hold the top. A shot showed the fasteners fitted to the all the aprons - 2 on each long side and two on each short side. He then screwed the top to all of them. I have never used these things and may be missing something, but wouldn't the long side ones restrict the movement that the end ones allow by pivoting. Surely as the top expands or contracts then it would exert either a straight pull or push on the fasteners and they would stop the movement?

 

[michaelgarner]

I have used wooden buttons before, never have used the 8's before.

 

[DavidF]

If that is what he did, then it is not correct. On the end pieces the movement is along the skirt and on the side pieces the movement is into and out of the skirt. Therefore, the side piece should be installed so then lay on top of the skirt--in slight depressions the depth of the thickness of the figure 8--when the top is in it's neutral position. To do this you need to install the side figure 8's first, move the tabletop so the figure 8's are parallel to the skirt and then install the end figure 8's.

You need to keep in mind the direction that the wood will move. Installing the figure 8's on the sides the same way they are installed on the ends will not accomplish what it intended.

BTW, I am not a fan of figure 8's. They are not a very secure way of attaching a top. They are particularly vulnerable if you attempt to lift the item by its top. I prefer shop-made wooden buttons or elongated holes in glued on supports.

My thoughts exactly, as I said, good idea, poor execution. Good point about lifting by the top too. I normally use wooden "buttons" located in a slot in the apron.

 

[FIVEBYFIVE]

I have never used them before, but I have seen it used before. The ones on the sides make sense, but the short sides not sure how the 8s would work. Leigh got me a set of forster bits, so I could use the 8s.

:icon_thum

 

[DavidF]

I have never used them before, but I have seen it used before. The ones on the sides make sense, but the short sides not sure how the 8s would work. Leigh got me a set of forster bits, so I could use the 8s.

:icon_thum

They should go on the short sides and they pivot to allow the top to expand in width; unless they are fitted as Howard suggested parallel to the long sides and that just sounds like hard work! Where as Z clips or traditional buttons could be used all the way around

 

[Howard Acheson]

>> Where as Z clips or traditional buttons could be used all the way around

You need to be careful with the Z-clips and the buttons too. You can't seat them all the way in against the inside of the apron that supports the long grain top. They need to be set out so they can be free to move in when the panel expands. Of course, if you assemble when the relative humidity is at or near its seasonal high, you can seat them. The panel will be at its maximum expansion and can only get smaller.

 

[DavidF]

>> Where as Z clips or traditional buttons could be used all the way around

You need to be careful with the Z-clips and the buttons too. You can't seat them all the way in against the inside of the apron that supports the long grain top. They need to be set out so they can be free to move in when the panel expands. Of course, if you assemble when the relative humidity is at or near its seasonal high, you can seat them. The panel will be at its maximum expansion and can only get smaller.

Agree, or there's no point having them. I normally allow at least a 1/4" on each one.