Oak Table top

[cherilton]

I have got to make an extending table with a 1.5 inch thick Oak Top. It will be 6 feet long max and 4.5 feet min, with a drop in section when extended. I wish to have the top laminated together by a company and i asked him to fit strips on the ends to cover the end grains ( 4 inch wide )
The table will be 3 feet wide. The guy told me that he would not recommend having the pieces on the ends due to the expansion problems, what do you guys think! Will it be a problem? If i dont fit the strips how can i stop the top from cupping? I have seen a lot of oak tables with these strips on the ends and i presume they must not suffer from expansion problems.

 

[Philly]

Hi C
What you need are "bread-board" ends. These hide the end grain but still allow the natural expansion/shrinkage of the timber.
Cheers
Philly

 

[Scrit]

The guy told me that he would not recommend having the pieces on the ends due to the expansion problems, what do you guys think! Will it be a problem? If i dont fit the strips how can i stop the top from cupping? I have seen a lot of oak tables with these strips on the ends and i presume they must not suffer from expansion problems.

Well they'll (the ends) expand and contract at different rates to the main part of the top so the ends won't always be the same length as the sides are wide (if that makes sense), but that's the way it works. Once the piece is in equilibrium with its surroundings the movement should stop.

Scrit

 

[orangetlh]

hello cherilton,
Without getting into complicated joints to allow for expansion you could use stretcher plates like these making sure you dont overtigten the screws in the long holes and that should allow for movement in the top whilst keeping it flat

http://www.isaaclord.co.uk/prodData.asp ... 1&SubCat=1

 

[GCR]

cherilton

When you say laminated do you mean lots of solid 1.5 inch strips glued together? If so, the company should be able to arrange the strips so that cupping is virtually eliminated by ensuring that the annual rings "run" in different directions when viewed from the end of the top (thus cancelling any cupping). The movement across the grain in oak can be in the order of several mm (even when the top has stabilised) as humidity changes. Because wood does not really move along the grain, it follows that a strip at each at 90deg to the top will cause stress and if fixed permanently will cause the top to crack or the joint to break.

Bob

 

[Scrit]

Bob

A breadboard end is not fixed permanently along the entire end of the top, rather it is attached at the centre and located on something like a loose tenon, otherwise as you say the glue joint would break.

Scrit

 

[johnelliott]

I expect the maker will join the strip together with the grain (viewed from the end) alternating. This will reduce to a minimum any movement in the wood. Apart from that precaution, I would leave it as it is. It may well move a bit, but if there's one thing that gives away a venereed table is the dead flat surface.
Veneered tables often have breadboard ends to conceal the substrate.
Nothing like some well rounded over end grain to let everybody know that your table is SOLID wood
John

 

[cherilton]

Thanks for all the imput, just to clear up the laminated part of my post , i meant strips about 3.5 to 4 inches wide all glued together and yes the rings will hopefully be alternated. The breadboard attached at the centre sounds promising. How is it located along the rest of its lenght?

 

[DaveL]

Hi cherilton,

A breadboard is usually made as a tongue and groove, with a single tight fixing at the centre. There maybe a fixing towards each end but this will be slotted to allow the end to move across the width of the table.

The fixings are often dowels, the centre one with a snug round hole though both tongue and groove, glued into both boards. While the end fixings have a double width slot in the tongue, only glued into the grooved board. This slot will allow the timber to move but is unseen, inside the groove.

 

[cherilton]

Thanks, sounds like i should have know that. Think i will make a small test piece up with some 19mm pine board i have and bring it indoors to see how it moves with the change in heat/humidity
Many Thanks.

 

[Newbie_Neil]

Hi Cherilton

Have a look here for an example of bread board ends.

Cheers
Neil

 

[DaveL]

Thanks, sounds like i should have know that. Think i will make a small test piece up with some 19mm pine board i have and bring it indoors to see how it moves with the change in heat/humidity
Many Thanks.

Just remember that the movement on pine will not be the same as the movement on oak. :? It will only give you a demo of how the end looks not how it will work out on your final project. 8-[

 

[cherilton]

Yes , sorry misstyped, i did mean oak. Thanks !

 

[cherilton]

Thanks Neil for the bread board info, i have made a small sample piece now and will see how it shapes up in a warm house over the weekend. It is only half of the width of the actual table so presume any movement i get will be doubled on the finished table. Maybe if i was clever i would make the boards oversize ( length ) to compensate for the expected expansion of the rest of the table top?

Many thanks
Graham