Thread: Expanding Dining Table - any tips?

I haven't seen the FWW articles you refer to
Whats wrong with making timber slides yourself, metal runners are overkill
The grain can run any direction you want it to run
Edge banding is for sheet materials
Do not edge band solid timber - it will self destruct with normal timber movement.

If you want the best quality posible table top make it from ply
(even use a torsion box configuration if you wish)
Then apply veneers to the surfaces.
Far superior to solid timber

The explanation for having the grain run crosswise was that the expansion for wood movement across the grain would tend to minimise any gapping.

As far as the edge bandiung of solid wood goes, there seems to be plenty of antiques around that haven't self destructed.

I was at some friends place last night and they have a 19th Century Oz cedar expanding dining table so I was able to check out how it was made.

The grain runs crosswise on it but due to the edge molding profile there is actually very little end grain visible. So I doin't think that it's going to be an issue so long as I put an edge molding on it.

Craig heres a rundown on one of the traditional methods of making a rail

These pictures show the method used on the Mahgogany D-End table i made a few years back. I also made a little model of the runner and it shows the action for anyone interested.

The orentation of the boards always run across the table because their is no way of keeping the boards flat with no rail because of the extension. And with the movement in the width will mean the locating pins joining the two halves and the extension will always get stuck, bind or just not mate.

The main runners, sections 1, 2, and 3 are usually 65 x 30 mm and best in a straight grain 1/4 sawn timber that is dry and stable. When cutting the rabbets (sown in blocks 1,2 and 3) do all three sections then adjust the saw/shaper a smidgeon ( a few cigarette papers) and go back over rabbet numbers 1 and 3 and do an extra pass, so when you glue in the long tenons both sides into No 2 they slide well. The trick is to get it very snug with "no" slop at all.

Make the runner section first and make sure it runs smooth as you possibly can. I will rub a small amount of paraffin wax along the tenons "after" its running smooth.

After you have completed the runners, place them as in the closed photo and attach securely to the table on one end each only. Section A to one end, and section C to the other end. Section B is not secured as it runs free.

On the bottom where you secure section A to the table you will need a small spacer around 2mm attached to the under side of the section B rail and 4mm under the section C rail so their is clearance when you extend the table out. Repeat the process on the top section in reverse.

Its reasonably straight forward, just requires good clean, straight and stable Ash/oak and i would suggest making a model like i have. No need to rabbet and tenon, just let it slide loose.

Also metal runners are usualy $60 for a 600mm ext and $100 for a 1200mm they are rated around 60 and 90kg (on either length) and run very smooth. But i much prefere the look and feel of a handmade wooden one

Excellent post. Thanks Lignum! I reckon that even I will be able to make a set of runners from that.

Very nice table too btw. What timber is it made out of?
Mine will be a fair bit simpler than that one.

Cheers
Craig

Originally Posted by craigb

.
What timber is it made out of?
Cheers
Craig

Thats Mahogany, and its fully extended as you can see the cover strips on the side rail hidding the join.


As we speak im making a contemporary Vic-ash extension that is 2400 extending to 3600.

The first pic shows the side rails conected to the legs with Domied and epoxied corner blocks, and the second pic shows the split in the rail with locating tenons. (keep the measurments spot on as they have to transfer exactly to the extension rail) Pic 3 shows a few metal runners. The small one is a 600mm ext and the one beside is for 1750 ext and they are around $210. Ill post more pics for you as it progresses

Originally Posted by Lignum

Ill post more pics for you as it progresses

Thanks, I'll look forward to that.

I'm sure it will also be of interest to any other members who've contemplated making an extending table.

Is it an order for a client or are you just doing it "on spec" ?

Craigb,

I can't remember all the particulars of the FWW articles on extension tables (I don't think I could find the magazine even if I tried), but just wanted to warn you about the correct procedure for matching up leaves to the table.

You will have some kind of leveling system to level up the joints, table to table, table to leaf, leaf to leaf (if you have more than one leaf to insert): wooden dowls, steel pins, table self levelers, some other system.

The trick is to sand/scrape the table perfectly level across the join (i.e. no leaves). Then open the table and install one leaf. Hopefully the leaf will be thicker than the table! Carefully sand/scrape the leaf down to the level of the table, on both joins. Again, the trick is to accomplish this WITHOUT sanding or scraping the table sections in any way.

If you have more than one leaf I recommend numbering them so they can be installed exactly the same way every time. When you insert the next leaf, you will then want to sand/scrape it down to the level of the other leaf and table top (i.e. joins on either side).

In this way, when you take out the leaves, the two table sections will still join up. I made a double split pedastal table which is 2.5m fully closed and 5.2m fully open (it will seat about 18 people comfortably). This procedure worked really well. (Then again, this is probably in the article...)

Also, with tables which have their grain running across the width, you must make sure you have adequate aprons running around the outside. The problem here is that in order to get a substantial apron, they often get in the way of a person's knees when sitting down. I solved this by laminating several thicknesses to build up strength in a "shallow" or "narrow" apron. Finally, I find that the table I made (Tasmanian Blackwood) expanded and contracted quite substantially across the grain. Initially, I made the aprons the same length as the width of each leaf (six leaves in all). This was a no, no, since the leaves all contracted and left a crack at each join where the aprons were hitting end on end. I had to take them all off, cut them shorter, refinish, and reinstall. A pain, to say the least.

Finally, can't help you with slides. I got mine from the US, and unfortunately I can't remember the brand name. Anyway, you wouldn't want them as they were just pressed steel against pressed steel and were quite hard to open and close. I think you are on the right track either to use a heavy duty drawer slide, or else make your own. There is something special about an "all wood" construction! Good luck and have fun!

Some good info there. Thanks LuckyDuck.