Thread: Dining Table Modification WIP

All finished.

Table is now 1.6 M X 1.0 M. Love the Dutch legs.

IMAG0133.jpg

Six years of planning, then just two posts, and it's done ! Anyway, it certainly looks the part, well done, & done well!

I would've spent much time & a good many expletives trying to make the tops of those legs all the same rather than use different lengths for the apron boards, I think. Given my predilection for scew-ups, I would've ended up with at least one in the wrong place for sure, if I'd tried your solution. You didn't say how the new frame is attached - M&T, or more 'modern' fixings?

The boss has a mahogany desk from a similar source, which was also a 'good' price. It's made from quite nice wood, and the construction is reasonably sound except for the way the legs are fitted into the top. Presumably, it was made to pack down into a flat carton for shipment, & the legs are joined into the corner pieces of the apron by short dowels turned on their tops. I know from experience that they don't fuss too much about moisture content where it was made, nor take account of the fact that the stuff might end up in places with a pretty wide moisture cycle. Of course, the dowels have all shrunk, the glue let go, & the desk sits precariously on 4 very wobbly legs. Moving it involves great care & much angst. I have offered to fix it a few times, but she says it was only meant to be a temporary possession (so far, 20 years & counting.....) & she intends to get rid of it, so I haven't had to decide how I'd actually do it. I can think of several ways to tackle the job, but it wouldn't be an easy fix, however I went about it, so I'm secretly glad my offer hasn't been taken up (yet!).

Cheers,

Ian,

Sounds like the boss' desk is very similar to this table, which was surely transported to Oz completely knocked down.

After nil responses to the first post it appeared that there was little interest, so I stopped posting until the job was done. It was hardly an exciting project, so no surprises.

The rectangular sections at the top of the leg were not only different in dimensions, but also their location relative to the turned section was different. When cleaning up the old joints I made on the linisher, on two of the eight faces the sandpaper touched the ball under the rectangular section. Easy to fix.

Also, I could not get the tops of the legs into my smallish vertical morticer, and was not convinced I had the skills to cut them by hand. The approach used was as per the following pic showing how the legs were joined to the frames in plan view.

Leg Joints.png

The grey section was glued onto the frames at each end before they were docked to size. It is a bit thicker than the frames. The red sections are biscuits. The legs were joined to the frames with double biscuits. Once the joints were dry, I drilled a series of pocket holes using a Kreggs tool and then 9 mm dowells (yellow) were tapped in, cut flush and sanded. 9 mm is a perfect fit for a Kreggs pocket hole bit. The dowells penetrate a minimum of 30 mm into both sections. I like this approach to dowelling (where it is applicable) because the hole is drilled into a glued joint, meaning perfect alignment because only a single hole is drilled.

The next issue was that the piddling metal brackets were not doing a good job of holding the table top in place. The nearest to a corner the bracket would fit was about 200 mm when I got it, but much more after I had glued on the grey section in the pic. I made up a rectangular frame (about 75 mm wide) that sat on top of the legs and frame, protruding about 35 mm past the frame. This rectangular frame was routed so the exposed lower edge was rounded over and it was glued to the table legs and skirts. 22 mm holes were bored about 5 mm into this frame where screws would be used to fasten the top to the frame. 10 mm holes were then bored all the way through the frame and flat headed screws and washers were used to fasted the table top. So, the top has potential for 3 mm movement in all directions at each hole, or 6 mm movement across the top. Before doing all this I cut 15 mm off the top of the legs on the band saw, so it did not grow a lot in height.

I like the approach for fitting the table top. It is secure, allows a fair bit of seasonal movement (slots would allow even more) and when it was delivered my son and his wife did not notice it. I needed to point it out.

When I did the first fix all those years ago I refinished the top with a hand rubbed polished mirror finish, just to see if I could do it. My son's wife hated the high gloss polished finish. Every finger mark and speck of dust showed up. I was given strict instructions that the top was to be re-finished with a matte product. My son's wife had sat a plant pot on it ... one without a suacer ... I am sure you can imagine the damage that caused after a few waterings, The top was cut to size, stripped, sanded, routed, re-stained and finished with 50% gloss NC lacquer. Her indoors was very pleased.

Finally, I used builder's bog to fill the gap between the tips of the legs and the brass cups that hold the wheels. Quick, simple and effective.

Originally Posted by John Samuel

......The rectangular sections at the top of the leg were not only different in dimensions, but also their location relative to the turned section was different. When cleaning up the old joints I made on the linisher, on two of the eight faces the sandpaper touched the ball under the rectangular section.......

John, that sounds to me like the legs were turned at a pretty high M.C., and there was lots of subsequent (& irregular) shrinkage, as you'd expect. I've seen a few exceptionally well-made bits of Mahogany furniture from over that way, but so much was/is made to a price, I expect. There was a pair of bedside tables from the same shop as the desk came from. I suppose they were meant to resemble 'antiques', & crudely whacked together. The drawers were ill-fitted & had no kickers, so they invariably jammed or fell on the floor whenever opened. They were replaced by a couple of slightly better-made items quite a while ago....

Girls & their bleeding indoor plants! My precious Tannoy speaker boxes suffered a similar indignity, which is even more disasterous for veneered pieces!

Cheers,

Ian,

The funny bit is that the timber looks to be good quality, and the turning on the legs is pretty good, but everything else left a bit to be desired. Her indoors has sworn a great oath not to put a plant pot on my table ... ever. In its current incarnation it should give many years of service.

Originally Posted by John Samuel

....The funny bit is that the timber looks to be good quality, and the turning on the legs is pretty good, ....

Ditto for the desk I described. I don't doubt the people who made it were capable enough, and they had access to some pretty nice Mahogany alright (it was used as a shade tree for coffee plantations, according to my sources). But either mis-matched moisture levels, or poor sizing of the stub dowels on the legs let them down in our case...

Cheers,

Ian,

As an accomplished woodie, I would be interested to hear your comments on the method used to join the frames to the legs.

The last time I made those joints they were double biscuited only and then the corners were blocked ... or rather, over-blocked.

My estimate is that adding the dowells makes for a better joint, but I would be pleased to hear your opinion. I did not block the corners this time. However, there is a 20 mm X 70 mm frame that sits over the legs and side frames, and is glued to both, adding to strength.

John, to be frank, I'm not a lover of dowels and have rarely used them in my own woodworking projects. I have repaired far too many failed doweled joints (made in factories, for the most part!) on chairs & tables to trust them in any high-stress joint. Almost half of the circumference of a dowel is meeting end-grain inside the leg, which gives a poor glue bond, & compared with even a small tenon, you have little of the 'best' surfaces mating in the joint. So it's little wonder that dowels frequently fail on tables & chairs. Being a boring traditionalist, I always use M&T joints for table aprons because of the vastly increased side-grain to side-grain contact. Biscuits can be somewhat better than dowels, there is proportionally more side-grain contact, so as long as you use enough of them to get a significant surface area of glue-bond, they are theoretically as good as a floating tenon or solid tenon of the same side-surface area.

So far (touch wood) I haven't had any apron-leg joints fail (at least not since I learned to make a decent fist of a M&T), but no glue-joint can ever be guaranteed, of course, and I've seen the odd joint on old stuff that has let go, even with blocked corners. The ones I'm thinking of were glued with hide glue, and I suspect the glue was mistreated or something wasn't done right....

Just my opinion.......
Cheers,

Actually, I agree.

Dowell joints are a second best approach. I have repaired dozens of factory made dowell joints over the years, but take some consolation from the fact that when I make a dowell joint 100% of the surface will be covered by glue, something the factory joints are miles away from. As I repaired fuirniture over the years I was amazed at how small a proportion of the dowell actuially had glue on it. 50% coverage is actually not to bad ... apparently.

I agree that an M&T joint is superior, but that was not an option for me in this case. That's why I went for the combo of biscuits and dowells. In this case, I am confident that the joint will stand the test of time. Your comment about short and long grain on dowells is well understood. Nevertheless, even if we only assume half of the dowell is actually glued in place, that joint, along with the biscuits, will likely do the job. Stand by ... a report will follow in ten year's time.

I am a scientist by bent, so I actually make and test joints for myself. Doubtless, M&T joints are superior. However, if I make a biscuit or dowell joint, and the timber spilts before the joint lets go, am I losing anything? I somehow doubt this. In this case I have two biscuit joints and three dowell joints, in every case the entire surface of the joint is painted with glue, unlike the factory joints I have repaired.

I reckon youare right, when what appears to be a decent joint lets go, it is likely that something was not done rioght. This is especially true of hide glue, which ages rapidly in the pot, and which is sensitive to moisture content.

Originally Posted by John Samuel

......I reckon you are right, when what appears to be a decent joint lets go, it is likely that something was not done rioght. This is especially true of hide glue, which ages rapidly in the pot, and which is sensitive to moisture content....

Yeah, I think this is supported by the number of hide-glue table joints that are still sound after 150 plus years. Failure isn't because (properly handled) hide glue isn't 'strong' enough. Perhaps the most common 'fault' would be a poorly-made mortise, with very large voids & gaps between M and T. (I often make the claim that making a good mortise & tenon joint by hand is much more difficult than cutting good dovetails!) Mistreatment of the glue would be up there too - overheating, and bacterial contamination don't do a lot for strength & longevity of hide glue.

Originally Posted by John Samuel

.....I am a scientist by bent, so I actually make and test joints for myself. Doubtless, M&T joints are superior. However, if I make a biscuit or dowell joint, and the timber spilts before the joint lets go, am I losing anything? I somehow doubt this. In this case I have two biscuit joints and three dowell joints, in every case the entire surface of the joint is painted with glue, unlike the factory joints I have repaired......

Indeed, this has been the theme of numerous magazine articles over the years. And so long as the glue maintains its integrity, all should be well. Early articles used to always include the caveat that protein-based glue has been around for probably thousands of years, and we know that it has held up in lots of furniture that is still intact for 250 years and more, whereas the 'synthetics' have only been around for a relatively short time, so we don't know how they'll handle the centuries, yet. I had to pull something apart a while back, that had been glued with a PVA type glue about 25 years previously. When it finally let go, there was at least 95% wood failure, so there hadn't been any deterioration in that (relatively) short term!

I am perfectly happy to use biscuit/ floating tenon or whatever is quick & convenient for utility stuff. I've done a few kitchens using double-biscuits for the panelled door frames. I calculated the glueing surface was at least equal to that of any tenon I could make for that size joint, and biscuiting got the job done a lot faster. So far, 20 years & rising in two cases, they're all holding, and let's face it, 20 years is more than the average life-expectancy of kitchens & bathrooms, nowadays.

However, when it comes to an heirloom' piece, it's 'traditional' joinery all the way, for me. Apart from the enjoyment of doing it, it's a matter of pride & the thought of what someone who may need to repair it long after I'm gone from this world might think of my workmanship......