Table legs. Am I over thinking this?

[CWatters]

Relative newbie could use some advice..

If you want/need to make simple 80mm chunky square table legs by joining 2 bits of 80mm*40mm do you....

1) Just glue, clamp and move on... ||
2) Worry about the wood cupping over time so carefully arrange the grain.... (()) ..too prevent joint opening.
3) Hollow one face slightly so the two bits are only glued at the edges... [] ..perhaps to make clamping up tight easier?
4) Route/table saw a pair of groves and use biscuits or similar strips to help keep the two bits together?

and then there is the issue of which glue to use?

a) Regular PVA? Gorrilla PVA?
b) Polyurethane
c) Something else?

Will be working in planned kiln dried oak. I don't yet have a planer thicknesser but the wood looks fairly flat as supplied.

Thanks

 

[JustBen]

I would go with 1.
I find titebond (aliphatic resin) to be very good. I've used I,II and III and they have all been great.
I tested them for strength against pva and they are a lot stronger.

Biscuits have very little strength and are mainly used for alignment.

At the end of the day if the oak wants to move, it will move no matter what you do to it.

 

[MickCheese]

1a for me.

Two flat faces, PVA glue. plane to size & trim to length once dry.

Mick

 

[marcros]

1a

 

[Random Orbital Bob]

+1

With so much surface area of long grain you don't need any expensive branded glues, literally the cheapest pva you can find as long as the mating surfaces are nicely planed flat and leave it in the clamps for 24 hours. It'll take a nuclear holocaust to prize that apart.

 

[custard]

Hello Colin, here's my checklist,

1. Think about how the leg will look after the glue up, try and get the grain to match so the joint is as unobtrusive as possible. You'll be very lucky if all four legs have invisible joints, so think about which leg will be located in which corner to get the most harmonious/least jarring effect.

2. Think about how many cramps you've got, you can glue up all four legs next to each other but then you'll be pushed for time so you'd welcome having a couple of dowels or biscuits to assist in location, plan the glue up in advance and have a dry cramp before the real thing to flush out any problems. Remember that with most glues you'll only have about ten minutes from first pouring the glue to finishing the job.

3. Don't sweat about choice of glue, they're all more than adequate in terms of strength.

4. I very much doubt your wood is actually as flat as you think, but a dry glue up will help you decide if the glue lines will be tight or gappy.

5. Have a cup of hot water ready to wipe/brush away as much glue as possible before it sets. Be scrupulous about this and repeat a couple of times. If you don't you'll see patches where your finish didn't adhere to an almost invisible film of glue.

Good luck!

 

[kernowjoiner24]

Lots of good advice been said here, definately do a mock 'dry' assembly to check it will close up tight.

If it were me doing it I would arrange the grain on the two halves so it looks circular, like a tree and use a few biscuits just to align things, it will slide on the glue when you clamp it up else. As for glue you wont get better than PVA, we did a test when I was in college with a tensometer machine thingy (technical term), basically two 50mm strips of ply clamped over each other so glue area of 50mm square. PVA out pulled epoxy by over a tonne ! All the other glue types we tested failed long before and the wood actually failed on the PVA'd one not the glue ! food for thought !

 

[Phil Pascoe]

Surely if you arrange the grain to be circular, you are asking it to open up, as both bits of wood will cup away from the heart?

 

[Steve Maskery]

All good above.
Just one point where I would do it differently, and that is to do with grain orientation.

Grain orientation is VERY IMPORTANT and it has taken me until recent times for it to fully sink in. Select your stock very carefully so that you have similar grain patterns on all four faces. If you do not, you will have legs with very quartersaw grain on some faces and very flatsawn grain on others. That's not pretty. DAMHIKT.

The way to ensure harmony is to select the boards so that the endgrain runs diagonally. No faces are flatsawn, not are quartersawn, they are all somewhere in between. And I would glue any that are "half trees" back to back, not face to face, so that any shrinkage pulls the glue edges tighter, not apart.

It will be a good exercise in hand planing, go for it.

S

 

[Myfordman]

Grain orientation is VERY IMPORTANT and it has taken me until recent times for it to fully sink in. Select your stock very carefully so that you have similar grain patterns on all four faces. If you do not, you will have legs with very quartersaw grain on some faces and very flatsawn grain on others. That's not pretty. DAMHIKT.

The way to ensure harmony is to select the boards so that the endgrain runs diagonally. No faces are flatsawn, not are quartersawn, they are all somewhere in between. And I would glue any that are "half trees" back to back, not face to face, so that any shrinkage pulls the glue edges tighter, not apart.



S

+1

I made a table a while back with solid tapered square legs. the first timber I planed up had grain running side to side which gave QS faces alternating with FS faces. With table legs, the only way to get two adjacent faces looking similar is to choose the endgrain to run diagonally as Steve says. With fabricated legs, there is also colour to be matched.
If you want a real challenge then mitre the joints as well!!

Good Luck

MM

 

[RobinBHM]

The glue will want to make the pieces slide as you cramp them. I would make them over length and use a screw at each end, in the waste or use biscuits. If you are using sash cramps you can glue all 4 sets in one go (only, if you can get all glued up and avoid pre-curing, a bit of an issue with pva)

I would use large section cramp battens, say 3 x 3 to spread the cramping pressure.

Robin

 

[Benchwayze]

If the worst comes to the worst, you could always rout a shallow groove along each joint, and glue in a strip of contrasting timber. Maybe even a D moulding). Then it would be a design element rather than a mistook! :mrgreen:

 

[CWatters]

Thanks for all the tips!

I've used a lot of "ordinary" PVA wood glue over the years (mostly on model aircraft) and found it can be a bit soft and soften with time. I need to buy some more glue anyway so will probably give the titebond a go. There is a local supplier near me so looks like I'll be offering to drive the kids to school tomorrow ;-)

I did think about making the legs hollow from say 18 or 20mm with mitred joints but it's a lot of work considering the table (actually a pair of tables) will be used by my kids. eg "home office" rather than dining tables.

Great forum by the way.

 

[CWatters]

If the worst comes to the worst, you could always rout a shallow groove along each joint, and glue in a strip of contrasting timber.

That's what I plan to do I can't get the top right

It's going to be made from a veneered blockboard with a thicker mitred frame . If I can't get everything tight I plan to route a groove and put in some Ebony/blackwood strip or possibly even a banding of some sort if I can find one that doesn't look too OTT.

 

[Benchwayze]

If the worst comes to the worst, you could always rout a shallow groove along each joint, and glue in a strip of contrasting timber.

That's what I plan to do I can't get the top right

It's going to be made from a veneered blockboard with a thicker mitred frame . If I can't get everything tight I plan to route a groove and put in some Ebony/blackwood strip or possibly even a banding of some sort if I can find one that doesn't look too OTT.

I am not counselling shoddy work, so the following is only to be adopted in extreme emergencies.

Remember 45 degrees + 45 degrees = 90 degrees. So is 44 degrees + 46 degrees.
In other words if one half of your mitre joint is out by a shade, and you haven't enough timber to make a new piece, cut the other half of the mitre to suit. Within reason, you won't notice it.
Best of luck. :wink:

 

[Racers]

I have seen laminated legs with veneer on the joined face so it looks solid.

Pete