Table Legs to top

[Jim Riseborough]

So I’m going to join the legs to the table top with dowels and glue. The board that is going to be joined is 40” long, and 2” wide.

was thinking 2 rows, staggered and 6” spacing. A shit load of dowels, but want it to be strong.

Any one see an issue othe than the meticulous layout I will have to do!

444906

[Lee Schierer]

Hopefully the top is wider than 2" wide. If you don't allow that top to expand and contract seasonally you are going to have problems and likely a failure in the form of a cracked top. Place dowels along the centerline but use figure 8 fasteners where you planned to place the other dowels.

[Jim Riseborough]

The top is 2 thick. The board I am joinin to the top is 2” wide, it will be perpendicular to the top.

Top seems stable. It went a whole
Year glued up, no splitting, expanding etc. cold dry winter to hot humid summers.

[Lee Schierer]

Top seems stable. It went a whole
Year glued up, no splitting, expanding etc. cold dry winter to hot humid summers.

Yes, but it wasn't being restrained by the 2" wide cross pieces you plan to attach it to.

[Jim Becker]

Um...wood movement. You can fasten secure in the middle, but you do not want to glue out toward the edges of the table or you're going to have a hot mess with seasonal changes in dimensions for that cross-grain joint. Screws/bolts in slotted holes in the cross member are typical for this task.

[John TenEyck]

The top is 2 thick. The board I am joinin to the top is 2” wide, it will be perpendicular to the top.

Top seems stable. It went a whole
Year glued up, no splitting, expanding etc. cold dry winter to hot humid summers.

Unless the RH was dead constant, it was expanding/contracting the whole time; you just didn't notice. Go put a tape across the width. Chances are it's not the same exact width as when you made it.

John

[Bill Dufour]

I think it will be fine if you are really attaching just the legs. It looks like two screws per leg. Leave one hole a little big or slotted to allow movement. If you mean the legs AND the apron. It will split the top in one or more locations in a few seasons.
You say the top did not move in a year. How often and how accurate did you measure it? The human eye will notice a difference of 1/1000 inch in a flat surface like a table top. Were you measuring to that level of accuracy using correct temperature correction for your scale, gloves etc.Climate in shop, storage and end use location?
Bill D.

[Jim Becker]

Now I'm confused....I took this as attaching the leg assemblies to the table top, not the legs to the leg assemblies... :) 'Hopefully, the OP will clarify.

[Jim Riseborough]

Its the top of the leg assembly to the top.

I didnt measure it while it sat.

Its going to be in the house, and its a conditioned space, RH will be constant for the most part.

The boards didnt open up and joints, nor did they expand at the ends differently.

I will build in some expansion somehow.

[John TenEyck]

Its the top of the leg assembly to the top.

I didnt measure it while it sat.

Its going to be in the house, and its a conditioned space, RH will be constant for the most part.

The boards didnt open up and joints, nor did they expand at the ends differently.

I will build in some expansion somehow.

There would be no reason to expect a glued up panel of boards to split if they aren't constrained. They were free to expand/contract.

Unless you have some pretty special HVAC the RH is going to change quite a lot over the year. Best to plan and build for it.

John

[Jim Becker]

Seasonal wood movement is real no matter how well the home environment may seem to be. So do take care to allow for the top to expand and contract because it will.

[Bill Dufour]

I was pretty much being sarcastic but I would like to know where does the RH not change?

[John TenEyck]

I was pretty much being sarcastic but I would like to know where does the RH not change?

Outer space. But back here on plant earth it certainly changes. My house has central AC but in the Summer the RH can easily range from 70% when I'm not using it to as low as 40% when it's running hard. In the Winter it will go even lower unless I turn on the humidifier, and I do because I had some veneer seams split one Winter when it got down to 30%. A 40" wide table top made of plain sawn black walnut made when the lumber was at 8% MC (45% RH) will grow by 0.5" if it comes to equilibrium at 70% RH, and shrink by 0.22" if it comes to equilibrium at 30% RH. Of course, wood takes a while to equilibrate to changes in RH, and film finishes further slow the change, but wood begins to move with any change in RH and will change a lot if the difference in RH is large enough and lasts long enough. We've all seen sticky doors and drawers in the Summer and gaps in wooden floor boards in the Winter. Environmental controls can help minimize this expansion/contraction, but good design and thoughtful construction will allow the piece to survive even without controls.

John

[Bill Dufour]

I live in central California so my humidity is reverse of yours dry in summer and damp in winter. I looked it up and San Francisco, whose climate does not vary that much, has a 20% change in RH over the seasons.
Bil lD

[Bill Dufour]

I suppose the other constant RH is underwater. There are redwood logs buried in rivers and lakes that have not rotted or cracked in centuries but dry them out and they start to twist. Wood wine vats are over 120 years old and still hold liquids fine.
Bil lD

[John TenEyck]

I live in central California so my humidity is reverse of yours dry in summer and damp in winter. I looked it up and San Francisco, whose climate does not vary that much, has a 20% change in RH over the seasons.
Bil lD

I was referring to the RH inside your house. The RH outside is really higher here in the Winter, too, but once you warm up that air inside your house it's much lower. The RH inside a house in San Francisco likely experiences an RH swing much greater than 20% for the same reason, though likely not to the extremes we have because it doesn't get nearly as cold there.

John

[Jim Riseborough]

So my final idea is to just dowel at the middle. 2 rows with 4 dowels at the center, about 2" spacing. Yes, it will restrain the very center two boards, but im confident its not going to explode. Will let you know how things go.

445069

[Kevin Jenness]

Why do you want to permanently fasten the top and leg assemblies? It will be much easier to move them separately in the future if detachable. I would suggest one unglued dowel in the center of the stretcher for location and wood buttons or steel s-clips in a groove or figure-8's to hold the top down to the stretcher and allow for the inevitable seasonal movement.

On second look, it appears you may not have any stretchers between the "trestles", in which case you may need a more rigid attachment than buttons or figure-8's will provide. Large screws or lags in oval or oversized holes in the stretchers may be the way to go.

[Jim Riseborough]

Why do you want to permanently fasten the top and leg assemblies? It will be much easier to move them separately in the future if detachable. I would suggest one unglued dowel in the center of the stretcher for location and wood buttons or steel s-clips in a groove or figure-8's to hold the top down to the stretcher and allow for the inevitable seasonal movement.

On second look, it appears you may not have any stretchers between the "trestles", in which case you may need a more rigid attachment than buttons or figure-8's will provide. Large screws or lags in oval or oversized holes in the stretchers may be the way to go.


See updated pic, the cross tie thats doweled in will be the permanent fixture, the legs can unbolt.

I want it to be 'fastener free' look. I know I could put a stretcher down the center and fix that into the table, and bolt everything to it. At the worst that could come later.

445078

[Lee Schierer]

See updated pic, the cross tie thats doweled in will be the permanent fixture, the legs can unbolt.

I want it to be 'fastener free' look. I know I could put a stretcher down the center and fix that into the table, and bolt everything to it. At the worst that could come later.

445078

You could put threaded inserts into the bottom of your table top, in place of your dowels and then counter bore holes up through the cross member and attach the table top with a couple of long bolts that would be hidden unless you climb under the table and look up.

[Jim Becker]

So my final idea is to just dowel at the middle. 2 rows with 4 dowels at the center, about 2" spacing. Yes, it will restrain the very center two boards, but im confident its not going to explode. Will let you know how things go.

445069

That should be fine you you really should also use some figure eights out at the ends to keep the top flat. Even with substantial weight, it can, yup...move.

[Dan Hahr]

Not sure where you came up with this design, but it is lacking in strength and function. The design without stretchers will not protect against racking. The top attached only at the center will not resist warping as it surely will not being restrained by proper attachment methods. I would pay attention to those who advocate a change to the design.

The use of fasteners to attach table tops is the proper way to do this. Dowels are not appropriate in this situation.

Dan

[Kevin Jenness]

This may have been suggested in your earlier thread on this project, but one way to make a reasonably strong, removable connection would be to use some steel plates aligned with the length of the tablescrewed up into the top and down into the stretchers. Something like 1/4" x 3" x 10" fastened with # 14 panhead screws into the top with elongated holes where needed, flathead screws in the stretchers and mortised halfway into each surface. The dowels and figure 8's could work but seem marginal to me. Pocket screws don't really belong in the mix. Dancing on this table is not advised.

[Jim Riseborough]

This may have been suggested in your earlier thread on this project, but one way to make a reasonably strong, removable connection would be to use some steel plates aligned with the length of the tablescrewed up into the top and down into the stretchers. Something like 1/4" x 3" x 10" fastened with # 14 panhead screws into the top with elongated holes where needed, flathead screws in the stretchers and mortised halfway into each surface. The dowels and figure 8's could work but seem marginal to me. Pocket screws don't really belong in the mix. Dancing on this table is not advised.



Not sure where you came up with this design, but it is lacking in strength and function. The design without stretchers will not protect against racking. The top attached only at the center will not resist warping as it surely will not being restrained by proper attachment methods. I would pay attention to those who advocate a change to the design.

The use of fasteners to attach table tops is the proper way to do this. Dowels are not appropriate in this situation.

Dan

Dan, Kevin, thanks for your concern.

I have looked into this. I am not too worried, the leg assembly does have a bottom stretcher, and its a significant connection. As you said, we wont dance on this. I was surprised how much capacity the wood dowels have, just 2 of them in line I was upwards of 200lb capacity at 12" offset. I am going to use 6 dowels, plus 8 of the "figure 8" type devices, (they are 3/16" plates in reality) they will be fastened with 5/16" threaded screws into anchors epoxied into the table and the legs.

In light of these connections, the whole thing also will have some Virendeel truss action. I am truly not worried about racking, but my back up plan is some "X" bracing with steel cable and hardware like you see for hand rail if it does rack.

Jim

[Jim Riseborough]

Got it all assembled. Its very stout. hardly any movement unless you really put your back into it.


https://share.icloud.com/photos/0FlBItOm8PIdynxpGnrDnZr3w

[Jim Becker]

Seems to only be a picture of a leg on the carpet at that link, Jim.

[Jim Riseborough]

Seems to only be a picture of a leg on the carpet at that link, Jim.


supposed to be a video. Might have to click the thumbnail bottom left.

[Lee Schierer]

Got it all assembled. Its very stout. hardly any movement unless you really put your back into it.


https://share.icloud.com/photos/0FlBItOm8PIdynxpGnrDnZr3w

You need to click on download once you get to the site to see the short video.......

[Jim Becker]

Very nice! I like the design for sure. Your helper clearly made the project go smoother, too. :) :D

[Jim Riseborough]

Very nice! I like the design for sure. Your helper clearly made the project go smoother, too. :) :D

Lol thanks, he likes to be involved in everything.

[Randy Heinemann]

You can buy table clips at Rockler (or probably other places) online. They fit into a slot in the base around the top and are screwed to the underside of the table top. Since the part of the clip that is in the slot isn't screwed it allows the top to expand and contract as much as it does whatever environment it's in. The clips may be a bit difficult to install if you have already assembled the base since I usually cut the slots with a router or table saw prior to assembling. I found these easy to use and very effective in holding the top to the base while still allowing expansion and contraction. The other suggestions will work also, but I would definitely allow for expansion and contraction in some way or, over time, something is likely to give; most likely the top.

[Jim Riseborough]

You can buy table clips at Rockler (or probably other places) online. They fit into a slot in the base around the top and are screwed to the underside of the table top. Since the part of the clip that is in the slot isn't screwed it allows the top to expand and contract as much as it does whatever environment it's in. The clips may be a bit difficult to install if you have already assembled the base since I usually cut the slots with a router or table saw prior to assembling. I found these easy to use and very effective in holding the top to the base while still allowing expansion and contraction. The other suggestions will work also, but I would definitely allow for expansion and contraction in some way or, over time, something is likely to give; most likely the top.

I made my own for this build, Used 3/16" thick washers with anchors dropped into the top and the stretcher across. Will allow for 1/2" movement each way.

[Ronald Blue]

This what I used recently. Cut a groove on the inside of the stretcher or apron (not sure what the right terminology is) where is wasn't visible on the table saw. Worked great. I don't recall if I used one or two screws in the center (pocket hole) and let the clips secure the rest.

amazon.com/gp/product/B001DSZRDS/ref=ppx_yo_dt_b_asin_title_o09_s00?ie=UTF8&psc=1