Sliding dovetails or not

[Joshjosh]

Hi I've been asked to build a table to very minimalist design, the table has no aprons and I'm attaching the legs as shown with bolts into threaded inserts through elongated holes, my question is do people think the bolts will be enough to keep the top flat or any I best adding some siding dovetail braces to the underside? Fyi the top is 40mm thick
Cheers Josh

 

[TheTiddles]

40mm of what and prepared how?

40mm of WBP, yes sure.

Aidan

 

[Joshjosh]

Ha good point,
Its 200mm Oak boards planned to 40mm and edge jointed to make a 1m wide table top

 

[MikeG.]

Bloody hell. Yes, that needs something under it, and it needs a damn sight more than what's in that photo holding the legs. If someone bumps the end that'll rip those threaded inserts straight out. Tell your client that there is a good reason tables look the way they do.

 

[Joshjosh]

Problem is, there are allot of mid range furniture stores selling this sort of design and that's what the clients want, I told them I'd make it and make it to a better quality than what they saw in the store but they wanted the fundamentals of the design to remain the same. The legs splay out from the table at an angle and once bolted up they are quite sturdy (yes not as sturdy as a classic table with apron but not as bad as you'd think) my question is whether the braces bolted to the underside will be sufficient to keep cupping a bay or wether I should just bang somee sliding dovetails next to where the legs are to ensure this?
Cheers Josh

 

[AndyT]

Isn't this one reason why a lot of commercial tables use veneered chipboard or MDF for the tops?

An odd case where the cheaper material gives an advantage.

 

[Joshjosh]

I suppose so, this is the table design I'm copying, https://www.heals.com/oslo-table.html
Made from solid oak with steel c channel used to keep it flat, I decided on sliding dovetails as I don't know where to source stainless steel c channel and what the price would be

 

[samhay]

How will you manage the edge of the table where the dovetailed grooves will be?

 

[Joshjosh]

How will you manage the edge of the table where the dovetailed grooves will be?

I'll fill it with a piece of dovetailed timber so when cut flush there will be an end grain detail of the dovetail profile

The top will also have a big bevel on the bottom edge so this will be quite subtle

 

[profchris]

If you want a solid wood top to stay flat, I'd have thought you need to choose all vertical grain timber. That will expand and contract width ways (are you allowing for that) but not cup (much). Could be more expensive, worth checking of you can source that within your budget.