Attaching table top to brackets

[transatlantic]

I'm in the process of a building a breakfast bar type thing, basically its just a very large heavy duty shelf. I'm wondering what the best way would be to attach the top to the brackets? I'm thinking that I need to account for wood movement across the width, so whatever I end up using needs to have some allowance for that. I'm also not confident that I'm going to get the top flat, so I'd also like the hardware to be strong enough to help in keeping the top flat on the brackets.

This is made from pine btw.

 

[PAC1]

I think I would change the top to something stable.
You could try sliding dovetails or you could get the metal brackets with slotted holes and fix them to the inside edge of your gallows brackets and the top. But I doubt anything will keep new? pine flat

 

[DoctorWibble]

I recently used furniture connector bolts and inserts on a pine bench build. The apron leg connection is not dissimilar to what you have here.
If you set the inserts in the underside of the top you wont have to plug any bolt heads and elongated holes would be hidden in the frame.
I experimented a bit on scrap with the short type of insert sold "for softwood" and the longer type sold for hardwood. The hardwood ones were hands down better in pine. In your case ordinary bolts in the frame would do instead of furniture bolts and would be cheaper. I'd suggest M10. M8 gives substantially less thread on the inserts. Use a 25mm washer under the bolt head and you'll have substantial pulling power without crushing the soft pine.

 

[transatlantic]

I recently used furniture connector bolts and inserts on a pine bench build. The apron leg connection is not dissimilar to what you have here.
If you set the inserts in the underside of the top you wont have to plug any bolt heads and elongated holes would be hidden in the frame.
I experimented a bit on scrap with the short type of insert sold "for softwood" and the longer type sold for hardwood. The hardwood ones were hands down better in pine. In your case ordinary bolts in the frame would do instead of furniture bolts and would be cheaper. I'd suggest M10. M8 gives substantially less thread on the inserts. Use a 25mm washer under the bolt head and you'll have substantial pulling power without crushing the soft pine.

Can you show an example of what you mean? not really following.

 

[Racers]

I use counterbores in the top of the supports which allows for movement, but large washers, buttons etc will work.
You can fix the back and allow the front to move.

Pete

 

[DoctorWibble]

I recently used furniture connector bolts and inserts on a pine bench build. The apron leg connection is not dissimilar to what you have here.
If you set the inserts in the underside of the top you wont have to plug any bolt heads and elongated holes would be hidden in the frame.
I experimented a bit on scrap with the short type of insert sold "for softwood" and the longer type sold for hardwood. The hardwood ones were hands down better in pine. In your case ordinary bolts in the frame would do instead of furniture bolts and would be cheaper. I'd suggest M10. M8 gives substantially less thread on the inserts. Use a 25mm washer under the bolt head and you'll have substantial pulling power without crushing the soft pine.

Can you show an example of what you mean? not really following.

This http://www.theinsertcompany.com/steel_hex_drive_inserts_for_wood_unheaded.php

 

[sunnybob]

Breakfast bars take a huge amount of weight. people lean on them when talking, put their bums on them when its party time, put their elbows on them when sitting eating and wives load them to the roof with heavy crockery when clearing out cupboards, etc.

Unless that wall is solid brick and youre using rawl bolts and at least theee shelf brackets, I strongly recommend at least one leg to the ground.

 

[transatlantic]

Breakfast bars take a huge amount of weight. people lean on them when talking, put their bums on them when its party time, put their elbows on them when sitting eating and wives load them to the roof with heavy crockery when clearing out cupboards, etc.

Unless that wall is solid brick and youre using rawl bolts and at least theee shelf brackets, I strongly recommend at least one leg to the ground.

It's for my elderly mother to put things on while she's cooking, plus the odd fruit bowl and basket of eggs, not so much a breakfast bar in practice. But you raise a good point and I have already explained to her it's not for sitting or leaning on.

I'm planning on using only 2 brackets, but can make a third one if I feel it needs it when it gets installed.

 

[transatlantic]

I use counterbores in the top of the supports which allows for movement, but large washers, buttons etc will work.
You can fix the back and allow the front to move.

Pete

So is that an enlarged hole, or a slotted hole in the direction of movement? and do you use a threaded insert for the top, or just screw directly into the wood?

 

[MatthewRedStars]

I recently used furniture connector bolts and inserts on a pine bench build. The apron leg connection is not dissimilar to what you have here.
If you set the inserts in the underside of the top you wont have to plug any bolt heads and elongated holes would be hidden in the frame.
I experimented a bit on scrap with the short type of insert sold "for softwood" and the longer type sold for hardwood. The hardwood ones were hands down better in pine. In your case ordinary bolts in the frame would do instead of furniture bolts and would be cheaper. I'd suggest M10. M8 gives substantially less thread on the inserts. Use a 25mm washer under the bolt head and you'll have substantial pulling power without crushing the soft pine.

Can you show an example of what you mean? not really following.

This http://www.theinsertcompany.com/steel_hex_drive_inserts_for_wood_unheaded.php

Agreed. I call these tapex - not sure if that's common nomenclature. One fixed at the rear - one on an oversize hole to the front.

Or make the shelf from veneered board.

 

[Roughcut]

If the timber has been suitably acclimatised to an indoor environment then I wouldn't of thought it would move a lot.
I might be inclined to use screws in oversized counter bored holes and then cover the holes with wooden plugs, or maybe even use Miller Dowels.

 

[sunnybob]

It's for my elderly mother to put things on while she's cooking, plus the odd fruit bowl and basket of eggs, not so much a breakfast bar in practice. But you raise a good point and I have already explained to her it's not for sitting or leaning on.

d.[/quote]

OH, so you think your elderly mother is going to take notice of what you say? Are you THAT special? (lol)

my mother in law was still climbing on chairs and reaching over the sink to take the curtains down for washing when she was 91. despite her daughter going spare at her time after time after time.

Build it bullet proof.

 

[transatlantic]

OH, so you think your elderly mother is going to take notice of what you say? Are you THAT special? (lol)

my mother in law was still climbing on chairs and reaching over the sink to take the curtains down for washing when she was 91. despite her daughter going spare at her time after time after time.

Build it bullet proof.

 

[Racers]

I use counterbores in the top of the supports which allows for movement, but large washers, buttons etc will work.
You can fix the back and allow the front to move.

Pete

So is that an enlarged hole, or a slotted hole in the direction of movement? and do you use a threaded insert for the top, or just screw directly into the wood?

I drill a 8-10mm hole then drill a clearance hole for the screw and countersink, I usually use screws straight in to the top.
You need to make a judgement about how big a hole so as not to weaken the wood.

Pete

 

[ED65]

I'm thinking that I need to account for wood movement across the width, so whatever I end up using needs to have some allowance for that. I'm also not confident that I'm going to get the top flat, so I'd also like the hardware to be strong enough to help in keeping the top flat on the brackets.

Does the fixing method need to be hidden or are you not averse to visible fastenings?

First response above mentioned what I was going to suggest: expansion plates. If they're good enough for tables they're good enough for this, but you have to not mind that they'd be visible from the underside.

 

[ED65]

If the timber has been suitably acclimatised to an indoor environment then I wouldn't of thought it would move a lot.

Obviously the stability of the environment is a factor but 400mm is more than enough width that movement needs to be accounted for in nearly any wood and certain species move much more than others. Pine is one of those woods where the change in width can be surprisingly large, enough that a comfortably oversize clearance hole might not be enough to fully allow for it.