Solid Oak kitchen work top

JimmyL

Hi,

I am thinking of making a solid oak worktop with wide(ish) oak planks (30 or 20 mm thick). I will be using either dowels or biscuit joints (plus clamping of course). Would these be sufficient to keep the worktop together - I have already tried this with pine without any problem.

I will also be making flat cabinet doors (18mm) using same the technique.

Thanks

Jimmy

P.S. Why are normal worktops made of short narrow strips? for strength? economy?

kadman

JimmyL wrote:

Hi,

I am thinking of making a solid oak worktop with wide(ish) oak planks (30 or 20 mm thick). I will be using either dowels or biscuit joints (plus clamping of course). Would these be sufficient to keep the worktop together - I have already tried this with pine without any problem.

I will also be making flat cabinet doors (18mm) using same the technique.

Thanks

Jimmy

P.S. Why are normal worktops made of short narrow strips? for strength? economy?

Hi Jimmyl,

I'm going to answer this in reverse order, so lets take the last question first.

Worktops that are made from narrow short strips, are utilising otherwise non usable timber sizes, and as such are a stable economic forms of construction.
It is a sensible use of valuable timber, that would otherwise be discarded.
Worktops that are made from long narrow strips , are constructed as such to be a stable form of producing a wide surface in solid wood. You mention that you are going to construct your tops from widish planks. I would be reluctant to use any planks wider than about 125 mm. The narrower the planks, the more stable the top.

If , for aesthetic reasons, you intend to use wider planks, then make sure that the timber you use is quarter sawn oak if possible. Looking at the end grain, the growth rings will be seen to run from top to bottom of the plank.
This type of board is less likely to cup or twist after construction.

As for your joining methods, i would be inclined to use additional dovetail keys on the bottom of the top along the joints. These would be placed at about 600 mmm intervals or nearer. They are about 15 mm thick in a 25 mm board, and look like a dikky bow. If you can visualise that you should understand their purpose. If not post again and I will draw it for you. When you are joining your boards, make sure that you alternate the grain pattern at the end of the boards, one up, one down, and this will be a more stable arrangement.

I would also reccomend finishing the bottom of the top as well as the top, with whatever surface finish you are using. This will prevent moisture from entering through the bottom of the top, and warping or swelling the top.

When you are fixing your top, do not use steel screws. These will react with the tannin in the oak and cause black staining, which may bleed through to the surface. And remember to use shrinkage plates that will allow movement of the top, if you do not you run the risk of splitting the top.

You have to have the same regard for the door construction, as it is the same process . You should also consider a top and bottom batten inside your doors , to keep the door straight. These battens should be slot screwed, again to allow movement. You could also fit a loose construction batten top and bottom of the door, to serve the same purpose.

Considering you are using solid panel construction methods , I would advise that you search the internet for as much info as you require. Solid carcase construction methods are so used for the purpose of allowing timber to move. And in your case this is the type of instruction you need.
In the current climate of chipboard/ mdf construction, solid panel construction methods are slowly being forgotten.

I think I,ve covered most areas, if I have n't , someone else will surely pick up on it.

Any other questions please ask.

kadman

JimmyL

Thanks Kadman. That was very informative.

I wasn't planning on using quarter sawn timber (due to cost) but will reconsider. I have seen dovetail keys but not sure if my skill is up to it (might finally have to buy a router). Another crude method I was thinking of using is to drill through each plank (widthwise) and use long bolts to hold them together - I will be sticking on a wide front piece to give a really chunky look.

Thanks again.

P.S. I will be use oak veneer mdf for the carcase but with solid end panels (if they are visible).

kadman

Hi Jimmyl,

If you propose drilling width wise, you would need extremely long bolts, and drill bits. If your timber is jointed correctly, and dovetail keys used, you should have no problem.

Another thing to do would be to buy oak that is suitably kiln dried down to 8-10% for cabinet making. In order to condition your oak for the environment it will be used in, its a good tip to leave your roughly dimensioned timber for three to four weeks in the house. Put it in a cool room first, and over a period of three to four weeks , bring it into the kitchen ,to let it get accustomed to the humidity/temperature levels it will be left in.

Its no use buying oak from a supplier that was kiln dried 12 months ago, and left in an open area since drying. Chances are it will have absorbed moisture from being left in the open. And to subject this to kitchen heat levels is courting disaster. :eek:

Do your home work now , and avoid expensive repairs later.

kadman

JimmyL

Kadman,

Thanks again.

Jimmy

JoeB-

kadman wrote:

And remember to use shrinkage plates that will allow movement of the top, if you do not you run the risk of splitting the top.
.
.
You have to have the same regard for the door construction, as it is the same process . You should also consider a top and bottom batten inside your doors , to keep the door straight. These battens should be slot screwed, again to allow movement. You could also fit a loose construction batten top and bottom of the door, to serve the same purpose.

Hi Kadman
Would you be able to explain what you mean by 'shrinkage plates'? And if possible also explain a little bit about 'buttons', used to join table tops to the table apron? (I think 'buttons' and 'apron' are the correct terms.)

When something is 'slot screwed' it is screwed through an elongated hole but how does one prevent the screw from tightening so much that it pinches the wood so tight that the whole purpose is defeated? i.e. the screw can't move in the slot?

And finally (:p) could you explain what a 'loose construction batten' is?

Cheers, much appreciated.
Joe

carpainter

Just to add to the already excellent advice; narrow strips of wood keep timber shrinkage and movement down to a minimum and will help to minimise cupping; try and alternate the grain direction for each board to balance any movement that does take place. I've used biscuit jointing very successfully to make up wide boards from narrow stock, applying plenty of clamping force with sash cramps. I've been using Gorilla Glue and find it very effective, especially for joints exposed to water.