Timber for worktop advice please

I am planning my new kitchen worktops. In the last house I had laminated beech block and was very pleased with it but I wonder if there is any good reason that the pieces were so small

Reason being that I have been offered some large pieces of timber, either 12 inch wide air dried oak planks or wide (not yet cut so not sure about size) walnut and I would like to laminate three boards together edge to edge. Would this make a reasonably stable worktop? Any comments about what timber to use? How thick should the timber be? Someone suggested that I laminate a cross piece to each end to stop the ends splitting

I'm exploring ideas at the moment and as this is new to me I welcome any advice

When I say that 'I will laminate' I actually mean that someone with all the right woodworking kit will do it for me

Anna

-- Anna Kettle Lime plaster repair and conservation Freehand modelling in lime: overmantels, pargeting etc Tel:    (+44)  01359 230642 Mob:  (+44)  07976 649862 Please look at my website for examples of my work at:

formatting link
 

Reply to
Anna Kettle
Loading thread data ...

"Air dried" will probably be 15% moisture content if you're lucky, whereas manufactured beech worktops are normally kiln dried to below

10%. It's asking a lot of a 12" plank to remain stable enough for a kitchen worktop, which is partly why the beech ones are made up of small sections. Nice idea but....
Reply to
stuart noble

Cost. And I suppose stability.

Small pieces of wood mean vastly less waste at manufacture. Hence the ultimate like chipboard. Also mixing them up like this means less chance of warping.

Reply to
Dave Plowman (News)

Depends on what type of house its going into. Did something very similar 30 years ago with a few old Oak planks in our first house and its still there .. and looks fine still:))....

Reply to
tony sayer

This is non-trivial woodworking. At least if you want it flat afterwards.

A 12" oak board will stay flat in a kitchen _provided_ that it's quarter-sawn from a very large log. If it's flat-sawn from something barely 12" wide (or even 24" wide") then it will go all over the place.

I've done 12"-wide 2" oak in a kitchen twice, because there was a big stack of it that had to be used up that week (workshop move) and it was a "use it or lose it" situation. This was prime grade stuff and it worked well afterwards. In general though, I wouldn't go anywhere near that wide. Made myself a new workbench out of the same boards at the same time and I ripped those down to 4" wide and re-laminated them first. Do you _need_ 12" width? I might think about it for a posh dining table, but if you're not going to sit there admiring it all day, why deal with the hassle. For a typical worktop I'd probably rip to "a third of the width" as a nice round number of boards. Even board widths will look better than making them an exact dimension. We judge results with our eyes and a sense of proportion, not with a ruler.

Moisture content and kiln drying is a red herring. Doesn't matter if it was dried to 8% once, stick it in a kitchen and it's all going to be 15%+ afterwards. You can't just "take the water out" of timber, it goes back in again afterwards.

As a practical issue, you really don't want to make kitchens out of timber that's currently at 8%. Let it equilibriate to 15% before you start cutting it, then you'll see less movement when it does finally shift to 15%. Working it bone-dry is crazy if you know it's going to spend the rest of its time somewhere slightly humid.

You need to have read Bruce Hoadley before going near this stuff. Seriously.

Kiln drying matters for softwoods (and for the colour in beech). For oak though, and for most dimensional issues with beech, then air- drying is just as good and generally thought to be better. Certainly most kiln-dried English hardwood is only done that way because someone was in a hurry to process low-end timber and make a buck out of it (so it's likely to be low-grade because the input green wood was low- grade).

As always, good quality wood (i.e. English hardwood) is cheaper than low quality, but you have to look further to find it.

Don't like oak myself. Love it in the dry, hate it for kitchen worktops. Iron stain from wet cast iron pans is the problem. Oxalic acid cleaners help, but they always seem to pick up a persistent stain in the end.

Whatever looks good, up to about 2" thick. You could go down to 1" easily. Thinner than this works too, but it's going to cost more in the work of building up a stable constructed slab than you'll save in timber. It also feels bouncy on the surface.

That will screw up for sure. If you glue it, it will split. This is called a "breadboard end" and it's a commmon practice. However it's a rare practice to do it properly. It's a long-grain / end-grain joint which is the worst-case for joinery and dimensional movement. The point about it is that it is a _SLIDING_ joint, so that it can cope with movement. If you glue it, it will split. You don't glue or laminate breadboard ends. If you glue it, it will split. Doing them for kitchens or big tables needs knowledge (Fine Woodworking issue #140 seems to be burned into my memory) They also have a secondary role in resisting cupping of the main surface, but only if they're strong enough to do so and if the tabletop is short enough that a force on the ends is still enough to hold the middle flat. If you glue it, it will split. The usual good breadboard end is a _big_ tongue and groove (tongue on the worktop) and a few wooden pegs through the tongue to hold it together. One peg is in a hole through the tongue, the others are in slots (tongue only) to allow movement. Worktops are rigid-pegged at the front edge, tables are rigid-pegged in the middle. If you glue it, it will split.

A useful trick is to make the breadboard ends thicker than the worktop, with a great big projection underneath where you can't see it. This make them stronger and makes the whole thing look thicker and "posher". 2" ends on a 1" worktop is common. You can also thicken and move the tongue to the bottom of the worktop so that there's only a single shoulder on its top half. Thick, strong tongues are good and you can extend the ends' thickness downwards to keep that strong too. If it's a tabletop, hide the thickness step with shallow chamfers, or else do something decorative about it. I've done nice tables where the step flowed into the top end of a diagonal, tapering leg.

Did I mention not to glue it?

Reply to
Andy Dingley

AFAIK kiln drying is pretty well required to get to 15% in the UK. Even indoors the RH is above 50% most of the time.

Reply to
dennis

Look up the difference between RH and EMC. Like I said, read Bruce Hoadley.

Reply to
Andy Dingley

What is the recommended EMC for a wet place like the UK?

Reply to
dennis

Depends what the average relative humidity is in your particular kitchen. 8-10% moisture content is the norm for manufactured furniture in a centrally heated environment.

Reply to
stuart noble

Have ordered Bruce Hoadley from the library and will read with care thanks but meanwhile how is this for a plan

Use walnut not oak. I dont like the idea of iron stains either. Cut into pieces 4" by 16" (these dimensions are off the top of my head and to be modified in the light of reality and design) and 1" thick with

2" thick around the edge so it looks chunkier and then laminated together to make the worktop

Breadboard ends to be avoided (the worktop will be about 14 ft long) unless I and the woodworker have really got to grips with the idea. Definitely no glue!

The walnut will cost 40 pounds per cubic foot. Is this a reasonable price?

Anna

-- Anna Kettle Lime plaster repair and conservation Freehand modelling in lime: overmantels, pargeting etc Tel:    (+44)  01359 230642 Mob:  (+44)  07976 649862 Please look at my website for examples of my work at:

formatting link
 

Reply to
Anna Kettle

A big gamble I'd say. Buying one off the shelf might be cheaper in the long run. This type of laminating is a highly specialised affair

Reply to
stuart noble

You don't get to recommend EMC, it;'s forced on you by the RH in your climate. You can dry timber to any MC you like, right down to 0, but once it's out of the kiln it will tend to equilibriate again back to that EMC value. It will also change through the year, as the RH (and so the EMC) changes.

One of the surprising things about this is that all timber species follow the same curve of EMC vs. RH (as a good approximation). Typical numbers are:

RH EMC

0 0 25 5 50 9 75 14 100 25

So indoor, dry, centrally heated, poorly ventilated timber is going to find itself sitting around EMC of 6% (i.e. drier than kilned) whilst outdoor timber will be around 15% (i.e. wetter than well air-dried). "Typical" comfortable indoors will be around 10% (a design figure for predicting finished shrinkage) and maybe 12% for kitchens or bathrooms.

Water is held in timber in two places: within the cells and between the cells. Once dried, the intra-cell water still comes and goes with humidity but the inter-cell water is gone and won't return unless you submerge it. For that reason, even wood in a sauna won't return to the MC it had when green.

If you go from MC figures to dimensional change, you'll find that species starts to make a difference, as does the radial / transverse axis. However tangential is roughly twice radial, across species.

Incidentally, Hoadley's at Google Books

formatting link
's also the Forest Products Handbook which is online as PDFs, AFAIR.

Reply to
Andy Dingley

So what chance does the OP stand of getting a stable worktop from laminated walnut of unknown moisture content?

I've heard that the RF glue used in commercial laminating requires a sub

10% MC to function, which is a good guarantee that the wood is dry enough.
Reply to
stuart noble

By doing it another way: by constructing a design that remains "stable" (i.e. flat) despite changes in moisture and dimensional change, using the 800-ish year old techniques of "joinery". This is an advance over mere carpentry in that the design of a joined panel, a panel held loosely in a frame of long-grain (i.e. no-shrinkage) members, won't warp even when things do shrink.

Alternatively you can use 10 year old air-dried timber that has been through enough seasonal cycles that it no longer moves as much when its moisture changes.

It _should_ only be used on dry timber, but that's only because it's your basic microwave heating that heats water molecules. You're supposed to do this to wet glue on dry timber, so that only the glue is heated. If you do it to wet glue on wet timber they're both heated and you get a weaker joint. AIUI this won't matter at the level we're discussing here, but it's an issue if you're building structural Glulam or aircraft.

Reply to
Andy Dingley

If you have to achieve similar results repeated down the length of a long worktop, then consider chunky sliding dovetails underneath and framing it that way.

You could even look at veneering onto thick marine plywood, then a coating of Rustin's Plasticoat. You're probably looking at commercial veneering (i.e. big heated press) to get it robust enough, but I wouldn't rule it out.

4 to 400 for walnut. _Everything_ depends on the grade of it. American stripey is cheap(ish), English (i.e. local-grown) is variable according to how big / sapwoodey / bug-chewed it is. English is often cheap (but low quality) because you're seeing local crap that no-one would bother shipping. Armenian gunstock blanks (i.e. near the top) can be an insane price and then there's veneer-grade as well...

If you like the looks and you can afford the finished result, then that isn't a bad price.

Reply to
Andy Dingley

HomeOwnersHub website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.