timber movement

[mrgrimsdale]

table tops:
dry but unheated workshop, dry heated living area; result; timber movement
yes I know about alternating the grain. I'm also wondering if a thick top is just not viable if you don't know where it's going and can't control drying.
I wondered about making a timber seasoning box with 8x4 chipboard etc. Just to keep the current workpieces in, and a bit of stock. 8' cube with shelves/racks
Does anybody do this? Suggestions for a small temperature controlled heater? Or de-humidifier?

[mooretoolsplease]

for the heater you can use a green house heater, the small tube ones.
I've got a couple here to put into my paint storage.

[paulchapman]

I sometimes wonder whether we worry too much about timber movement, Jacob. I'm coming round to the view that provided the construction method allows for seasonal movement then, generally, there isn't too much of a problem.

I'm old enough to remember the days when nobody had central heating or double glazing. When they had central heating and double glazing installed their furniture didn't all fall apart. So maybe it's one of those things where there is potentially a problem but, provided the furniture is constructed properly and allows for movement, the problem seldom arises - apart from a few minor irritations like drawers sticking.

Cheers

Paul

[sainty]

quarter sawn timber would be a start. A possibilty if you can get to all the nice planks before everyone else gets there grubby hands on them. Not probable if you have to use your own stock.

I have a similar problem, someone called me re a tabletop, in beech. I have some beech that's been sitting in the workshop for a bout 6mths, so if they want to come and have their christmas dinner in my workshop I can guarantee to thop will stay flat. In the end I suggested that if they wanted a quick solution - that wouldn't end up suffering from timber movement I could use veneered MDF (3 Laminations, 18,12,18) and lip it with solid.

I , like you have an unheated workshop and have wondered about having a controlled area to keep timber for upcoming projects - but unlike you I have done nothing about it!!!

I will watch this with interest.

rgds

Stu

[sainty]

Dec 3, 2008 10:01:49 GMT paulchapman said:

I sometimes wonder whether we worry too much about timber movement, Jacob. I'm coming round to the view that provided the construction method allows for seasonal movement then, generally, there isn't too much of a problem.

I'm old enough to remember the days when nobody had central heating or double glazing. When they had central heating and double glazing installed their furniture didn't all fall apart. So maybe it's one of those things where there is potentially a problem but, provided the furniture is constructed properly and allows for movement, the problem seldom arises - apart from a few minor irritations like drawers sticking.

Cheers

Paul

I thought that Grim was talking about cupping when he mentioned alternating growth rings. Like you say, movement across the width of a board can be designed out.

rgds

Stu

[paulchapman]

My workshop is unheated and I've just finished an oak table with a thick top made up from eight boards. I'll let you know what happens..........

Cheers

Paul

[mrgrimsdale]

Dec 3, 2008 10:10:38 GMT sainty said:

I thought that Grim was talking about cupping when he mentioned alternating growth rings. Like you say, movement across the width of a board can be designed out.

rgds

Stu

Yes cupping. They stay dead flat in the workshop but cup slowly in the house. Maybe do nothing and tell clients tuff titty this is real furniture not mdf ;D

[engineerone]

interesting jacob.

i wonder whether in part it is the result of people not allowing any real airflow through their houses because of central heating.

as we have discussed before, with sash windows etc you have a little air flow, but too often people stop all the draughts, and thus the air on the top of the table is at a sufficiently different temp to that on the bottom, so the "drying " is unequal.

of course you could always make an mdf top that you edge ;D

david charlesworth certainly has told me he does not believe it is possible over the long term to guarantee that every flat solid top will stay flat. i think he means that there is an element of luck in it. one thing you build might well stay flat, the next not.

however it is certain that the dryer the wood before and after working the less it is likely to cup. but also the design is important too as paul says.

paul

[robo]

I like a bit of cupping - it adds character and confirms it is made from real wood? ;D ;D

R

[paulchapman]

I think the only answer, if you can't use quarter sawn wood, is to rip it into narrower pieces and join 'em up - but that sometimes gives a look that you don't want.

Cheers

Paul

[mrgrimsdale]

Dec 3, 2008 13:14:05 GMT robo said:

I like a bit of cupping - it adds character and confirms it is made from real wood? ;D ;D

R

And if you spill anything it stays on the table - a clever traditional design feature ;D

[jaco]

Dec 3, 2008 13:52:35 GMT mrgrimsdale said:

Dec 3, 2008 13:14:05 GMT robo said:

I like a bit of cupping - it adds character and confirms it is made from real wood? ;D ;D

R

And if you spill anything it stays on the table - a clever traditional design feature ;D

AND, So, What Is Wrong With That?

[mrgrimsdale]

Dec 3, 2008 12:12:07 GMT engineerone said:

however it is certain that the dryer the wood before and after working the less it is likely to cup.

It's more the change of environment.
Winter absolute air humidity is low, but relative humidity is high outside (cold) but very low inside (warm). So movement can be greatest at this time of year if timber which has reached equilibrium ('dry') in one situation is then moved to the other.
In summer the relative humidities and temperatures, in and out, are closer, so less of a problem for wood which has reached equilibrium. but more of a problem for wet or unseasoned wood.

[dom]

Comb joints ? Used to work well for me.

[thebloke]

Dec 3, 2008 10:19:44 GMT paulchapman said:

My workshop is unheated and I've just finished an oak table with a thick top made up from eight boards. I'll let you know what happens..........

Cheers

Paul

Hi Paul - we need pics...then it's finished ;D - Rob

[gazza]

Dec 3, 2008 10:01:49 GMT paulchapman said:

I sometimes wonder whether we worry too much about timber movement, Jacob. I'm coming round to the view that provided the construction method allows for seasonal movement then, generally, there isn't too much of a problem.

Have to agree Paul, some of the antics people get up to is verging on the ridiculous, stacking in the living room for a few months is one example