bowed timber

[dangermouse2020]

Hi guys, since i last posted i have been working away i got back yesterday and decided that today i would build my new gate. This morning when i went in the garage i noticed that the stiles for the gate were bowed, i suppose its to be expected as both the lengths are 2.4m redwood stock from the local merchants.

I realize there probably isnt anything i can do to straighten the timber (i dont have thickness planer), so i was wondering how i can construct the gate but still stop it from warping and twisting all over the shop. Is it a case of of using the stiles but having the bow in each timber bowing in the other direction? So effectively one stile bowing out and the other stile bowing out in the opposite direction? Then when i drawbore all the M&T joints the stiles should both pull straight and plum? Or will it all just split if i try that approach?

Any advice on how to work with bowed timber?

Cheers

 

[Steve Maskery]

This is a difficult one.
Is the bowing in just one dimension or two? If two, use it for firewood.
If they have just gone banana-shaped in one direction and it is not too severe, you can prise it back into shape. It rather depends on the design of your gate, but if it has a top, bottom and mid-rail, I'd put the bow inwards and clamp up the top and bottom before installing some pretty hefty pegs ( 1/2" rather than 1/4"). That way the mid-rail will be in compression.
Good luck.
Steve

 

[barkwindjammer]

My advice would be to forget about using the bowed timbers for your stiles, it sounds like you bought timber which was dried and then stored indoors under cover, go to the timber yard and find replacements for your stiles from the stacks stored outside, look for sun bleaching within the stack-this will indicate the timber has weathered outside for some time.
HTH

 

[Dangermouse]

Don't listen to this IMPOSTOR !!!!! :twisted: :shock:

 

[dangermouse2020]

Yeh the timber was stored indoors, i assumed as its redwood it would need to be kept under cover until it was treated.

The timber only bows in one direction, banana shaped as you say. But it doesnt bow in the direction you suuggest, as the stiles would be bowing front to back as opposed to side to side. So i wouldnt be able to bow the stiles inwards the middle rail.

The construction of the gate will be a framed ledge and brace, with T&G boards for the panel which will be grooved into the stiles and top rail, and then sitting on both the mid rail and bottom rail.

I was hoping i could have one stile bowing front to back, and the other stile back to front and then hopefully the rails would pull it all in? Or is it just a no go.

Don't listen to this IMPOSTOR !!!!! :twisted: :shock:

:mrgreen:

 

[Random Orbital Bob]

I tell you what......you're already at a critical (and common) designed in failure point. Ie bowed timber
I would immediately stop the inexorable stampede towards compromising the entire project.
You will never, ever get the peace of mind a good quality build gives you with a bowed starting point.

Take your lumps now, before its too late and get the wood back to the yard. Ask for replacements on the assumption that timber was not fit for purpose. Ie for free. Examine each board before you buy for trueness and get weathered timber as the other poster suggested.

Worse case scenario, they won't take it back. Buy new boards anyway. Start well and it will reward you, start with a compromise and you'll regret it

 

[Random Orbital Bob]

The way to look at it is the cost of those original boards was an inexpensive training course in the value of straight timber. The yard will almost certainly be able to plane them for you anyway

 

[dangermouse2020]

Well i followed your advice and bit the bullet and went to the yard for some new timber. The problem i did have was every single length had at least a very slight bow in it (i checked all the stock they had both inside and out), also they refused to take back the bowed timber and declared all long lengths of timber have a bow in them.

So im assuming the only way i am going to get perfectly straight stiles is to buy 5x3" stock and get the yard to plane it down to the required dimensions. Although i am going to try and find a more helpful yard on my way home from work, that hopefully have a better quality of timber which isnt bowed.

 

[Random Orbital Bob]

Thats too bad. The idea that literally ALL long lengths are bowed is just rubbish. Of course many are but there are many variables which affect bowing...obviously the speed at which it drys being the primary one.

When I build furniture, I'm forever sifting though every single board before I buy and its tru to say there wil always be "some" level of deviation unless they're literally just off the planar. But Ive found (with decent yards) that there are enough boards with sufficiently little deviation to satisfy the quality, particularly if they are in a stable environment in terms of moisture.

I do admit that because of having a planar in my workshop, I always run them at least a pass or two....but I have used timber direct from yards many times and its do-able. Particularly for an outsie project where finesse isn't hugely important.

Its a real shame the yard you mention took that attitude....you should name and shame them!!

Arnold Laver, where I get a lot of my hardwoods, know me well enough to only deliver straight boards or I take them back. If I drive their myself, I spent ages picking out individual boards. There will usually be "some geezer" that handles the furniture type people and someone else who handles the builders. The furniture guy will be familiar with the request for very true timbers. The construction guys are more used to working with bowed timbers (particularly roofers) and have strategies for dealing with them.
So...I would find a better yard and make it clear when you go in that you are only interested in true timbers. You could have them over sized and planed to your spec, but you'll need to join them fast after that because they can bow in very short time....very short indeed.

 

[dangermouse2020]

Well im not to keen on giving people bad publicity, but to help anyone else getting stung like i was the yard in question was Hancock and Brown, i actually found them very dismissive with me and wont be going there again. My farther in law has pointed me in the direction of a yard he uses and says they are very helpful so i will try them next time.

In time i hope to get myself a garage workshop, and then will get my own thickness planer. But unfortunately that is a little while off yet and until then i am going to be at the mercy of the yard's.

So whats my best options to avoid having to use bowed timber, and to stop any straight timber i buy from bowing?

Is it a case of hand pick the straight timber myself, and once i have got the timber use it straight away getting it cut and framed together so that it cant bow/twist etc

Should i always avoid storing any timber as it can bow/cup if not used almost immediately?

When I build furniture, I'm forever sifting though every single board before I buy and its tru to say there wil always be "some" level of deviation unless they're literally just off the planar. But Ive found (with decent yards) that there are enough boards with sufficiently little deviation to satisfy the quality, particularly if they are in a stable environment in terms of moisture.

What would be considered sufficiently little deviation? If there is always going to be some slight deviation is there any rule of thumb to tell the difference between the good and the bad?

On a plus note though, i have been given a good lead on a local yard that has a massive stock list on hardwoods, and that will mill/plane any timber i pick out. So once i progress to more high class woodwork, i should be able to get all the timber to the exact dimensions i want (until i have my own workshop plus planer) and construct the piece at least in a basic frame before the timber can distort on me.

 

[Random Orbital Bob]

Interesting question.....I went through all the same dilemmas before getting a planar. The good news is dont despair....you certainly can buy timber direct from the yard thats easily good enough. Remember this is a gate....not a chippendale Outside projects are always "rougher" than fine inside pieces so a bit of tolerance drift wont matter.

As to the how do you know whats good/bad/acceptable......your eye will tell you once you're in the yard eyeing down the length of the board. You just need to get used to the idea of trusting your eye...believe me....its easily good enough. Imagine a spectrum of bowed boards from dead straight to a veritable banana! Once you pick out individual boards of your chosen dimension, you'll quickly observe what I mean....the whole range will be right there...banana to good enough.

Remember, you're eyeing down the length of the board with one edge right next to your eye. Once you've done that to 20 boards odds are 3 of them or so will be straight enough for your purposes....those are the ones you take.

Now the issue of bowing at a later time is due to two things:

1. When you cut or even plane timber, you alter the stresses and tensions in the grain....that can be enough to cause movement
2. When you move timber from one environment to another where there is a considerable difference in moisture content (humidity in the air).

If your board is sourced from a position outside (in the yard) it will be wet....cos of rain etc....if its straight....good...cos you're going to use it outside right. If its sourced from inside the yard and its dry....you then take/store it outside....bad...cos the massive shift in moisture of its surrounding air will catalyse any likelihood of it bowing or worse, twisting.

So your ideal source of timber is a decent yard (sounds like the in-laws have dealt with that), that has a decent qty of stock kept outside....which is true enough (your eye test).

Buy what you need and then only cut it just before you're ready to frame up and that will minimise any movement. Certainly don't cut and leave overnight and if dry when bought...work in the dry...if wet when bought....keep the boards outside ie try and match the humidity from source to destination and delay the cutting till just before you join them.

That should see you through.

Also remember...its a gate....perfection is nice...but not always possible. If you use the drawbore tenons and some decent gap filling type adhesive (Cascamite for eg)....well I cant wait to see the piccys

 

[dangermouse2020]

Yeh i am quite the perfectionist, or as my missus says OCD lol. But i must admit i love planning to the finest 'T' as things seem to go more smoothly for me then. I just hope the pics are worthy of posting once all is said and done.

Ok brilliant there is some really helpful very advice to help me avoid bowed timber and it is very much appreciated.

Cheers

 

[Random Orbital Bob]

You're very welcome.

Now, even though I dont know you...I can predict that plenty of things will go wrong during the build. Things you didn't, couldn't forsee. These are what I call "gumption traps" after my favourite author Robert Pirsig.

When you fall into a gumption trap it will sap your energy and make you want to throw the towel in. Stop. Go make tea (always helps). If you keep working while your gumption has drained you will risk building your bad mood right into the job. Peace of mind is what you're after...that which creates it is good for the gate....that which disturbs is is bad. The" bowed timber before you even start" gumption trap is an absolute killer...you've already nailed that one with a dam good plan...

A really tired cliche but a trueism nevertheles is "you never learn to ski without falling down". So when the mistakes come...and they will, dont be too hard on yourself.

Take the pics and post them, no one here will judge you harshly. On the contrary, you'll get nothing but good humour, encouragement and excellent real world advice thats been hard won in many cases. Everyone here loves wood....showing bits of it being cut and shaped is kind of what this place is all about

 

[dangermouse2020]

Hi Bob, i just wanted to let you know i wasnt ignoring your last post but i have been working away for the last few weeks and my internet access was very limited.

Thanks for your support and advice and i will post pics even if there isnt much of a gate to look at lol

 

[Random Orbital Bob]

No worries old son

 

[rafezetter]

I was reminded of something on New Yankee W/shop whereby Norm said that he used to cut the wood to approximate size then leave it overnight to re-acclimatize / release tensions before trimming to final...

does anyone agree with this procedure?

 

[Random Orbital Bob]

very good idea. If I have freshly cut something for a project the night before and don't get to assembling it (which I try to avoid by the way), I tend to clamp all the boards together and then to my bench which is a known flat surface. That way I keep it guaranteed true.

Acclimatising it overnight sounds like a different way to skin that cat, but there's still additional work to be done.