Pre-planing/thicknessing rough stock

[Woodypk]

Hi all,

I was wondering what is best practice when it comes to planing and thicknessing boards for future use.

Say I make a lot of products to order that I would like to sell. These products just so happen to be 20mm thickness for example, and I buy in my rough sawn timber at approx 25-27mm thick.

To save setup time, Is it a bad idea to spend a chunk of time, maybe a whole day, thicknessing a load of boards down to 20mm ready for when they will need further dimensioning (cutting to length/width for example) and then storing them. Or is it better to only plane and thickness them as and when you need them? OR... would it make sense to take them to maybe 21/22mm and then give them a final run through the thicknesser on the day you'd like to use them?

Obviously wood moves and changes shape due to environmental factors and you wouldn't be able to guarantee the EXACT thickness of the finished board after it's been stood for a while, but for non critical finished thickness boards, does this matter much?

My worry is that If I dimension the board to the correct thickness and then store the boards for future use, that they may become cupped, bowed or twisted and then unusable because they're unable to be planed further as this would take them under their final dimensions.

I'm just trying to get my head around what's the best way to make the most efficient use of my time and reduce the amount of time moving from one machine to another, setting up, cleaning down, tidying up etc, but also what's the best way to ensure the timber is ready for use and doesn't become unusable for when it's needed.


Thanks guys.
Tom

 

[Droogs]

If I wanted to have 20mm at the end, I would pre-process to 24mm taking material from both sides and put in stick. But I would want to have a good amount to do ,so that once in stick the weight helped to prevent any cupping or bowing on the shelves. I would have 2 sets of shelves as well. This way once a month I could turn the pieces over & rotate the stack with the top pieces going to the bottom to help with that as well. That way I could minimize the risk of problems on an actual build.

edit grammar

 

[julianf]

I won't pretend to know what anyone else should do, nor what I should be doing half the time, but -

I'm cutting parts by template routing.

If I thickness the whole board, any cupping is even more of a problem, as the whole board needs to be taken down to the lowest common denominator.

Instead, I go over one side, and the other side where I want to see anything specific, with a hand held belt sander, and then rough cut parts.

So then I can tessellate shapes and not loose as much stock. The boards are largely dry prior to this, but I can then store the smaller rough blanks much easier than I can whole boards, let them acclimatise better and do their final movement, before taking them down to final thickness and edge finishing.

Again, I don't know what's best for you, but this seems to be working for me currently

 

[Jacob]

Hi all,

I was wondering what is best practice when it comes to planing and thicknessing boards for future use.

Say I make a lot of products to order that I would like to sell. These products just so happen to be 20mm thickness for example, and I buy in my rough sawn timber at approx 25-27mm thick.

To save setup time, Is it a bad idea to spend a chunk of time, maybe a whole day, thicknessing a load of boards down to 20mm ready for when they will need further dimensioning (cutting to length/width for example) and then storing them. Or is it better to only plane and thickness them as and when you need them? OR... would it make sense to take them to maybe 21/22mm and then give them a final run through the thicknesser on the day you'd like to use them?

Obviously wood moves and changes shape due to environmental factors and you wouldn't be able to guarantee the EXACT thickness of the finished board after it's been stood for a while, but for non critical finished thickness boards, does this matter much?

My worry is that If I dimension the board to the correct thickness and then store the boards for future use, that they may become cupped, bowed or twisted and then unusable because they're unable to be planed further as this would take them under their final dimensions.

I'm just trying to get my head around what's the best way to make the most efficient use of my time and reduce the amount of time moving from one machine to another, setting up, cleaning down, tidying up etc, but also what's the best way to ensure the timber is ready for use and doesn't become unusable for when it's needed.


Thanks guys.
Tom

In general it's a very bad idea, for the reason you give and also because you can get better 'yield' from shorter lengths - you don't have to plane off so much to get them straight.
All your timber should be cut to size according to your design/cutting list, before planing anything, except for short lengths more easily handleable as one piece to be cut after planing.
As you select for cutting to size you start with the longest lengths required and cut them from the shortest lengths of stock available and work down through your list. Stuff with bends and twists may be unusable at length and gets set aside for shorter pieces.

Years ago I watched somebody learning this the hard way: he was a joiner setting up his first workshop with a chunk of grant money, new machines, new stock of yellow pine and other sawn stuff.
He was used to buying PAR, assumed that this was the starting point and set about enthusiastically planing his new stock. He got a bit worried about how much he had to plane off to get them straight and square.
He got more worried on day 2 when he found that all the day 1 stuff had bent a bit and needed planing again.
By day 3 he was getting tearful about the sheer impossibility of the task - some stuff quite impossible to get and keep straight as it would be reduced to zero thickness in parts.
But he did have a huge beautiful pile of shavings and his wife was really impressed by the amount of work he'd done!!

 

[Adam W.]

I'll second what Jacob said.

Just buy really high quality timber of the right cut and store it somewhere dry. Keep some in your workshop if you have the space and replace it when you use it.

 

[Woodypk]

In general it's a very bad idea, for the reason you give and also because you can get better 'yield' from shorter lengths - you don't have to plane off so much to get them straight.
All your timber should be cut to size according to your design/cutting list, before planing anything, except for short lengths more easily handleable as one piece to be cut after planing.

Jacob, that's what I'm currently doing.

It makes sense as the longer the length of rough board, the more you usually need to take out to get it to a regular, flat size. So I usually cut them into maybe a double the length of the product, per board after being crosscut at the rough stage, before I plane out the rough defects.

It also helps that the shorter the piece, the less of a bow/cup/twist will usually be imparted into the timber if it decides it want's to move.

So, even at shorter lengths, are we thinking that this is a bad idea?

I take your comment on board Droogs. Maybe thickness them down slightly. Perhaps not as far as 1 or 2mm off final thickness, but enough to take all the rough out of the board.

When I first started milling my own boards, I used to find I would run the board through the thicknesser, and after maybe 6mm or so, would find the board extremely bowed. A note to those just starting out - if you use a thicknesser, flip the board end over end on each pass to ensure equal amounts of material are removed from each side which allows the wood to relieve tension and moisture at an equal rate.

 

[Peter Sefton]

If I wanted to have 20mm at the end, I would pre-process to 24mm taking material from both sides and put in stick. But I would want to have a good amount to do ,so that once in stick the weight helped to prevent any cupping or bowing on the shelves. I would have 2 sets of shelves as well. This way once a month I could turn the pieces over & rotate the stack with the top pieces going to the bottom to help with that as well. That way I could minimize the risk of problems on an actual build.

edit grammar

You took the words out of my mouth

 

[Woodypk]

Thanks for the info guys.

On a side note, how far apart would you usually place your stickers to ensure you had adequate support on the board stack?

 

[Adam W.]

1/2" - 3/4" and 2' apart. Put the stack edge on to the wind.

With a roof on it. You can paint the ends with emulsion, but if a board has tension in it, it'll split badly anyway.

 

[pgrbff]

I usualy cut to length plus 4", straighten but leaving it oversize to straighten again before final use and also put one square edge on as well, again leaving some extra to straighten before use if it moves again. I do not put weight on it as if it's going to bend it will anyway once you take the weight off.
i take the view that every time you take some material off you relieve some of the stress and it will tend to move. If possible I will stack it where it will be ultimately used.

 

[Woodypk]

1/2" - 3/4" and 2' apart. Put the stack edge on to the wind.

With a roof on it. You can paint the ends with emulsion, but if a board has tension in it, it'll split badly anyway.

Adam,

Fortunately, I can keep my stack inside my workshop so fully covered all year round. There is adequate ventilation in there too.

And pgrbff,
Thanks for the input. What you suggest seems just about what I'm doing now.

Hopefully at least partly milling the pieces and taking all of the rough off will save me time when it comes to working through my order list, rather than sorting, picking and milling rough sawn boards at the start of each job.

Thanks guys.