Cutting into Two Pieces of Equal Thickness

[samg86]

I'm just starting out with woodworking as a hobby, and have been trying to figure out no doubt quite a basic question - what is the best method to split a piece of wood into two pieces of equal thickness?

Kind of like my low quality diagram:

I would guess that generally a jigsaw could do this (I believe Steve Ramsey did this on his chess board video) , but whats the height/width limitations for an accurate cut? Is this even worth attempting with just hand tools (and without a planer for afterwards?)

Is 'resawing' the correct term for this type of cut?

Thanks for your help - looking forward to getting more involved!

 

[nev]

Hi Sam welcome.
A small piece (e.g. smaller than the tenon saw height) I could probably do with a decent tenon saw, otherwise it would be a bandsaw job I think. But I'm only a tinkerer, maybe the pro's will have a better idea?

 

[joiner_sim]

Welcome to the forum,
I'd only attempt the cut with a jigsaw if the blade is longer than the depth of the timber you wish to cut. Even then it probably is not the best way to do the task as jigsaw blades can wander. A nice sharp handsaw is the cheapest way to do it, but accuracy will depend on your skill level.
Other ways to do it would be to use a bandsaw or table saw and sometimes you can pick up cheap second hand ones from ebay.

 

[Steve Maskery]

The process you are describing is called re-sawing or deep ripping. It needs a blade with fairly coarse teeth. In a home workshop that usually means about 3 teeth per inch (TPI). The wider your board the coarser the blade should be, so a re-saw blade on a sawmill resaw may have one tooth every 6". This is because it is not the tooth that matters, it is the size of the gullet, which is the hollow area behind every tooth. This is the part of the blade that carries away the sawdust, so a wider board means more sawdust, which means bigger gullets are needed which mean fewer TPI.
If your workpiece is not too wide, you could do it with a standard rip saw. You would need to practise, but it can be done.
A bandsaw is by far the better option but obviously requires you to have a BS in the first place. You would need to have the right blade fitted (ask Ian John's advice at Tuffsaws) and the machine would need to be set up spot on. The thickness of the workpiece means that any laxity in setup is magnified because of the resistance of the wood. If it is not set up well you will start to wander off the line ("drift") and your job will be ruined, although you can control the cut quite well using a single-point fence, even if the setup is not perfect.
HTH
Steve

 

[bodge]

It seems that Mr. Maskery replied while I was typing and explained everything far better and in more depth than I ever could, so I'll just say hello and welcome to the forums!

 

[samg86]

This makes a lot of sense, thanks for the quick replies!

 

[Jacob]

It's surprisingly difficult and involves a lot of waste, not least because the pieces tend to bow after sawing and will need planing. I'd gauge two lines and try to keep the saw between them.
You might find only one board will meet your desired size in which case it could have been better to plane down to size and forgot about splitting.

 

[Peter Sefton]

Hi Sam welcome to the forum
As Jacob says it can be wasteful to the extent you end up with two thin bits of fire wood. I call this cut Deeping as you are cutting the timber in its depth - if this is undertaken in the timber yard they call it re sawing (usually in larger bulks of timber).
To try to control/minimise the timber movement I would plane the timber on all four sides but keep it as thick as possible and as narrow as you can so you are deeping less timber. Planing all round (PAR) means the timber is straight and accurate prior to cutting and the plank has already had its surface exposed to fresh air. When you deep the board it's a shock for the timber which has never seen the light of day before and the timbers inner tension is released, pre planing it gives you a better chance of keeping two useable planks. You may wish to put the boards back in stick and held with G cramps after cutting for a day or two, to try to hold it flat although I usually let nature take its course.
You will stand more chance of being successful if the original board is quarter sawn and dry.

Cheers Peter

 

[Jacob]

Hmm not sure about doing any planing first - if it bows after cutting you might wish you hadn't planed, so you could have had more to play with.
Personally if I've got to rip anything I'd do it "as is" and leave all planing til afterwards.

 

[Steve Maskery]

+1, unless the workpiece is very badly twisted or bent to start with, in which case yo are probably wasting your time anyway, unfortunately.
And don't underestimate how much wood you will lose in practice. It's very tempting to think that a 1" board will yield two 1/2" boards, it won't. TBH you will be lucky if each ends up a full 1/4" when planed.

 

[Peter Sefton]

I agree that generally Deeping is a waste of time and timber unless you have got a lot of thickness to play with.

 

[Kalimna]

May I suggest that the easiest/ best way to achieve your aim would be to ask someone with a bandsaw who might be able to re-saw for you? The caveat of timber waste would still be there, but less likely for someone familiar with milling timber. Failing that, and unless the wood has already been acquired, purchase at a thickness you require. If, however, book matching is what you are after, then maybe veneer over a substrate would be easier?

Cheers,
Adam

 

[Karl]

I'd break out the rip saw and get sawing - I did it here on much bigger pieces.

Cheers

Karl

 

[Fromey]

It's surprisingly difficult and involves a lot of waste, not least because the pieces tend to bow after sawing and will need planing. I'd gauge two lines and try to keep the saw between them.
You might find only one board will meet your desired size in which case it could have been better to plane down to size and forgot about splitting.

Quoted for fact.

I've given up on resawing 1" wood in half because of this subsequent bowing problem. Counter intuitive as it may seem, it's often best to just plane down evenly from both sides and get one board. A good scrub plane and/or jack plane is what you need for that.

 

[Mr T]

Can I ask why you want to do this? It may be easier just to buy two thin pieces of wood and use the thick piece for something else!

What size is the original piece and how thick do you want the split pieces to be, is it hardwood or softwood? All questions that would help to decide the best path.

Chris

 

[samg86]

Thanks for all the responses - much appreciated. It seems that as a novice with limited tools I'll stick to buying sizes I actually need rather than getting ahead of myself!

Can I ask why you want to do this? It may be easier just to buy two thin pieces of wood and use the thick piece for something else!

What size is the original piece and how thick do you want the split pieces to be, is it hardwood or softwood?

At this stage, its mostly just theory to be honest. I've been watching a video on a chess board project I want to try, where he resaws a 1" piece of walnut with a bandsaw. I figured that really you only need a board a 1/8" thick for that top layer, and can only seem to find 3/8" walnut boards online in the UK so wondered whether it was possible to split them given the cost of walnut.

I'm a complete novice though, and I'm waiting to move house house in about four weeks so that I even have the space to get started.

 

[Steve Maskery]

Ah, I see.
First, I think that the chances of resawing a 3/8" board into 2x1/8" are approximately nil.
However, if you were to start with a 2" thick piece of walnut, you could quite reasonably expect to saw off 1/4" veneers (given all the caveats about bandsaws above) and end up with what you want.
Doing all that by hand, successfully, would be quite an achievement, for me at least.