Speechless

Well we all know THAT is an exaggeration! However.

Finally had a chance (and the justification) to fit my new 1″ 1.3TPI, TCT resaw blade on the bandsaw today.

Before I get into what I think of the blade, (and as far as bandsaw blades go, it wasn’t particularly cheap), I’ll mention what prompted me to splurge on a replacement blade.

I was trying to resaw some kiln dried hardwood (Tassie Oak), that was around 200mm wide.  I was using a 1″ 1.3TPI blade that came prepackaged from a woodwork supplier.  Not sure if it was a carbon blade, but I strongly suspect so.  I was struggling.  The blade was complaining bitterly, the amount of force needed to push the timber through the blade was getting stupid  (the range of force needed is “butter”, “easy”, “moderate”, “hard”, “difficult”, “impossible”, “dangerous”, “stupid”), and I was blowing the circuit breaker on the bandsaw circuit continuously (it isn’t rated particularly high, so trips way to easily).  To the point that I was oping for the 15A tablesaw to do the resawing, taking a couple of passes to cleave the timber.

So onto today.  More resawing required.  Fitted the TCT blade with a bit of trepidation – what if it isn’t much better?

The blade fitted, tensioned, and finally the timber ready to cut.  I touched the end to the blade (to make a mark to ensure I was centred).  Well I meant to touch the end.  Being so used to the previous blade, I put a little bit of pressure in, and immediately sliced into the timber over 5mm.  Whoa.

Checked I was centred, then fed the timber in, through, and out the other side (1800mm) cleaved in twain without beginning to try.  I need a new category for ease – “Soft butter”  And this was hardwood.  Be very interesting the day I need to resaw some serious Aussie hardwood.  Do not expect this blade to have any trouble – wonder how easy it will be!

It goes to show, the right blade, a quality blade makes it so much easier, safer, enjoyable.  So the blade was $180 or so. After experiencing what it could do, it is worth every cent.  Just a pity I can’t get blades thinner than 1″ with a TCT.  Not that the bimetal 1/2″ blade has been any slouch either.

As mentioned earlier, purchased from Henry Bros Saws if you want your bandsaw to become everything it can be!  Sounds like a sales pitch (perhaps it should be!) but no.

Real Smooth Shave

Gave the first new bandsaw blade a quick workout today – the 1/2″ 3TPI bimetal blade.

It has a regular tooth set, and slices beautifully.  When resawing, it vastly out-performed my current 1″ carbon resaw blade – it is obviously significantly sharper – not surprising given how easily carbon blades dull off.

So not only it is superbly sharp, because it is bimetal it will hold that edge for longer.  I guess I have found my new “standard” blade – the one that will stay on the bandsaw by default, so whenever I want to do a quick cut without going to the trouble of changing blades, this is the one that is a jack of all trades. So yes, very happy with this first blade, and looking forward to testing the others.

The general rule is to have as few teeth in the cut as possible.  Too many, and the gullets fill and clog and the blade cannot cut well.  Too few teeth, and the cut is rougher than is necessary.  Having a range of blades, sizes, tooth configurations, tooth numbers will mean you will have the best blade for the job.

Straight-faced tooth with deep gullet to remove shavings.

Deep gullet and 10o undercut face which digs in more, and tends to curl the shavings.  Good for harder woods.  I would imagine though, that it is likely to dull off quicker, given there is less material backing the tooth edge up.

Similar to Hook Tooth, but has the teeth at 90o . Chips rather than shaves – good for materials that would otherwise clog up the blade.  Effectively increases the gullet (which clears the formed chips out of the cut), without having to increase the overall tooth size.

Has a combination of teeth closer together for a finer finish, with some teeth having large gullets for chip clearance.

Bandsaw Blades

Just ordered some new bandsaw blades for my 17″ machine.  Done, as always, over the phone.  Bandsaw blades are one of those things you get made to order, not precut and packaged, sitting on a shelf.  I’d rather have a relationship with the supplier, rely on their expertise, and know they are surviving on their reputation, which means they are only as good as the last blade they sell you, so they better sell you a good one!

Blades come in massive continuous rolls, which are then cut to length and welded.

This latest order comes from my original supplier, Henry Bros in NSW, so I am expecting good things. (And no, I don’t get a discount).

I’ve ordered a 3/16″ carbon blade, a 1/2″ bimetal, and my very first 1″ carbide tipped resaw blade.  I’m rather excited to see what that blade can do!

The point about a CT blade is not that they are the sharpest tool in the shed (no, I don’t mean they are dumb!), but they have excellent durability of the cutting surface.  The resaw blade I have at the moment (which came with the saw as part of a deal) is a very basic blade, and from what I can tell is a straight carbon blade.  Which for a blade needing to survive thick, Aussie hard timbers is basically useless after a few short jobs.

A CT blade is meant to be screamingly expensive, and when I priced one for my 14″ Jet bandsaw (which has a 6″ riser block), it was quite a price that I decided not to bother.  Around $80/metre (plus GST) (and I needed 2680mm), it was over $200.  The equivalent bimetal blade cost me about $40 at the time (1.3 TPI). The 14″ Jet can take a maximum 3/4″ blade, and as it turns out, this really pushed the cost up.

This time I decided that it would be really good to get a CT blade for resawing, so steeling myself against price tag shock, I asked how much it would cost for my 3335mm length blade (which is what I need for the 17″).  $38/metre (plus GST) for a 1″ blade.  Means I am up for around $150 inc GST!  Oh yeah, bring on the carbide tips!

Just a bit on blade material, fwiw

A cheap blade is generally a carbon blade.  Carbon steel in other words.  Cheap, initially sharp, but unable to hold an edge for long.  I don’t but carbon blades for anything but the smallest blades (scrollsaw type work), such as 1/8″, 3/16″, 1/4″ (if I have to).  Anything larger than that, don’t waste your money.

As soon as I can I move into bimetal blades.  These are as they sound –  a blade made from two different metals.  The base metal is a carbon blade (spring steel), but where a carbon blade’s shortcomings are the teeth durability, there is a different metal welded to the front of the blade which the teeth are cut out of.  This is often a cobalt high speed steel, so much more suitable for teeth.

And finally, TCT blades.  Not as sharp initially as the others, but significantly longer lasting, so overall they are sharper on average over the life of the blade.  In the case of the 1″ blade, it has cost me about 3x as much as a standard blade.  A worthwhile investment to my mind.

So when the package arrives (it’ll take a couple of days for the blades to be made and shipped), I will be very interested to see how they all perform.  I pity the timber!

Finishing off the boards

From the thicknesser, the final step in producing the components is the tablesaw.

With the side against the table (and now either side can be used as the reference, both being flat, parallel to each other, and at 90 degrees to the machined edge), and the planed edge runs against the fence.

The boards are then cut to width.

Ripping the board

Next, the fence is moved out of the way and the mitre fence added to the mitre slot.

Mine is the Incra, and like many, has a T end to the bar.  Rather than fluff around trying to insert the end at the near end, place the bar into the slot – it will ride up because of the T end.  Slide it forward past the end of the table, so the T slot clears the end, then drag it back.  So much easier than the other!

Crosscutting the ends

With the Incra Mitre 1000SE and Shop Stop, it is very easy to both dock the ends, and cut the boards to an exact, repeatable length.

First crosscut one edge, just enough to remove any checking, then flip the board over to dock to length.

Box sides

The final, nicely figured box sides.  Each is exactly the same thickness, the same width, the same length as its matching side, all ready for whatever joinery method is going to be chosen.

The extra, significant satisfaction that these boards have been formed, hewn from the trunk of a tree in your own workshop.

Completing timber dressing

The boards have been resawn on the bandsaw, and had a side and edge dressed on the jointer.  Next step is the thicknesser.

15" Thicknesser

I have a 15″ thicknesser, with a fixed head and the table rises and falls.  I prefer this style of thicknesser, but it isn’t everyone’s cup of tea.

The other version has a fixed table, so any additional infeed and outfeed support can remain at the same height, and the motor and blades rise and fall.  Winding the height down isn’t a problem – gravity and all that, but increasing the height is a lot more work, especially with the weight of a decently-powered induction motor overhead as well.

On the other hand, my thicknesser has a motor in the cabinet, and rise and fall is only the weight of the table – very smooth, very easy.  Added bonus, as the head doesn’t move, I have my drum sander located on top,  and a very functional arrangement it is, especially as the thicknesser and the drum sander both have the same requirement for infeed and outfeed.

Dressing boards

With the side dressed on the jointer face-down, the boards are fed through.  There is no point rushing the process – a little taken off each pass will still result in a finished product very quickly.

If I had a spiral head, things may be a little different, but I still have a thicknesser head with straight blades, so loading the machine and chipping away needs a little more finessing.

This doesn’t refer to the ‘spiral’ heads that have a bunch of the small square cutters arranged in a spiral around the head, but are still presented to the timber straight on.  This means the loads on the blades and machine are much less, but they are still chipping at the surface.

Instead, there are spiral heads where the small blades each present to the surface at an angle, producing a slicing motion.  This gives the best finish, combined with the benefit of much lower loads on the tool, and excellent waste clearance.

Completed boards

The boards, now complete (and you can see the bookmatching, if I intended to use the timber for that).

In this case, I now have a dressed side, the other side also dressed and parallel to the first side (and the boards are a uniform 10mm thick).

One edge is also flat, and at 90 degrees to both sides.  This side will be very relevant for the next step – the tablesaw.

How a thickness planer works.

From Wikipedia - a diagram of thicknesser operation

An illustration of the operation of a jointer ...

From Wikipedia - compare the above operation to this one which is how a jointer works.

Preparing Timber – Resaw (part b)

Before beginning a resaw, we obviously need the resaw blade fitted and properly set up on the bandsaw.

Opening both top and bottom doors reveals the blade, tension mechanism, drive mechanism (motor is at the back) etc.

Covers open, revealing the wheels

The top wheel is the tensioning wheel, the bottom wheel is the drive wheel.

Tension wheel and gauge

Around the back is a quick-release lever which takes significant load off the blade and bandsaw when not being used, and during blade changes.

Table support pin

The table support pin is removed – there is a cut through the cast iron table so the blade (which is an endless loop) can pass through to the centre of the table. The support pin prevents the two sides from becoming displaced / moving independently of each other.

Completely release blade tension

Once the quick-tension lever is released, the remaining tension is quickly wound out of the bandsaw, leaving the blade loose on the wheel. It can then be carefully removed.

Coil blade for storage

It is very good practice to coil and store the blade. An uncoiled blade is difficult to store, but in one respect at least if you have the space there is a benefit not coiling. The smaller blades (1/4″ etc) have little spring in them, however the large blades (1″ for example) can have a great deal of energy stored in the coiled blade, so care is needed, particularly when uncoiling. Still, space is a precious commodity – I coil all my blades.

Check out my second-ever episode on Stu’s Shed (1 Jul 07!!) for a bit of a video on bandsaw coiling.

Back off guides

Before installing the new blade back off all the guides, especially when fitting a much-larger blade such as the resaw.

Insert new blade

Slide the resaw blade through the slot in the table then fit it over the two wheels. First retension with the quick-tensioning lever, then wind on the tension until the blade is at the required tension (pluck it, and if you get a High C note, it is about right.

only joking!! But you do want decent blade tension , with minimal sideways deflection when pushed).

Side guides alignment

Bring the side guides into position (just behind the teeth gullets)

Side guides clearance

Then adjust the gap – post-it notes make a good feeler gauge. Don’t forget there is a second set of guides below the table. Bring the thrust bearings up behind the blade as well. Again, a Post-it note provides a good clearance. My take on guide bearings is that they need to be almost touching (but don’t rotate) when the bandsaw is on, and the blade is not loaded up (aka cutting).

Sometimes you need to be able to reach a hex bolt, and the short, power end of your allen (hex) key can reach, but there is no room to operate it. The long end can reach, but you can’t generate enough power to turn it.

A trick I picked up while in the Navy is using a ring spanner to get extra power on the short-end of a hex key.

Ring spanner trick

You can generate significant power this way, so you need to be a little careful not to over torsion the hex key.

Once the blade has been changed, it is time to do the resawing. Depending on how accurate you need to be, you can either free-hand it, or use a fence. When free-handing it (especially when following a line drawn on the timber), you will notice you have to feed the work in at an angle to the blade. This is called blade drift. All bandsaws do it, and it is a combination of the blade, blade tension, and the timber. If you are using a fence, you still need to take this into account.

There are many fences available for bandsaws. Some come with the saw, some are aftermarket. My favourite though, are the MagFences from MagSwitch. They use switchable magnets to lock down onto the cast iron table wherever you need it, and at whatever angle to the blade that you want.

Ideal resaw fence (MagSwitch)

The single-roller MagFence has the roller set proud, with the remainder cut away (again, so they don’t get in the way of the drift).

MagFence clearance

My method of using the fence is to lock it down at the distance from the blade that is equal to the thickness of timber (or veneer) you want to produce.

MagFence alignment

The rollers are set to line up with the teeth, and again I choose to line them up with the bottom of the teeth gullet.

Ripping a veneer

Ripping mm (or less) veneers is easy once everything is set up correctly.

Accurate resawing

If you want to split a board down the middle, you can either measure and assume it is accurate (including taking into account the kerf of the blade), or while holding the work against the fence, touch the blade with the timber. Then, flip the board over and touch the blade again. Between these two cuts is the true centre of the board.

This will give you the boards you need. If they are still green, you need to leave them to season. Next, we need to start the machining – joint/plane and thickness.

Addendum:

As Larry has correctly pointed out, I tend to use “bandsaw tracking” when describing the phenomenon of a blade running at an angle to a drawn line (or “track”) on the timber, and “blade tracking” to describe how the blades are running on the bandsaw wheels.

The common terms however are bandsaw “drift” when it cuts at an angle to a given line, and blade “tracking” for how the blade runs on the wheel.

I don’t like the term “drift” – it implies the bandsaw is not working correctly, and it is drifting all over the place instead of cutting straight, but for the sake of clarity, I have amended this article to the common nomenclature.

Preparing Timber – Resaw (part a)

Over the course of a number of posts (not necessarily consecutive), we will follow a piece of timber through a whole range of machining and processing steps, until it becomes a finished product.  You may not need all the steps – it depends on your particular source of timber for one.

Sourcing timber is always a bit problematic, and I will be looking further into the whole timber supplier thing later on.

Unless you have purchased a kitset (and even then in some cases), timber does not come in any sort of finished state, and particularly a dimensioned state ready for your project.  Even if it is sold as DAR (dressed all round), you can be pretty sure it will have twists, warps, cupping etc, even on a minor scale.  Perhaps difficult to pick up while shopping, but painfully obvious in the final project if not dressed properly before it is used.

However, first things first. If timber is too thick (or if you want bookmatched boards), the ability to resaw timber (which can be considered to be taking a board and splitting it into two thinner boards) is an incredibly liberating function.  You are not restricted to the thickness of boards you buy (or having to resort to wasting to sawdust good timber), or even if you are provided/manage to scavenge branches and sections of tree trunk, you have the ability to turn them into useable, rough-sawn boards ready for drying and processing.

The tool to achieve this is one of the most valuable in the woodworking workshop, and one of the most versatile: the bandsaw.

This is not what I’d call a (and apologies if anyone gets upset by this) toy bandsaw 8″- 10″ (and smaller) – you need something with a bit of power, and the capacity to take a reasonable blade, and they don’t start until you get into the 14″+ size.  There will be some who’d still call these toys until you hit at least 24″, but a 14″ bandsaw should be able to resaw a 12″ diameter log.

This does get into bandsaw sizing, and when you first come across the bandsaw, you’d think the size (8″, 12″, 14″ etc) refers to the resaw height – the depth of cut.  It actually refers to the diameter of the bandsaw wheel (at least on a 2 wheel bandsaw), which dictates the maximum throat depth.

Depth of Cut vs Depth of Throat

What I have found in the past, is (as a general rule) the smaller bandsaws have real tracking difficulties – not only in following a line, but also in simply keeping the blade running on the wheels.

A bandsaw blade needs a fair amount of tension to work properly, and the little bandsaws just cannot get the blade tight enough, which makes them worse than useless.  I’m sure if you pay good money that there will be small bandsaws that can do a good job, but if you are forking out $100 – $200 (or less!), then you might be better saving your money.

My current bandsaw is the 17″ one seen above.  I still have a 14″ Jet which I am still very fond of – with the 6″ riser block, the Jet is capable of resawing 12″, and still has a reasonable throat.  This 17″ one does pick up some things that make my life a lot easier.  The tension wheel is underneath the top wheel (hard to see in the photo), and is at a good working height to crank the tension on easily.  Both this, and the Jet have a quick tension release, and both can take a reasonable resaw blade.  3/4″ for the Jet, 1″ for the Carbatec.

Blade Comparison

A bandsaw may come with a single blade, but it most certainly should not be the only blade you own.  In fact you should be seriously considering changing blades for each job you do (assuming they are inherently different tasks).  A blade that may be suitable for cutting tight circles (such as the 1/4″ 10 TPI blade seen fitted here) is completely unsuitable for cutting through thick timber, where you have a much deeper depth-of-cut, or for resawing.  The other blade seen here is my primary resaw blade.  1″ across, 3 TPI, it will not leave anywhere near as smooth a finish as the small blade, it cannot go around a corner (well about as well as a bus can, compared to a mini!), but it can handle significant blade tension, will stay very straight during the cut (including not bowing, so the cut remains vertical, and flat!), and won’t result in burning as it has significant chip clearing capacity.

I’d suggest having 3-4 blades of different widths, and different teeth counts to cover the range of typical tasks.  The blade that came with the saw you can keep (put aside), and use it for jobs where you wouldn’t want to subject a good blade to, such as sand-encrusted timber, aluminium etc.  (Yes, cutting aluminium on a bandsaw is a perfectly reasonable task, as is plastic).

The bandsaw is, in my opinion one of the safest cutting tools in the workshop – certainly much safer than the tablesaw, SCMS, or router table.  You can still do significant damage to oneself if not careful, but it is a tool I’m more comfortable in using (standard guards and safety gear all still bought into play of course).  The cut direction is down, into the table so work is much less likely to be thrown at you, and if there is a failure (such as a broken blade), it doesn’t fly around the workshop and instead simply stops moving.

You can still cut yourself though – no tool can be used with impunity.  A bandsaw has teeth, and any tool with teeth is designed to eat.  If it has no trouble with hard timber, then your hand/arm/body will prove no problem if you happen to offer it up as a sacrifice.

So the bandsaw – one of my must-have workshop tools.  Whether it is for resawing

Resawing

or scrollsawing,

Scrollsawing

circle cutting (as will be covered in the next edition of ManSpace magazine)

Circle Cutting

Circle Cutting

or anything in between, it is often going to prove to be the go-to-tool.  In this case, (for the purposes of this article), its ability to break down logs and resaw boards is invaluable in the workshop.

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