Dovetail Keys as a Timber joint, (Part 2)

 

Dovetail keys as a timber joint. (Part 2)

In part 1 of this article, we covered the joining of the boards and the creation of the trenches for the dovetail keys. In this part well expand on cover how to cut the dovetail keys and glue them into the trenches.

One of the key points to remember is to cut the keys along the grain of the board to give maximum strength to the shelf.

As we’ll be using a trimmer to cut the keys, it’s critical that you pay careful attention to clamping the boards into place. In my case, the Sydney blue gum that I’m using is recycled tongue and groove floorboards, so I was able to screw a sacrificial board about 50mm in from the edge of my bench with the groove facing toward me, then screw an offcut of pine onto that for additional lateral support.

20111009-095237.jpgIt was then a matter of sliding the tongue of the board the key was being cut into, into the groove of the board screwed to the bench and the material was secured and ready to cut.

As i did in the previous article on sliding dovetails, I’ll be using the Bosch GMR trimmer to cut the dovetail keys. Once the keys are shaped, I’ll be using the band saw to cut the keys from the main board, then planing the cut edge of the board flat before clamping it back in the jig and beginning the whole process again.

The first step is to attach the fence to the trimmer. I’ve attached a piece of melamine to the fence to give the trimmer more support when used in the horizontal position. There is a notch cut out of the board to let me see the location of the cutter and to allow the wood chips to be ejected, so they don’t clog the cut.

Please use safety glasses or face shield plus a dust mask and earmuffs when using any router

We know that the height of the dovetail key is the same as the depth of the trench we’ve just cut, so now we need to reduce the dovetail keys to the correct width so they can be inserted into the trenches we’ve completed.

Set the fence, so it covers about 3mm of the cutter and, after checking that everything’s clamped and tight place the trimmer on the workpiece, turn it on and cut the first side of the tail.

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If you’ve never routed horizontally before make sure you have a go at doing a couple of test cuts first. The key points to remember are to keep the base of the rout pressed firmly against the edge of the workpiece and the fence pushed firmly down on the top of the piece.

Once you’ve cut the first side unclamp, then flip the piece over, re-clamp and cut the second side.

20111009-095951.jpgGrab one of the pieces with the trenches in it and see how it fits. If you’ve managed a perfect fit on the first cut, I take my hat off to you. If it’s too big just move the fence in by a small amount, then try again. This part of the process can be a bit tedious, but it’s necessary to get as tight a fit as possible.

Once you’ve achieved a nice firm fit, and by this I mean that the tail slides into the trench with a little effort but not so much that you need to whack it in with a mallet, firmly lock the fence on the trimmer into place, so you don’t lose the fence position.

The next stage is to free the tail from the workpiece and for this, I used my band saw. My workshop is small and I don’t have a table saw, so all of my rip cuts are done on the band saw then cleaned up with either hand planes or by doing a series of .5mm planing cuts on the router table.20111009-100313.jpg

Since my tail needed to be a minimum of 6mm long, I set the fence on the band saw to 8mm and using a push stick removed the tails from the workpieces.

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After removing the tailpiece from the main work board, I planed the edge flat to remove the tooth marks from the band saw and started the whole process again.

If you don’t have access to either a table or band saw you could also use a jigsaw or plain old handsaw to remove the tails from the main board.

Once I had everything set up it took me just over an hour to cut the 24 dovetail keys for the 12 shelves that I’d made.

Once all the tails were cut it was then just a simple matter of gluing them and sliding them into there corresponding trenches. I had a mallet handy to help “persuade” a few troublesome keys to get into the correct position.

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I left the keys about 20mm oversize from each side of the shelf, planning to trim them flush when everything was dry.

After 24 hours drying time I used my Japanese saw to trim the excess keys flush with the edges of the shelves and then used a Stanley smoothing plane to trim the excess height from the keys, so they were flush with the shelves.

The next process was to place a 5mm radius cutter in the Bosch GMR trimmer and round over all the edges on the shelves to remove all the hard edges.

The next article in this series will show you my method of applying Tung oil to achieve a beautiful finish.

As usual, your comments and questions are appreciated

Thanks for reading this article,

Bryan

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How to get the most from your Rotex, (Part 2)

A Hard Burnished Wax Finish.

To protect and preserve the work, I usually apply a wax finish to the piece. I’m not a fan of varnish or lacquer style finishes as I feel they can give the finished piece a “plastic” sort of look when they’re completed.

The wax I use and recommend is Gilly Stephenson’s cabinetmakers wax. It is a combination of beeswax and carnauba wax in a gum turpentine base. From my own experience I’ve found that beeswax, on its own, never thoroughly dries and can become sticky and attract dust, and carnauba wax, on its own is tough to work with. The cabinet makers wax from Gilly Stephenson ticks all the boxes for me as it is easy to use, polishes up beautifully, and is very realistically priced.

The method I use to apply it is detailed below.

Sand your workpiece up to 1200 or 1500 grit using the method described in “How to get the most from your Rotex, (Part 1)
Put your sander aside but don’t remove the sanding disc
Use a soft cotton cloth and apply a thin coat of the wax to the surface. Rub it evenly over the surface making sure there are no lumps of wax. Remember to only use a thin layer. You can apply more coats as you go Once the wax has been spread over the surface leave it aside for about ten minutes.

Now, the next stage is the enjoyable part.

Grab your Rotex and double check that it’s on speed 1 as well as in Rotex mode. Place the sander on the workpiece, turn it on, and slowly and steadily work over the entire surface of your project. The small amount of heat that your creating is sufficient to open the pore of the timber and let the wax in, while the 1500 grit abrasive smooths and distributes the wax evenly over the surface.

Don’t overwork the surface: just a few minutes should do it.

When you’ve finished this stage you need to grab a paper napkin; yes, you read it right, a paper napkin. When I was teaching for Festool, and I knew I had a sanding workshop coming up the first thing I’d do would be to head down to the local McDonald’s and grab a handful of their paper napkins.
So, now you’ve got your napkin, place it on the workpiece, then put your Rotex, (with the 1500 grit abrasive still on it), on top of it. Double check that you’re in Rotex mode and on speed 1.
You should begin to see the shine develop very quickly. The paper towel equates to about a 6000grit, (approx) abrasive and cuts back the surface beautifully.
You can repeat the process and add as many layers of wax as you like. The more layers you have, the more vibrant and lustrous the finish but I recommend that you leave at least 24 hours between applications.
Try this finishing method on some offcuts of a few different species of timber. By doing this, you’ll create a “library” of finished samples which can really add the ‘wow’ factor to any presentations you give to potential commission clients if the future. What it also does is give you more practice with the sander so you can become more familiar with, and refine your technique on the sander.

I hope this article helps you in working with your Rotex and achieving better finishes that you’d previously thought possible. As always, please post a comment or send me an email if you’ve got any questions.

Cheers,
Bryan.

How to get the most from your Rotex, (Part 1)

How to get the most from your Rotex, (The Basics)

Okay, so you’ve done. You’ve bitten the bullet, spent the bucks, and now, sitting on the bench in front of you is possibly the best sander thus far to emerge from the melting pot that is European power tool engineering.

So; now what?

The first thing you probably want to do is whack a sheet of paper on it and sand a piece of wood until it’s paper thin. If you need to, go ahead, but make sure to clamp down your work first; there’s not much worse than being hit in that tender part of the anatomy by a piece of Rotex propelled timber.

Once you’ve got that out of your system, let’s start by having a good look at your new machine. Hopefully the salesman you purchased the sander from fully explained all the functions to you, but in case he didn’t, let’s start from scratch.

The Rotex 150 is a dual mode sander with an aggressive, gear driven mode, (Rotex mode) and a random orbital mode with a 5mm orbit.
You switch between these modes by pressing the green button on the top of the machine, down & to the left When the button.

is in the upright position the sander is in the Rotex mode.

To test this, make sure the power is turned off, then turn the base plate with your hand. You should feel some resistance and hear a “growl” coming from the sander. Now, push the top button down and to the left. This puts the sander into the random orbital mode. Turn the base plate again so you can feel and hear the difference between the two settings.

You’ve probably noticed the small green button on the right side of the Rotex just above the base plate. This is the spindle lock, and it’s used when we need to change the base plate because it’s either worn out or you need to switch to a pad of a different density for a specific application.
It’s a bit of a bugger to change, particularly the first time, but it will get easier to practice.
To use this function, first make sure the Rotex is unplugged, then put the sander into the Rotex mode.

Hold the sander upside down in your left hand so that your left thumb can depress the spindle lock button. Depress the spindle lock button with your left thumb and turn the pad anti-clockwise with your right hand until you feel the spindle lock engage, ( the spindle lock button will depress an extra couple of millimetres).

Continue holding the spindle lock and turning the pad anti-clockwise until the pad comes off.
To put on a new pad, depress the spindle lock, put the pad on the machine and turn it clockwise until you feel it drop into position and the locking mechanism begins to engage. Once this happens, grip it firmly and turn it clockwise until it locks. Now put the machine down and give your hands a shake. Told you it was a bit of s bugger to do; but trust me, it will get simpler with practice.

At the rear of the machine just above the plug it lead is the variable speed control for the sander and the green button on the inside rear of the “d” handle section releases the dust extractor port so you can polish the car without running the risk of it accidentally banging into the paint surface.

Using the Rotex.
Now, whatever your project, having a good understanding of how to use the functions of the sander will always help you to achieve the best finish possible on your work.

Rotex and Random Orbit Modes
One of the most common questions I field when showing people the Rotex is, “how do I know which mode, I should be using?”
Well, the simple answer to this is that you should always use both modes. Let me explain.

The Rotex mode will, with coarser papers, raise the grain while the random orbital mode cuts the grain back. From experience, I’ve found that if, for instance, you’re starting with 60 grit, whack it into Rotex mode and sand your work then stop, put the machine into the random orbit mode and sand it again. It’s important not to try to change from Rotex to random orbital mode while the tool is running; it’s like trying to change gears on your car without depressing the clutch.

Then change up a grit to 80 and repeat the process. As you progress through the grades, getting finer and finer, you’ll see the surface start to develop. It’s really important that you feel the wood with your hands as you’re sanding. Getting a good feel for the timber will help you gain a greater understanding of how a surface develops.
Continue sanding with 120, 180, 240, and 400 grit abrasives, being sure to repeat the Rotex, then random orbit modes

Sanding speeds

To achieve the best result results in your work, speed is another crucial factor to consider. The main things you have to remember are, the coarser the paper, the higher the speed.


Coarse paper on slow speed tends to dig in and ‘bite’ the work, which can lead to scratches and swirls that can be bloody hard to get out. Coarse paper on high speed tends to ‘skim’ over the work, and while it may take a little longer, you’ll achieve a more controlled result.
When you start sanding and are using, a 60 grit paper begin with the sander on speed 6 and use the Rotex, random orbit method as described above. As you start moving into progressively finer grades, gradually begin to lower the sander speed. Use the chart below as a rough guide for sander speed related to sanding grit.

Sanding grit. Speed
40. 6
60. 6
80. 6
120. 5
150. 5
180. 5
240. 4
320. 4
400. 3
500. 3
800. 2
1000. 2
1200. 1
1500 & finer 1

This chart is a suggested range only and results can vary depending on the type of timber that you choose.
The transition point when sanding is 400 grit. This is the stage where you stop sanding the timber and start burnishing it. From 400 up you’ll begin to see the surface of the wood develop and become smoother with every sanding stage that you complete. Don’t forget to feel the timber as you sand it so that you become more familiar with how each sanding grade contributes to the overall finish. Keep using the Rotex / random orbital sanding technique until you pass 1000 grit. From experience, I’ve found that when you reach 1200 grit switch to using the Rotex mode only. You should begin to see the timber surface begin to develop a lovely lustre and the surface will start to shine. This happens because the super fine grits that we have been using are burnishing the timber surface and closing the pore of the wood which gives us this glass-like finish.

That’s it for part 1 of this post, in part 2, I’ll go thru how to apply a burnished wax finish to your piece.

Cheers for now

Bryan

New Dust Extractor, Protool VCP 260 E L A/C

Hi All,

I had a chance to see the new Protool dust extractor from Tooltechnic Systems, the home of Festool. The new VCP26o is a very impressive machine and has identical power and capacity to the Festool CT 26. A major difference is the addition of  a modified form of

the auto clean function that is on the Festool CT36AC. The autoclean on the VCP260 ac , when activated, cleans the filters at preset intervals of 10 seconds which helps the extractor cope with such challenging materials such as plaster, concrete and stone.

When in auto clean mode it’s recommended that you use the plastic liner to collect the dust. Alternatively there is a self cleaning bag, similar to the bag in the CT26, but with a larger pore to allow the bag to cope better with concrete, stone and plaster dust. The standard bags for the CT26 fit the VCP 260 AC.

When using the VCP260 with timber,  in applications such as routing and sanding you can turn off the autoclean mode and use the standard self clean bags.

As with the CT 26 and 36 there is a removable plate which allows you add a continuous supply powerpoint to the front panel of the extractor. You cannot add another tool actuated power port to the VCP260 AC

I was  really impressed with the dimensions of  the VCP260 The overall size is 673mm long X 365mm wide X 455mm high. The low profile means the extractor is more stable on uneven surfaces and also means it will easily fit under the hardtop of most ute’s and  into most vans.

The VCP260 comes with a 36mm antistatic hose in the scope of delivers as well as a rear mounted tool holder. There is reducing sleeve available as an extra which allows tools with a 27mm port to be nused with the 36mm hose.

The VCP 260 as shown in these images is fitted with a sys dock. This is not included in the scope of delivery and is available as an accessory.

One other cool new feature is the inbuilt hose holder, as shown in this photo. The hose is securely held in place when the extractor is transported and there’s no more battling to get a 36mm diameter hose into a hose garage.

This is an impressive all rounder which will tick all the boxes for the tradie who works in a variety of fields and is looking for one machine to suit all his needs.

We’ll have it in store next week so If you want more information either post a comment or send me an email.

Cheers

Bryan

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