On Board with Mark Corke

Heating pad for epoxy resin

When I have time I like to get down to the workshop as often as possible. I use the term advisedly as my wife would prefer that her car was in the garage, er workshop. That said although it is under the house and not as cold as it could hardly be called toasty in the winter. I do have a selection of heaters and these help a little but do little more than take the chill off when I am actually in there and although I tend to stay warm enough by a combination of heaters and work this is not good for epoxy resins which is a material that I tend to use a fair amount. If the part is small that I am working on then I tend to move it into the basement which is warmer to allow the adhesive to set up, larger sections and projects that cannot be easily moved to tend to be put off until the warmer weather if at all possible. Although the workshop never gets down to freezing which is bad for epoxy the adhesive if very cold is very thixotropic and hard to pump out of the containers. For consistent mixing and to make it easier to handle it pays to keep the unmixed epoxy at consistent warm temperature. I have seen all sorts ideas from using an old fridge or a wooden insulated box with a low wattage light bulb inside which provides sufficient heat to keep the epoxy at a good consistent workable temperature. But I have found a better way, now I just keep the containers of resin and hardener sitting on top of a heating pad. No complicated boxes to build or old fridges to find room for. Turned down to the minim temperature it works a treat. To stop the pad from getting covered in epoxy drips and other crap I keep the pad in a thick plastic bag. The other thing that you can do with the pad that I never thought of is that you can actually move it and assuming that the part I am gluing up is not too large I can actually set down the glued component down on it where the heat will make the epoxy cure nicely with no amine blush. The heating pad that I use cost $15 at Walgreens.

Easy build Dado jig

 

I spend a fair bit of time in the wood shop making projects for the boat and the house. Often times that involves some cabinet work of one sort or another and although it may be acceptable to simply glue and screw cabinets together if they are to be painted it is not the best way if they are to be finished bright or the showing any sort of fixings is unacceptable. One of the best ways is dado or as we say in British English cut some housings. These are simply a groove across one board into which another board slots. Useful for all sorts of things but the trick is making sure that one board fits neatly into the other. Sometimes the component parts will be solid wood but most often they will be some type of panel material; MDF, plywood etc. To a novice one would think that if you bought three quarter inch plywood you would only have to cut a three quarter inch dado and all would be well but plywood can often be slightly thinner or even slightly thicker than it's stated width so a more accurate method needs to be found to ensure that no matter the thickness of the material the fit will be snug and attractive.

 Whilst it is true that you could simply measure the thickness of the boards and cut to that you are still faced with the problem of accurately machining the dado. This simple jig which is shown below is but one way of overcoming these problems. Simple to make it will work with almost any router and can be knocked up from offcuts in about 30 to 45 minutes.

 The actual length of the jig is dependent upon the actual width of the material that you wish to dado but for most purposes I have found that 24 inches will suffice for all but the largest cabinet jobs.

 

First up is to prepare two lengths of 2 by 1 inch material. These have to be dead straight and true, any inaccuracy here will be transferred to any dadoes that you cut. I used poplar which is a stable timber and trued them up on the jointer but planing them by hand works equally well but carefully check them with a T square for true.

 

These are then screwed to a couple of pieces of plywood the same length as the timber that you just cut. I found that prefinished birch is ideal but use what you have. Make sure that the plywood is at least half the width of your router's base plate.

 

When the wood has been screwed to the plywood it should look like this.

 

The next stage is to chuck a router cutter into your router which can thinner than the width of the dado you wish to cut but not wider. I have found that a half inch cutter is ideal as I mostly work on three quarter thick boards, just remember that the cutter that you choose can be smaller than the material than that you will be cutting but not larger. This will become apparent as you become familiar with the process. With the jig clamped firmly down to some scrap make several passes and cut through the jig. Do not try to cut through the thickness of the ply in one go, you will have a cleaner cut with less tear out if you take it steady. Also make sure that the base of the router is held firmly against the timber screwed on fence. The width of the jig is now very accurately machined from the fence to the edge of the plywood. Do this by cutting through the plywood along both fences so you end up with two identical but separate pieces.

 

To cut a dado line up the edge of the ply with the marks on the board where you want your shelf or whatever to go and clamp the jig in place. Set the cutting depth of the router so that it removes between a quarter and three eighths of an inch for three quarter thick material (LESS if the material you are cutting into is thinner) Then keeping the base plate of the router hard against the jig cut the dado.

 

Without moving the first part of the jig squeeze a sample section of the material that is to fit into the dado between the section of the jig that you just used and the new section and clamp the second section in place. Remove the sample material and the first half of the jig and without altering the depth of cut on the router make a second pass.

 

TA DA. A perfect dado every time all ready for glue up.

 

TIPS

 

When routing against a jig always move the router from right to left to avoid it snatching and running away from you.

 

Mark the jig with a sharpie to show which cutter you used as the jig will only work with that particular cutter and router combination. Using a different cutter will lead to inaccurate dadoes.

 

 

Bosch Trim router PR10E review

 

I have always thought that money spent on tools is never money wasted. However money spent on cheap tools is definitely money wasted so I like to buy the best that I can afford. Although I have amassed a vast array of hand tools during my career I do like power and machine tools for the speed and accuracy that they offer making the mundane into, dare I say it, fun. I well remember using an electric router for the first time when still in high school. I was building a boat, what else, and needed to round off the edges of the gunwales. Mr Penfound the wood work teacher produced what I later found out to be a router and after showing me how to use the new fangled machine I rounded over the corners of the gunwales in just a few moments. It was some years later before I had a enough cash with which to buy my own router but since that time I have had several and presently have four machines of differing sizes.

Bosch router from Mark Corke on Vimeo.

 

Small routers are often called trim routers and have small less powerful motors. Frankly although I have used these smaller machines in the past I have never actually owned one of my own thinking them something of a toy but I was wrong. Recently I purchased the Bosch PR10E Colt. This machine features a1 hp motor and accepts cutters with a quarter inch shank so almost any cutter with a diameter of up to about three quarters in diameter will be fine. Features include a spindle lock, step-less variable speed control from 16000 to 35000 rpm, depth micro adjuster and a fence for straight cuts. That last feature will most likely stay in the box and is something that I shall probably never use for if I have a job that requires the use of a router with a fence for cutting dadoes for instance then I shall most likely reach for one of my other routers. No, where small routers like the PR10E shine is for light weight cutting, chamfering and molding and if is for this very task that I purchased this machine. I am currently working on a new boat building project and many of the wooden components require a small round over. Although a larger machine would work they are big, heavy and cumbersome for this work and a small body grip trim router such as this one shown are ideal and actually safer. With so many parts to round over the machine can almost be permanently set up and quickly grasped and the cut made without a second thought. Big machines make a lot more noise and the heavy weight require two hand for safe work. As you can see from the pictures and the short video I shot this is s very handy little machine. Bought for $60 from an online retailer this is my new go to tool.

 

A spindle lock makes bit changing a breeze

Although there you can set the speed anywhere from 16000 to 35000 most of the time I run it at the top end.

The on off switch is a little small but conveniently placed on the side of the ruberized motor housing.

There is a fine micrometer adjustment for precise depth settings. Large changes or to remove the lower section of the machine entirely is accomplished with a small cam lever.

 

The PR10E is ideally suited for bearing guided cutters such as this round over bit.

Filming from a boat

I wish I could claim to have shot this video but I did not but it is very instructional in getting a nice steady shot. This is shot on a calm lake and working on a tossing boat would be a little more trying and require different techniques. However what is also worth noting is that the video is shot on a full frame DSLR camera. I have just taken delivery of a Nikon D800 which has this capability and have yet to try shooting any movies with it but I will try to get something up on the blog soon just as soon as I have waded through the two hundred or so pages of the user manual!

 

Clamping beams

 

I was gluing up a large worktop the other day and thought that readers may be able to make use of what I call bench beams.  Basically these are runners that hold the work at a convinient height allowing access to both sides; simply made from two strips of 6 inch wide three quarter plywood glued and screwed together.  Then when gluing up a large top of other structure it is a simple matter to get the clamps underneath the work without disrupting what ever it is that you are sticking together. I should add  that I placed a clamp on top for photographic purposes but normally there would be a selection of clamps on both sides of the work to even out the pressure and prevent any chance of cupping.

One word of caution however, and that is do make the beams accurately and second make sure that the bench top that you are using them with is flat also. Any twist in the bench top and this will be transferred to whatever it is that you are gluing up.

 

Handy tools

 

There is no doubt in my mind that carrying a few tools on board is a great idea. Even if you are the sort of person that gets the boatyard to do all of you maintenance things can still go awry when out on the water and few well chosen tools could well save the day. Obviously the choice of tools will depend to some extent on where and how you cruise. You will not have to carry as many tools on a small outboard boat as you might on a large cruising trawler away from the dock for weeks at a time. In an effort to address these issues I put together a tools kit that will serve for most routine maintenance tasks and emergencies. I bought a plastic tool box and everything packs into it for protection and storage. Obviously you can supplement or change tools to suit yourself but the tools that I have included work well enough for me and have got me out of a jam more than once. Finally as with anything and especially tool you get what you pay for, cheap tools often yield disappointing results so buy the best tools that you can afford. Buying any tools represents a significant investment so it often pays to build up your tool kit a bit at a time . The tools detailed below are those that I regularly carry aboard my own 26ft wooden sailboat and with them I can undertake the majority of likely repairs. I choose multi-purpose tools and everything fits neatly into the small
plastic toolbox. I store spare parts separately in small, easy-to-stow plastic tubs.

WD 40.

So useful that I class it as a tool. Lubricates and frees corroded and frozen parts.

Duct tape.

Strong and easy to tear. Useful for making temporary repairs to plumbing and so much more.

Plastic insulation tape.

Insulates chafed electrical connections and can be wrapped around turnbuckles and other fixtures and fittings.

Tape measure.

You never know when you'll need to measure something. Remember to measure twice and cut once.

Hand drill.

The ultimate rechargeable requires no batteries and takes drill bits up to 3/8in diameter. A model with a keyed chuck holds the bits without slippage.

Matches.

Melt the cut ends of synthetic line and rope to prevent fraying.

Hacksaw.

Can be used to cut metal, fibreglass and wood.

Hammer.
Persuades things to go together and come apart!

Vice grips.
Useful as a portable small vice and adjustable wrench at a
pinch.

Mirror on a stick.

 For locating errant components that
fall into the bilge or get lost in other corners of the boat.

Multitool.

Wear this on your belt so that you will have a knife, pliers
and bottle opener at hand.

File.

This one is double-sided; one side is a metal file and the other is a rasp for wood and fibreglass.

Drill bits.

 A selection of bits from 1/32in to 1/4in will do almost all the drilling you might need. Anything larger is hard work with a hand-powered drill.

Socket wrench and sockets.

One to fit every nut and bolt on the boat. Add a plug socket if you have a gas engine.

Multi-meter.

 Invaluable for electrical and fault tracing. Learn its functions and how to operate it before you have to use it on the boat.

Pencil.

 Handy to use with the tape for marking and measuring.

Screwdrivers.

 A selection of Philips and straight blades in various sizes and lengths.

Putty knife.

 For scraping up excess bedding compound and the like.

Circlip pliers.

You'll need these to take a water pump apart - it takes ages without them.

Rigging knife.

 A sharp rigging knife is the best thing for cutting line and cordage.

Adjustable wrench.

 This is one of my favorite tools on the boat. Made from high-grade stainless steel it not only loosens and releases nuts and bolts but also incorporates a shackle key and bottle opener in the handle.

Crimping tool.

A cheap crimping tool cuts and strips wire and crimps new terminals onto cable ends.

Wood chisel.

 A very sharp wood chisel will cut wood -obviously - and fiberglass at a pinch, although you'll need to sharpen it afterward.

Extending magnet.

The perfect tool for retrieving fittings from inaccessible places. Spend a bit more and get one with a rare earth magnet, which is immensely powerful.

Needle-nosed pliers.

To hold small parts; the built-in cutters will cut seizing wire and small cable.

Allen keys.

The only thing that will undo socket head screws.

Toolbox.
To keep essential tools where you can find them

Using a bench plane

Here is short video that my son and I shot the other day of me edge jointing a mahogany board with a number 6 bench plane. The blade had been sharpened using the technique described in my earlier post and as you can see and hear the curly shavings just 'whisper' from the sharp edge. Mahogany can be notoriously difficult to plane up as it has interlocking grain but sharp tools that are honed to a razor edge make things much more pleasant, easy and quick.

It is also worth mentioning that many hand planes require some fettling to make them work at their best. The more that a plane is used the smoother the sole becomes but one straight out of the box or a plane that is rarely used will definitely benefit from having the bottom trued up and polished. The best way to do this is to tape a large sheet of 150 grit emery paper to a flat machine table  or sheet of plate glass and with the blade removed rub the sole back and forth until you can see your face in it. The shiny surface reduces friction considerably and takes out any uneveness; few planes are perfectly flat. One final point, to make the plane glide across the surface is to use a little candle wax on the sole from time to time; I keep a length of candle in the tool bag for this specific purpose.

 

Sharpening Chisels

It you do any sort of woodwork keeping a sharp edge on your tools is very important. Sharp tools produce better work, they cut with less effort and can actually be safer as you do not have to force them so there is less pressure behind the cutting edge.

Sharpening plane and chisel blades is not that difficult but there has always been some sort of mystique surrounding the process so in an effort to dispel any sort of myths once and for all here is my method for producing very sharp edges on chisels and plane blades. You do not need a lot of equipment but what you do use must be in good order and I'll explain a this in more detail as we go through the process. I must also explain that there are many different ways of sharpening tools but after 40 years I think that I have found a method that works very well for me. Other people will have different opinions and methods and that is fine but as with many things you need to practice and perfect one method before trying something new. I used to work for a national woodworking magazine and each year we would have a 4 day show, during which I would demonstrate tool sharpening. One of the first questions that I would be asked was which grinder do you use never what's the best way to get a very sharp edge on my tools.

With a few exceptions chisels and plane blades have two bevels often called a primary and secondary bevel, other names are the grinding angle and sharpening angle. Irrespective of what you call them these are 25 and 30 degrees respectively, except in rare cases for chisel planes and so on. It may be tempting if you are new to sharpening to have a go initially with a narrower blade but this can be a mistake and I would caution you against this until you become proficient. It
is easier to burn the smaller width blades on the grinder as there is less of a heat sink to direct the heat away from the ground edge, the blade is more likely to rock giving an out of square blade and perhaps most importantly the water stones are soft and it is easy to gouge them and nick the surface. The pictures show a well chewed up
inch and a half chisel but an inch wide chisel is a good compromise.

When I started off in my woodworking career just about everybody used oil stones, often double sided manufactured carborundum stones. These work well enough but some years later I tried water stones and have never looked back. They cut much faster than oil stones and as their name suggests they use water as a cutting agent and lubricant. They are natural stones that come in a variety of grit sizes and although I have a large selection I tend to fall back on two grits; a 800 for fast removal of metal and restoration of the primary or grinding angle and a 6000 grit for final sharpening. With these two I can do just about all my sharpening. Although I am using the electric grinder in the photographs I only normally revert to the grinder if the edge has been severely damaged in some way. For day to day sharpening I use the 800 grit on the primary bevel initially then put the final edge on the tool,with the 6000 grit stone. It all sounds like a lot of work but in reality providing you keep your planes and
chisels in good order sharpening is fast and effective. If you have the luxury of a workshop or a space that you can call your own a permanently set up space for sharpening is the ideal; touch ups happen without interruption and the inevitable mess can be kept away from the woodworking area.

 

A couple of points about the care and feeding of water stones would not go amiss here. Water stones are more fragile than oil stones so if you drop them they will most likely break. Also keep them in water, this does two things, keeps them instantly ready for use and any dirt floating around in the workshop will settle on the top of the water and not on the stone itself. Change the water often; I like to add a little dish washing detergent to the water, it breaks the surface tension and I think it adds a little extra speed to the cut. Finally if the workshop is cold do not let the water freeze in the winter time or the stones will shatter, add some non toxic antifreeze during the winter months if this is a concern to you.

 

One of the old issues with oil stones was that if they started to wear unevenly it was almost impossible to true them up. Water stones on the other hand are soft and can be trued up by rubbing two stones face  to face or on a sheet of plate glass to which is taped some wet or dry abrasive paper, well lubricated with water, taking minutes for what used to take hours previously.

 The pictures are important to this feature so you can click on them to make them bigger so they will be easier to see

 

The chisel that I am using here is in rough shape and has been used for everything from opening paint cans to scraping barnacles off a propeller. Normally I do not recommend this treatment for any chisel they should be kept for the purpose for which they are designed; cutting wood.

 

If the edge is chipped or rounded over then restoring the primary bevel is the first step. You can do this by hand but the best way is to use a high speed grinder if things are especially bad. One word of caution here. More tools have been ruined on a high speed grinder that by almost any other machine. A grinder will remove a lot of metal in a hurry and it is very easy to burn the steel and remove the temper. Caution is the watchword here. I use an 8 inch diameter wheel which is far better than the 6 inch models. Firstly the wheel is obviously a larger diameter and so the hollow grind will be less pronounced and secondly there is a lesser chance of burning the tool edge. As an added
benefit the wheels are wider and produce a more consistent edge across the blade.

I think it fair to say that the tool rests that come supplied with the grinder are for the most part useless and certainly no good for grinding chisels and plane irons. What is needed is a robust easily adjustable tool rest that holds the tool at the correct angle. I have used the superb O’Donnell jig, which is sadly no longer manufactured but either buy or make a tool rest that will allow the tool to address the wheel at 25 degrees, the angle required for the primary bevel and this will do much to start you off on the right foot.

 

With the chisel resting on the tool rest gently feed it forward until it contacts the wheel. Slide the blade from side to side making sure to keep it perpendicular to the wheel.

You will see that I have a slot in the tool rest and a small tee square to hold the blade at right angles to the face of the wheel which does much to ensure success. If you keep the blade moving by traversing from side to side across the wheel and use a light touch you will not overheat the edge and blue the steel. Frequently remove the chisel from the tool rest to check progress, do not be in too much of a hurry. Keep grinding until you start to see sparks just coming over the top of the blade edge, a sure sign that you have ground down to a feather edge. Remove the tool and turn off the grinder.

 

Place the blade in a sharpening jig and do up the knurled knob finger tight. Place a steel straight edge or ruler across the wheel on the sharpening jig and the blade edge. Hold the blade up to the light and adjust the jig up or down until the straight edge rests on the jig wheel and the front and back edges of the hollow grind.

 

Use a screw driver and fully tighten the jig so that the blade is firmly gripped, then recheck with the straight edge to ensure that nothing has moved.

 

Remove the 800 grit stone from the water bucket and place it on the non slip pad. 

Making sure that the blade and jig wheel are in contact with the stone move it back and forth. Keep moderate pressure on the tool edge with your forefingers. Keep the stone wet by dripping on more water as required.

 Occasionally lift up and inspect the chisel to check progress, after a few minutes you should notice the marks left be the grinder starting to disappear and a flat bevel
forming.

 Keep going until all grinding marks are gone and you end up with a perfectly flat bevel.

Use the full width and length of the  of the stone to prevent wearing a groove. If you have done this correctly the blade bevel should be dull and flat. You should keep going until you can feel a very slight burr at the tip of the blade on the flat back face.

 

The next step is optional but it does produce the keenest edge. Without moving the sharpening jig replace the 800 grit stone with the fine 6000 grit. Then return the chisel to the stone and continue as before but this time all we are doing is removing the marks left by the coarser 800 grit stone. Very swiftly a highly polished surface will result.

 

Slacken off the clamping knob on the sharpening jig and slide it down the blade about a half inch which will increase the bevel to 30 degrees.

Then re-tighten the jig and firmly but lightly rub the blade edge once more up and down the fine stone. Because the prepared edge is so fine and true this should only take  8 to 10 light rubs on the stone. The edge should be no wider than 1 mm, there is no purpose in continuing to rub longer than this all you will be doing is wearing away more metal and the blade will not be any sharper. Carefully remove the chisel from the sharpening jig and turn the chisel over and with it perfectly flat on the stone rub it back and forth a couple of times to remove any slight burr.

The blade will now be perfectly sharp and in fact although I do not recommend it you should be able to shave with it.

 

 A word on grinding wheels

 

A grinding wheel that is ridged or rounded over is very poor from grinding planes and chisels. The best wheel will be one that is square, clean and true. Wheels can be dressed with either a star dresser or a diamond.

I prefer the latter as it is easier to control and does a better job I feel. The diamond type can be rolled from side to side across the face of the wheel to true it up.

 As with anytime that you use a grinder wear adequate eye protection. You might want to wear a dust mask when trueing up the wheel also as the dust is not good to breathe.

 

Sanding Heaven

 

If like me you do a  lot of working on boats you will know just how much sanding there is. Everything from rubbing down painted surfaces ready for the next coat, smoothing out new woodwork for the interior to sanding a whole hull and everything in between. Sanding can be mind numbing to say the least and anyway that it can be sped up and made more pleasant then so much the better. Dust is another factor too, we don't want to breath the dust nor do we want it floating around the shop, airborne waiting to land on a freshly varnished piece of wood. I have just finished testing the Mirka Ceros Compact Electronic Random Orbit sander and I am very impressed. In fact I would go one step farther and say that this is the best RA sander that I have ever used. At first glance it looks just like an air powered sander but it is fact electric, the motor is a DC unit which runs from a fairly large transformer that comes with the unit. The transformer sits on the bench or whatever and a long lead then connects this to the sander itself. Like an air powered sander there is a paddle on top of the unit which as you grasp the sander turns on the power and starts the motor. Because the unit is so light and compact I was able to use it all day without fatigue. It is also much quieter than either an air sander or a more traditional electric unit and I was easily able to
use it without wearing ear defenders. When connected to a suitable vacuum unit there is almost no dust; although you can use standard hook and loop sanding sheets it works best with Mirka's Abranet sheets which are a mesh style and allow the dust to flow easily through the abrasive and up the dust pipe.

OK so what's the down side. On word; price. I tested the 5 inch version (it's also available as a 6 inch) but it costs almost $500 dollars without the extractor. For this reason alone I don't think they are going to sell many to hobby boat builders and at the other end of the scale the professional boat shop is unlikely to buy these tools either as they normally have a large compressor and can use air sanders costing $50 which have fewer moving parts. So I am not sure who exactly is going to buy this tool, I for one would love to own it as it makes sanding almost a pleasure, fast, quiet and virtually dust free. If money is no object then buy one you'll love it just as much as I do.

Teak grating - Final result

Regular readers will know that I have been reconfiguring the cockpit on Mallard. The cockpit itself is complete but I was unhappy with the look of the waterproof hatches in the sole and wanted to cover these with a traditional teak grating. I started this some time back and in
between other projects have managed to get this finished up. In an earlier post I gave a brief description of how I cut the housings for the slats so this post leads on from there.

 

For most boat work you cannot go far wrong with epoxy but in this case I made change and went with PU (polyurethane) glue. This is moistened cured adhesive and I have had good results with it. Although I would probably not use it for main structural items it is great for jobs like this grating. For one it can be used straight out of the bottle and two, which was very important in my case clean up is a snap.

 

Because it a moisture cured adhesive if the wood is too dry it will not set up well. The teak had been hanging around in the warm workshop for a couple of years and the moisture content was very low so brushing on a some water to the slat before it was tapped into the glued housing made sure that the bond was good.

 

After a 10 to 15 minute period the squeeze out started to foam which is good indicator
that all is well. The open joint time is also quite short so you have to be swift with the gluing up process.

To suit my project I made up two identical slatted sections.

 

After leaving the slat sections to dry overnight a quick going over with a belt sander fitted with 120 grit belt cleans up everything perfectly. Any remaining glue can be removed with a sharp chisel, one of the advantages of the PU adhesive. You can also the tenons here which will slot into the frame.

 

The frame is made of one inch by three inch teak. Cutting the mortices with an electric morticer saved a bunch of time. I could have cut them out with a mallet and chisel but it would have taken all day. A morticer is a great tool which basically drills square holes.

 

The frame was glued up with some thickened epoxy but not before I had a trial dry run. I have found to my cost in the past that when everything is covered with sticky goo that is not the time to have to make last minute adjustments.

 

The completed grating after a final sanding up before placing in the cockpit.