Fascinating all these blogs and posts. Keeps me doing funny things in the workshop.
Div - as I peruse over all these wonderful blogs, I have noticed that various people talk about posting photo's of their work - even you talking about posting a photo or two....
But I don't see them....Any place that they might be hiding?
Now don't ask me to be specific. Too much read and 'old timers playing a part here too. But I do recall one where you saying that you will post photo's of the beams that you were lifting. And other people telling about their builds with photo's.
Am I just going kookoo or what? Just inquisitive boet.
Fascinating all these blogs and posts. Keeps me doing funny things in the workshop.
I am doing a job with wooden drawer runners and ask the fowling
Where would you place them at the bottom ,middle or the top.
I've pondered where to categorise this blog.
"Can you help"....?
So I settled for "Workshop Chronicles" Even though all of the above would be the ideal place for this. I feel that this is an event that will cover the breaking down of my workshop now and rebuilding it up later.
So here goes.
I'm ready for a big move. Lock stock and all the barrels.
60 years of accumulated stuff that will be needed where i'm going.
Where, you might ask? Well it will be down to the coast. Knysna area.
My farther had a building and construction business 10 years prior to when I came into the world. 5o years on and I have added onto that pile.
Now before anyone says that "I have to purge" I can't. I need it all.
What I have you can't replace. I can't sell it up in Johannesburg and expect to find the same thing down there for the same price. First they won't have it, and second, if they had I would not be able to buy it for the same price I got for mine.
This is the final move. There will be no more after this. This is where I lay my hat till I peacefully 'retire' for good.
The place i'm going to needs tons and tons of time to repair, fix, landscape, plough, demolish and build up. I need all my "stuff" And thank heavens it will all now come in handy. All will be used. All those odds and ends saved over the years because "I can use this. Or- This still works. or Eventually this will come in handy" Well that time is now.
What my dilemma is - is getting all this stuff packed and ready for the move.
Where the heck do I start. What get's boxed first. All my planks, all my metal lengths, all my tools, my machines, bit and pieces, paint tins, cupboards, benches, drawers, etc etc etc. And I have lot's. When I say I have lot's then you just have to believe that I have.
And to add to all of the above....... We still have not even begun to empty my girlfriends (Life Partner) place.
I'll start to document the build up to the packing. Photo's. Low's and highs.
Bear with me.
Contribute by means of helpful hints and skills needed for this mammoth move.
All will be devoured to make this as easy as it can be.
So excuse me while I step out................................................."Aaargh!"
The term scraper brings to mind a tool for cleaning old paint from wood. That is certainly what you will get when asking for a scraper at the local hardware shop. It seems a poor term for a tool capable of the finest of cuts and with great accuracy. I would say it is an indispensable tool in any decent woodworking shop. I will also say that it is a forgotten tool in this era of power tools where everyone will have you believe that Ryobi is the answer to all you problems!
The term is something of a misnomer, for when properly sharpened, the scraper actually cuts rather than scrapes, much like a chisel or plane, slicing of paper thin shavings of wood. As useful as the scraper is, few people understand how to sharpen and use this very simple, much underrated tool.
Scrapers can come in various thicknesses and sizes but the sharpening method I will describe is the same for all. A standard scraper will be a rectangular piece of steel, about 60mm x 125mm and less than 1mm thick. For curved surfaces thin flexible steel that will conform to the curve is better. The gooseneck scraper has a variety of curves that can be used on tight curves or moldings. I keep a number of scrapers around for different purposes.
A rectangular scraper consists of four edges and two faces. The cutting is done by a small burr formed at the juncture of a face and an edge. Such a juncture is called an arris. The quality of this burr and the cut it makes is entirely dependent on the quality of the intersecting faces.
How to sharpen a scraper:
To sharpen the scraper, first dress the two long edges with a single cut mill file. Clamp the scraper vertically in a vise and draw the file length ways along the edge, trying to achieve a straight edge that is also square to the sides. The arrisses should feel sharp to the touch. If not, keep filing until they do.
Next polish or hone the faces on a flat oil stone. I use a medium India stone followed by a fine, hard finishing stone – a black Arkansas in my case. Water stones or Diamond stones (if you can afford them) will also do the trick. Be careful to keep the scraper flat on the stone or you’ll round the arris.
Then, polish the long edges of the scraper by holding it vertically between both hands and rubbing it to and fro on the stones. Hold it diagonally across your stone to prevent uneven wear! Again, the arrises should feel sharp to the touch.
A burnisher is required for the next step. It must be round, smooth and of a harder steel than the scraper. Many things will work well as a burnisher; the round shaft of a screwdriver, the back of an old gouge. I made a good one by fitting a turned wooden handle to a buffed up pushrod from an engine. Whatever you use, a little lubricant between scraper and burnisher helps a lot. A drop of oil is fine, or just rub the burnisher across your nose –it really does work!
Two steps are required to make the burr; raising the burr and turning it. To raise the burr, lay your scraper flat on the edge of a firm surface, hold the burnisher just a few degrees off horizontal and stroke it firmly back and forth along each arris. You should hear a loud tick as the burnisher goes off the end of the scraper with each stroke. What this does can be seen under magnification, an ear will protrude from each edge that has been burnished. The drawing shows an exaggerated cross section.
Next the burr need turning. There are different methods but this is how I do it. Clamp the scraper vertically in a vice, place the burnisher on the far end of the edge and firmly pull it toward you with downwards pressure. Two or three firm strokes should do, first at 90 degrees and then with the handle lowered slightly at around 85 degrees to the side of the scraper. It is important to hold the burnisher firmly and make long slicing strokes which extend over the whole blade. This will keep the edge smooth and prevent nicks or grooves. Taking several passes will turn a large burr which will take a large shaving. However, a large burr takes longer to turn and I’ve found them to be more brittle and they degrade rapidly. I prefer a small burr; it is less work in the long run.
Why scrape, rather than plane or sand?
Scrapers are commonly used to remove a fair amount of wood from a surface. A plane can easily tear interlocking or wavy grain but the scraper can manage nearly any awkward grain. They remove material quickly and leave a finished surface. No need to work your way through different grit sand papers!
Some notes on technique.
To scrape a flat surface, hold the scraper nearly perpendicular and push or pull it to take wide shavings. To maintain the flatness of a large surface, like a tabletop, it is essential to cover as large an area as possible with one stroke of the scraper and to introduce as little curvature to the cutting edge as possible. A curved scraper will make a concave cut, the more you curve it, the more the concavity. Good for some applications but not for the tabletop! To avoid curvature, hold the scraper with your fingers behind the cutting edge and thumbs in front. Maintain a constant angle to the wood, as close to perpendicular as possible and draw the scraper towards you, attempting to produce a shaving almost the full width of the scraper. Proceed across the surface with a series of long and slightly overlapping strokes. I prefer to pull the scraper but you can push it too.
Unlike a plane, the scraper has no sole and may therefore ride up and down over hard and soft areas and create ridges on the surface. To avoid this, the scraper should be slightly diagonal to the direction of the wood grain. Alternate the diagonal direction every other stroke so that the edge will only take material from the high spots, leaving a flat surface.
For a fine, finishing cut, a small, sharp burr is needed. If the scraped surface isn’t good enough, re-stone the scraper and turn another burr. Obstinate grain may require that the angles diagonal to the grain be increased to produce a skewed cut.
Concave or convex surfaces.
Depending on the curves, use a flexible rectangular scraper or a gooseneck scraper. By springing the scraper between fingers and thumb, the cutting edge can be made to conform to a variety of curves. As the curve of the scraper tightens, the cutting angle is inevitably lowered. As the scraper is lowered, the burnishing angle of the burr must also become more astute to maintain the proper cutting angle of the burr to the wood. You may need to experiment with various angles at first, but you will get the feel of it with experience.
As soon as the scraper no longer takes a shaving, it is time to resharpen. You want shavings, not dust! It is possible to re-turn a burr with the burnisher several times before having to go back to the file and stones. Burnish the face first, and then turn the burr. When the burr becomes ragged and leaves marks on the wood surface, it is time to go back to the beginning of the process.
Remember, putting of sharpening because of laziness, ultimately costs more time and energy!
As with all edge tools, the joy of using a sharp scraper is well worth the effort of taking the time to sharpen.
The million dollar question: Where do you get a scraper?
Your local hardware shop probably doesn’t even know what a cabinet scraper is. I doubt you could buy one in SA, maybe at Hardware Centre in Cape Town or Johburg.
Don’t despair, they are easy to make. First find an old handsaw. Any type or brand will do. I always see sorry examples of handsaws in pawn shops, about the only thing they are good for is to make scrapers with. Use one of those thin steel cutting discs on a baby grinder to cut a number of different sizes and shapes from the handsaw blade. After filing the edges straight and square, you are good to go! I have gathered a good collection of pretty decent scrapers this way.
This quote from a BBC radio program about craftsmanship. Grayson Perry is a British Turner Prize winning artist.
"A lot of young people are somehow put off struggle and difficulty. Boredom thresholds now because of the nature of entertainment, people are adrenalin addicted and I think that one of the big unspoken addictions in our society is adrenalin. We are addicted to drama, everything has to be exciting, black and white there's no middle ground, we're all being gradually pushed into this area where our attention span is that of a gnat. Difficulty, learning a skill that might take 10 years over 10,000 hours is something that frightens to death, when in fact when you attain that it is probably the happiest most joyful thing you can do".
Grayson Perry BBC radio4 Thinking Allowed April 2008.
However good your table saw is, the cut will only be as good as the blade fitted. Let’s look at important points and how to choose the right one for the job.
In a previous blog I talked a little about the versatility of the table saw and how to operate it safely. To realize its full potential the right blade must be fitted. Condition of the blade is also important. Blunt, chipped or missing teeth, a warped plate and resin build up will drastically reduce the accuracy and effective cutting power of your saw.
TYPES OF BLADES.
I’ll only look at Tungsten Carbide Tipped (TCT) Blades. High Speed Steel blades are rare these days, although they still have a place in specialist applications where their much thinner kerf and greater initial sharpness outweigh their disadvantages.
FLAT TOP (FC)
Flat top or raker blades have their teeth ground square across the top, giving a chisel shape to each tooth. This pattern, with its chopping rather than slicing action, gives good waste clearance and fast cutting with the grain. It is most suitable for ripping, used for cross cutting it will produce a poor finish and severe tear out.
ALTERNATE TOP BEVEL (ATB)
ATB blades have their teeth ground at alternate bevel angles, one tooth angled one way, the next the other way. This gives a slicing action to both sides of the blade, making it the most suitable for cross cutting.
ATB blades with extreme bevel angles are used for clean cutting of veneers, laminates and melamine faced boards. They produce a superb finish and are especially good for mitering. Their downfall is that they wear very quickly.
Combination blades are also available which feature both ATB and FT tooth patterns. The idea is that they should give a good finish together with fast waste clearance. In practice they don’t perform noticeably better that an ATB blade with a modest bevel angle. They will leave a flat bottomed kerf when used for grooving though.
These blades have teeth which are ground in 2 alternate patterns: first is an FT grind with chamfered corners, second a lower profile standard FT grind. The chamfered tooth cuts the centre of the kerf whilst the following raker tooth cuts the sides. The whole purpose of this pattern is to minimize tear out, especially on melamine faced board. These specialized blades are generally produced with zero or even negative rake angle to resist wear from abrasive materials such as MDF.
CLARIFYING TOOTH ANGLES.
The Rake Angle
is the angle at which the face of each tooth is ground, measured against the radius of the blade. As a general rule, the greater the rake angle, the faster and rougher the cut. Thus a deep ripping blade might have a rake of 18º to 20º, a general purpose blade around 15º, a good cross cut blade about 10º and a specialized blade for melamine board anything from 5º to -7º.
The Side Clearance Angle
is the angle at which the side of each tooth is ground, measured against the radius of the blade. As a general rule, the shallower the angle, the finer the finish. It also means more friction and therefore heat, so a shallow side clearance angle is only worth using on end grain and where finish is critical.
A typical kerf width is between 3mm and 4mm. Blades with a narrow kerf width of as little as 2mm to 2.8mm are available. The advantages of a narrow kerf are:
Less power required to drive the blade, therefore improved performance from small machines.
Less waste produced, important when cutting valuable exotics, less of your money on the floor!
The drawbacks are faster wear and a greater risk of heat build up. Too much heat can distort the blade’s plate – which is also thinner than that of a standard blade.
NUMBER OF TEETH
Circular saw blades are graded in terms of their total number of teeth. The only way to compare will be between blades of the same diameter. I will assume a blade of 250mm (10”) for this example. It is the most common size for table saws.
General rules are:
Fewer teeth means faster cutting but the trade off is a rougher finish.
The thinner the material being cut, the more teeth are required. More teeth mean a better finish, but a slower rate of feed. You get the idea!
RIPPING – When fast ripping, clearance of the sawdust produced (in the form of bulky shavings, relatively speaking) becomes a major issue. Good clearance will be obtained with a large gap between teeth, allowing a deep gullet. So a dedicated 250mm ripping blade should have no more than 24 teeth. Some rip blades have a hump behind each tooth. This is not a fashion statement, it is a chip limiter. Its purpose is to restrict the amount of cut. The hump not only saves wear and heat build-up, it also reduces the risk of kickback from a blade jammed in the cut.
CROSS CUTTING - Fine cross cutting demands many teeth to sever the wood fibers cleanly. The waste is a fine dust which is easy to clear so it isn’t a problem. For relatively thin material, 96 teeth will give good results, medium thickness around 80 teeth and heavier sections, 60.
GENERAL PURPOSE – For general purpose cutting between above two extremes, the following rule of thumb is useful:
With the blade set to just clear the thickness of the material, it should have no less than two and no more than five teeth in the cut.
A FEW NOTES ON QUALITY:
Sawblade quality starts with the plate itself. However well the teeth are ground, if they are wobbling about on the edge of a buckled plate, what is the point! Good plates are roller tensioned, visible as a faint ring on the plate at about three-quarters of its diameter. Not easily found at your local hardware centre, I know! A good plate is also dead flat. This is easily checked with the blade of an engineers square or similar.
The second most important factor is the quality of tooth grinding. This is less easily checked, although a magnifying glass will reveal some truths. Whilst peering at that tooth, have a look at the brazing – this should be smooth and free of pinholes. Lumpy brazing is a bad sign!
Carbide quality is hard to check. If the manufacturer talks of “micrograin” and quotes a grade number, you should be reassured.
The arbor hole is a vital element as a misaligned, oversized, or eccentric hole will ruin a blade’s performance. It is something that is often overlooked but is a good sign of quality: Good holes are reamed to exact size, a process that leaves a smooth burnished finish. AVOID blades with sharp burred holes. Any indication that the hole has been punched out is cause for instant rejection.
As always, price and brand name is normally a good indicator of quality – you do get what you pay for, most of the time!
RECOMMENDATION – WHICH BLADE?
If you are a specialist, you will have special requirements but for the average guy at the bench, it is easier to suggest a basic requirement. Assuming a 250mm (10”) blade, your first buy should be a 40 to 48 tooth ATB blade with a 5 - 10º bevel. This blade will cope with most work and will be your general purpose workhorse.
Add the following as they are needed: If you use a reasonable amount of rough sawn hardwood, a 24 tooth FT ripping blade will prove useful.
For fine cross cutting, joint-cutting and board work, keep an 80 tooth ATB blade with a 10 - 15º bevel nice and sharp.
If you want to cut a lot of melamine board, then the clean cut and wear resistance of a 80 tooth, negative rake, triple chip blade is you weapon of choice.
Remember, it is better to have a limited number of quality blades than a stack of cheap ones!
Resin build up on the blade will drastically reduce its performance. Clean your blades often. I use oven cleaner in a spray can. Spray the circumference of the blade with the white foam and let it soak for a while before scrubbing with an old tooth brush. Then wash off under running water and dry with the towel you stole from the bathroom! A second treatment might be necessary for stubborn deposits.
You won’t believe the difference it makes; feels like you just fitted a new blade!
Next time you go to the hardware shop, ask the “expert” some informed questions….Then watch for faces that drop and listen to the ummms and ahems!!