Above is an audio of the post below. Read or listen, whatever is easier for you.
The use of abrasives goes back almost since the beginning of recorded history. Prehistoric men, for example, sharpened their tools and weapons by rubbing them together.
Stone used in building the Pyramids of Egypt which were smoothed with a naturally “bonded” abrasive–sandstone! Around 2100 B.C. a creative Egyptian engineer mounted a circular wheel on a crude sort of lathe and ground bronze tools and ornaments, launching the art of cylindrical grinding. During the Middle Ages, armour and swords were ground and polished. The first recorded manufacture of coated abrasives goes back to the 13th century when the Chinese used natural gums to bind crushed seashells to parchment.
Sandpaper was made out of crushed shells, seeds, sand, and gum, shark skin, rough horse tail plant when boiled and when dried, is finer than sandpaper which is used for polishing in Japan.
In the 18th century shark skin and sand not combined but as separates were used, Anthony Hay’s Cabinet shop at Colonial Williamsburg used shark skin with great success.
In 1775 Carter wrote in his day book on how to make sandpaper.
“To polish wood – Take brown paper, make it wet with glue, then scatter fine sand thereon, through a hair sifter – Sandpaper is equal to fish skins.”
You could safely say, that sanding is older than hand planing. As I mentioned above, the Egyptians were sanding blocks using sand stones for smoothing. Hand planes were invented by the Greeks or Romans much later in history, no one really knows who invented it first or when, but my gratitude goes out to them for doing so.
When should you sand?
Whenever you want really, but in the 18th century, depending for whom the piece was being made, surface imperfections like small tear outs were left. If the piece being made was for the wealthy usually this would need to be French polished, so everything had to be free of surface defects, and abrasives were used. In this modern age of craftsmanship and I’m not including mass manufacturers, regardless of the piece were making, any form of tear out is unacceptable. I am not stating that we are better than our crafting ancestors since we cannot compete with such high levels of craftsmanship, to stand in their defence they made a living from the craft and, working by hand is laborious and time consuming enough, let alone to hand sand every piece in order to flatten or take out every imperfection would be ludicrous and expensive. Sandpaper according to Anthony Hay’s cabinet shop cost about 6 pence which equalled to a day’s wage.
If you didn’t know you will now, yes it is possible to make a surface completely flat using only sandpaper starting from a course grit and working your way up. It may be a dusty option but a solution to really nasty but beautiful timbers. I guess this would be the only time I would ever pull out my belt sander, but the timber would have to be something so beautiful and unworkable with hand planes, that would force a machine in my hand. You may ask if there is an alternative and I would say yes of course, scraping but not always will work, however, for 99.99% of the time it will suffice.
As you all know, I make clocks, and clocks are usually elaborate high end pieces. So scraping and sandpaper would be used for such fine work. The steps I would normally take may or may not involve sandpaper, everything depends on the wood and the type of finish desired.
These are steps I would normally take:
Rough sawn surface prior to hand planing.
Flat and smooth with various hand planes and scraper. These are two boards edge joined seamlessly in fact you can’t even see the join.
I hand plane all the surfaces until they are flat and smooth, if there is tear out I would use my low angle jack plane that has a 50 degree bevel on it. This will normally smooth most timbers and, I say atleast 95% of difficult grain I have encountered. Sometimes when planing Camphor Laurel, even the high angle blade will not make the board completely smooth, so in this case I will use a card scraper. Even then sometimes with this particular timber, a card scraper isn’t enough, that’s when sanding is your only option left. You can however skip the card scraper and just go directly to using sandpaper however, the card scraper does the majority of the work thus cutting your sanding time by more than half. I don’t particularly like using a cabinet scraper in replacement for a high angled plane. The reason is, a cabinet scraper doesn’t leave as polished a surface as you would get from a hand plane. To use a cabinet scraper or any scraper for that matter, you need to flex the blade. I’ve discovered if you take the blade out and scrape that way it works beautifully without the need to flex the blade and the results I get are much better than I would get with it being installed in the tool. I wonder if that 45 degree bevel has anything to do with it. This calls for another experimentation.
The beautiful nature of timbers is their unpredictable nature, even though you may work with one particular species, each board are subtly and some extremely different to each other. I look at timbers like people, you have five fingers not all are of equal length, therefore not all people are the same. Each person is an individual and if treated with kindness and respect you will get the same in return. So too with wood, you never force the wood into submission like you would with kiln drying and machinery and then expect it to behave in the long run. When you work with it with hand tools it will quickly tell you what it likes and doesn’t like, the end results are far superior and the process is a lot more enjoyable. This is something unfortunately a machinist cannot understand and by the way, a power planer will never create a perfectly smooth and flat board. Only a hand plane can do this. Having said that I have heard that helical blades will create a smooth and flat surface but I will reserve my judgement on this until I see it, but more importantly feel it with my own hands.
If any of you have upgraded your planers with helical blades I would you like to hear your thoughts on them. Do they really produce a flat smooth surface without any planing skip marks and snipes.