The Precision Sander

[woodbloke66]

This is a little sander I usually make from time to time when I need to sand where other bits of sandpaper won't go: the 'Precision Sander'. Essentially is a block of wood with a bit of sandpaper stuck to it in such a way that it's very, very accurate in use.

The current job uses a number of exposed and wedged mortice and tenons that need to be tarted up:

The top has been planed flat with a block and the corners are now rounded over with a very sharp Japanese paring chisel:

The problem now is that I need to smooth out the chisel marks which is where the Precision Sander comes in handy. To make one, take a block of hardwood and shoot the sides square; then stick on a piece of double sided tape, then turn it over and trim off the excess dead flush with the block:

...and then stick it to your sandpaper of choice. Here I'm making a double sided sander using 240g:

Now the PS can get right into the corners to smooth out the contour of the joint:

After a few minutes of sanding, the joint has been smoothed off but there remain behind some tell tale sanding marks on the leg:

These can be easily sanded out using the Precision Sander as it will sand right into an otherwise inaccessible corner. The sandpaper lasts no time at all and after a short time it's pretty useless, but quick enough to make another sander...or use the other side.

The finished joint:

These take next to no time to make and are invaluable for going places that no sander has gone before. Live long and prosper :lol: - Rob

 

[D_W]

Curious as to why this joint with facets wouldn't be more pleasing to the eye?

Not picking, I recognize that my taste for hand finished less sandpaper is often not the norm, and I've seen it in spades on guitars where I've ventured in the last two years. Even the factories will have a very skillful crisp planed and chiseled scalloped brace (perfect to my eye) and insist that sanding the crispness right off of it (no sonic difference, and this is on the inside of the guitar) is needed for final finish.

There are times that I must sand certain things, too, and will rely on devices like this (small pieces, etc), especially for fret leveling, etc. No commercial stuff needed, just properly applied sandpaper, a straight edge to check and a piece of planed wood that's jointed dead flat. Works a treat.

I have found that the PSA rolls (which are probably intended for machines) are far more durable and very reliable in sticking to purpose made shapes for sanding. they don't shed their grit immediately, and if they are good quality (european, scandinavian or american), they are very even in grit.

 

[That would work]

Sanding sticks are handy things.
I make a variety of them by contact adhesive sticking abrasive to all sorts of sections... flat, round, half round, boards. ... endless possibilities.

 

[woodbloke66]

Curious as to why this joint with facets wouldn't be more pleasing to the eye?

Simple answer; 'cos I like them rounded off - Rob

 

[Phil Pascoe]

and round ones on cardboard tubes from ali foil.

 

[D_W]

Curious as to why this joint with facets wouldn't be more pleasing to the eye?

Simple answer; 'cos I like them rounded off - Rob

good enough answer for me!

 

[MikeG.]

How come your paring left marks?

I use a file if I can, and I am sure I would in those circumstances. But if there isn't one that works just right, I'm sure we've all stuck sandpaper to a suitable bit of wood. They are nice, Rob, your little signature wedged through-tenons. There's probably an off cut or two of bog oak kicking around here which should keep you ticking over with this detail for a year or three, if you ever happen to be down this way.

 

[xy mosian]

Silly question here. Can the tenon, protruding end, be shaped before making up the joint? That way it is only the wedges which need shaping.
xy

 

[woodbloke66]

How come your paring left marks?

I use a file if I can, and I am sure I would in those circumstances. But if there isn't one that works just right, I'm sure we've all stuck sandpaper to a suitable bit of wood. They are nice, Rob, your little signature wedged through-tenons. There's probably an off cut or two of bog oak kicking around here which should keep you ticking over with this detail for a year or three, if you ever happen to be down this way.

Indeed Mike; the paring is a series of 'flats' left from the chisel which need to be rounded to a smooth profile and agreed, a fine file would do the same job. Again yes, everyone's stuck a bit of sandpaper to a block of wood, but here what I've done here is to ensure that the edge is dead square exactly where the sandpaper finishes so that you can get right into a corner.

I'm definitely up for a chunk of your Bog Oak and I certainly will be down your Suffolk way in September, as per our conversation a while ago on WH2, in fact SWIMBO will shortly be looking for accommodation for the night of the event.

Silly question here. Can the tenon, protruding end, be shaped before making up the joint? That way it is only the wedges which need shaping.
xy

It could, but I'd still need to bang in the wedges which would then need to be profiled - Rob

 

[D_W]

missed the low-life expectancy of the sandpaper comment in your first post. try the PSA roll in a light or medium weight. You can stick it right to the stick, then flip it over and cut it off flush with the stick face. It probably lasts at least 5 times as long as regular paper as long as it's decent quality.

Actually, for the price, it's almost highway robbery that the paper backed stuff intended for manual sanding doesn't last a tiny fraction as long as the non-stearated machine rolls.

Mirka gold would be at the high end of the market, but an eastern-euro roll branded porter cable usually sells here in the states for about 1/2 of mirka and life expectancy is about as good.

PSA paper and disc sold at harbor freight here (cheap import stuff) last only barely more than typical manual sand paper.

I use this stuff a lot for tools because it holds up well to hand lapping, etc, but only chanced upon how well it works (without being totally clogged up on the surface like stearated paper from the start) turning chess pieces a few months ago.

 

[xy mosian]

Silly question here. Can the tenon, protruding end, be shaped before making up the joint? That way it is only the wedges which need shaping.
xy

It could, but I'd still need to bang in the wedges which would then need to be profiled - Rob

Fair enough.
xy

 

[Phil Pascoe]

... Again yes, everyone's stuck a bit of sandpaper to a block of wood, but here what I've done here is to ensure that the edge is dead square exactly where the sandpaper finishes so that you can get right into a corner ...

I made several some years ago with pieces of scrap architrave and other mouldings and different grades of w&d for cleaning up silver jewellery - I found it much better to have them very slightly under right angles. The leading edge gets right into the corners better.