Wooden Straightedge ?!?

[Derek Cohen (Perth Oz)]

I made this one last year ...

The short article is here: http://www.inthewoodshop.com/ShopMadeTo ... quare.html

My 15 minutes of fame came when Chris Schwarz linked to it in one of his blogs.

Regards from Perth

Derek

 

[Corneel]

Probably a stupid question, but do you use these wooden edges with a marking knife. and doesn't it harm the straightness? You could mark with an awl of course, but I don't happen to have a suitable awl and I have plenty of knifes.

While planing boards I use my wooden winding sticks all the time. Not just to check for wind, but also as a straightedge to check for flat.

 

[Derek Cohen (Perth Oz)]

Hi Corneel

I use this one with a pencil. It is for layout.

Regards from Perth

Derek

 

[J_SAMa]

Can i make straightedges out of MDF or Plywood? They seem to be more stable than most wood.

 

[twothumbs]

The simple answer is yes. MDF better than ply as it can be a bit hairy on the grain.

 

[J_SAMa]

The simple answer is yes. MDF better than ply as it can be a bit hairy on the grain.

Anything I need to be cautious about? Do I need to apply any oil to MDF (because it swells in thickness when wet)?
And would those straight edges be good enough for checking plane soles for flatness?

 

[Cheshirechappie]

The simple answer is yes. MDF better than ply as it can be a bit hairy on the grain.

Anything I need to be cautious about? Do I need to apply any oil to MDF (because it swells in thickness when wet)?
And would those straight edges be good enough for checking plane soles for flatness?

For normal furniture setting-out jobs, unfinished MDF will almost certainly be good enough, but check it from time to time, especially if the edge gets dinged.

For checking plane soles, NO wooden straightedge is good enough. The British Standard tolerance for plane sole flatness is 1 1/2 thousands of an inch either side of a mean - a maximum of 3 thou out over the plane sole. Nobody can guarantee that wooden straightedges will be straighter than that, and many metal ones won't be, either. I strongly suspect that many people who complain that their plane soles are not straight when compared to their 'straightedge' have a non-straight straightedge.

Probably the best 'workshop' test for plane sole straightness (without having access to inspection grade surface plates, co-ordinate measuring machines or other engineering toolroom exotica) is to work the plane on a piece of mild 1" timber about twice or three times the length of the plane. Keep reducing the set until the plane almost doesn't cut at all. When the plane will produce a tanslucent shaving of gossamer thinness, it's sole will be straight enough for all but the most pernickety of woodworkers.

 

[GazPal]

The simple answer is yes. MDF better than ply as it can be a bit hairy on the grain.

Anything I need to be cautious about? Do I need to apply any oil to MDF (because it swells in thickness when wet)?
And would those straight edges be good enough for checking plane soles for flatness?

You can varnish/oil the surface, but avoid applying finish to the guiding edge as it can distort. I'd prefer to use plywood than MDF, because MDF has a propensity for swelling when humid and turning into boomerang like objects and swelling well beyond reason when wet. Plywood edges can be planed clean and sealed with minimal risk of distortion.

 

[J_SAMa]

For checking plane soles, NO wooden straightedge is good enough. The British Standard tolerance for plane sole flatness is 1 1/2 thousands of an inch either side of a mean - a maximum of 3 thou out over the plane sole. Nobody can guarantee that wooden straightedges will be straighter than that, and many metal ones won't be, either. I strongly suspect that many people who complain that their plane soles are not straight when compared to their 'straightedge' have a non-straight straightedge.

Probably the best 'workshop' test for plane sole straightness (without having access to inspection grade surface plates, co-ordinate measuring machines or other engineering toolroom exotica) is to work the plane on a piece of mild 1" timber about twice or three times the length of the plane. Keep reducing the set until the plane almost doesn't cut at all. When the plane will produce a tanslucent shaving of gossamer thinness, it's sole will be straight enough for all but the most pernickety of woodworkers.

How did woodworkers check plane soles for flatness back when there weren't any metal straightedges? Did they use the test you described?

 

[GazPal]

For checking plane soles, NO wooden straightedge is good enough. The British Standard tolerance for plane sole flatness is 1 1/2 thousands of an inch either side of a mean - a maximum of 3 thou out over the plane sole. Nobody can guarantee that wooden straightedges will be straighter than that, and many metal ones won't be, either. I strongly suspect that many people who complain that their plane soles are not straight when compared to their 'straightedge' have a non-straight straightedge.

Probably the best 'workshop' test for plane sole straightness (without having access to inspection grade surface plates, co-ordinate measuring machines or other engineering toolroom exotica) is to work the plane on a piece of mild 1" timber about twice or three times the length of the plane. Keep reducing the set until the plane almost doesn't cut at all. When the plane will produce a tanslucent shaving of gossamer thinness, it's sole will be straight enough for all but the most pernickety of woodworkers.

How did woodworkers check plane soles for flatness back when there weren't any metal straightedges? Did they use the test you described?

In truth, they didn't unless a plane was proving troublesome to set up. The best means of checking for flat is by seeing how your plane performs once fine tuned for use. A timber straight edge is accurate enough, but you can also use a steel rule (As found on combination squares) or a large try square blade. If either blade type is bent or out of true it has no place in anyone's toolkit.

As a retired professional cabinetmaker with almost 50 years int he trade I'll put my neck well and truly on the line by saying the following:

The present fad for chasing true flatness in plane soles, plane irons and chisel blades is a comparatively recent phenomena inherited via sales babble and DIY woodwork writers trying to market and sell their wares. They have to find something to write about and did. The fact is a heavy day or two's planing on abrasive/high silica timbers can induce inaccuracies which negate the manufacturing tolerances everyone seems to be going mad about.

An old workshop rule of thumb (Escaping the gossamer thin shaving route) is a smoothing plane is well set up if you can produce shavings which are sufficiently transparent to read standard newsprint through. There's no real need to measure shaving thickness. Simply practise, practise, practise tool use and sharpen whenever necessary and without allowing honed edges to become blunt. You'll become master of the tools within your kit far sooner than imagined and capable of far more in terms of crafting.

 

[twothumbs]

I whole heartly agree with GazPal. A luxury of the modern world.
It was not so long ago that a tradesmen sharpened his tools at home at night. Dont know when 'tool time' was factored into a mans wage. Understanding the need and where for accuracy is important. In my simple view...the clever bit is knowing when to be exact, and I mean that in a general way. I could add all the tools you need to buy before you start. The machines, exactly the correct saw, etc. Simple is the way. Sticks are one example of this (previous threads on this).
My thoughts J-Sama on str. edges are as follows;
To give you an idea......Been out and checked my winding sticks (not used for years) and one is a bit out, perhaps 1 mm ( I can see a bit of light between them). They are about 900 wide and made about 2001/2 from ordinary 12mm redwood and I keep them hanging up on a nail next to my 50% hygrometer in the garage. There were only to be for temporary use at the time, so I think not bad for stability after 10 years. The beauty of wood is they are light and don’t dent the wood. MDF or ply if you are making decent long ones of say 1200 (half a sheet width) then would respectfully suggest 18mm thick by say 100 high. Put a flat bevel on the top edge, 30 degs. and taper off the ends to take some weight of them. If you think or find the 18mm thick true edge is going to be too thick, then bevel off a bit (say 3-6mm but chose the thickness s to suit the plys) to allow any light to show up the differences. Made within the hour...what could be better? Reduce the height down to say 50mm for a shorter one of say 450mm. I went this way as I found metal rules (straight edges?) were not good and the idea of fiddling with a metal file was going to be like the proverbial chair legs. I have found ordinary strip steel can be quite straight. Use a fine sharpened pencil and not a flat carpenters one. You will never look back. As others have said, odd bits can be used so look out for old bits of hardwood off old furniture, etc as good source of stable wood. Now draw a fine pencil line then flip it over to draw another line which shows double the inaccuracy, if any. You only need one true edge although you won’t want it visually to look wrong of course. Hope this all helps in the big picture Best wishes.

 

[J_SAMa]

For checking plane soles, NO wooden straightedge is good enough. The British Standard tolerance for plane sole flatness is 1 1/2 thousands of an inch either side of a mean - a maximum of 3 thou out over the plane sole. Nobody can guarantee that wooden straightedges will be straighter than that, and many metal ones won't be, either. I strongly suspect that many people who complain that their plane soles are not straight when compared to their 'straightedge' have a non-straight straightedge.

Probably the best 'workshop' test for plane sole straightness (without having access to inspection grade surface plates, co-ordinate measuring machines or other engineering toolroom exotica) is to work the plane on a piece of mild 1" timber about twice or three times the length of the plane. Keep reducing the set until the plane almost doesn't cut at all. When the plane will produce a tanslucent shaving of gossamer thinness, it's sole will be straight enough for all but the most pernickety of woodworkers.

How did woodworkers check plane soles for flatness back when there weren't any metal straightedges? Did they use the test you described?

In truth, they didn't unless a plane was proving troublesome to set up. The best means of checking for flat is by seeing how your plane performs once fine tuned for use. A timber straight edge is accurate enough, but you can also use a steel rule (As found on combination squares) or a large try square blade. If either blade type is bent or out of true it has no place in anyone's toolkit.

As a retired professional cabinetmaker with almost 50 years int he trade I'll put my neck well and truly on the line by saying the following:

The present fad for chasing true flatness in plane soles, plane irons and chisel blades is a comparatively recent phenomena inherited via sales babble and DIY woodwork writers trying to market and sell their wares. They have to find something to write about and did. The fact is a heavy day or two's planing on abrasive/high silica timbers can induce inaccuracies which negate the manufacturing tolerances everyone seems to be going mad about.

An old workshop rule of thumb (Escaping the gossamer thin shaving route) is a smoothing plane is well set up if you can produce shavings which are sufficiently transparent to read standard newsprint through. There's no real need to measure shaving thickness. Simply practise, practise, practise tool use and sharpen whenever necessary and without allowing honed edges to become blunt. You'll become master of the tools within your kit far sooner than imagined and capable of far more in terms of crafting.

Hi Gary,
I'm actually more worried about getting continuous shavings. Most of my shavings are full length, but are either not full width, or are "split" in the middle (so two separate threads of shavings come out instead of one full-width shaving). Sometimes when I try to take a really shallow cut, the shavings come out in hair strand-like forms. Does this have anything to do with the sole flatness? By the way I checked the No. 4 against a cheap square's blade, a piece of MDF and a wooden countertop (non of them sound really straight :? ) and I could slip 3 pieces of printer paper under the sole in the middle, is that too concave?
However despite all that, I do get a nice surface left behind on the wood though.
Sam

 

[GazPal]

Hi Gary,
I'm actually more worried about getting continuous shavings. Most of my shavings are full length, but are either not full width, or are "split" in the middle (so two separate threads of shavings come out instead of one full-width shaving). Sometimes when I try to take a really shallow cut, the shavings come out in hair strand-like forms. Does this have anything to do with the sole flatness? By the way I checked the No. 4 against a cheap square's blade, a piece of MDF and a wooden countertop (non of them sound really straight :? ) and I could slip 3 pieces of printer paper under the sole in the middle, is that too concave?
However despite all that, I do get a nice surface left behind on the wood though.
Sam

It is a little too concave for my liking, but an easy fix. Your #04's flatness is easily resolved by fixing a sheet of 120 grit sandpaper to a flat surface and easing it's sole flat by using steady longitudinal sweeps of the plane with minimal downward pressure. There's no need for a polished finish on the sole as it will soon return as the plane is used. Don't forget to retract the plane iron, plus ensure all screws, etc., are at working tension. Cross-hatch/mark the plane sole using marker pen and you'll be able to see and keep track of where it's making contact.

Two separate shaving tracks/threads of shaving could indicate a nick in the blade edge, or possible flaws in the timber. The combination of fine setting and radius in the blade edge could be the cause of narrower shavings. Try honing the blade so it has a straight edge and restrict rounding - to avoid plane tracks - over strictly to each corner. This should help resolve the shaving width issue.

 

[J_SAMa]

Hi Gary,
I'm actually more worried about getting continuous shavings. Most of my shavings are full length, but are either not full width, or are "split" in the middle (so two separate threads of shavings come out instead of one full-width shaving). Sometimes when I try to take a really shallow cut, the shavings come out in hair strand-like forms. Does this have anything to do with the sole flatness? By the way I checked the No. 4 against a cheap square's blade, a piece of MDF and a wooden countertop (non of them sound really straight :? ) and I could slip 3 pieces of printer paper under the sole in the middle, is that too concave?
However despite all that, I do get a nice surface left behind on the wood though.
Sam

It is a little too concave for my liking, but an easy fix. Your #04's flatness is easily resolved by fixing a sheet of 120 grit sandpaper to a flat surface and easing it's sole flat by using steady longitudinal sweeps of the plane with minimal downward pressure. There's no need for a polished finish on the sole as it will soon return as the plane is used. Don't forget to retract the plane iron, plus ensure all screws, etc., are at working tension. Cross-hatch/mark the plane sole using marker pen and you'll be able to see and keep track of where it's making contact.

Two separate shaving tracks/threads of shaving could indicate a nick in the blade edge, or possible flaws in the timber. The combination of fine setting and radius in the blade edge could be the cause of narrower shavings. Try honing the blade so it has a straight edge and restrict rounding - to avoid plane tracks - over strictly to each corner. This should help resolve the shaving width issue.

Hi Gary,
Could a concave sole also be the reason that I always remove more material when the plane is coming off the workpiece?

Last weekI tried lapping the sole on some 180 grit wet or dry sandpaper stuck to a piece of MDF. After 1 hour of rubbing and 4 sheets of sandpaper I'd barely done anything to the sole (the concavity was actually 4 pieces of printer paper before and the lapping reduced it to 3). I was lapping it dry because I see no point in wet lapping. Could it be that wet and dry paper doesn't perform well when dry? Or is MDF not flat enough?

 

[GazPal]

You need to use a coarser grit in order to remove surplus iron from the sole, then refine the finish with finer grades. You could even go to 80 or 60 grit if necessary, but I'd err on the side of caution and use 120 grit as a starting point and only use heavier grits if necessary.

As with grinding, if a grit removes insufficient material within a given timescale it often proves best to move to a coarser grit in order to speed the process, but always start with a finer grit as a means of gauging your requirements.

Much of the time, if removing a heavier shaving at the end of each planing stroke, it's caused by too much downward pressure from the forward/leading hand. Ease pressure from the front of your plane and - instead focus on keeping the heel of the plane in contact with the timber. Quite often lifting the nose of the plane clear of your work at the end of each stroke can resolve such issues.

Wetting your paper can improve the way it cuts, plus keeps it cleaner during use. Wet and dry paper can also be washed/rinsed clean and refreshed. Soaking the paper overnight before use can help prevent it from tearing and WD40 or water (With a little bicarbonate of soda added to retard rust) are good wetting mediums.

 

[bugbear]

The present fad for chasing true flatness in plane soles, plane irons and chisel blades is a comparatively recent phenomena inherited via sales babble and DIY woodwork writers trying to market and sell their wares.

There are traces of it a little earlier than that.

http://swingleydev.com/archive/get.php? ... =1#message

BugBear

 

[GazPal]

The present fad for chasing true flatness in plane soles, plane irons and chisel blades is a comparatively recent phenomena inherited via sales babble and DIY woodwork writers trying to market and sell their wares.

There are traces of it a little earlier than that.

http://swingleydev.com/archive/get.php? ... =1#message

BugBear

The downside to such assumptions based upon content of a woodworking annual dating to 1918 is whether or not such a publication was widely read and by who. Not too many professional woodworkers had access to such publications, nor the spare time or inclination to read them and especially so when the majority of able bodied men - up to the age of 35 - were involved in trench warfare, whilst a considerable lower number of conscription exempt craftsmen (Re "The Military Service Act 1916) continued to work in their homeland.

 

[bugbear]

The present fad for chasing true flatness in plane soles, plane irons and chisel blades is a comparatively recent phenomena inherited via sales babble and DIY woodwork writers trying to market and sell their wares.

There are traces of it a little earlier than that.

http://swingleydev.com/archive/get.php? ... =1#message

BugBear

The downside to such assumptions based upon content of a woodworking annual dating to 1918 is whether or not such a publication was widely read and by who. Not too many professional woodworkers had access to such publications, nor the spare time or inclination to read them and especially so when the majority of able bodied men - up to the age of 35 - were involved in trench warfare, whilst a considerable lower number of conscription exempt craftsmen (Re "The Military Service Act 1916) continued to work in their homeland.

Oh, we can try to find more evidence about how many people were concerned about flat plane soles, but the question and answer prove that the answer is "not zero".

BugBear

 

[J_SAMa]

Totally confused now.
Plus, it just occurred to me that no-one has ever explained to me what the advantage a flat plane sole is. :?

 

[GazPal]

Oh, we can try to find more evidence about how many people were concerned about flat plane soles, but the question and answer prove that the answer is "not zero".

BugBear

Percentages and an idea of the readership/participants included within your assumption would be far more useful than your non-empirical "not zero" statement. :roll: