Tag Archives: woodworking

Snipe Hunting – Your Planer and You

By   26 Jun 2014

     The good news is that technology and free market capitalism have brought small thickness planers into home-shop affordability.  The bad news is that without the 5-digit price tag, 24-inch wide planning capacity or 3-foot infeed and outfeed beds of an industrial production planer, there’s a lot of things to keep in mind with these inexpensive marvels.  The typical hobbyist thickness planer is 12 to 13 inches wide and can handle stock up to several inches thick, which is darn respectable.  But the most common problem with small thickness planers is, of course, snipe.

 

Planer Snipe

Snipe is the defect left at the initial and departure ends of the stock from over-planing.

 The Fault

     Snipe is the defect left on a piece where the initial and departure ends of the board are over-planed for the first and last few inches of length than the rest of the board in the middle.  This is caused by insufficient support on the board during infeed and outfeed because of the anorexic in-and-out feed tables on most portable planers.  The workpiece doesn’t enter the machine level and steady; the far end (away from the planer) droops, rocking the end in the planer up off the bed slightly and into the cutter head, until the end in the machine gets to the second set of feed rollers.  Then, the two rollers on either side of the cutter head manage to keep the workpiece flat and true in the machine.

Planer Snipe

Snipe happens when the stock comes up off the table before it gets to the 2nd set of feed rollers

The Snipe Fixes

     There are three simple fixes for snipe.  One, mill the board longer than finish to account for the fact that you will lose several inches from both ends to cut the snipe off… not necessarily cost effective when using expensive exotic lumbers.  Two, if you have the real estate available in your shop, build long, sturdy infeed and outfeed tables precisely at the height of the planer’s bed.  Three, use the “hold the end up” technique when feeding and catching stock through the planer.

Feed Tables

Long feed tables are ideal, but space hungry.

     The easiest, least costly and least space consuming is option three.  The technique is to put a slight amount of upward pressure on the far end of the stock, forcing the infeed end down against the planer bed.  This is held until you feel the second set of feed rollers (the one’s on the opposite side of the cutter head) grab the stock.  The technique is repeated in reverse on the exit side of the planer as well.

 

Mike @ Doobly-Do Wood Works
mike@dooblydo.com 

Free Woodworking Content

By   31 Mar 2014

If you like the free woodworking content Doobly-Do Wood Works (DDWW) is offering in our articles, our project videos on YouTube and our photo gallery, why not share what you’ve found with your friends and family across the social media networks?

DDWW has a social media presence on Facebook, Twitter, LinkedIn and Google+, as well as a YouTube channel for our woodshop videos.  Also, visit our website at www.dooblydo.com and feel free to post comments on the articles and other content you see there.

Doobly-Do Wood Works is a staunch supporter of free woodworking content across the internet, both by the content we provide and those of our favorite fellows across the saw-dusty spectrum.  There is an incredible amount of talent out there offering their activities for your entertainment consumption at a price you can afford… free!  And every Like, Tweet, Follow, +1, View and Subscribe helps keep the woodworkers working.  Thanks!

 

Mike @ Doobly-Do Wood Works
mike@dooblydo.com
 
 

The Most Boring Post in the World – Sanding.

By   24 Mar 2014

Yep, I’m going to spend just a few moments discussing the martial art of sanding.  Change channels now if you like, I understand.  Still here?  Okay then, let’s talk about how to get better results and minimize the amount of elbow grease involved.

Over-sanding

The most common error is over-sanding.  To get a feel of how much is just right, practice on a piece of scrap by taking a pencil and making a serpentine pattern down the face.  Then, for the chosen grit, sand the piece until the graphite is gone… that’s “just right”.  You’ll get a feel for how long that particular grit takes to abrade the appropriate amount of the top surface of the wood away.  Then repeat this practice session with each grit you regularly use.

Plywood and anything with a veneer on it is especially tricky.  If you are new to woodworking, I highly suggest taking a bit of scrap plywood and sanding through the face veneer on a portion.  Do this to learn, by feel, just how easy it is to ruin your work piece.  When sanding on a veneer, or on a hardwood piece adjacent to a veneered piece, extra attention must be paid to not penetrating said veneer.  In our production woodshop, we avoid sanding on plywood-thickness veneers with anything less than 180 grit.  And even then, it’s just a light clean up pass on the veneer.  Obviously, if you’ve veneered something with a much thicker material, you can be more aggressive with your sanding; use judgment.

Grit vs. Finish

Secondly, what grit you sand a work piece to is controlled by the type of finish you are going to use (again, most tend to sand more than necessary).  For example, lacquers, paints and urethanes build up a surface on top of the surface of the wood.  The wood grain will not be felt when touched because the paint or lacquer builds up a “plastic”-like film over the wood.  Only large imperfections will pronounce through the covering.  Therefore, sanding up to 120 grit is usually sufficient to knock down any big-enough imperfections to get a nice, smooth finish with paints, urethanes and lacquers (Oh My!).

Stains, oils and varnishes, however, actually ‘soak’ into the wood, and become part of the wood fibers themselves.  The wood grain and texture will be felt, so, much more detailed sanding must be performed to remove smaller imperfects, including those that may not be visible but can be felt by the sensitive finger.  Therefore, a sanding progression up through 220 grit (in most cases) and perhaps even 320 grit (in some special instances) will get you that fine finish you desire.

The Right Tool

Also, don’t forget that sometimes the best way to sand an imperfection out of a work piece is not to sand at all.  Don’t overlook using a rasp, a file, a chisel, a scraper, a flush trim saw, a rotary tool, an eraser, a fingernail… you can almost always find a tool to remove an imperfection that is the right size and fit without having to sand an entire area just to get the thing that was mucking up your piece.

When using any kind of power sander, the speed at which you move the sander over the piece will affect its efficiency.  The secret here is, “Let the sander do the work.”  A good rule of thumb is about 1″ per second.  You’ll see most people frantically whipping that sander around on the work piece; this technique is considerably slower, but it is not so slow as to make the work take absolutely forever.  Steady movement is key to good results.  Also, resist the urge to: 1) press harder than an ordinary arm resting (listen to the motor; if it’s bogging down at all, you are pressing too hard), and; 2) tilt the sander on a side or corner to “get that little spot right there.”  Keep the sander fully flat on it’s entire sanding surface.  Heat is the sandpaper’s worst enemy; cool paper sands much more efficiently and last much longer.  Remember that when thinking about pressure, speed and tilt with your power sander.

Quality vs. Cost

Last thing I’ll bore you with is the quality of your sandpaper.  Believe me, less is not more when it comes to the price of your sandpaper.  Economy sandpaper seems like a better deal because you get more sheets and less cost… up front.  But, cheap paper handles heat poorly, clogs more frequently and loses abrasiveness much more quickly… noticeably so over the long run.  Premium paper last longer, often multiple times longer than the ‘inexpensive’ stuff, and abrades much cleaner, cooler and usually with better results.  You will actually save money investing in premium sandpaper because you will use less sheets over time, and so much so that the premium paper is more economical.  I know… its not intuitive.

See our latest video on YouTube:  The Hamill Serving Cart

Mike @ Doobly-Do Wood Works
mike@dooblydo.com

 

 

Gettin’ jiggy with it? – A Dreaded Dilemma

By   25 Feb 2014

There you are, humming right along on a rather repetitive operation, when you think, “You know, I could make a jig that would help speed this along.  But, I would have to stop doing this to actually make the jig, and I’ll be done soon enough this way.”  If you’ve been woodworking for any appreciable length of time, I am sure you have had this thought roll through your mind.  Professionals will all intone, “Make the Jig!”, while the hobbyists will cry, “I have limited space and no production schedule pressing me, so this way is just fine!”  And they both are right, but for different reasons.

As a professional woodshop, Doobly-Do Wood Works has considerably more space available, a production schedule that must be met and the need for quick, accurate repetition.  Yet, we still do this same cost-benefit analysis before we make a jig or a machine for our shop.  That last part is also the value analysis of any jig: Accuracy, Repeatability and Speed.  The cost analysis is:  Time, Space and Usage.

“Give me six hours to chop down a tree and I will spend the first four sharpening the axe.”  — Abraham Lincoln

Accuracy

Creating a (proper!) jig for an operation drives out variability in the resultant parts.  This makes for better glue-ups, tighter finished assemblies and overall higher quality products from your work.  Just as a novice learns to cut all the pieces of the same dimension from the same tablesaw set-up (for example) so the pieces are identical, a jig basically freezes that ‘set-up’ in time, so it can be used over and over again.

Repeatability

As with accuracy, the ability to do the same operation over and over again, the same way over and over again, is an often overlooked benefit to using jigs.  In a production woodshop, it is absolutely invaluable, but the weekend woodworking warrior can employ these same principles.  In fact, if you are producing anything on a regular basis, say for an Etsy shop or an Ebay shop or a flea market stall or a shopping mall kiosk, I would argue the hobbyist’s need for repeatability is identical to a production shop.

Speed

The weekend hobbyist has the luxury of time.  When one is making a project for themselves or their own home, it’ll get done when it gets done.  But attach a monetary incentive to the production and suddenly, “how fast can I produce how many,” becomes an all consuming question.  Even in personal projects, speed is valuable (even if misunderstood).  If you get this one done faster, how many other projects could you get done in your limited, valuable time?


But what will Accuracy, Repeatability and Speed cost you?


Time

Assuming you don’t buy a jig from a manufacturer (ew!) and you have useable materials on hand, a jig will cost you time to design and build.  A jig isn’t intended to be a show piece, so form can be ignored for function and expediency, but it still takes time to build.  This means you aren’t working on the project you intended while you are building the jig.  But will the time saved making the remainder of the parts be worth the time spent making the jig?  The hobbyist must answer this for themselves, but for the production shop the answer is almost always a resounding, “Yes!”

Space

A jig, once made, must be stored, and this means it will take up some amount of space, somewhere, in your shop.  If you are working in a basement or a garage workshop, real estate is at an insane premium.  But even if there is more space available like in a production woodshop, the business discipline against waste in all its forms makes the calculus the same.  The decision to make and store a jig, and therefore sacrifice the space the jig will use up, is also tied to the last cost, Usage.

Usage

The most important cost aspect of a jig is the question, “How often will I use this jig again in the future?”  If the part the jig makes will be regularly produced, then the space is well spent to make and store the jig.  If the jig is a single-use case, then there is no sense in storing the jig and it should be broken down back to scrap when the intended purpose is complete.  This means the Time factor becomes the controlling factor in the jig-making decision process.

 
Parting Shot…

If you do decide to spend the time and space to make a jig to perform an operation with fast, repeatable accuracy, give one last thought to the future usage of the jig.  Even a single-use jig could be worthwhile based on the decision factors enumerated above; however, if the jig is ‘one-and-done’ then I would suggest forgoing glue and just using screws during assembly.  The jig can then be broken down back to scrap when the operation is complete.

 

Visit our social media pages, including our videos on YouTube, to follow the projects that are under production at Doobly-Do Wood Works.

Mike @ Doobly-Do Wood Works
mike@dooblydo.com

Gabriel Janka and the Hardest Tree in the World.

By   14 Jan 2014

What makes a hardwood a hardwood, a softwood a softwood, and are hardwoods actually harder than softwoods?

     Believe it or not, the terminology has nothing to do with the density of the wood fibers (hardness).  Hardwoods are simply those species that are deciduous trees, and softwoods are conifers (evergreens).  It’s just that simple. However, simple seems to rarely remain simple.  While it is GENERALLY true that hardwoods tend to be harder than softwoods, the actual hardness of the wood may not follow that tendency.  For example, remember those Balsa wood bridges we made in science class in middle school?  Balsa is a deciduous tree, and therefore a HARDWOOD, as is the softest known wood specie, Cuipo (aka BongoHameli or Macondo).  Yet, they are considerably softer than, say, the softwood Douglas Fir that constitutes your average 2×4.

How does one measure such a thing objectively?

     Around the turn of the last century, an Austrian-born emigrant named Gabriel Janka (1864-1932) was employed as a researcher for the Forest Products Lab of the US Department of Agriculture.  His task was to objectively and scientifically measure the hardness (and therefore, durability and structural quality) of the lumber products coming out of America’s forests in that day.  He came up with a methodology for testing samples of these wood species that allowed objective comparison.  Janka’s hardness test consists of an instrumented mechanical press driving a .444-inch steel sphere (ball bearing approximately the size of a .44 bullet) into the surface of a between 1- to 2-inch thick sample.  The amount of force required to press the sphere 1/2 its diameter into the sample’s surface is the Janka Hardness Rating.  Janka’s hardness test method was adopted as the industry standard in 1906, and is measured in units of pounds in the US, kilograms in Europe and Newtons in Australia.  Though, a rating is commonly referred to in a simple unit of Janka, i.e. “Cuipo is 22 Janka, Balsa is 100 Janka and Doug Fir is 660 Janka”.

Janka Hardness Test

 

     The hardness rating depends on the direction of the grain.  A hardness test on the face of a sample is called a side hardness rating, whereas a test on the end grain is called an end hardness rating.  Unless otherwise noted on a Janka hardness chart, it is assumed that a chart is side hardness.  Also, the hardness rating in the chart represents an average of a huge sample size for that particular species, to mitigate the variability of hardness within the trunk of the same tree, i.e. heartwood is harder than the “live edge” growth ring.  The standard deviation is unique for each specie’s sample set, but they all median around 20%, so the accepted rule of thumb is that a number from the Janka Hardess Chart is +/-20% for that specie.

“Great, you told me some scientific history.  What use is it?”

     The straight Janka Hardness Rating for a specie of wood is probably useless in and of itself.  I seriously doubt anyone will use that number in some sort of engineering calculation.  The Janka chart allows us to compare the relative hardness of various woods during design and/or fabrication decisions.  For example, on a current client project in the Wood Works, we edged Birch ply panels in Black Walnut to get a nice light-dark contrast.  Black Walnut is 1010 Janka, and Birch is 1260 Janka.  This means that when sanding, the Walnut will abrade away faster than the Birch, which is good to know when one is trying to flush up the trim without sanding through the veneer of the ply!  Also, the flooring industry uses the Janka chart to determine material suitability and durability of engineered wood flooring products.

   You can find the Janka Hardness Chart on Wikipedia, or here in our K-base:  Janka Hardness Chart.  Oh, and the Hardest Tree in the World?

Australian Buloke… 5060 pounds-force!!

Mike @ Doobly-Do Wood Works
mike@dooblydo.com