Wednesday, June 29, 2011

Bent Laminations and the Path of Least Resistance

Resawing just got easier ?
In my last post I made a coopered door for a new cabinet I’m building. The design features two curved doors, the one coopered and the other a bent lamination and mirror image, although taller version of the first. ( coopered on left hand side opening out and away from center )
They’re both absolutely and over the past four days, painfully concave!  ; )
The shape of this piece, once complete, may or may not reflect the inspiration I’ve taken from a famous building here in ‘down town’ Toronto.  Seeing as the wood itself was unearthed from this urban graveyard I thought the shape should instantly reflect this unique city where I live and work.
‘Center of the Universe’ or so I’ve been told.
As for bent lamination work, you don’t find much in hand tool shops and I’ve strayed away from it over the last three years in my own ‘hand tool only’ wood shop for the reason of the labor involved and the accuracy needed in manufacturing. Veneer work is another example. Whenever I use veneers I prefer to use my own shop made veneer and again the challenges are wrapped up in what boils down to sawing and accuracy. The power tool shop can resaw boards on a band saw and I’ve done my share using my  ‘ol Corporate Kangaroo, 28″ rip saw. Not ideal but I’ve done it.
Stock used for bent lamination or ‘real’ veneer work is a different story and generally in the area of 1/8″ in thickness. It can be a challenge to keep an accurate and consistent saw kerf while working with thin dimensions like these so I’ve been working on a system to achieve better results.
The first and obvious tool involved is my new frame saw.
I’ve been experimenting with different forms and saw blades but soon realized the problem wasn’t entirely in the saw I was using but a missed step in the process. I’m saving my new frame saw design for a little while longer but would like to give you a ‘sneak peak’ at another new hand tool I’ve come up with that will really help in the resawing process.
I think we can all agree that the saw, assuming it’s properly set and sharp etc… will follow the path of least resistance. For the sake of resawing, while trying to maintain absolutely consistent results ( 1/8″ in this case ) and not drifting and wandering off and sometimes out of the face of the stock, I realized that if I could first establish a deep enough scribe line all the way around the perimeter of the board then the saw should in theory follow it. My first instinct was how can I make this scribe line wider and deeper.
I looked at my small plow plane from Veritas and tried plowing a groove around the perimeter of the stock for the saw blade to follow. The path of least resistance remember?
It worked but I was left with a wider groove than nessecary. All I really wanted was something the saw plate would track into.
I thought briefly about filing the narrowest iron I had for the plow and trying that to achieve the thinner kerf I was after but it would be incredibly thin and potentially dangerous to both the tool, the wood and the user. The fires burning as I thought the problem through and as I glance across my moulding planes it hit me.
I could make a moulding plane style hand tool and instead of an iron I’ll install a saw blade.
With a pre-determined fence built into the profile of the tool I’d be able to saw/plane a kerf exactly where I want it from the board face working down to a set depth, again the profile of the tool, and give myself this perfect ‘track’ for the frame saw blade ( or large panel/ back saw )  to follow. Guess what- it works!
I made a stair saw about 7 years ago as well as another small tenon saw with adjustable depth skate and this seemed like a natural evolution from the two previous designs. Having the idea burning and the earlier experience making the other special purpose saws I started messing about.
What I’ve come up with is something I call a ‘Kerfing Plane’.
Now before you email me for specs I’ll  tell you that they’ll all be in my new book. The plans, the procedure to make one with multiple profiles and yes, even a resource to purchase blades!  ( I’ve got kids to feed ~ ; )
In this bent lamination I’m working with a stock 1″ thick and only 3″ in width. The same procedure can be done with larger stock as well but resawing will covered in another post down the road. This series of photos will continue along the slippery slope of working with ’round’ furniture.
Both of these articles are only a quick look into the world of building curved furniture using only hand tools but both topics, coopered doors and bent lamination ( as well as bending wood, shop sawn veneer and all the shop made tools to go along with those techniques ) will be covered much more extensively in my new book destined for 2012.
Here’s a brief run down on my bent lamination process and of course, using only hand tools.
start with a kerf at both ends.
continue down both board edges.
This is perfect for bent lamination and shop made veneer work but you'll have to wait until the new book for more...
After sawing I plane the strips to remove any saw marks. I use my 'sticking board' to hold the thin pieces in place.
Slice to desired width.
At this thickness they easily break along the scribe lines.
Put the pieces in order and mark with a builders triangle.
The offcut from the coopered door, make a bending form.
Assembly time.
Glue Bear refill first.
TIP: A wipe and some wax for easy open next time.
Into the clamps they go. fin!

Monday, June 27, 2011

A Coopered Door

two becomes four...

Thanks for the comments and questions on my last post,
the following series will chronicle the process in making a coopered door.
This is not the only way to make curved furniture parts and in my next post I’ll show you how I made the match to this door using a bent lamination process.
I’m working with six pieces approx. 7/8″ thick x 1 1/2″ to 2″ widths. These are random as the hemlock has many checks, cracks and splits making much of it unworkable for cabinet making but great for wall paper!
The overall length is about an inch longer than needed on paper although I honestly don’t know that exact final measurement at this point nor do I need to. It’s all about the curve right now and to achieve this I need to bevel each of the six pieces. Once glued they’ll become the convex shape I’m looking for.
It’s funny, as one composes a cabinet in this manner instead of working off a cut list, whenever the wood pile dwindles the over all size of the cabinet does as well. ?? Hmmm..
Proportion is essential to maintain but I have no worries about the over all size being effected.
I liked the shape of this design when I first scribbled it into my sketchbook a few weeks ago and that was only a few inches tall!
So back to the coopered door~

full scale drawings. parchment paper works great. 

...additional uses on bottom of box. ha !

a suggestion?

scribe the lines. 

plane down to scribe lines to establish bevel 

glue bear says, 'that's half a dozen if anyone's-a-countin'.

out of the clamps it needs some love.

getting closer.

marking the length. yikes!

scribe line set up

finest x-cut. 24" saw. 11 ppi. perfect for this application.
hold fast. deep breath.

'just' to the line.

fair the curve.