Week 10 – Edgebands

I have mentioned edgebanding in some of my previous posts.  Those were captured edgebands which are glued to the side of a plywood substrate and then veneer is applied to the top and bottom capturing the edgeband.  There are two reasons that we do this at The Krenov School.  First, if this is an exposed edge then a strip of solid wood is definitely finer than looking at the edge of a piece of plywood.  Second, and sometimes debated, is to provide a strip of solid wood that can be more easily hand tooled to a smooth surface and seamless joint.  Try making the edge of a piece of plywood perfectly smooth.  Go ahead, I'll wait.

This week I've been working on the applied edgebands for the top and bottom of the cabinet.  An applied edgeband is a piece of wood that is often glued to the edge of a veneered panel to add profile detail or hide the view of the raw edge which may look like a sandwich of veneers and captured edgeband (or plywood if you don't do the captured edgeband thing).

For this cabinet, the applied edgeband wraps the kidney bean shaped top with  a  strip of wood that swoops up into a spoiler detail at the rear of the cabinet.  The applied edgeband on this cabinet provides the overhang of the top and bottom that visually captures the vertical sides of the cabinet.

The edgeband is about a 1/4 inch thick and is made up of 4 thin strips of wood that are flexible enough to be bent around the profile of the kidney bean.  I divided the edgeband into two parts: the smooth concave curve of the front edge wrapping around the sides of the cabinet, and the rear edge where the curve has both concave and convex sections (i.e. a squiggle).  The two parts of the edgeband are made separately and then applied to the edge of the panel.

The longer edgeband which wraps most of the panel is bent around a large form.  The form made of plywood and routed to match the profile of the top/bottom panel.  The inside of the plywood is removed to make a ring that will allow clamps to be used to apply even pressure to the laminate strips while it is being glued.  In the picture below you can see a few long plywood pieces radiating from the ring.  These pieces are used to align the bottom edge of the strips during glue up.  You can also see a few extra holes drilled into the form around the tight radius corners that allows me to double up on clamps as the strips bend around that curve.  After making up the thin strips of wood, I apply some Unibond 800 glue and wrap the strips around the form along with a bending caul made from cardboard and veneer and other bendy things.  And then I use a few clamps to apply even pressure along the entire length of the edgeband.

After the glue cures, I remove the clamps and clean up the edgeband surfaces.  I made a sample edgeband from poplar, which is shown below, to test out the form and the process.  Jumping ahead a bit, you can also see the prototype spoiler that will be mated to the edgeband that will complete the applied edgeband for the panel.

I need to make sure that the ends of the edgeband have miters that are perfectly smooth and square so that the edgeband/spoiler at the rear of the panel can mate seamlessly.  After sawing the end of the edgeband to the proper length and approximate angle I use my shooting board with a wedge to hold the curve at the proper angle (along with some blue tape) to plane the end of the edgeband square and smooth.

The final step is to glue the edgeband to the panel without any gaps or glue lines.  This turned out to be much more difficult than I had predicted.  After a day or two of trying to find a clamping scheme that produced the desired results and chasing down the tiniest imperfections that I had introduced on the inside edge of the edgeband and outside edge of the panels, I came up with a solution that seemed to work consistently.  First I wrapped the edge band and panel with one of the most powerful strap clamps that I had ever seen.  Second I encased the entire setup with a set of hard cauls and bar clamps.  Finally, by tightening the bar clamps in the right order I could slowly move the pressure around the panel closing the gap along the way until I ended up with a seamless joint.

Week 9 – Doweling

This week the project went from 2D to 3D when I added the joinery for the top, bottom, and rear panels that I have been working on the past 8 weeks.  I am still many weeks away from gluing things together, so you will still need to use your imagination to picture what the piece will finally look like.  On the bright side, when the time comes the project is going to transform from a pile of parts to a nearly completed piece with a few quick glue ups.

The top and bottom of the cabinet are joined to the rear panels with a series of dowels.  The dowels provide additional strength to the joint as well as alignment of the curved panels in relation to the doors and other cabinet parts.  The top and bottom panels are 3/4" and 5/8" thick respectively and the dowel holes are carefully (and with trepidation) drilled to within 1/8" of breaking through the veneer on the other side.

The key to doweling is to make sure you drill the holes for the dowels are in the right spots on the two parts that you are joining together and that the holes that you drill are pretty darn close to being straight and true.  If the holes do not align then the parts will not align, and if the holes are not straight and true then you will not be able to bring the joint together.  The Krenov School way of accomplishing this is to build a doweling jig out of hardwood and use it to guide a drill bit as you drill the two sides of the joint.

The doweling jig for these joints is made out of a piece of maple.  I used a template to cut the jig to precisely match the profile of the rear panels which also matches a portion of the curves on the top and bottom panels.  I glued a series of small strips of wood to the edge of the jig that are used to register the jig against the edge of the panels.  The jig is attached to the piece being drilled with a few screws and a drill press or an electric drill (with the help of a drill block) are used to transfer the holes from the jig to the workpiece.  The photographs show the jig in place on the flat panel and the resulting holes on the curved panel.  The drill block is also pictured in the lower left corner of the curved panel photograph.

After the holes are drilled, a couple of the dowels are inserted and the pieces are put together to find out if the whole operation was a success or if you need to plug the holes and try again.  In this case it was relatively successful!

Step A complete!  I now have two panels and a top and bottom that mostly fit together but I have not yet figured out how I want to join the left and right rear panels together and what kind of detail I want running down the spine of the cabinet.  Since I am in the habit of kicking most decisions down the road on this project I decided to build a mating piece with two groves in it that I can use later to stick in my desired detail  (in software engineering terms, I just slipped some feature creep into the project and sold it to the project manager as an extensible feature).

The spine is held into position by a few locating dowels that run through the spine and into the rear edge of each panel.  I used the spine as the doweling jig to transfer the holes between the two panels.  Next challenge to consider was clamping.  The only feasible option that I could come up with was to glue temporary clamping blocks on to the interior edges of the panels and use those to pinch the edges together and bring the spine joint home.  I really did not want to add a bunch of glue blocks to my beautifully prepared birch veneers on the interior of the cabinet and I do not know yet how painful it will be to remove them.  I am sure it will all be just fine.

Spine joint with glue blocks attached

It will still be a very long time before things get glued together permanently as I have come to accept that I need to build and fit the interior shelves and drawers while the carcass of the cabinet is still in pieces and I can drill holes and trace curves.

To top off a challenging but productive week, I roughed out some hinges for the doors.  More about those in another blog post but here are pictures.

Week 8 – Tops and Bottoms

Sipo Veneer

Now that the doors and rear panels of the cabinet are done, I need a top and bottom so that I can get to work on assembling things.  The top and bottom are flat panels which are a lot easier to build than the curved panels of the doors and rear panels.   I have chosen Sipo (very similar to Mahogany) as the veneer for the top and bottom panels.

The process for flat panels is generally the same as the curved panels I have been making in the vacuum press.  I cut the substrates from off-the-self furniture grade plywood and shape them to match a template of the cabinet.  I apply an edge band of solid wood.  I cut and process a plank of Sipo into veneers and cut them to match the size of the substrates.  Then the substrate gets covered with glue and everything gets sandwiched together in a mechanical press.

It still took me the entire week to make the top and panels because I’ve been working on the volleyball court, a memorial bench for Matt Mecaro (class of 2016/2017), and have a quick trip back to Ohio to attend to some family matters.

Week 7 – Volleyball

Dirt and dust of the volleyball courtFor years the woodworkers have looked up from their workbenches at the end of a long day and shuffled their hunched bodies outside in response to the daily plea to form two volleyball teams that will engage in a few rounds of “prison rules” volleyball.  For years the woodworkers have lamented playing in the the dirt and the dust and the weeds.  For years the woodworkers have talked about getting sand for the volleyball court.  Perhaps things are just fine the way they are and there is no need to change these traditions, perhaps these are not traditions at all but just a lack of action.

This year I decided I would help organize a fundraiser and we would see if we could raise enough money to buy some sand and improve the volleyball court.  We set a goal of $1000 in order to get 26 tons of beach sand delivered (2-3 inches).  We set up a GoFundMe and Todd emailed the alumni with a call to action.  We exceeded our goal and raised over $1700!  No turning back now.  Perhaps this is an improvement to the volleyball pastime or a detriment to it.  Only time will be able to judge the actions of the class of 2018.

Week 6 – Rear Panels

Making the rear panels for the cabinet is not much different than making the door panels.  I am a little bit wiser now, that is about the only difference.  This time around I made some extra long cauls that I hoped would put additional pressure on the edges of the rear panels to make sure that the veneers were pressed firmly against the substrates.  These seemed to work out well and by the end of the week I had two rear panels to match my two doors.  Pictures are worth a thousand words.

Sycamore veneer for the rear panel

Sycamore veneer waiting to be applied

Parts of the rear panel waiting to be glued

Parts of the rear panel waiting to be glued and vacuum pressed

Rear panel in the vacuum press

Rear panel in the vacuum press

Rear panel with matching door

Rear panel with matching door.

Note the Volleyball Fundraiser