Kumiko Sampler - #7 Making the Frames – Part 1

When the last post ended, I was trying to decide what to do with the stressed piece of mahogany that pinched the saw blade while it was being ripped.  Have to say that I am glad the splitter was in place.  Things could have gotten really exciting in an instant if it wasn’t installed.  When the partially ripped piece was set against a straight edge a bit of a curve on one side showed up.  Measuring each end of the board confirmed that the curved side had moved.  Here is a photo of the uncut end showing the board 3 5/8” wide.

This is the other end and it shows the board 3½” wide.  When I shut the saw down and removed the board the saw kerf had closed e.g. the pinch.  I tried to take another pass to open up the kerf and complete the cut but once again as the internal stresses were removed the kerf closed pinching the just cut edges against the splitter.  I started to try a third time but part way through the cut I decided I was pushing my luck and quit.  That’s why there is an open saw kerf at this end rather than you seeing the two sides of the kerf pinched together. 

After letting the piece sit overnight the kerf was still there and the board seemed to be stable with one edge still straight.  Based on that I decided to try and salvage the board.  The photo below shows the end result of three steps.  First, the edge that was opposite the one adjacent to the fence when the board pinched the fence is the straight one and it is at the top of the photo.  That straight edge was put against the fence and run through the saw truing up the curved edge giving me straight parallel edges.  Second, the fence is reset a bit wide of the previously ripped blanks and with the original straight edge against the fence a blank is cut.  Third, the board is flipped so the new straight true edge is against the fence and it is ripped until the cut meets the original pinched cut giving me a slightly wide blank.  I have to say that I was a little surprised that it cut just fine with no pinching at all.  It seems all the stress was released in the first set of cuts.  The offset cut in the middle piece shows how much the board moved as the stresses were relieved.  Resetting the fence to match the other blanks and ripping gives me two usable blanks. 

The last step is to stand the blanks on edge and pass them through the thickness sander to remove any surface irregularities and smooth out the saw cut.

In looking at the frame profile I have decided to revise the plans again.  The top photo below is the previous version and the bottom one is what I am thinking about now.  It allows for the frame to be finished before the plexiglass is installed and I think will make for a simpler assembly of the glass, sampler, matt board and foam core backer.  Although it may change some more before I get done.

Next is to decide then mark which face will be out and the top of each of the blanks.  The idea is to align the blanks so that any flaws are either cut away or hidden from view when the frame is completed.  There are also three pieces to be used for testing.

Cutting the dado in the frame is next.  It starts with a ¼” stacked dado blade almost centered on the blank set to cut just shy of ¼” deep.  Here is what the setup and first pass look like. 

For the second pass the fence is moved over about ¼” and the blank run through again.

The blank is flipped end for end and run through the saw again.

A third pass is made along the top edge leaving an uncut strip slightly over ¼” wide.  That’s followed by another pass at the bottom leaving a 3/16” wide strip.  In the photo below the thin edge is at the top.  That edge is narrower to give the needed depth in the frame for the glass, sampler, black matt board and a foam core backer.  If the blanks had been cut a little wider then that would not have had to be done but since I changed the design, I needed to pick up just a little more depth.  Also, as you can see the bottom of the dado is not the greatest looking.  If this were a typical frame that would not be a problem as it would all be hidden.  However, in this case because the sampler is about half an inch tall and the inside of the frame will be visible it needs to be cleaned up.

The cleanup is done using a straight flat end router bit taking off just enough to clean up and flatten the bottom of the dado.  Here you can see the bit and its relation to the frame blank. 

After cleaning up the dado’s bottom a small radius is added to the top corners of the blank using the router.  This photo also gives a good look at the narrower leg that I had to make to give me a little more frame depth.

Removing the thin leg is next and is done on the table saw.  The blank on the left up next to the fence is ready to cut while the one on the right has had the leg removed.  The thin strip is all that was cut off.

When I used the router to clean up the bottom of the dado.  I did not want to trim the inside face of the leg and in doing so left a little strip that needs to be cleaned up.  It’s really small but you can just see it circled in red at either side of the dado.

It’s easy to cleanup by gently using a scraper and then some light sanding.  At this point the blanks are ready to have their ends mitered and cut to length.

Next Up – Completing the Frame, Lacquering & Assembly