With the veneering of the two panels done it was time to make and attach the frames. I used mahogany for the frame and had a piece on hand with some awesome chatoyance. After milling the mahogany I cut it well oversized lengthwise in preparation for cutting the mitred corners.
I don’t cut my mitres by measuring them. The measurement needs to be on the inside of the mitre and can’t easily be set. I guess I could take that length and then factor in the width of the wood and do some math with the Pythagorean theorem to figure out the proper length but I prefer the following.
I take the veneered panel and the four border boards to my table saw. I use one of those Incra gauges with a sacrificial fence that has already been passed through the blade. This shows me exactly where the blade is going to cut. I then take each of the four border pieces and cut the right-hand side of the board at 45°. Then I place the first frame board in its spot on the centre panel and position it exactly. I then take a pencil and score the left side of the border piece. I then flip the border piece upside down and use a combination square to draw a 45° line from that mark on the top of the board.
Next, I take the board to the mitre gauge and setup the wood so that this marked line aligns exactly with the part of the sacrificial fence where the blade will cut. I then cut the board. This can be very accurate. I will then test fit my piece. I always err on cutting slightly oversized as I then come back and do the Charles Neil ‘sneak up on it’ method. With the mitre gauge setup I can trim off as little as 1/64th at a time. I then repeat until all four pieces are done.
Glueing up can be a challenge. You want you four mitres tightly glued together and you want your frame dead even to the top of your veneered panel. If it isn’t even you can’t exactly throw it through a drum sander to flatten it. To ensure all these dimensions stay in alignment I use dominos. I put a domino in each mitre corner to hold them together and I put 6 dominos between the frame pieces and panes to keep them aligned at the top. For the mitred corners I use 8×40 dominos and for the frame and panel alignment I use 5×30 dominos. Once prepared, it looks like this.
The actually glueing process is different. Due to the way the dominos go in the mitres you can’t glue on one side, do the next and so on. You will find that when you align with mitre domino that the frame to panel dominos won’t align. To help this I cut the dominos into the frame at the exact domino size. However in the panel I change the domino setting to cut at their widest oversize setting. This gives some leeway to slide things together. Thus a different approach is required and here is one that works for me.
I use Titebond III to get the most working time. I start by gluing in the dominos into the frame and one into each of the mitre corners. After inserting each one I take a paper towel and wipe off the glue squeeze out. It may be another 10 minutes before the whole thing is brought together and this squeeze out can start to dry on you. Next, set your four frame pieces on edge and spread glue on all the inner sides. Do not put glue on the mitre corner or on the dominos. Next, take your panel and apply glue to all four of its outside edges. The end grain of the plywood will absorb the glue quickly which is why you do the frames first. Now go back to the frames and apply glue to all the dominos and all the mitres. You will now have glue on all surfaces and yet nothing put together. Put two frame parts together at one of their mitre corners but don’t push it all the way in. put these into their matching domino holes in the panel but also don’t push them all the way in. Next do this with the third frame piece and then the forth. When you are done you will have all the dominos in their mating holes but nothing pushed together. Your frame won’t even yet be contacting you panel. Now alternate between tapping the two sides and then two tops together so the dominos in the mitres start going all the way together. This will draw the frame into the panel.
Once you get it most of the way stop and move the assembly to your clamps (which should be ready ahead of time). Use the two outside clamps right on the mitre corners to pull them almost fully together. Then add two clamps on top at the corners and tighten them to pull the corners together from the other direction. Alternate tightening until the corners are drawn together. Next add clamps to the centres to tighten the border fully to the frame. When its all pulled together, fully tighten your clamps. It will look like this.
Before the glue-up I put blue tape on the frame and veneered panel. This helps greatly with the glue squeeze out, especially to keep it out of the veneer where you have only a limited ability to sand.
Once the panel is dried I remove the blue tape and give it sanding at 120 to remove the inevitable bit of glue that gets on the frame. With the use of the dominos I’ve found the panels come out of the clamps aligned very well. Now the next step is to do the inlay.