Making Picture Frames from Flooring Scraps
After installing some oak hardwood flooring in my home recently, I had some leftovers lying around for a while and figured I could make some over-sized picture frames out of them to decorate the house.
Here’s what you will need:
Wood, obviously, for the frame itself
Plexiglass as glazing
MDF sheet with one-sided white cover serving as mat board (the visible part around the actual picture) and backing board (holding the picture in place within the frame)
Miter saw to accurately cut miters (= angles)
Table saw to cut the boards to width
Step 1 : Plane flooring boards to thickness
Now you might get away without this first step, but my oak flooring had been treated with a rather dark oil finish which I figured would look strange when sanded. With 3,8cm in thickness, I also found them to be a bit too clunky. I therefore ran them through my thickness planer a couple of times which left a super smooth finish – very happy with this piece of machinery!
Step 2: Cut boards to width & length
Also, the flooring was installed with tongue and groove joints. The boards therefore had pre-cut tongue (= male) ridge projections on one side and a matching groove ( = female) slot recession on the other. I got rid of both on the table saw and then cut the boards length-wise in two halves, making sure they ended up having the exact same width. You can then proceed to roughly cutting them to length on the miter saw. I would recommend leaving some extra real estate lengthwise so that you can dial in the precise dimensions when cutting the actual miters.
Step 3: Add rabbets for the backing board & glacing
The idea is to use some MDF cardboard as backing board and plexiglass as a glacing to stabilize and protect the picture. Those two parts need to rest on a recess cut into the edge of the back. I cut these so-called rabbets with a hand-held router and a straight router bit and instantly wished I had finally gotten around building my router table... It is possible to do so without but for each board you will need to set up a guide again and again in order to determine the right rabbet width. On a router table the same setting could simply be left in place and be repeated for all work pieces in one go.
Step 4: Cut the miters & glue the frame
Before cutting the miters to glue the 4 picture frame sides together you want to make sure that your miter saw actually does cut a perfect 45 degree angle. A simple 2-step trick to cut a perfect 45 is to use a speed square:
1) Table to blade alignment : Check and adjust if necessary to make sure the saw is in a perfect 90° angle to the saw table
2) 45° setting: instead of using the locking mechanism (that most miter saws come with) for pre-set angles, use your speed square instead to align the blade to a perfect 45.
The opposite frame sides must be absolutely identical in length, otherwise the sides will not line up to a precise rectangular frame. I would therefore recommend to cut the miters of the opposite sides at the same time by stacking them on top of each other.
You can then simply glue the sides together. I mostly use Titebond III wood glue because its waterproof and non-toxic. The glue up is best done on a perfectly flat surface to ensure proper alignment of the pieces. You will notice that clamping a 45 degree angle is quite awkward, so you might want to consider building a 45 degree angle clamp jig yourself or simply get one of those super handy band clamps from Bessey which will clamp all for corners simultaneously.
Two assembled picture frame back sides, notice the grooves that come with the flooring boards, they serve as a “relief area” to deter cupping by relieving internal stress. You’ll also see the rabbets for the backing board on the inward-facing edge.
Step 5 : Add splines to the mitered corners
(optional, but recommended)
Admittedly, simply “butt-joining” the angled miters together is not the strongest method as seasonal wood movement may lead to the joints eventually breaking. So you might want to consider adding splines to each corner. Splines are basically additional wood strips glued in each miter corner which serve as reinforcements. You will first need to cut an opening in each outer miter corer and then cut some thin strips and glue them in those openings. To safely cut those openings on the table saw, you will inevitably need a spline jig (which is an easy build, check out this tutorial). You then cut your wood strips and glue them in the openings. Once the glue has dried, you cut off any excess wood using a flush trim saw.
Step 6: Sanding and finish
To avoid any sharp edges and rough surfaces, give your finished frame a good treat with the random orbital sander by sanding it all the way up from 80 to 180 grit sandpaper. Wipe off any residual dust on the wood before applying your finish. I chose Danish Oil because I reckon it makes the wood grain and color really pop out well.
