My friends were getting married and wanted to have their initials in the ceremony, so that was the gift I made for them. They wanted them to look solid (or "monolithic"), able to be stand up and heavy enough so that the wind wouldn't tackle them.
I went with 16mm MDF making a front and a back layer and 3mm mdf sheet on the perimeter, using some kerfing for the small radii curves. Since the MDF sheets sold locally were 1.22x2.44m, the most convenient size for the letters in my case was around 1.20m tall for the R and J and 80cm for the &. Thickness is about 15cm They can be done any size or thickness as long as some rules are respected.
Let's take a look and remember to check the video for better understanding!
Step 1: Choose Your Typography/design and Transfer It to the Wood
Of course you can make any design you want! I started with "Georgia" typography and modify to better fit my needs. Avoid thin traces and small radii, this will help with stability and make the construction easier. Notice how I went from the thin traces of the Georgia typography to a thick letter that won't blink if you punch it!
After that it's just a matter of fitting the letters into your wood sheets. You can use paper templates or, as in my case, use a projector to transfer the design with a pencil.
To make sure the dimensions are right introduced the letters in a square with the dimensions of the MDF sheet I would use. This way you can check for squareness and proper sizing measuring over the wall and and then transfer it.
In this process I marked the intersection points and the rough curves and then refined the shape using a bandsaw blade as kind of "physical spline". It's a good way to get smooth curves using tangents and maybe push points. In my case rulers and a heavy handplane.Worked great!
Step 2: Cut, Cut and Sand!
This step is simple. You can use a circular saw to make the big cuts and a jigsaw for refining and curves, but as long as you cut outside the line, it's fine! After that comes a lot of sanding, depending of how much you cared in the previous cuts!.
Since we need a front and back for each letter, it is a good idea to cut the 2 sheets of MDF at the same time and refine just one. After that one is completely sanded and in shape, it can be used as a template to refine the other with a flush trim bit. That will save time and help a lot with accuracy!
You should end up with 2 equal faces for each letter.
Needless to say, dust mask is mandatory, specially with MDF!
Step 3: Give Them Volume!
We need to create a recess in the inside face of each letter side to receive the MDF sheet that will cover the perimeter. I used the router to remove about the half of the thickness of the material and went 4mm deep into it, since the MDF sheets will be 3mm thick. Round inside corners will need to be straightened up with a chisel or a file.
After that we will need to provide some structure to the letters, so I cut 14cm particle board strips to act as spacers and added reinforcements in the big curvers or at any point in which a curve meets a straight line. This will not only help with stability but will make alignment of both faces much easier. Everything was glued and held in place with bradnails, and added some screws just in case.
Step 4: Dress the Letters
Now it's time to close the "box" with 3mm sheets of MDF.
The width of these strips is critical, it should be almost tight in between the recesses created in each side of the letter. Of course both sides will not be perfectly paralell so there will be some gaps and places where you will need some sanding and adjusting. You can later fill the gaps with glue and sawdust and nobody will notice!
For the small radii curves I made paralell cuts 1.5mm deep into the sheet with the tablesaw to create a kerfing that would make it easier to bend. (this is easier to see in the video). The strips are cut to lenght ant tacked in place with glue.
Tip: When a curve meets a straight line, the best way to do it is installing first the straight sheet, leaving just enough room for the curved sheet thickness (last picture of the step)
Step 5: Finishing Touches
I removed the excess material in the edges with a file or a hand plane and rounded those corners by hand. After that I ran a flush trim bit around the perimeter of both sides to elliminate the excess of each face. Finally the edge fillet is created with a round bit, giving it that "continuos-material" look
Some sanding and woodfiller will be required to leave all surfaces smooth and continuous. I added metal feet to the letters because they will sit on stones or grass.
Finally, I got my friends to help me applying a coat of primer and then another one of medium-gloss paint, and they are good to go!