This soap mold is a simple construction project that creates a useful tool for soap making and that is fun to make in the process.
The project can be made from any finished wood that you might have laying around – if you have some 1 X 4 stock laying around (for example oak, birch or even pine) you can even avoid some cutting (1 X 4 actual dimensions are 3/4” X 3 1/2” which is what the project calls for).
The tools to build this soap mold are very basic – a saw, a drill, some glue, and a screw driver. I liked to use pocket screw joints but you can also join the piece by placing the screws from the end. A clamp is very helpful but you build the box without one – just takes a bit more patience.
My wife decided that she wanted a mold that would make 12 bars of soap at a time by making a single cut of the finished soap – you can adjust the dimensions as needed based on how large you want to make the mold. The finished bars of soap will be 3 1/2” X 2 3/4” and can be cut to between 1” and 1 1/2” inches (personal preference).
Keeping with the simplicity theme – the parts list is simple:
(2) 3 1/2” X 3/4” X 18” – 2 sides
(1) 3 1/2” X 3/4” X 18” – bottom inset
(2) 3 1/2” X 3/4” X 5” – 2 ends
(1) 3 5” X 3/4” X 19 1/2” – bottom
Screws – (1 3/4” – 2” to join the sides; 1 3/8” to attach inset to bottom)
Once the wood is cut to the prescribed lengths (the measurements need to be very exact due to the small tolerances), the mold is ready to be assembled. Start the assembly by “dry fitting” all of the wood parts – the insert is placed on the bottom, there will be 3/4” of an inch on all sides of the inset exposing the bottom. The 2 sides and 2 ends are then placed on the bottom with the inset used to position them properly. Now is the time to make any final adjustments to the size of the pieces (particularly the inset – it must be snug but able to slide into the frame created by the sides). Once you are satisfied with that the parts are cut correctly, the 2 ends and 2 sides are joined using 1 3/4” screws – it is recommended that the inset be placed inside the frame as it is being assembled (it makes the joining easier). This is also the step where a clamp comes in handy to hold the 2 ends in place while holes are drilled (counter sink or use pocket screws) in the end pieces and the ends and sides joined.
With the box frame assembled, and the inset in place inside the frame, position the bottom by aligning the bottom with the outsides of the frame. Once again, a clamp is handy but if you don’t have one, place the frame on the work bench, place 3” of scrap wood inside the frame, place the inset into the frame (sitting on the scrap wood) and then position the bottom on the frame aligned with the sides). Again, drill pilot holes (counter sinking) in the bottom to attach the inset to the bottom.
That’s all there is to it – if your measurements have been precise and the inset fits into the frame snuggly, the mold will stay together without any assistance. If the bottom/inset piece is a bit loose – no problem – a couple of large rubber bands can be used to hold the bottom/inset in place, realizing that they are not really necessary when the mold is in use as gravity and fit will hold the frame in place. To use the mold, cut a piece of freezer paper 6” wider and longer than the soap dimensions (in this case the paper would measure 9 1/2” X 24”. Measure 3” from each side of the paper and fold the paper making a folded paper 3 1/2” X 18”. Open the paper and fold the ends outward to create a paper box which will now be inserted into the soap mold frame.
To use the mold, the prepared soap is poured into the mold (within 1/4” of the top), cover the mold to assist it with heat retention while the soap is hardening (an old piece of styrofoam will work well). Once the soap sets, the bottom/inset can be removed easily allowing the soap to be gently pressed from the mold.