Tips on Determining Your Soap Cutter Size, by Michael McAuley
The best method to determine the size of your cutter is to do a volume measurement of the bar size you want. Figure out how wide and how long you want it, then look at the depth to which is less important for cutting but needed in determining the size of your mold. You can ignore the 12 X 18 part of the directions and make your mold any size you want…just remember your mold will determine the size of your cutter.
So, if you want 45 bars it will be 5 bars wide and 9 bars long and X inches thick (thickness here will determine the weight because it will be the only thing you can alter from batch to batch – the width and length are unchangeable).
The volume is found using the bar size you want to give you the weight you want by the following formula: AxBxC – where A is the width, B is the length, and C is the depth. Then you can expand that to the entire 45 bar mold: 5A x 9B x C. This will give you the volume of the mold you need to build for your 45 bar batch. This can really be pared down to making sure the mold is 5 of your bars wide, 9 long and at least as deep as you need. I prefer a mold that is deeper than necessary in case I want to make some extra thick bars – it’s nice to have a little wiggle room for depth adjustments. Your width and length are whatever you want them to be, I like a little larger bar but I have bigger hands (Anne-Marie prefers bars that aren’t huge) so my width and length would probably be different from yours.
So, the cutter is nothing more than vertical wires set to cut 5 bars when you push your block through in one direction and set to cut 9 bars when you push it through the other section (see Fig. 9 on www.teachsoap.com). Think of it as nothing more than a large cheese wire – where you put those wires is determined by how wide and long you want the bars.
The following is only an example, please use your own measurements in place of those I put in below:
So….the first leg of the cutter is let’s say 5 bars wide and your bars are 2 inches wide so that leg will be 10 inches wide(make this a bit bigger for wiggle room). So your mold is 10 inches wide. You push the soap block through the first leg of the cutter, and make 4 slices (4 wires spaced 2 inches apart and 2 inches from the sides will cut five pieces). Now your block is in the corner and ready to push through the other set of wires. You will make 9 bars (8 wires) that are, let’s say 3.5 inches long – 3.5 inches x 9 equals 31.5 inches so this leg will need to be 31.5 inches wide. The 8 wires will be spaced 3.5 inches from the sides and from each other so when you push the block down the other leg it will cut your bars 3.5 inches wide. You now have 45 bars evenly cut to 2 inches by 3.5 inches – the depth is whatever you determined earlier.
If you want to pour a single block or cube instead of a flat rectangle, I have a much more convoluted and expensive design that will cut a cube into 3 dimensional pieces. The cutter above only cuts in 2 dimensions and your third, the depth, is controlled by you and how thick you want your bar.
Question from a reader, Erika S.
Q: I am new to soapmaking and am currently only using the Melt and Pour technique. I am planning to build the Soap Cutter, but am wondering how I can either build or buy a soap mold to produce a large enough slab of soap to push through the cutter in the diagram. I would love to be able to mass produce at this 1000 bar level, but am not sure how to start. I have seen wooden soap molds available online, some with built in seperators, some without, but none as big as I need for the soap cutter I want to make from your website.
A: The best way to build the cutter is to wait until you have determined the size of your bars in three dimensions. The width and length measurements will be necessary for placement of your cutting wires; while the thickness is only determined by how strong you are when pushing the soap through your cutter but a thickness greater than 1 bar requires additional cutting. The best method is to create a mold that is X bars wide by X bars long and 1 bar thick.
It is possible to build a cutter that can cut a cube of soap that is more than 1 bar thick but is more complicated. If your production method requires creating a soap block more than 1 bar thick, by all means, create a cutter that works for that block. If you want to do that, I have an old plan shelved for such a cutter.
As for your mold, I would recommend building or contracting for a mold. Using any stock plastic containers will create waste since molding of plastic containers requires the sides to be beveled or “angled” just a bit so your outside bars will either have a funky side or you’ll need to trim off the angle. Hold up a rubbermaid or tupperware container and notice that the top is tilted outward just a bit. If you find a container that has vertical sides, you’ll never get your soap out. Also, having a mold that you can remove four sides is a godsend when you go to unmold. You’ll just pry off the sides then work on sliding off the bottom.
The wooden mold we sell has inserts that prevent the soap from sticking in the mold while at the same time creating the individual bars. If you have access to plastic, that might be an option. I’m currently working on a loaf style mold that requires no liner so if you are interested in something like that, let me know.
Question from a reader, Tom S.
Q: Follow you all the way to the wire. So you’ve got the wire threaded through and secured to the bolt. Then it’s threaded through the crossbar and down through the bottom, through a washer, up through another washer, up through the bottom, up through the crossbar, and then secured … ? How so? If they share adjustment with the next bolt and its wire, how do you prevent having different tension on adjoining wires and risk breaking one trying to get rid of slack on its twin?
A: These directions are for one bolt and 2 vertical wires. The wire holes are independent of the bolt holes. The bolt holes are equidistant between the wire holes. If your cutter has 6 wires, there should be 6 wire holes and 3 bolt holes.
The cutter can have odd numbers of wires but at least one wire will be secured differently.
Drill the 6 (or whatever number) of wire holes then drill a bolt hole between each 2 wire holes. Starting at the bolt, thread the wire through the hole drilled in the bolt, run the wire across the top of the crossbar, through a washer, down through the wire hole, through the bottom crossbar or base, through a washer, across to the next wire hole, through a washer, up through the next wire hole in the base, up through the corresponding wire hole in the upper crossbar, through a washer then back across and through the hole in the bolt where started. Think of the wire creating a rectangle starting and ending at one bolt. When the wire is threaded through and tied off at the bolt, tighten the wire by turning the bolt and secure the bolt to the crossbar with whatever means you’ve devised for your particular crossbar. Thus, one bolt will tighten 2 wires.
If you have a single leftover wire just secure that to the base and run the wire up through a wire hole over to your last bolt. I would recommend using a dedicated bolt for a single wire instead of looping over to a previously used bolt.
