Silicone caulk be hacked into all kinds of useful things. This adhesive has the unique qualities of sticking well to some things and not others. This makes it easy to cast into many shapes. If you add corn starch, it can be cast or formed or glued into shapes of any thickness and it can set up within an hour. I call this mix Oogoo.

This instructable shows how to fix or make seven things:

Step 2- Make heavy duty rubber bands

Step 3- Make your own custom erasers

Step 4- Make a wallet pen

Step 5- Make a hot pot gripper

Step 6- Fix a broken bucket handle

Step 7- Make liquid tape to insulate splices

Step 8- Make a thread locker for nuts and bolts

Step 1: How It Works

Oogoo is a mix of 100% silicone caulk and corn starch. The corn starch evenly distributes moisture which it has absorbed from the air. This helps to activate the polymerization of the silicone in a controlled way. So, unlike regular caulk which can take days to set up, Oogoo can set up in an hour or two no matter how thick it is cast.

Materials
For these projects you only need a few materials:

Puffed Rice

Corn starch

100% silicone caulk-the type that smells like vinegar and has no acrylic or latex additives. The newer silicone caulks that have a different smell such as GE silicone II will not work for this.Available from Walmart or the dollar store for about $3.

plastic cups

plastic bag

Nitrile gloves

1/16" and 1/8" thick plastic sheet material. PVC, polycarbonate, acrylic or any other plastic sheet material can be used. Plywood sprayed with lacquer can also be used.

Spray Lacquer from hardware store.

Naphtha or Turpentine solvent from hardware store

Artists oil paint (optional)

The Standard Oogoo Mix
The standard mix of Oogoo consists of 2 silicone caulk to 1 corn starch by volume. It is usually mixed in small quantities so that it can be formed or cast before it starts to stiffen up. I will typically mix no more than 3 tablespoons of silicone caulk to 1-1/2 tablespoons of corn starch. For more details on mixing Oogoo see here: https://www.instructables.com/id/How-To-Make-Your-Own-Sugru-Substitute/

WARNING: While mixing, Oogoo will give off the strong smell of Acetic acid which can be irritating to the eyes and respiratory system. I strongly recommend that the mixing and forming be done outside or in a VERY WELL VENTILATED room. You should also wear nitrile gloves while mixing as the uncured silicone contains other solvents that might be absorbed by the skin.

Step 2: Make Heavy Duty Rubber Bands

You can replace damaged rubber bands of any size or create your own custom heavy duty rubber bands. These rubber bands are very stretchy and do not deteriorate as fast as regular rubber bands.

Pic 1 shows a replacement headband made of Oogoo for a headlamp. The original headband had lost its elasticity after a few years of use. The pic also shows two 1/8 thick rubber bands that were cast.

Make A Mold
Pic 2 shows the type of mold used for most of these projects. It is made of three sheets of plastic 1/16" to 1/8" thick. Any kind of sheet plastic can be used. Plywood can also be used if it is first sprayed with Lacquer to act as a release. Make a mold by taping two long strips of plastic that are the thickness you want, to a larger base. Adjust the distance between them to the width of your rubber band.

Mix And Screed
Make a standard mix of Oogoo and fill your form, being careful not to leave any bubbles that can weaken the final rubber band. Use a metal straight edge to screed (level and smooth) the top of the cast. See pic 3.

Connect The Ends
After the cast has set up, remove it from the mold and cut the ends square. Make a loop and tape it back into the mold with the ends about 3/16" apart. See pic 4. Mix a small batch and fill and screed the gap to make a continuous band. Oogoo glues to itself extremely well and will fuse the two ends together.

Other Possibilities
Bungee cords and elastic backpacking straps can also be made in this fashion.

Step 3: Make Your Own Custom Erasers

If your pencil eraser goes bad, you can easily fix it by making a replacement in a shape of your choosing. Pic 1 shows two erasers that were made from a modified Oogoo mix. While these erasers do not work quite as well as a commercial eraser, they are very close in performance. I have come up with two mixes that work well, but with experimentation, better mixes could probably be found.

An eraser is just the right combination of stickiness and crumble-ability to be able pick up a pencil line while crumbling apart fast enough to prevent smearing. A filler is added to make it crumble.

Eraser Mix 1
This mix works the best but requires slightly exotic ingredients.
4 Diatomaceous Earth to 1 silicone caulk to 2 corn starch, plus a solvent. You can add a dab of artists oil paint, if you want color.

For the square eraser, I made a mix of 4 Teaspoons Diatomaceous Earth to 1 teaspoon silicone caulk to 2 teaspoons corn starch. I added enough Naphtha solvent to make it mixable. I then added about 26 drops of liquid dish soap. The soap increases the frictional qualities of the final eraser.

Diatomaceous earth is available fairly cheaply from: http://www.douglasandsturgess.com/mm5/merchant.mvc?Screen=PROD&Store_Code=DAS&Product_Code=FM-1007B&Category_Code=FILLERSTHICK-LIGHTWEIGHT

Eraser Mix Two
This mix works almost as well and uses easier to obtain ingredients

6 Teaspoons Puffed Rice to 1 Teaspoon Silicone Caulk to 2 Teaspoons corn starch. Add enough solvent to mix.

The Puffed rice has to be first pulverized in a coffee grinder to a fine powder. It is then strained through a fine-holed cooking strainer. Naphtha can be used as the solvent, but turpentine also works.

Making The Mold
You can make a mold of any shape by surrounding the object with a standard mix of Oogoo. Once it has set up overnight, it can be sprayed twice with Lacquer, to act as a release. You can then cast the erasers in this mold and once the Oogoo has set up, the pieces will separate and the lacquer will just flake right off.

Step 4: Make a Wallet Pen

A pen that can be carried in a wallet can be easily made. Start with a pen that is half used up and remove the pen refill and cut it down, leaving 1/2 inch of air space in the tube at the open cut end.

Make a 1/8" thick plastic mold and fill and screed it with a standard Oogoo mix. I mixed 1 teaspoon silicone to 1/2 teaspoon corn starch. Add a dab of artists oil paint if you want color.

Embed the pen refill and then screed it again. After it as set up, remove it and cut it with knife or scissors to the shape you like. Leave pen point end wide enough to be easily grasped between thumb and finger.

Step 5: Make a Hot Pot Gripper

This is my version of a pot gripper I saw at Walmart. It can be used to handle hot objects such as boiling hot beakers or hot pan handles.

Pic 1 shows the finished gripper. Pic 2 shows it gripping.

Pic 3 shows the 1/8" thick form with the pattern the cast will be cut to.

Cast a Sheet
Cast and screed a 1/8" thick sheet of Oogoo that is about 11" long by 6-1/4" wide. This is a large mix so it has to be done fast or it will set up quickly. I did a mix of 10 tablespoons silicone caulk to 4 tablespoons corn starch.

Cut The Pattern
Cut the set up square sheet to the pattern.

Finally, glue the gripper with Oogoo as shown in the final pic. Then fold in half and glue again at the two ends of the fold. Lastly, I glued on two blue pads to make it thicker where it grips.

Step 6: Fix a Broken Bucket Handle

A five gallon bucket may still be good while the handle has fallen apart.

To make a replacement, mix up a standard Oogoo mix and cast it in a mold that is 1/16" to 1/8" thick. you should end up with a sheet of silicone that is about 3" wide by 4.5" long.

After it has set up, mix up another batch of Oogoo. Mix enough to fill the sheet as you wrap it around the wire.

Step 7: Make Liquid Tape for Wire Splices

You can buy liquid tape for insulating electrical wire splices, or you can make your own. Oogoo is an excellent electrical insulator.

You can mix up a standard mix and add solvent to allow it to be painted on thinly. This works fine.

If you want to make it more fire retardant and heat resistant, you can add red iron oxide. A mix of 2 red iron oxide to 2 silicone caulk to 1 corn starch works well. Add enough solvent to thin as desired.

Step 8: Thread Locker

A light to medium duty thread locker for small nuts is easily made. It prevents a nut from vibrating off while still allowing it to be easily removed.

A standard mix of Oogoo is thinned down with solvent. naphtha or turpentine can be used to thin the mix. 6 solvent to 1 silicone caulk to 1 corn starch works well.

The idea is to thin the mix enough to allow capillary action to suck the solution between the threads of the nut and bolt.