If you've ever come across a hard rubber band like wood after it has detached itself from a bunch of stickers, got out of your old favorite pair of tennis shoes, or you've ever found your vacuum cleaner in pieces because of a small gasket., belt or band has broken, then you know that the rubber, over time, becomes hard. Natural rubber hardens and degrades due to the chemical reactions that occur with heat, oils or even with simple oxygen. So, if you manage to limit the exposure of the material to these natural agents, you can postpone the hardening process; at the same time, by using heat and oil properly, you can soften some objects, although, in many cases, it may turn out to be a losing battle.
Steps
Method 1 of 3: Delay the Curing Process
Step 1. Check the condition of your rubber items regularly
Everything that is made with this material, from the wiper seals to the elastic of the pants of your favorite pajamas, slowly and inexorably hardens over time. Evidence that this chemical reaction is taking place is the presence of white or colored substances on the surface of the rubber.
- Rubber is not very resistant to both ozone and UV rays, as well as to oils derived from petroleum. Temperatures below 15 ° C and above 105 ° C accelerate the degradation process, while, in general, extreme temperatures facilitate the hardening and aging of this material.
- Rubber stretches and bends because it is made up of long chains of molecules knotted together, which can stretch when subjected to a certain tension. These molecular chains break down due to excessive and repeated tension (think of a frayed or too tight rubber band) or from exposure to the elements described above.
Step 2. Check the elastic for damage
A cracked piece of rubber will stay that way even if you soften it. Once a rift forms, the only possible attempt is to try to repair the item with a kit that contains patches or resign and replace it. With damage of this kind, miracles cannot be done.
It is worth pointing out that the common methods of softening rubber - heat and oil - actually damage the material in the process. So, whenever you treat a hardened seal or shoe sole, you are also helping to accelerate the aging of the rubber
Step 3. Keep rubber items clean
There is a limit to what you can do to prevent contact between rubber and oxygen, temperature variations and light, but if you clean it regularly of any residue, then you can limit the damage of oily substances.
- Clean your items only with warm water and a clean cloth whenever possible. If necessary, use a mild soap and rinse thoroughly.
- The solvents found in cleaners can ruin and even dissolve the rubber.
Step 4. Store the material in an airtight container to delay the curing process
If possible, remove the air from the container (and therefore also the oxygen) before closing it.
- Put the rubber items in a snap-lock bag and use a straw to suck out most of the air. This delays the hardening process. If you compare the rubber bands stored in the bag with the ones you left in a mess in the drawer, you will notice the difference.
- Rubber, in particular, is very susceptible to oxidation due to the sulfur that is added during the production of items such as rubber bands. The oxygen reacts with the sulfur, essentially removing it from the rubber and thus making it more brittle.
Step 5. Store the container in a cool, dry and dark place
You can put your tennis shoes, properly packed, in the bag, in the same place where you store the apples and potatoes.
- The ideal storage temperature for gum is between 20 and 25 ° C, although you can afford a few degrees less.
- You can consider putting the rubber items in the sealed bags and then in the refrigerator. The cold and excessive humidity of the freezer, on the other hand, make it a poor place for your purpose.
Method 2 of 3: Soften the Rubber with Heat
Step 1. Choose the heat source you prefer
The oven or hairdryer are the most used tools, although some people decide to expose the rubber soles of their shoes to the heat of the radiator, for example. Check that the electrical resistance of the oven can be heated to the minimum and that the hair dryer, on the other hand, can be set to maximum, so that they reach similar temperatures.
- An alternative is to use the dryer on a very high temperature, especially for tennis shoes.
- Basically, your device needs to reach 93-104 ° C; higher temperatures could cause more harm than good.
- Remember to wash rubber items, preferably with water, before heating them.
Step 2. Place the material in a low temperature oven
Place it on a pan suitable for oven use (or another container you don't use for food), in case the appliance overheats and melts the rubber.
- If you are warming up shoes, remember that the soles must face up to reduce the risk of them melting into the shelf or pan.
- Leave the item or items in the oven for 5-10 minutes. If you have an infrared thermometer, you can use it to check that the rubber reaches a temperature within the optimal range.
- Be careful not to overheat the material, otherwise it will degrade; it is also not fun at all to clean the oven from melted rubber.
Step 3. Alternatively, heat the item with a hair dryer
As for the soles of the shoes, set the hair dryer to maximum power and turn it on for 7-10 minutes (at least). Many claim this method is effective.
- Do not aim the heat flow on a single area of the sole and regularly check the rubber, for early signs of deterioration or melting.
- Be very careful, though, as the gum is very hot. Again, if you own an infrared thermometer, you should use it.
Step 4. Wait for the gum to cool for 10 minutes
Afterward, try to handle it. If you're lucky, the material should remain softer and more flexible even after returning to room temperature.
Keep in mind, though, that there are tires made with different formulas and some respond better to heat than others. Furthermore, this is not a miracle cure and certain hardened materials are simply too damaged to be recovered. There is also a risk that, in trying to soften it, the gum will get damaged and you will have to throw it away
Method 3 of 3: Soften the rubber with the soak
Step 1. Separate the rubber parts from the rest of the object, so that you can soak them separately
This method is suitable for industrial or mechanical components that can be reassembled on site at a later time.
- Unless you have a model whose soles come off and reattach easily, this technique is not suitable for shoes. The soaking liquid could damage or discolor areas of leather or fabric.
- Remember that, first of all, you have to clean the object thoroughly, preferably with simple warm water and a clean cloth.
Step 2. Make a solution of three parts denatured alcohol and one part Canadian tea oils
Allow enough liquid to completely submerge the rubber object when placed in the container.
Although these liquids, in small amounts, can be handled safely, it is worth wearing gloves and using forceps when putting the element in and out of the solution. At the very least, you'll keep your hands from smelling of Canadian tea
Step 3. Dip the rubber object into the liquid, close the container and check regularly that it softens
It is important to close the container to limit the evaporation of the liquid, resulting in partial exposure of the rubber to the air.
It may only take a few hours for you to notice the results, although in some cases, it will take several days. Be patient and keep monitoring the process. It is unlikely, however, that prolonging the soak beyond a few days will improve the results further
Step 4. Remove the gum from the liquid and pat it dry with a clean cloth
Wait for it to air dry completely. Although it will have a strong smell of Canada tea, it is best not to use water to rinse it.
- If you leave the oil in contact with the rubber, the softening process will continue.
- Of course, keep in mind that the oily residue slowly damages the gum as it softens it, so use common sense to figure out whether or not it is best to rinse the item with water. However, avoid using harsh detergents.
