For those seals that are slightly weathered, a more straightforward method of submerging the seal in boiling water and soap will work fine. Using the tongs, you should look to remove the seal every 5 minutes to test its flexibility and overall condition.
Vegetable oil: Applying vegetable oil to hard rubber and allowing it to soak can also help soften it. This method is particularly useful for rubber seals and gaskets.
I use Glycerin liquid to keep the seals supple. It's obtainable at Target and just about any Pharmacy. It comes in a liquid form and you just rub it into the rubber seal. Back in the 60's, 70's and 80's when Porsche's had a lot of rubber seals visible to the atmosphere, they recommended glycerin to protect the rubber.
Gently heating the rubber can sometimes make it more pliable. Use a heat gun or hair dryer on a low setting, being careful not to overheat and damage the rubber. For deeper cracks, you can use rubber adhesive or a flexible sealant. Apply it to the cracks and allow it to cure as per the manufacturer's instructions.
ATF is used to lubricate, cool, and clean the transmission components, while also providing the necessary hydraulic fluid to shift gears. When exposed to ATF, rubber components may experience swelling, softening, and discoloration due to its high viscosity and low solubility.
When rubber is exposed to vinegar, it can cause the rubber to swell and become soft due to the acidic nature of the vinegar. This can lead to a decrease in the strength and durability of the rubber, as well as discoloration. Additionally, the vinegar can cause the rubber to crack and degrade, leading to further damage.
There are also a variety of home remedies for rejuvenating hardened rubber. We've heard of using brake fluid, transmission fluid, and a combination of both—something we strongly discourage. On the other hand, a combination of alcohol and wintergreen oil (3 to 1) is said to work well on rubber parts that can be soaked.
While sulfur was the original plasticizer for natural rubber, you can soften most modern rubber by allowing it to soak for at least 24 hours in a solution of three parts isopropyl alcohol and one part methyl salicylate. Spray the rubber with silicone spray. This spray can be found at any camping supply store.
WD-40 Specialist® Silicone Lubricant safely lubricates, resists water and protects metal and non-metal surfaces such as rubber, plastic and vinyl. Once dried, this formula leaves a clear, non-staining film that doesn't stick or make a mess, so it won't attract dirt.
In order to restore rubber band, just pour it over with boiling water. It will go back to shape immediately.
Silicone grease is safe as well as effective on O-rings and rubber seals, posing no health risks or contamination by contact when using your hands for application. It can be used on rubber and plastic without the risk of damage.
When rubber is exposed to petrolatum, the rubber can become brittle and cracked due to the solvents in the petrolatum. The petrolatum can also cause the rubber to swell and harden, reducing its elasticity and leading to eventual failure.
It will rot rubber. If you put petroleum jelly or mineral oil on natural rubber, that 'softening' is actually the very start of a rotting process. It's never a good idea to use mineral oil or Vaseline on any natural rubber.
Next, apply a silicone-based protectant specifically designed for rubber surfaces. This will help keep the rubber moisturized and prevent drying out and cracking. Be sure to follow the product instructions for application techniques and frequency.
Products like Vaseline and silicone spray contain petroleum (crude oil) and many solvents. These penetrate well into your rubbers and affect them from the inside.
Silicone Oil or Molybdenum Disulfide can be applied to the surface of molded rubber products. These options are low cost and work with most polymers. Temporary coatings are an excellent choice for aid in assembly. Moly's grimy nature may preclude it from some uses.
Exposure to oxygen can often cause the rubber to harden, reducing its flexibility and causing cracking. Oxidation and ozone attack occur when oxygen atoms react with the polymer chains within a rubber. Rubbers with double bonds in the polymer chain are particularly susceptible to degradation by oxygen.
To do this, simply drizzle a few drops of glycerine onto a rag and rub it into the clean and dry rubber seals.
Some automobiles use mineral oil-based brake fluids which can attack EP rubber.