Proper care of Footwear begins with choosing the right product. You can't cross streams in athletic shoes and expect to have dry feet. If you have the appropriate boot for the job, regular maintenance and a few simple routines will maximize performance and greatly increase life. "Be Prepared" is the key to success. You'll get lots of help and advice about choosing a boot, fitting a boot, breaking in a boot, but when it comes to making them last you're on your own.
When leather becomes wet from perspiration, rain, wet grass, or stepping into water deeper than the boot top, it should not be ignored. As soon as possible, the boot should be removed and slowly dried. Force drying – especially with heat will cause leather to harden and shrink. In a few cycles, the boots are trashed.
Drying should be done with little or no heat and enough air circulation to dry them completely from soaked in 2 days. If the boots are only half soaked, it should be OK to dry them in one day. Obviously, someone who soaks a pair every day must rotate two or three pair of boots. This is critical for your feet as well as for the boots. In cold climates where cold feet can be life threatening, it is important to avoid soaked boots whenever possible. Even if boots contain Gore-Tex® Liners, they must be kept dry or your feet will feel wet and cold.
There are several types of products to make boots water repellent and a few that claim to make them waterproof. Some boots have waterproof liners and factory treatments, but even these require maintenance. We will consider several types of waterproofers but often the choice is limited by compatibility with what the factory has applied. Silicone treated leather easily accepts more silicone, etc.
Before waterproofing or water repellent is applied, the boot should be clean and dry. Heavy dirt should be scrubbed off with a wet brush. Light deposits can be wiped away with a cloth moistened in water or solvent. Solvent has the advantage of evaporating quickly so you don't have to wait before applying waterproofing. The oldest way to protect and preserve leather is by applying something incompatible with water to fill the pores, fibers, and spaces in the leather. The ancient Egyptians used Beeswax if they could get it, and even today, it is a premium product. Other fill materials are Goose Grease, Bear Grease, Mink Oil, Neatsfoot Oil (from shin bones and feet of cattle), Lanolin, Petrolatum (petroleum jelly), silicone oil, mineral oil, or pitch and pine tar. They simply aim to occupy all space in the surface of the leather so that water cannot enter.
Most of these are fluid at room temperature. You apply them to the outer surface but they soon soak in. You must frequently reapply them to maintain the waterproof quality. After a few applications, the liquid has soaked thru the leather. Now it fills all the spaces thru the entire thickness of the leather, and begins to show up on your socks. The leather gets soft and mushy and can no longer absorb perspiration to keep your feet comfortable.
The alternative is to choose a product that is solid after application. Quality waxes with solvent to aid in application and little or no oil are ideal because they remain fixed in the surface of the leather.
Beeswax provides the maximum waterproof quality and durability for smooth full-grain (top of the skin) leather footwear. Oil or chrome tanned leather accepts wax readily after removal of any factory coating. (Glycerin and Carnauba wax, which are both water-soluble, often are applied for temporary shine and scuff resistance). To remove these temporary coatings a new boot should be washed with a soft brush using residue free detergent or a mild liquid dish washing soap, and allowed to dry completely before applying waterproofing.
Beeswax products also protect split, sanded, suede, rough, and recycled leather. These materials need the protection of wax for rugged use, but it will change their appearance. As wax coats the exposed fibers and fills surface gaps, these non-top grain materials become darker and slicker. Needless to say grease, oil, animal fat, and pine pitch products will not be used where appearance or odor is important.
Gore-Tex® fabric lined boots should be protected the same as you would treat them if Gore-Tex® was not present. Beeswax does not affect Gore-Tex® and Gore-Tex® does nothing to protect the outer boot from water and other abuse. To benefit from the breathability of the Gore-Tex® liners, the inside of the leather must be dry and free of oil, grease, or animal fat so that it can absorb perspiration from the foot. At night, this moisture will evaporate thru the Gore-Tex ® and pass out of the boot leaving it dry and comfortable for the next day's use. The Gore-Tex® liner will hold water away from your foot, but the wax will keep your boot warmer and lighter by preventing water from being absorbed by the outer layer of the boot or leaking into the space between the leather and the liner. When the leather is wet it can add 1½ pounds to a boot.
Why is Beeswax so good? The superiority of wax results from the combination of its ability to remain fixed in the outer layer of the leather and the superior water resistance of Beeswax. Beeswax has a melt point of about 146o F. It is very dry and oil free. Thus once applied it is not only waterproof but also extremely durable.
Beeswax provides just enough lubrication to prevent hardening of leather in typical use. It does not soften leather. The first commercial Beeswax waterproofing for leather was invented in 1933 by Ome Daiber to waterproof leather mountain climbing and downhill ski boots without destroying the stiffness required to climb or steer a ski. Boots, gloves, holsters, etc. will maintain their strength for years if treated only with Beeswax. A baseball mitt can be softened with a light application of mineral oil. When exactly the right ball pocket and fit have been achieved, applying Beeswax will maintain exactly the same fit for the life of the glove.
Grease, oil, animal fat, and many wax formulas are liquid (or at least soft enough to migrate thru leather) at wearing and storage temperatures. They should be avoided because they soak away from the surface and migrate through the leather. They require frequent re-applications to maintain effective concentration on the surface. After a time the heel counters and box toes soften. The leather becomes soft and spongy then the product begins to appear on your socks indicating it has soaked all thru the leather. Animal fats become rancid, decaying leather and promoting fungal growth until one day the leather is so rotten the eyelets pull out when you lace up your boots. Saturated leather cannot absorb perspiration and loses its insulation value so your foot feels clammy and cold. Beeswax stays where you need it, in the outer surface of the leather. The balance of the thickness remains open and dry for increased insulation and the absorption of foot moisture. By resisting migration, wax assures that there will be no weakening of thermal or adhesive bonds, a common problem with oil type silicones, and other liquids.
Silicones offer easy application but less water resistance, durability, and protection than Solid Wax. Silicones resist water two different ways. The first is similar to wax, oil, animal fat, and grease: it simply occupies space in the leather so that water can't occupy the same space. This is of limited value compared to Beeswax and other wax products that occupy space better, more permanently and with less migration. The second method is by reducing surface tension so that water beads up and does not "wet" it. This is similar to the function of Fluoropolymers but Fluoropolymers - when successful - reduce surface tension further so that even oil and some solvents can't "wet" it. (This is why Fluoropolymer is superior for stain resistance.)
Silicones are usually in solvent systems for water repellent products because water systems (aqueous emulsions of silicone) can't match the performance of the solvent systems. A variety of solvents will work but there are advantages and disadvantages with each. The non-flammable solvents are bad for the environment. Even the flammable solvents are VOCs but some are more harmful than others are. There is also a wide range of flammability. Mineral spirits dries slowly but is much less dangerous than solvents that dry more quickly. Even the aerosol propellant can make a difference. C02 is non flammable and a few grams will empty a can. Propane Isobutane is extremely flammable and, because it is heavy and cheap, may be used to fill half the can with no value to the consumer. Polymerizing silicones actually form a film that resists washing away much better that simple silicone oils. For heavy-duty applications where repellent effectiveness is more important than appearance, choose a product that is at least 10% silicone by weight. A heavy-duty silicone formula is an excellent choice for split, or sanded leather or leather / fabric, especially if the suede appearance is more important than long lasting waterproofness of wax.
Fluoropolymers are designed and intended for use on textiles for stain protection. They require an absolutely clean surface for adherence and 300° F heat is used at the mill to orient the molecules for maximum effectiveness. Applied under perfect conditions they work well and last for many washings if washed only in residue-free detergent.
Fluoropolymers are generally superior to silicone for oil and stain repellency but generally, inferior to silicones, waxes, and fill products for water repellency. Factory applied Fluoropolymer treatments on textiles can be restored to full effectiveness by washing with residue-free detergent to remove residue and then Ironing on Steam setting.
Fluoropolymers can give inconsistent results depending greatly upon what surface they are applied to. Baking at 300° F as in textile mill applications is impossible for boots and it is also difficult to keep boots clean enough for maximum repellency. In any case, Fluoropolymers are better left for clothing applications or limited to suede shoes where stain resistance is more important than Heavy Duty Waterproofness.
There are some crossover products that use technologies such as aqueous wax or wax fortified with polymer. Some of these can be applied to wet leather. This sounds enticing when you have failed to prepare your boots beforehand and they are now soaking wet. However, you still must dry them after application before they are ready to keep you warm and dry. Unfortunately, emulsified waxes (with or without polymers) are about as ineffective as emulsified silicones. When wax, oil, or silicone is emulsified, a surfactant has been used to make it mix with water. The surfactant residue defeats the repellent by enabling water to mix with it. This quickly defeats the purpose of excluding water.
There are many choices for the casual user. A quick dash from the car to the door isn't likely to test any appropriately applied product. But when you need serious waterproofness nothing is as effective or long lasting as Beeswax