Wednesday, April 21, 2010

Does leather conditioner clog pores?

I've heard some strange theories about the care and maintenance of leather. Recently, it was brought to my attention that there are people who hold the belief that conditioners are bad for leather as it will "clog the pores." I have no idea how they come up with their theory. Clog the pores? What does that mean? Is the leather going to develop a "black-head" or a pimple due to clogged pores?

Here are the facts. Keep in mind that the cow is dead. The pores are non-functional. The animal isn't sweating anymore. There are no more body oils being produced by the animal. Nothing is coming up from inside the skin through the pores. What's to get clogged?

Furthermore, a pore is just one structural element found across the topography of a hide. Looked at under a microscope (even a simple magnifying glass) will demonstrate that the pore structure represents a small percentage of the overall surface area. Leather is absorbent across its entire surface, not just the pores.

If you put a massive amount of a heavy, greasy substance as some leather conditioner manufacturers propose, the real problem is that the skin can't absorb it. So it dries on the surface and leaves the leather feeling sticky, gooey (clogged pores?).

Consider the following:

1. Leather has about 25% moisture content coming out of the tannery.
2. That moisture evaporates to the atmosphere at a rate based on 3 variables: A) humidity B) temperature and C) porosity of the hide. (An unfinished leather will dry out faster than a finished leather because it loses moisture at a more rapid rate as the natural skin surface is not coated. A finished leather has a coating that will hold the moisture in longer. In both cases moisture is lost from the suede side as well.) The more heavily finished, the slower the rate of moisture loss. The corollary is that a heavily finished leather will be less absorbent of any moisturizing agent. If its slow to go out, then its also slow to go in.
3. As the leather loses moisture, the fiber bundles lose its internal lubrication, the leather stiffens. Furthermore, it loses a portion of its mass, consequently shrinks.
4. The purpose of a conditioner is to re-instill that lost moisture - improving suppleness, prolonging the life of the leather. Period.
5. Don't replenish moisture (don't apply conditioner) and it surely shortens the life of the leather as the leather desiccates.

pH Balance

What is far more important is to understand that leather is acidic (4.5 to 5.0 oh a pH scale). A lot of harm is done by applying a chemistry that is not pH balanced to leather as it will induce a chemical reaction breaking down (rotting) the fiber structure. Consider body oil accumulation - some people are very caustic (pH below 3.5), causing the demise of the leather. Advanced Leather Solutions cleaners and conditioners are pH balanced to leather, thus helping to correct any pH imbalance combating the rotting affect.

Museums use non-volatile moisturizers.

At the conservation and preservation (museum) level, it is true that a standard grade conditioner MAY do more harm than good. Once leather gets to a certain level of moisture loss (estimated at below between 5 and 10%) then adding a greasy conditioner at that point may render the leather to mush. (Think about cardboard when it gets wet). So the goal is to make sure the moisture content of leather never gets to that low a level by regularly conditioning your fine leathers.

Most conditioners are made from organics like neatsfoot oil which is also the "natural oils" infused into the leather at the tannery. Organics are volatile, meaning they evaporate, which is the fundamental reason why leather needs moisture added from time to time.

A non-volatile moisturizer is a synthetic and does not evaporate. However, they are very expensive so the tanneries generally don't use them. Advanced Leather Solutions has developed a Deep Penetrating moisturizer which is a non-volatile conditioner. It's a highly specialized chemistry that acts like countless tiny ball bearings infused within the fiber structure. In that sense its not a liquid (doesn't evaporate). Once applied, you don't have to continually moisturize as there is no loss to the atmosphere.

Copyright 2010, Kevin Gillan

1 comment:

  1. we have recently acquired a secondhand leather sofa which has been in store and one of the seats appears to be wet by giving a shiny appearance could this be the damp coming from it as a result of it being stored?