I have been working with leather for over thirty years, both in the production of new items and in preservation of antique leather. What I am about to say will offend some, my sincere apologies but what I say is based on experience and consultation with experienced professionals, so here goes.
Do NOT use anything that contains petroleum products on antique leather items, you can check the label of the product you will be using, it will list the contents. Among items that contain petroleum products are:
(1) Sno Seal
(2) Mink Oils by all of the various companies that make their own versions.
(3) Neatsfoot oil compunds - these allegedly contain neatsfoot oil (good) but are cut with petroleum products and/or other undesirable elements.
and last on my list may be the worst:
(4) Pecards. Pecards is not used by any museum on the face of the planet that has an experienced preservationist on staff. Even their own website has removed that claim.
(5) LEXOL. I put this product in the do not use column, but I really do not have a problem with it other than it needs to be constantly reapplied. It is a water based product and does a fairly good job of preserving as well as cleaning but dries out relatively quickly.
(6) Many other modern "goops" that claim to preserve leather.
Now, all of the above can be used on a good pair of work boots that will be used until worn out and thrown away, they are fine for that as well as a less expensive baseball glove, belts that have gotten severely worn and are on their last legs before disposal, less costly leather garments that have gotten wet and have dried unevenly, etc., etc.
Leather is a natural product that begins to decay soon after it is made, that is simply the nature of the beast. The process is slow (or fast with careless handling) but it does happen. Once you have received an antique leather item, it is best not to use it. Store it properly in a good environment. Avoid at all costs direct sunlight, high or low humidity and extreme temperatures, especially hot temperatures. Do not bag it in a plastic bag, allow air to circulate. And dust it frequently, dust attracts moisture and can lead to mold and mildew.
So, if the above are not good, what do you use? The best thing as Bob in OHIO said in his post is nothing. As I said above, store it properly and, let me add, do not strain it. If you feel must use something, say the item is solid but extremely dry and beginning to stiffen leading to possible breakage, use one of these two items:
(1) Pure neatsfoot oil - NOT the above mentioned commonly available neatsfoot oil compound. Pure neatsfoot oil has a bad reputation because of legend and because people don't know the difference between it and the lesser quality compounds. Therefore, they will use the less expensive and more readily available neatsfoot oil compound. They also don't know how to apply it or anything else for that matter, do remember however that neatsfoot oil is used in the tanning process so all leather does and always has had neatsfoot oil used on it long before you received it. More on application below.
(2) Lanolin – an excellent product and natural, good for leather.
So, now that you know my opinion of what to use, there are a couple of things that need to be said about the application of whatever you decide to use:
(1) Be sure to clean the leather item, especially if it has suffered mistreatment. At the very least, it should be wiped down with a clean, cotton cloth on both sides if possible. That means the hair (smooth) side and the flesh (“rough”) side. Sometimes the flesh side is best cleaned with a paint brush made using natural hairs. This is also good for getting into areas that are difficult to clean using a rag, say around buckles, loops and inside cartridge boxes, etc.
(2) The following is to be avoided if at all possible but sometimes it is necessary. If the item is especially dirty and rubbing and brushing does not remove sufficient crusted on dirt, then you must use a good quality saddle soap on it. Use a minimal amount of water and a soft brush to do the cleaning, too much water will cause problems but to little will not allow you to clean.
(3) If you have been forced to use saddle soap, allow the item to dry sufficiently before going any further.
(4) Now it is time to apply the preservative of your choice. First, remember that less is better. Do not over apply. too much, no matter what you use, will drown the leather and is to be avoided at all costs.
(5) I personally will apply neatsfoot oil (or lanolin) when the leather has dried (after cleaning using saddle soap where necessary) to the point of being almost completely dry, but not quite. Then apply the oil lightly to the flesh side. If, after the first light application, you feel that another application is necessary, do another light application. That should take care of the situation, no more will be necessary. I have seen good antique (and new items) completely destroyed by over application. Again, do not drown the item. To not try to “soften” the item too much, most items have a certain body that seems a little stiff when new and this is what you are looking for, soft leather is fine for garments and certain tannages, but soft leather will tear especially at the stitching and is to be avoided. After all, you should not be using a 75 or 100-year-old item for its original load carrying use, right? Let’s hope not.
That’s all I have to say, I hope that what I have said is helpful and only minimally offends those who may disagree, no offense was intended.
