how to restore dried leather

[Jareth]

As said before "leave well enough alone". there is NO treatment/product that will NOT change the leathers color & surface texture. It's a losing, ill advised compromise.

[Simon O.]

I have had relic helmets for years. I never treat them in any way, and nothing has ever fallen appart. Contrarly to what I often hear, rust isnt some kind of cancer that will keep spreading unless taken away. If you take the helmet out of the environmental conditions that made it rust, and put it in good conditions, the rust will no longer spread.
But it is true that on a helmet like the one you showed, in the first period after the helmet was dug up, lots of pieces of rust will fall off, but then the helmet will reach a stable point.
The thing I dont like with your treatment is the rust-oil part. I find it realy ugly, as it makes the helmet so shiny. But like you said, ca depends des gouts.

JL

Then it must be dependent on humidity and environment because everything i've found carries on rusting, even after cleaning and the removal of loose rust unless treated. The worst things seem to be steel shell cases. I've got a carrying frame for egg handgrenades right next to me now that i cleaned up and brushed off loose rust when found 2-3 years ago but now has rust flaking off it again, so it's going to be another round of loose rust removal and this time a coating of Owatrol.

[JIMP10X]

It is most definately about the humidity.With metal objects,the lower the humidity the better,but add leather into the equation and you have to find a happy medium,too little humidity and leather dries up,cracks,and eventually falls apart.I think 45-50% is optimum.

Take moisture(humidity)out of the picture and oxidation will have nothing to feed and grow on.

Jim

[CWP]

Jim is right. With low humidity, rust can not grow.

[pbuchh7715]

Just food for thought. I've worked with two seperate public museums that treat leather for CONSERVATION purposes, not restoration. Restoration IS possible but to parrot what another forum member wrote, no serious collector will want to mess with a piece of treated leather. Not because it WAS treated but you never know who did it, how or with what.

Something to remember is that once leather is treated, it requires regular maintenance. Anyways, not here to introduce Conservation 101 but thought some folks would find the following of interest.

Pete


Archaeological Preservation Research Laboratory Report 10:

Conservation Research Laboratory (CRL) Leather Dressing

C. Wayne Smith

D. L. Hamilton

Conservation Research Laboratory/Archaeological Preservation Research Laboratory

Texas A&M University


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INGREDIENTS:
Polyethylene Glycol (PEG) 4000
PR-12 Silicone Oil
Pigment (optional)

Preparation:

1. 2 parts PEG 4000 to 3 parts PR-12 silicone oil

2. Combine these ingredients in a glass beaker and warm them in an oven heated to 110 degrees Fahrenheit. Mixing will become easier as the mixture warms. **do not boil the mixture

3. Let the mixture cool slowly. Stir periodically to ensure smoothness.

4. Apply a thin even coat to the surface of the leather and buff with a soft cloth.

-For very dry stiff leather, the process can be repeated several times.

-If the leather is badly cracked, allow the dressing to soak into the surface before buffing.

5. Periodic applications of this dressing appear to soften stiff dried leather, acting as a humectant. Always off excess dressing before crating the leather artifact.

6. Add pigments such as bone black, graphite or oxides such as iron oxide or titanium dioxide as necessary.

-Our experiments have indicated that pigment additives should not exceed 3% of the total volume of the solution.

-Acrylic-based pigments can cause thickening or lumpiness of the leather dressing: if these must be used to obtain a desired color, make a test batch of the dressing before treating the artifact to ensure that there is no chemical reaction between the coloration and the basic dressing.



7. Store the mixture in a tightly sealed jar. The resultant mixtures form a moderately stiff paste that has a relatively long shelf life. Humidity may affect the consistency of the dressing over a long period of time.

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Citation Information:
C. Wayne Smith
1998, "Conservation Research Laboratory (CRL) Leather Dressing", Archaeological Preservation Research Laboratory (APRIL), Report 10 , World Wide Web, URL, http://nautarch.tamu.edu/APRL/report10.htm, Nautical Archaeology Program, Texas A&M University, College Station, Texas.

[Dennis J]

hide rejuvenator

Good day to all I bought 20 pair of German WW2 boots from a guy in West Germany back in 1975 and I put Dr.Jackson's Hide Rejuvenator on them because they were so dry and stiff and had been stored wrong since WW2.I still have 2 pair left and they are in great shape.I had a ground dug civil war leather strap that I dug up and it worked great on that.I got this Dr. Jackson's from Tandy leather co.I use to sell it at gun shows with great reviews from people who bought it.

Enjoy your hobby
Dennis J

[Petr]

Hi everybody with dried leather!
I treat dried leather with pure LANOLIN /adeps lanae/:I buy it in local dispensary.I warm it up ,melt it and by brush I put it on leather.Then I warm it more with hair -dryer until it soaks.That is all friends.It works fine for 12 years of my collecting.
I wish you good health. Petr.

[pbuchh7715]

Article on leather conservation #1

Greetings,

I regularly watch threads dealing with the "treat or not to treat" leather issue as I collect leather flight jackets and pickelhaube. One I clean and treat, the other I do not.

Regardless, one thing missing from all the pontification and comments siding for either school of thought fail to document any research on the subject. So, as it's Friday and I didn't feel like do anymore paid work for the day, I thought and look and see what I could find. I'm going to post two (maybe three) bits of info I found that lends creedence to both theories. Here's the first:

From: The Journal of Conservation and Museum Studies NOV97

THE DEGREDATION AND CONSERVATION OF LEATHER
Vicki Dirksen

Issues Regarding the Conservation of Leather Artefacts

Leather conservation is an area that is constantly changing as a result of research into the development and evaluation of historic and contemporary products. Such research illustrates the difficulties surrounding the conservation of leather. Currently there are two primary methods employed for leather conservation. The older method uses the application of dressings or treatments as a means of prolonging the life of leather objects. Recently, however, there has been a movement away from this interventive treatment of leather and towards a more preventive approach. This new method of leather conservation focuses on improving the way in which leather artefacts are stored. The advantages and disadvantages associated with each method will be addressed.

Because of the wide variety of dressings and treatments possible, space limitation prohibits a detailed discussion of the way in which this method of conservation works with specific interventive treatments. However, essentially a dressing is chosen based on the leather process used to create or care for the artefact and any dressing or finishing. The interventive dressing of interest is then applied to the artefact in the appropriate manner.

The principal reasons behind the application of a dressing or treatment for leather artefacts are outlined in great detail by Tuck (Tuck, D. H. 1983. Oils and Lubricants Used on Leather. Northampton: The Leather Conservation Centre). In his monograph, Tuck describes six reasons for applying oils and fats to leathers. First, the fibrous structure of leather may require lubrication. According to Tuck, dressings will help control the internal friction between the collagen protein fibres and the cross links created during tanning resulting in a more durable leather product. Second, by incorporating fatty materials, the softness and extensibility of the leather will decrease the likelihood of its drying out. Third, dressings retard the penetration of other chemicals into the leather. Fourth, natural voids in the leather or those resulting from chemical modifications will be filled with oils and fats increasing the support and solidity of the leather. Fifth, the oxidation of oils will be less likely since dressings containing unsaturated fats increase the chemical stability of leather. Finally, Tuck states that dressing leather with oils and fats will improve the artefact's overall appearance.

Unfortunately, the application of dressings can produce unexpected and serious problems for conserving the leather. While dressings may improve overall appearance, current research indicates that these oils and lubricants are not effective in preserving leather. Landman (Landman, A. W. 1991. "Lubricants." In: Calnan, C. and Haines, B. (eds.) Leather: Its Composition and Changes with Time. Northampton: The Leather Conservation Center, 29-33) questions the need for applying lubricants to museum objects. "For museum objects, which are handled only infrequently and where flexibility of the leather is no longer of prime importance is there a need for further lubrication?" He goes on to say that "in conservation the lubricant can only be applied to the leather surface, often only to one surface and with the minimum of mechanical action." This is unlike leather manufacturing where the leather can be fully immersed in the lubricant. Furthermore, the conservator needs to recognize that the lubricant might change over time, seriously affecting the object being conserved (Landman 1991).

In addition to the problems surrounding the use of a lubricant in leather conservation, their use does not meet the principle of reversibility set forth in the American Institute for Conservation of Historic and Artistic Works (AIC) Code of Ethics. The principle of reversibility states that the conservator "should avoid the use of materials which may become so intractable that their future removal could endanger the physical safety of the object. They also should avoid the use of techniques, the results of which cannot be undone if that should become desirable" (American Institute for Conservation of Historic and Artistic Works 1979).

In setting up guidelines for the proper storage of leather artefacts, it is important to look at the problems surrounding current storage practices for leather artefacts. Leather may experience problems with humidity and temperature levels, light, dust, fungus, mold, atmospheric pollution, and damage due to improper care. An assessment of these problems prompted the Canadian Conservation Institute (1992) to set up guidelines for proper storage methods. They recommend regulating the environment in which leather objects are stored by maintaining humidity and temperature levels in an acceptable range. Leather artefacts should be stored in an area with a humidity level in the range of 45% to 55% [Calnan, C. N. 1991. "Ageing of vegetable tanned leather in response to variations in climatic conditions." In: Calnan, C. and Haines, B. (eds.) Leather: Its Composition and Changes with Time. Northampton: The Leather Conservation Center, 41-50) suggests 55% – 65%] and a temperature of 18 degrees Celsius to 20 degrees Celsius. Regulating humidity levels is extremely important since leather responds to even the slightest change in humidity (Calnan 1991). By maintaining environmental control, conservators and other museum professionals will avoid problems with mold, which requires a relative humidity in excess of 65% to grow. Monitoring objects in storage will help to identify any potential problems with both mold and insect infestation.

The light to which an object is exposed is also of importance since painted and dyed leathers are extremely light sensitive. For this reason, the Canadian Conservation Institute (1992) recommends that leather objects should have minimal exposure to sunlight or direct light. Leather objects should always be stored in the dark. As dust is also an enemy of leather, objects should be protected from dust settling on them. Whenever possible, metal components that come in contact with leather should be removed.

Of primary importance in preventive conservation is the full support of leather artefacts while they are in storage to prevent stiffness or loss of shape over time (Canadian Conservation Institute 1992; Storch 1987; Guldbeck 1969). Full support minimizes the cracking and splitting of leather due to mechanical stresses resulting from use. Supportive devices should be developed for all areas of the artefact that may need them. For footwear, this means both internal support to help maintain their shape and external support to prevent the footwear from tipping over and to prevent abrasion from other materials.

When cleaning or handling leather one should have clean hands and should not use objects that may leave a permanent mark on the leather. The method of cleaning recommended by the Canadian Conservation Institute (1992) is brushing leather with a soft bristled brush to remove dust and dirt particles. While brushing, a vacuum cleaner with a fiberglass cover attached to the nozzle should be held so that the dust brushed off the leather will be removed.

The movement towards the proper storage of leather artefacts is partially in response to the questions surrounding the use of leather dressings. According to the Canadian Conservation Institute (1992), several of the problems outlined in the previous section could be avoided or minimized if leather were stored and displayed in a proper manner. For this reason, most leather conservators focus their efforts on identifying the proper methods for the storage and display of leather objects (Canadian Conservation Institute 1992; Storch 1987; Guldbeck 1969). One of the obvious advantages to the implementation of proper storage methods is that it adheres to the AIC Code of Ethics. It is completely reversible and does not endanger the physical safety of the object. Also this method is cost-effective in that the conservator does not have to buy or apply special dressings. By using material remaining from other conservation projects to create supports for leather artefacts, savings on expenses for supplies can be realized. Finally, the biggest advantage to this method is that a person with little knowledge of conservation methods could implement proper storage practices. This is of particular importance when one considers the large number of museums with a small budgets and staffs.

The main disadvantage associated with the adoption of proper storage methods for leather objects is that it does not treat leather that is exhibiting serious problems such as those discussed previously. Also the size and nature of some leather artefacts, i.e. saddles, may require rather large and elaborate storage. While these procedures would be the best for the preservation of the leather, they may lead to problems connected with the amount of storage space available. Finally, the multicomponent nature of many leather artefacts is not addressed by the implementation of proper storage methods. What may be a good environment for the storage of leather may be bad for the storage of wood, metal, and other materials.


Conclusion
The methods used to conserve leather objects are always under review.

[pbuchh7715]

Leather Article #2

National Park Service Conservo-Gram

New Problems Created

In practice, the dressing of leather is also a largely irreversible procedure because of the deep penetration of the foreign ingredients and the movement of soluble components within the leather. The dressing can also impede future conservation treatments such as resin impregnation.

One of the major problems with commercial dressings is that people apply them for their immediate results without awareness of their long-term effects. Instability of certain fats or oils, dressing additives, and solvents contained in dressings can be responsible for numerous undesirable and unexpected effects:

Oils and fats can:

become increasingly acidic
form unstable surface spews
oxidize and stiffen
discolor and stain
wick into adjoining materials
leave a sticky surface
encourage biological deterioration
Wax additives can:
block surface porosity
discolor and collect dust
change the surface appearance
impede further treatment
encourage biological deterioration
Dressing solvents can:
wet and swell the leather
dissolve/dislocate original components
affect surface finishes
Conclusions
It is evident that the dressing of leather is a popular and well established procedure, yet there is a fair amount of experimental and practical evidence that suggests it has little or no effect on leather's rate of deterioration. The regular dressing of leather is hard to justify in terms of conservation principles since it has little or no preservative effect when applied in a customary uncalculated manner and there are so many potentially dangerous side effects.

It is recommended that park staffs not apply leather dressings to their historical collections on a routine basis. However, in certain individual situations, it may be appropriate for dressings to be applied by park staff under the direction of a conservator. Lubricant solutions will also continue to be used on a limited basis during conservation treatment in which the specific components and quantity can be carefully monitored by a conservator.

[See NPS Museum Handbook, Part I (Rev 9/90), Appendix S. "Curatorial Care of Leather and Skin Products, " forthcoming. ]

Conclusion: Don't touch it!

[pbuchh7715]

Leather preservation Article #3

Leather Dressing

Leather dressings were at one time thought to be useful in extending the life of leather bindings. Experience has shown, however, that its benefit is primarily cosmetic and that the use of leather dressing by someone without professional expertise, does more harm than good.

Studies have shown that leather dressings can cause the leather to dry out over time.

Dressed leather may become stiff, and will be accompanied by darkening of the surface or staining.

If too much dressing is applied, or if it is applied too frequently, the surface of the leather may become sticky and attract dust.

Leather dressings can migrate through dry leather and stain the text pages of a book.

If a leather book has become stiffened through the use of leather dressing, proper handling techniques and support of the book structure will help to ameliorate the problem.

Polyester (Dupont Mylar Type D® or ICI Mellinex 516® ) dust jackets help prevent dry rotted leather from offsetting on to adjacent books and protect the covers from further deterioration as well.

To select the professional best qualified to treat your object, contact the referral service maintained by The Foundation of the American Institute for Conservation (FAIC). They will provide you with a list of conservators in your area that can help find appropriate conservation treatment.

The Foundation of the American Institute for Conservation (FAIC)
1717 K Street, NW, Suite 301
Washington, D.C. 20006
Telephone (202) 452-9545
FAX (202) 452-9328
E-mail: infoaic@aol.com
WWW: http://aic.stanford.edu/

Conclusion: This really applies more to books but....

[Carson]

Cleaning the leather of my bayonet portapee. The interlaced material is missing, but the leather is supple and solid. The 3/4" band that holds the knot has a lot of small perforations.

I start to gently clean the leather to "neutralize" its condition. The expensive leather restoration product is absorbed into the leather. I am gently cleaning it with GREAT respect for the material due to the age of the item. The band simply falls apart, kind of crumbled as I changed the original state of the leather.

My firsthand experience... and now I need a new portapee.

Interesting thread and thanks for the info!

Carson

[Ralph P]

Hello all - I have pinned this thread so that it is exposed as much as possible to the forum community.

Thanks to all who have posted some interesting information in this thread.

[lambstew]

I Concur..

Long-term studies by museum professionals have proven that although the application of leather dressings can temporarily make the leather more supple, they invariably cause irreversible damage to the item over a period of years.

Years ago I collected A-2 leather flying jackets and eventually got turned off them as there is really no way to correct dry rot or dry leather for the long term. This was verified for me by the leather preservation specialist at the Smithsonian in Washington who told me that leather care products ALL of them cause more chemical damage to vintage leather in the long term. They have been testing leather treatments and their long term effects for years and his advice to me was - LEAVE IT ALONE! He also said that they refrigerate old flying jackets to stabilize deterioration. Keeping old leather in a stable not too dry environment is the best way a collector can help preserve something.

Regards,

Konrad