# What really happens when a tool handle is "all dried out"?



## summerfi (Oct 12, 2013)

First let me say I'm not trying to be a smart aleck with this topic. I'm simply trying to better understand the process that occurs when we say a wooden tool handle such as a plane tote or a saw handle has "dried out" and needs to be oiled or rehydrated.

On many occasions I've heard people say something like, "that handle is all dried out. Better put some boiled linseed oil (BLO) on it." Not to pick on anyone, but there is currently a LJ thread by a fellow who wants to know how to rehydrate his plane tote. This makes no sense to me for several reasons. First, a living tree has a high moisture content, and it's not suitable for most uses until we dry the lumber. Kiln drying brings lumber down to, I believe, around 6% moisture content. So why is dry wood good on the one hand and bad on the other? Second, wood will eventually take on the same moisture content as the ambient relative humidity. Not many places have a relative humidity drier than 6%, so in most cases the tool handles in your shop will have a moisture content higher than kiln dried lumber. Third, I have a considerable amount of hardwood lumber that was stored in the attic of my dad's shop for upwards of 50 years. If any wood can be too dry, this wood should be. Yet it is perfectly good wood and shows no signs of needing to be oiled or hydrated. Fourth, I have many vintage tools in my shop that are 100+ years old. These tools show no indication that their handles are too dry and need some sort of treatment to restore them to wholeness. Fifth, with the exception of some tropical hardwoods, most wood does not naturally have much oil in it. Why would we need to add oil to it?

All that being said, I've certainly seen tool handles that have the appearance of being dry. I restore a lot of saws, and I often see old saw handles that have checks in the grain and the wood has a dead, lifeless, bleached out look. These handles are what someone might call "all dried out", but is that really what has happened to them? I would bet that if you measured the moisture content of these handles, it would match the ambient relative humidity. If these handles aren't too dry, then what has happened to them? Well, I'm hoping to stimulate some discussion on that so we can all become more knowledgeable. But here is my theory for starters. I think there are at least two things that can contribute to the dry look. One is repeated wetting and drying cycles (expansion and contraction of the grain), such as occurs when tools are left outside in the weather. The other is exposure to sunlight. Imagine two 100 year old tools in the same climate. One's handle looks perfectly fine after all that time. The other's handle is checked and lifeless. What has made the difference? It has to be exposure to the environmental elements.

So what do you think about this? Is it a misnomer to say tool handles are dried out? By the way, I never add BLO to wood because IMO it turns wood dark and is a magnet for dirt.

An old "dried out" saw handle (photo from the internet).









An even older saw handle in good condition.


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## Tim457 (Jan 11, 2013)

I should research this first, but my wild guess at what makes a handle like that top one look dried out is dry rot or a similar process where the wood decays, not just has a lower moisture content.

And I can't say exactly why, but adding BLO to a dry looking tool handle sure does make it look better. Though now that I've learned that BLO has little protection I prefer a BLO varnish mix.

I recall reading something else about what happens to wood over longer time periods, but I don't remember now.


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## Purrmaster (Sep 1, 2012)

I think you're on to something to say that "dried out" makes no sense. For one thing once wood is dried it should stay at the ambient moisture content of its area.

The dried out looking tool handle looks to me like it needs some sanding and a new coat of finish. As you said I think the first saw handle was exposed to sun and rain and we know what that does to wood. It tends to break down the lignin in wood.

I don't think sticking BLO on old, cracked tool handle is going to do anything for it. It might make it look prettier, but that's about it.

As you said, the idea of "rehydrating" a tool handle makes no sense. If it needs refurbishing I'd use wood filler or epoxy to fill in any cracks. Then give it a good sanding and a new coat of finish.


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## wormil (Nov 19, 2011)

Theory is fine but experience is better. If you take an old dried out handle, soak it in linseed oil, it will add weight and resilience back to the wood. And perhaps it kills the fungi responsible for dry rot. There is a point at which wood cannot be saved and must be replaced. You'll know if a piece of wood is "dried out" because it will be lightweight, like cedar that's been in the desert; and may be brittle or punky if too far gone. "Dried out" is not about how it looks but about the properties of the wood. I believe it is caused when wood goes through cycles of wet and dry over a period of years.


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## ElChe (Sep 28, 2014)

Decayed wood won't remoisturize back to health. It is done. Finito. Dry looking wood that is otherwise healthy can be made to look nice with BLO but I don't think this is a moisture issue. Rather it is adding a finish to the wood? I do know that certain woods will absorb a lot of oil and get heavier. Like beech mallets dunked in mineral oil. But again I don't see this as a moisture issue.


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## bondogaposis (Dec 18, 2011)

I think you are on the right track I believe exposure to UV is the culprit in most cases. Tools stored in a tool box or in a shop environment are protected from sunlight and as you have stated can survive 100 years or more w/ no ill effects. Then if you look at a tool that was hung on the side of a barn, the wooden parts will get that weathered fencepost look in a relatively short period of time. Sunlight will have destroyed the original finish and by putting BLO on it you are basically refinishing it. Any other finish will have the same effect of rejuvenating the look and feel of the wood.


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## wormil (Nov 19, 2011)

> Decayed wood won t remoisturize back to health.
> - ElChe


The wood in a handle is dead, "health" is a meaningless term. And decay is not a "1" or "0", decay happens gradually.


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## summerfi (Oct 12, 2013)

Thanks for the replies. It seems there is a consensus that what we call "dried out" is not really a moisture issue, but rather a degeneration that has taken place due to physical agents (sunlight, water) and/or biological agents (dry rot, fungus). Since the problem is not a lack of moisture, it seems illogical to try to solve the problem by adding moisture. I will go out on a limb here and say that, except for things like raising the grain before finishing, taking out dents, steam bending, and maybe a few others, it is never beneficial to put water on wood. But what about oil?

I'm not a chemist or physicist, so I'm making presumptions here. I think BLO and similar substances soak into wood, bind to the wood fibers, add weight and probably some degree of resilience to the wood, and cause the fibers to expand, closing off small checks or fissures that have developed in the wood. As some have said, it is a penetrating "finish" of sorts that makes the wood look better, at least temporarily.

In my mind, prevention is the way to go so that wood never develops that "dried out" look. This is best accomplished by sealing the wood against physical and biological agents, and then keeping it in an environment (indoors in a tool chest for example) where exposure to those agents is minimized. Sealing can be accomplished with various kinds of surface film (varnish, shellac, lacquer, paint, wax, etc.) or with penetrating substances such as oils. The surface films protect the wood without altering it, whereas the penetrating substances alter the wood by soaking into the fibers, binding to them and swelling them. They may cause chemical changes in the wood as well, and they alter the appearance of wood by turning it dark over time (probably a chemical change).

What do you do with wood that has already "dried out"? As Purrmaster stated above, my preference is to fill the checks with epoxy, sand and refinish with a film type of finish. I personally believe that produces both a better appearance and better protection from future deterioration than soaking it in BLO.


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## wormil (Nov 19, 2011)

I think you are getting hung up on the words "dried out". People call it that because that is how the wood appears, sometimes grey or white and always extremely lightweight as if there were not a drop of moisture left in it. Most people who see this are not wood scientists and are going to use colloquial descriptors. It is not a black and white state, there can be old wood that has simply dried out or wood in a state of decay whether by fungus or UV or whatever. If the wood is intact (not crumbling or punky), soaking in linseed oil does an pretty incredible job of revitalizing the wood. The next step is a wood hardener but usually something that bad I will just replace it.


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## houblon (Nov 15, 2013)

I can highly recommend "Understanding Wood" by Bruce Hoadley. 
He writes that there is no such thing as dried out wood that needs feeding.


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## chrisstef (Mar 3, 2010)

Considering im working an older saw handle at the current moment this is an interesting topic for me to read. On this handle I would have called it "dried out" for sure. Judging by the considerable amount of rust on the plate it sat outside for some period of time. I could even feel the grains of the wood raise and lower with my fingers. Is it shot? I don't think so but maybe. My plan of attack on this handle was to give her a couple coats of BLO and then use my standard finish of shellac and wax. Im not a huge BLO fan as a stand alone finish but with a film over the top it works.

Could it be that the pores of the wood have been completely opened up in search of moisture and the non porous portion has tightened up giving it that appearance and texture?


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## bold1 (May 5, 2013)

The main use of oil besides swelling the cells to tighten a handle (such as pick or axe handles), is to replace some of the water in the cells. Oil, once drawn into the cell, doesn't move as quick as water (less rapid movement of the wood). Oiled wood fibers also stay more plastic so that the movement doesn't cause as rapid a breakdown of the fibers. As has been pointed out the exposure the the wet dry cycle in direct sun causes the rapid movement of the fibers causing rapid breakdown and tearing(checking). Any finish (sealer) will limit the rapid movement.


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## Purrmaster (Sep 1, 2012)

Does a soak in linseed oil actually revitalize the wood or just make it look nicer to the eye? And if you wanted to use oil for protection wouldn't it be better to use tung oil?

Regardless, you won't get as good protection from linseed oil as you would a film finish.


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## ToddJB (Jul 26, 2012)

I'm not sure I've put a ton of thought into this topic except for I think I ultimately just like the look and feel of BLO (or BLO based finishes) for most handles. Plus I like the ease of reapplication. I hate getting the old crusty film finish of old saws and planes. I get that I likely would not need to refresh a film finish that I had put on in my life time - but I don't want to put anyone else down the line through that process either.

Admittedly, I have done film finishes on some things - mostly highly figured woods, but for wood that has character from work and age, I like the non-film options.


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## Tim457 (Jan 11, 2013)

> I m not a chemist or physicist, so I m making presumptions here. I think BLO and similar substances soak into wood, bind to the wood fibers, add weight and probably some degree of resilience to the wood, and cause the fibers to expand, closing off small checks or fissures that have developed in the wood. As some have said, it is a penetrating "finish" of sorts that makes the wood look better, at least temporarily.
> 
> In my mind, prevention is the way to go so that wood never develops that "dried out" look. This is best accomplished by sealing the wood against physical and biological agents, and then keeping it in an environment (indoors in a tool chest for example) where exposure to those agents is minimized. Sealing can be accomplished with various kinds of surface film (varnish, shellac, lacquer, paint, wax, etc.) or with penetrating substances such as oils. The surface films protect the wood without altering it, whereas the penetrating substances alter the wood by soaking into the fibers, binding to them and swelling them. They may cause chemical changes in the wood as well, and they alter the appearance of wood by turning it dark over time (probably a chemical change).
> - summerfi


Again, I'm no expert, but this seems to make a lot of sense for what's going on. I think it comes down to preferences. I like the feel of wood with the oil varnish better than a film finish, but a film finish like poly undeniably gives better protection as long as it lasts. Either way tools need to be protected from the elements for the protection to last, so that puts us back to preferences. If you prefer the film finish look and feel that's great.


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## wormil (Nov 19, 2011)

> I can highly recommend "Understanding Wood" by Bruce Hoadley.
> He writes that there is no such thing as dried out wood that needs feeding.
> 
> - houblon


If true, you've convinced me it isn't worth the paper it's written on; as I can assure you, there is such a thing as "dried out" wood in the context of this thread. But I suspect Hoadley is speaking in terms of furniture and the marketing of products to "nourish" the wood which is a completely different thing.

So none of you have ever been around old tools or farm equipment? Have you never opened an old book where the paper has become brittle? Or tried to leaf through an ancient newspaper that just falls apart? All part of the same thing.


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## summerfi (Oct 12, 2013)

I agree that whether to use an oil product or not on wood is a personal preference. If you like it, use it. I don't like it, so I use something else. That's a different issue, though, than the original purpose of this post. The purpose was to clarify whether wood dries out excessively and thus needs to be treated in some manner to put moisture back in. The answer to that question is, I think, no. A related question is, if wood does not dry out excessively, then what does cause wood to deteriorate over time. Most people seem to agree it is a combination of physical (climatic) and biological stresses that cause wood to look dried out. These can be avoided, or at least reduced, but applying a protective finish to the wood and then taking care of it by keeping it in a suitable environment.

Thanks to all for the good discussion that has helped clarify this issue for me. I will probably still cringe when I hear people say that wood has dried out and needs to be moisturized, hydrated, fed, oiled, etc., but I'll try to work on that. ;-)


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## ToddJB (Jul 26, 2012)

> I will probably still cringe when I hear people say that wood has dried out and needs to be moisturized, hydrated, fed, oiled, etc., but I ll try to work on that. ;-)
> 
> - summerfi


Hence the ye ol saying of "Ignorance is bliss".


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## wormil (Nov 19, 2011)

You are laboring under the misconception that wood cannot be dryer than the ambient humidity, that is false. Or that it cannot continue to lose moisture over time. If that were true, most of us would be working with wood that had a 50% or higher moisture content, it would be literally dripping water as we cut it.


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## summerfi (Oct 12, 2013)

For Rick M.

Why Do Some Old Books Turn Yellow And Fall Apart?

It's the acid used in the pulp bleaching process.


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## wormil (Nov 19, 2011)

What else contains acid?

edit; acid is just hastening the process. Acid free paper will also disintegrate.


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## houblon (Nov 15, 2013)

Wood is hygroscopic and reacts to changes of humidity in the air. Wood moisture is specified in equilibrium moisture content (EMC). This is related to the air relative humidity.
At 50%RH, the EMC is about 9%. These are the numbers when you talk about wood being kiln dried to 7%, or air dried, etc. At 0% RH (Arizona?) the EMC effectively goes to 0%. But you bring this board to Florida and after a few days in 100% RH it reaches about 30% of water content.

Take a look at the link to the book. The most important chapter "Water and Wood" is available on google.

What most people call dry is the process of deterioration, mostly to UV light exposure, wind, weather, rain, snow, fungus, bacteria, you name it. BLO can certainly improve the appearance and offer some protection. But it does not change the water content (after it is dry).


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## wormil (Nov 19, 2011)

You are not saying anything I have not already said. Read my posts. I'm not actually sure what you guys are claiming … That wood does not dry out? That wood does not decay? That oil does not add mass or moisturize the wood? Someone lit on protection, no one in this thread ever claimed that oil provided protection. You can take an old dried out piece of wood, lacquer it, and you will have a lacquered dried out piece of wood that feels like it's hollow inside. Take the same wood, soak it in oil and you have added mass (weight), and given the wood some resilience. Plus, many people do not want film finishes on certain types of handles because it cause blisters. I really can't add anything else to the discussion so I guess we will agree to disagree, if you still disagree, and I wish everyone a good weekend.


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