Sweet gum, a tree genus of the Latin name Liquidambar, is found around the world. The American Sweet Gum (Liquidambar styraciflua), native to North and Central America, is one of the most common hardwoods in the Southeastern United States, where it preferably grows in humid and temperate climates. Its beautiful foliage, which is particularly colorful in the fall months, also makes it a great choice as an ornamental tree.
Sweet gum is a unique and beautiful hardwood that is abundant throughout much of the eastern United States. With its reddish-brown heartwood and cream-colored sapwood, sweet gum can make striking lumber for furniture flooring, cabinets and other wood projects. However, sweet gum is notorious for being difficult to dry properly without defects like checking, splitting, bowing, cupping, and twisting. So how long does sweet gum take to dry?
Understanding the Drying Challenges of Sweet Gum
Sweet gum poses several inherent challenges when it comes to drying
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High shrinkage – Sweet gum wood shrinks quite a bit during drying, around 15% on average. This is much higher than many other hardwoods.
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Spiral grain – The grain in sweet gum often spirals around the growth rings rather than running straight along the length of the board. This interlocked grain exacerbates splitting and twisting.
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Internal stress – Growing trees experience internal stress from things like wind, leaning, crooked limbs, etc This stress gets locked into the wood and can lead to distortion like bowing and twisting when released during drying.
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Sapwood vs heartwood – The sapwood of sweet gum tends to dry faster and move less than the heartwood. Differential drying between heartwood and sapwood in the same board leads to checking and splitting.
These factors make sweet gum more prone to defects during drying than most other hardwood species. Proper drying techniques can minimize defects, but a higher percentage of loss should be expected.
Average Drying Times for Sweet Gum
The actual drying time for sweet gum can vary substantially based on temperature, humidity, air flow, lumber thickness, and drying method. However, here are some general timeframes:
- Air drying – Approximately 6 to 12 months
- Kiln drying – 4/4 lumber: 4 to 7 days at 130°F. 5/4 lumber: 7 to 14 days.
- Dehumidification drying – 4/4 lumber: 4 to 5 weeks. 5/4 lumber: 6 to 8 weeks.
These drying times assume reasonable temperature, humidity, and airflow conditions. Significantly longer times would be required in cooler and more humid environments. Smaller boards and thinner lumber also dry faster than wider stock.
Tips for Drying Sweet Gum
Here are some tips to help minimize drying defects when working with sweet gum:
- Saw logs during the dormant season rather than when the sap is actively flowing.
- Allow logs to sit for several months after harvesting to relieve internal stresses before sawing.
- Plain saw rather than quarter saw boards to minimize differential shrinkage across growth rings.
- Sticker boards tightly at 6-8 inches spacing to prevent twisting.
- Weight stacks heavily. Use 100-150 lbs per stack foot.
- Seal ends grain to slow moisture loss.
- Dry slowly, especially during initial stages. Use temperatures of 110-130°F in kilns.
- Monitor progress frequently and use moisture meter to test wettest boards.
- Allow air drying partially to 20% moisture content before final kiln drying.
- Kiln dry to only 6-8% final moisture content. Condition boards before use.
Dealing with Drying Defects in Sweet Gum
Despite best efforts, sweet gum lumber will often still exhibit drying defects:
- Light bowing can be removed by jointing one edge straight.
- Mild cupping can be removed by ripping cups to the same side when milling.
- Moderate twisting can be handled by ripping out the worst sections.
- Severe defects usually require cutting away and relegating the lumber to secondary uses where appearance is less important.
- Checking and splitting lead to direct yield loss, but lumber can still be useful for less demanding purposes.
While sweet gum may never achieve the drying quality of woods like maple or cherry, with care it can create beautiful and usable lumber. The abundance and low cost of sweet gum makes it appealing for secondary uses where some waste is acceptable.
Drying sweet gum presents challenges due to its high shrinkage, spiral grain, internal stresses, and sapwood/heartwood differences. Allowing logs to sit before sawing, sawing during dormancy, stickering tightly, and drying slowly are the best preventative measures. Expect the process to take 4-14 weeks depending on conditions and lumber thickness. Careful processing can minimize defects, but higher waste should be planned for when drying this problematic but beautiful wood species. With reasonable expectations, sweet gum can be a rewarding species to saw and dry yourself.
The Chinese Sweet Gum
Scientifically known as Liquidambar formosana, this is a popular Sweet Gum variety regularly called Chinese Sweet Gum. The Chinese Sweet Gum is typically found in Central and Southern China, Indochina, and Taiwan. It grows mostly in the woodland of the warm temperate region.
A native tree to the eastern Mediterranean area occurring as pure stands majorly on the Greek island of Rhodes and floodplains of southwest Turkey is the Turkish Sweet Gum.
Also is known as Changs gum, is a tree native to East Asia, specifically in Southeast China, the Liquidambar Acalycina. Changs gum can also be found in the United States of America and Southern China, though not in as great numbers as in Asia.
Properly drying out Sweet Gum is a difficult task, compared to drying out other types of firewood. This can even be more difficult if you are planning to use it for furniture. It might take up to a year to season a sweet gumwood.
After splitting your wood, properly store it under a roof or cover because Sweet Gum is more likely to rot quickly and produce mold when you expose them to moisture.
Due to its interlocking grain, it is more likely to warp severely when it dries. This wouldnt only increase the hardness but also change the overlook of the furniture.
To overcome this, you might have to use a 12-inch sticker spacing to increase the time of drying. Or, you could stack the wood in a tall stack using the right sort of firewood rack to get superior air-flow and thus better seasoning times.
The moisture content of 20 percent or less is okay for burning, but the optimal moisture content for Sweet Gumwood firewood is around 12 percent. Burning it with less than 20 percent moisture content gives off better BTUs, burns longer, and makes better coals.
Although Sweet Gumwood does take much work and energy in splitting into usable sizes it does burn hot. It produces around 20.6 million BTU per cord, which is pretty decent. It also burns for a long time, although when compared with other woods, such as Oak, it has a shorter burning time.
However, how long it will burn depends on the moisture content. If you are using sweet Gumwood solely, then you should buy more woods than you would if you were using an Oak tree or you can increase the burning time by mixing it with other woods such as Hickory and Oak.
Another great thing about this firewood is that it is very easy to start a fire with it. This is due in part to high the higher than average resin content found in it.
Is Sweet Gumwood useful for anything?
Yes, it is very useful aside from being burned as firewood. Sweet Gumwood is one of the main species of trees to produce commercial hardwood in the United States. It is used for numerous purposes, which include the making of upholstered furniture, electronic cabinetry, veneer flooring and siding, plywood, crates, pallets, and much more.
Is Sweet Gum any good for firewood?
FAQ
Is Sweet Gum good for firewood?
How long does it take gum wood to dry?
Hardwoods like gum can take up to 18 months.
How long do sweet gum trees drop their balls?
- Fall and Winter: The primary period for sweetgum ball drop is from mid-fall to winter.
- Early Spring: Some balls may continue to drop in early spring.
- Softening and Breakdown: By early summer, the balls will have softened and broken down into the soil.
- Seed Release: The balls release tiny seeds inside, which are then dispersed by wind and animals.
- Decomposition: The balls naturally decompose and provide organic matter to the soil.
How often do you water a sweet gum tree?
Feel the soil—if it’s dry an inch down, it’s time for a drink.
How long does sweet gum take to dry?
The amount of time it takes sweet gum to dry depends on a variety of factors, including the thickness of the wood and the relative humidity of the environment in which it is drying. As a general rule, under ideal conditions, sweet gum will take between 6 to 12 months to dry. Thicker pieces may take 18 months or more.
Does sweet gum move after drying?
In addition to this, the gum moves considerably after drying when the RH changes. Individuals that are looking to use sweet gum wood for furniture or other wood decorations should consider steaming the wood prior to drying. This will help keep the RH stable and achieve an overall more vivid color.
Can sweet gum wood be dried?
Drying sweet gum wood can be extremely tricky. This is especially true if you are going to be using the species for furniture. If you are simply going to be burning the wood then things get a little easier. The problem with sweet gum wood is that it tends to warp when it dries, as you learned above.
Does sweet gum wood shrink?
Some individuals will even use 12-inch sticker spacing to speed up the drying time. However, you will discover that through the seasoning process the wood will probably shrink right around 15%, which is much higher when compared to other firewood. It is the interlocking grain that makes the warping and splitting so prone with sweet gum wood.
Is gum wood hard to dry?
Bottom line is that it is a tough wood to dry. It is an underappreciated resource mostly due to these issues. My limited experience is that it is reasonably stable once dried. The excessive warp with gum is why it is not a commonly used wood. You can try 12″ sticker spacing and also very fast drying.
How long do sweetgum seeds take to dry?
Place the fruit in a shallow pan. Drying will be complete typically in 5 to 7 days. The seeds will be ejected at that point, and you can gather them. Since sweetgum seeds have a chilling requirement, insert them in an envelope, and refrigerate them for 30 to 60 days. Sow the seed outdoors after all danger of frost has passed.