Wooden structures are a thing of beauty in their natural state and even better when enhanced using different finishes. Other than beauty, wood posses no threat to the environment, are renewable and comes with high load-bearing capacity despite its light weight. However, when left unprotected, it can undergo changes like warping. Building with warped wood can cause problems, so you should know how to fix warped wood to avoid complications.
There are different methods you can apply to fix a warped wood. These methods include the use of iron, sunlight, heat, pressure or nylon.
In the tried and tested iron method, for example, you will be able to bubbles and kinks out of your wooden board. This method is effective and simple; all you need is a towel, a small bucket of water, an iron, and the warped piece of wood you are looking to fix.
Ready your working table; the table must not be in a compromising position like getting affected by water or heat. Put your wood together with the bucket of water on the table.
Dip the towel in the water, remove it when it’s wet, then ring it out so it is dump and not wet. Cover your warped wood using the damp towel, then plug in your steam iron.
Once the iron is ready go over the warped area of the wood with the iron for approximately five to ten minutes until you recover the shape that your would like. Remove the cover and observe how it is drying.
This post offers so much information regarding different aspects of wood warping and how you can go about correcting your warped wooden structures. Keep reading for more information on the topic.
What Is Warped Wood?
Warped wood is a wood that has stopped being flat and bending or curving towards a specific direction due to different environmental elements. Based on the condition, wood may warp by twisting, swelling, or shrinking.
It means that the choice of wood can affect functionality in areas with constant temperature fluctuation, like in doorways or around window frames.
Some wood species are less likely to warp than others because of their grain pattern and thickness. Redwood, for example, has a straight grain pattern and natural chemicals that block moisture.
It remains stable or endures minimal warping when its moisture content reaches equilibrium with the surrounding air. Other wood species that are resistant to warping include cedar and fir.
Wood warping concerns professionals and DIYers who engage in woodworking projects. Though it’s challenging to prevent wood warping, you can minimize its occurrence by taking precautions, which I will address later in this guide.
What Makes Wood to Warp?
Many factors contribute to wood warping, but the leading cause is uneven moisture distribution in the wood cells. Wood fibers shrink when drying, so different warping patterns can develop depending on the wood part that dries more quickly.
Here are some of the most common factors that promotes warping of wood:
Wood’s Thickness, Species, and Grain Orientation
Wood thickness can affect how quickly your wood warps and acclimates. Some wood species, such as cedar, are thick and have vertical grains meaning they are less likely to warp. They take longer to absorb or lose moisture, especially if coated.
Besides wood species, grain orientation also dramatically impacts the wood’s stability. For example, flat-grained woods are more likely to warp than vertical-grained wood because they are light and dry unevenly.
Temperature is another element that encourages wood warping. Constant temperature changes can cause wood warping because of the frequent expansions and contractions.
High temperature, for example, causes thermal expansion in wood and can cause swelling or warping. Low temperature causes shrinkage, so your wood dries irregularly in certain spots, causing warping.
Usually, woodworkers stain or finish wood to protect them from the elements. However, improperly finished wood causes the exposed sides to expand and contract while the finished sides remain protected.
This causes warping because the unevenly finished areas dry out much slower than the protected areas.
Can You Unwarp Warped Woods?
Building with warped woods can cause installation issues, but you can avoid that by using different techniques to unwarp your wood. For instance, you can address longitudinal warping by restoring moisture to the wood cells, then straighten the warped wood and let it dry evenly.
You can fix minor warping using a damp rag and a steam iron. However, it is challenging to repair warped woods, primarily if you’re not aware of the causes of wood warping.
This means you should first understand the distortion you’re fixing. If the warped wood piece on your tabletop is hugely affected, you must replace it with a new piece.
Whichever method you choose to unwarp your wood, exercise patience. Don’t rush the process, as you will likely split or crack your board beyond repair.
How Do You Fix a Water Warped Wood Table?
A wooden table can absorb moisture on its surface, causing it to swell or warp with time. The swollen wood can compromise your table’s appearance, making it look old and scuffed up.
Luckily, you can address this problem with a few basic supplies and instructions, which I have discussed in the guide below:
Method 1: Using an Iron
Here are the steps involved when using the iron method to unwarp your wood:
- Step 1: Wrap the Table In Moistened Cloth or Towel
Dampen one or two clothes and squeeze out the excess water, so the clothes are not dripping wet. Wrap the moistened cloth around your water warped wood table and ensure it is large enough to cover the whole table. It’s also good to use clothes that can tolerate the heat of an iron.
- Step 2: Heat Your Steam Iron to the Highest Setting
Switch on the steam iron, set it to the highest temperature level, and allow it to heat up for about two to five minutes. Note that lower temperatures will not fix the warped wood.
Reminder: Ensure that your iron is meant to work with steam. You should not use a dry iron.
- Step 3: Press the Steam Iron Over the Warped Areas
Use your dominant hand to press down the iron on one end of the warped wood and slowly slide it over the whole surface. Apply even pressure and hold the iron on the warped spots for 5 to 10 seconds before moving to the next area.
Tip: Don’t leave your steam iron unattended at any point because it can burn the towel and the table below it.
Step 4: Repeat Ironing the Warped Piece
Pull back and check the wood progress. If the issue has been resolved, stop here. But if some warping persists, repeat all the steps until the warp disappears. Switch off the iron after unwarping the wood. Then unwrap the table and let it dry thoroughly before use.
Method 2: Using Sunlight
The steps involved in this methods are:
- Step 1: Wrap the Wood In Damp Towels or Clothes
Remember to use towels that can retain moisture. Run two or three towels underwater until they are drenched. Then wrap them around your warped wood, ensuring they cover all the surface.
- Step 2: Place the Warped Piece in Direct Sunlight
Place the warped wood piece in a warm area exposed to direct sunlight. Ensure the inwardly bent side faces downwards, whereas the outwardly bent side faces upwards. It’s advisable to place a plastic tarp under the wood to prevent water from dampening the surrounding area.
If you don’t have plastic sheeting, place the wood piece above a rigid surface like a deck or driveway.
Note: This technique only works best during warm and dry weather. Cold, cloudy, and wet conditions are not recommended.
- Step 3: Spray the Wrapped Surface With Water
Depending on the warping condition, you may need to keep the warped wood in direct sunlight for two to four days. Spray the towels with water to maintain a moist surface during this waiting period.
The sunlight should heat the wet towels and encourage the wood to absorb moisture.
As the wood absorbs water, it should start to warp back to its initial state.
- Step 4: Dry Until the Warping Disappears
The unwarping process can last several days, depending on the extent of the damage. Check the progress regularly. If the wood is unwarped, remove the towels and let the wood dry. But If you don’t notice any difference after 2 to 3 days, try a different method to see if it works.
Tip: You should return the wood inside the house at night and store it in a warm place.
Method 3: Using Pressure
If you choose to go the pressure way, here are the steps involved:
Step 1: Cover Warped Surface With Wet Paper Towels
Dampen several paper towel sheets and arrange them over the inwardly curved wood’s surface. The paper towels must be large enough to cover a broad section of the wood.
Note: You can also use standard paper or a thin steaming towel for this step.
Step 2: Wrap Plastic Over the Standard Paper or Paper Towel
Wrap all sides of the warped wood with plastic wrap and ensure it’s tight and secure. This plastic wrap will slow down the evaporation process to keep the wood and paper towels moist for extended periods.
- Step 3: Clamp the Warped Wood Piece
Clamp the wood piece and tighten the clamp slightly to straighten out the warped area. Be careful while tightening the clamp because the wood might break rather than stretch out if you over-tighten it.
Step 4: Let the Wood Stay Clamped for One Week.
Keep your wood wrapped and clamped for 6 to 7 days. The storage area should be relatively warm to fasten the process. You can make the clamped wood warmer by placing it in direct sunlight, below a heat lamp, beneath your electric blanket, or above a warming mat.
Ensure you keep wood on the heat for five to eight hours per day if you choose these methods.
Note: Examine the progress regularly and remove the clamps if you notice any damage to the wood.
- Step 5: Discard the Wrappings
Remove the wrappings after one week and take off the paper towels and the plastic wrap. If the warp has disappeared, your wood piece is ready for use. If not, return it to its clamped position and let it air dry for one more week.
Tip: Don’t store the wood below 25 degrees Celsius. Also, you will need to examine the progress frequently to see if there is any change.
If this method fails, your wood is severely warped and can not resume its shape.
Tip: You can also use a jack plane to fix warped wood, but it involves scraping off the raised spots to blend with the surrounding surface. If the board’s center is lower than the edges, you will want to plane across the width. Move the jack plane back and forth until the uneven areas correspond with the entire surface.
How Do You Fix a Warped Farmhouse Table?
Farmhouse tables are well-built and sturdy enough to withstand daily use. However, they can warp if exposed to excessive moisture or heat. Find out how to fix your warped farmhouse table using the following steps.
- Step One: Uninstall the table legs using a screwdriver or disconnect the glue blond with a wood chisel and a hammer. Strip off the finish on your table with a harsh wood stripper and rinse the table to wipe off the residue.
- Step Two: Place a straight board above the table and slide it across the warps while examining the point where the board’s edge contacts the table’s surface. Use a pencil to mark the high points and low points.
- Step Three: Position your sander on the tabletop, grabbing it with both hands. The dominant hand should be on the front knob while the free hand holds the pistol-like grip. Begin moving the sander back and forth on the warped farmhouse table parallel to the wood grain.
Move 6″ forward and 5″ back in an oval pattern and avoid leaving the sander in one spot.
- Step Four: Sand down all the pencil-marked high points on the tabletop, then move to the low-marked points until the surface displays a consistent bare wood sanded look. Turn off the electric sander and proceed to step 5.
- Step Five: Slide the straight board again over the tabletop. Mark the high and low areas with a pencil and repeat sanding the surface as many times as possible until the table remains flat.
- Step Six: Lastly, sand the tabletop using an oscillating tool with 120 grit sandpaper connected to a hand block. Sand the surface moving 4 inches forward and 3 inches back until its smooth without any imperfections.
Types Of Wood Warps
Wood warps differently depending on the species and the grain pattern. Those with vertical grain orientation, such as redwood, are less affected by bending, while the flat-grained species are drastically affected. This guide offers insight into the various types of wood warps so you can decide on the effective remedy for each.
- Bow: A bow is a form of warp where the wood changes from flatness along the broad face. This type of wood warp has upturned ends.
- Kink: Wood warps along the width and often produces a pronounced kink due to knots. A quick fix to this warp is using a steam iron over the warped areas.
- Crook: A crook is a longitudinal warp, but it occurs on the narrow face or the wood’s edge. It makes the wood resemble a curved sword.
- Cupping: Cupping is a form of warp where the wood warps across the board’s width and causes the adjacent edges to face upwards, giving the boards a bowl shape.
- Twist/wind: This is a warping where the four corners of the board rotate slightly but in the opposite orientation. It creates a twizzler effect.
How to Prevent Wood From Warping?
Wood warping can affect the practical and aesthetic value of wood. It is an inevitable issue for woodworkers, flooring installers, and other professionals who manufacture wood and it’s products.
In flooring wood, warping occurs after installation, making the floor uneven. In carpentry, wood warping compromises the structural integrity causing the wood joists not to align correctly.
The most effective way to prevent the wood from warping is to regulate the moisture content in wood at the installation site and manufacturing site. Check out the following measures.
Woodgrain and Sawing Patterns
Understanding the sawing techniques can help prevent wood warping. For example, a wood cut parallel to the growth ring warps worse than one cut perpendicular to the growth rings. Also, a flat-sawn board is more stable and won’t be affected by bending since both edges are halfway from the tree’s core.
It’s also advisable not to cut your wood at an angle to the grain to prevent crooking.
Moisture Testing In the Kiln
Examining the moisture distribution between the shell and core wood layers ensures high-quality timber. If the moisture amount in the shell and core varies excessively, there is a problem in the drying process that requires correcting.
For example, if the wood’s shell is dry while the core is wet, the kiln is working at a high temperature. This can lead to wood warping because the shell dries out quicker than the core. Lumber manufacturers can address this issue by using an in-kiln monitoring system and a wood moisture meter.
Testing the Humidity
Another effective way of keeping wood warpage at bay is by regulating the humidity conditions at the storage site. You can achieve this using a thermo-hygrometer to gauge the relative humidity in your storage facility. Just hold the thermo-hygrometer in the air and engage the button.
To achieve the best outcomes, its essential to:
Avoid Restricted Airflow Areas
The relative humidity testing should be conducted in an open area where the air accurately represents the current conditions in the storage facility. Therefore, don’t take readings in corners where there is limited airflow.
Examine the Relative Humidity Meter’s Sensor Element
The relative humidity meter’s sensor can get faulty with time due to long-term exposure to air. This causes the meter to deliver false readings. Therefore, check the sensor element to ensure it’s in good shape.
Take Multiple Readings
Even the best quality thermo-hygrometers can offer false readings that cause a difference of +/-2 between the actual RH and the highlighted RH (Relative Humidity). So ensure you take multiple readings for a given area, then sum up the results.
Tip: You can check warped woods by placing a wood piece on a flat surface. Examine the wood along the edge to confirm if it’s aligned. If one end of the board appears raised than the rest of the wood, it is warped. Repeat this procedure on all faces of the board to determine if they have a uniform shape.
Here’s a Video On Preventing Warping:
Wood warping has adverse effects on timber, and wooden structures as a whole. As woodworkers, we have to live with warping considering that sometimes it is beyond our control.
As much as warping occurs to wooden structures, it is not the end and does not spell the end of the road for your structures. There are a number of thing you can do to curb and or rectify warping of wood. This takes us back to our topic of discussion…
How to Fix Warped Wood
As you might have read from this post initially, you can fix your warped wood using methods such as ironing, the use of sunlight, and pressure. Following the right procedure of whichever method you have chosen will results to unwarped wood. In most of these methods, patience plays a key role in ensuring that you get the best fix possible.
Even as I come to the conclusion of this post, I hope that you have acquired the right information to help you rectify warping issues on your wooden structures.
Do you have a question, opinion or suggestion that you would like to share with me? I hope so, please don’t hesitate to reach to me through the comment section below.