4 Common Problems When Cutting Boards

It’s every sawyers dream for everything to go just right whenever they’re cutting boards at the mill. Unfortunately, however, this can’t be the case every time. Mishaps are bound to happen, and when they do, productivity can quickly go down the tubes. Sometimes hours are wasted, and worse yet, the whole day might be shot. Oftentimes, experience is the best teacher, and most sawyers are quick to learn from their mistakes. But sometimes, things happen at no fault of their own.

Thankfully, there are some things that sawyers can do to have the best shot at having a great day at the mill. One of which is to be aware of the problems, so that they can be prevented. To help you out, here are four common problems, and solutions, when cutting boards.

1. Boards Are Wavy and Not Straight

Straight boards. That’s what every sawmill operator hopes to achieve at the mill. There is little that is more frustrating than cutting a board and it ends up being wavy. Why in the world does this happen? One of the primary reasons for wavy boards is that the sawmill blade is not properly set. If the blade is set more to one side, it either dips or climbs into the cut, and then flexes back the other direction, thus causing a wavy board.

In some instances, even though the blade is properly set, the boards still come out wavy. Most likely, the blade is still the culprit. The blades might simply be too dull. Or, the hook angle of the teeth on the blade are not correct for the kind of wood that’s being cut. The hook angle is the number of degrees that the tooth face leans forward of 90 degrees. This article from Timber Line Magazine, discusses the correct hook angles for certain blades and different kinds of wood.

Wavy boards might also be the result of the roller guides being out of alignment, the tension on the blade needing to be adjusted, or the feed rate is too high.

2. Cuts Are Not Very Smooth

Besides wavy boards, another frustration sawyers sometimes encounter are cuts that have rough lines or ripples. In other words, the cuts are not very smooth. Not using the right blade can significantly affect the quality of cut. Carbide-tipped blades are highly recommended for smooth cuts. Along with producing smooth cuts, carbide-tipped blades also have a longer lifespan, have high heat resistance, and experience less vibration. Sawblades with a high teeth count and triple-chip grind (TCG) can also help to produce smoother cuts.

The feed rate can also affect the quality of cut. While a higher feed rate used in combination with a high rotation speed (RPM) produces a smoother cut, going too fast can cause overheating. Using a consistent and slow feed rate can also produce a smooth cut, but going too slowly can reduce productivity. The key is to find the perfect balance between the feed rate and RPMs. When this balance is achieved, boards are likely to come out smooth.

3. Excess Pitch Buildup

Trees contain resin, which is a fluid that gets secreted when its bark is injured. Trees in the Pinaceae family, such as pines, cedars, firs, spruce contain resin. This resin is also known as pitch. Pitch buildup occurs when resin from the wood builds up on the blade, causing it to gum up. Pitch buildup poses a number of problems, such as:

• Causes the blades to become dull more quickly.

• Produces an uneven or wavy cut.

• Creates increased friction, which leads to warped or broken blades.

• Causes more downtime, which reduces efficiency.

The resin can also get transferred to the wood, which can make it sticky and difficult to work with. Resin can also change the appearance of the wood.

There are many proven ways to combat pitch buildup. Using the right blade tooth for the material, using sharp blades every time, and using the correct blade tension are all ways to prevent pitch buildup. Adequate lubrication also helps prevent this problem. Some sawyers prefer to use commercial pitch cleaners, while others use diesel fuel or liquid soap.

4. Blade Breakage

One of the most common reasons a blade breaks is that it’s been used for too long. According to some manufacturers, a sawmill blade should be replaced with a sharpened one every 2 hours. However, some sawyers replace their blade after cutting a certain amount of board feet (bf). It’s common to change out the blade at 1,000 bf. Others go longer than that. But there are other ways to know the blade needs to be replaced:

• The blade looks dull or has missing teeth.

• The blade is no longer cutting smoothly.

• It takes longer to cut through the same type of wood.

• The sawdust is very fine.

• There are unusual noises or vibrations.

Other things that can cause blade breakage include the blade guide rollers are worn out or incorrectly aligned, the blade wheels are not positioned correctly, the blade feed is too aggressive, or the blade was not sharpened or set correctly.

To prevent the blade from breaking, it’s important to inspect the saw blade before each use. Other preventative measures for blade breakage include:

• Ensure correct blade tension.

• Lubricate the blade.

• Maintain the blade guides.

• Sharpen on a regular basis.

• Prevent pitch buildup.

• Use the right blade speed.

• Know when to replace the blade.

Have you encountered any of the above problems when running your mill? If so, how did you resolve your issue? What other kinds of problems have you encountered? Leave a comment or head to our Facebook page to let us know! If you are having problems cutting boards and aren’t sure what to do, message us and we’d be glad to try and help.