If you wish to panel join boards for a table or any sort of glue up, you'll need to joint the edges.
The lumber from the store is most often bowed, bent or crooked.
If you have a table saw in your shop, you can joint the wood using a simple jig you can make in minutes.
In this guide I show you how to correct bows/bends in wood and also how to square the edges on a table saw.
All it takes is a plank of plywood and a couple of clamps.
Things You'll Need
- Table Saw with a Riving knife.
- Quick Grip Clamps
- Plywood or MDF
Jointing with Table Saw to Remove Bow/Bend on one Side (without jointer)
To remove bow/bend on one side, we'll make a simple edge jointer jig with plywood.
Take a piece of plywood.
Both MDF and plywood comes with factory edges which are always perpendicular and straight to each other.
Set the distance between the rip fence and the table saw blade at 4 inches using tape.
Now cut the plywood slowly and carefully.
Adjust the fence by 1/8th of an inch (thickness of the saw blade) towards the table saw blade.
Set the blade height accordingly and begin cutting the plywood again.
Cut only 2/3rds of the total length of the plywood
Once the plywood is cut, take the piece, flip it over, and align it with the riving knife.
Keep the rip fence fixed at all times.
The plywood piece will be flush with the blade up to the part which projects by 1/8th of an inch.
That part will be aligned with the riving knife/blade.
Ensure the plywood is aligned with the riving knife and that it is in full contact with the table saw top surface.
Once the wood is fit in between the rip fence and the blade, secure it with two quick grip clamps.
With that, your edge jointer jig is complete and ready to use.
Take any piece of wood with a bow defect on its edge.
Set the wood on top of the plywood and against the rip fence to assess the bend you are dealing with.
Once the bend or bow of the wood is apparent, set it down right next to the clamped plywood.
Set the height of the blade to match the thickness of the wood you plan to edge joint.
Make sure the bend side is on the side of the blade.
With the wood piece flush against the plywood jig, turn on the saw.
Then push the wood into the blade.
The bend of the wood might be corrected after a single pass, but sometimes, if the bend is severe, you might have to do multiple passes.
Jointing with Table Saw to Square Both Sides of a Wood Piece (without jointer)
Although the table saw can be used as a jointer to make the faces of a wood piece flat, it can also be used to square an edge to have perfectly perpendicular faces.
You can use the same jig to do this.
For adjacent faces to be perpendicular, the table saw blade must be square with the tabletop.
Keep the speed square next to the blade to check if the blade truly is perpendicular to the tabletop.
When using the table saw as a jointer, the only limitation lies in the fact that the size of wood you wish to square is limited by the size of the plywood and the height of the blade.
To square a piece of wood using the table saw (as a jointer),
Take a piece of wood with width and thickness less than the height of the table saw blade.
Set it down right next to the clamped plywood jig.
Set the height of the blade to match the thickness of the wood you plan to edge join.
Make sure the bent face is on the side near the blade.
From the end of the table, begin pushing the wood into the blade.
The bend in the wood might be corrected after a single pass, but sometimes, if the bend is severe, you might have to do multiple passes.
Once the bow is corrected, rotate the wood to its adjacent side and keep the newly jointed face flush against the table saw's base.
Set the height of the blade to cut the next edge.
Run the blade and slowly begin feeding the wood piece into the saw with the piece pressed against the plywood board.
The wood with the flat edge now acts as the base, and both the table and blade are perpendicular to each other.
This will result in the new face and its adjacent face being perfectly square to each other.
To square the rest of the edges, use the newly jointed side as the base and repeat this method.
Tips for Accuracy
- while using the table saw as a jointer make sure the wood is free from other defects like cupping and knots as they will not be fixed or removed. This method only removes bow from along the length of the wood.
- The alignment of the blade and riving knife is critical to is method so check how aligned the both are.
- Rip fence always stay parallel to the balde and hence will always yield straight edges.
- Use a sharp blade with an appropriate number of teeth. More teeth on the saw blade means better cut but takes longer to cut and large teeth means quick but rough cuts.
- If the length of the edge that is against the fence is shorter than the distance between the fence and the blade, Then dont cut it using the rip fence.
- Check the saw blade for missing teeth and splits on a regular basis.
Tips for Safety
- When using a table saw, You should not use gloves. In addition, remove any rings, bracelets, or other clothing that might become entangled in the table saw or material.
- When cutting, stand to one side of the saw blade; do not allow anyone to stand directly in front of the saw blade while it is running.
- Never remove or hold down a piece of wood by reaching across the saw blade.
- Never lift the saw blade above the material being cut by more than 1/4th inches.
- Don't stay too close to the running blade to avoid injury in case of kickback. Kickback is extremely dangerous and must be prevented at all costs.
- Before leaving the saw work area, lower the blade below the tabletop.
Frequently Asked Question (FAQ)
What does a jointer do to wood?
The face of a warped, twisted, or bowed board is flattened with a jointer. The jointer can be used to straighten and square edges after your boards have been flattened. Jointers are of many types and the table saw can be used as an edge jointer.
What are the three main types of wood warp?
Cup, bow, and crook are the three forms of warps.
Cup: a warp across the width of the face, in which the edges are higher or lower than the center of the wood.
bow: a warp running the length of the wood's face.
Crook: a warp along the length of the edge of the wood.
What Causes Wood to Warp?
Wood species, grain orientation, sunshine, uneven finishing, ventilation, and temperature are all factors that might cause warping. It takes longer for thicker wood to absorb and release moisture. As a result, quartersawn lumber shrinks and expands at half the rate of flatsawn lumber.