Sawdust on the Floor

The last time we were here we worked to mill the rails, stiles and the intermediate stiles for the sides of the bedroom nightstands.  After milling the flat panels that will reside in these panels it’s time to assemble them.  These are simply pieces of cherry that I planed down to 1/4″ thickness.  In an effort to save on the wood this project consumed, I resawed some 4/4 stock down to about 3/8″ on my bandsaw. From there the stock was run through the thickness planer to get it to its final 1/4″ thickness. 

Resawing on a bandsaw is a simple task that can drive any woodworker crazy.  The concept is easy. With the stock standing on one edge, run the stock through the blade of the band saw, splitting the board down it length.  A 4/4 piece of stock can be resawed into two 3/8″ thick pieces.  The reality is a little more complicated.  Most woodworkers will have several different blades for their bandsaw, just as you would for your tablesaw.  Bandsaw blades are sold by length, width and teeth per inch.  The length of the blade is set by the manufacturer of your bandsaw, and can not normally be altered. The width of the blade in fractions of inches, determines how flexible the blade is.  A 1/4″ wide blade will allow you to turn a very tight radius, great for intricate work but lousy for resawing. A 1/2″ or larger will allow you to do resawing, but don’t try turning a very sharp corner with this blade.  The number of teeth per inch (TPI) determines how smooth of a cut you can get. I have equipped my bandsaw with a 1/2″ 14 TPI blade, which should be good for resawing.

Having the correct blade is only a part of equation.  When resawing any stock, bandsaw blades have a tendency to wander either left or right.  Sometimes this is caused by the grain pattern in the wood, sometimes by the tension of the blade, or the build up of sawdust in the teeth of the blade.  There really isn’t much you can do about the grain, but setting the correct tension and the build up of sawdust are things we can control. Adjusting the tension of the blade is a little bit of black magic. Every woodworker that I have talked to about the correct tension has a slightly different method of making the adjustment. The idea in adjusting the tension is to create a blade tension that is high enough to keep the blade running true, yet not so tight that you deform the blade.  So what is the correct setting?  Well, my father in law taught me to listen to the blade.  If you tap the side of the blade with your finger, you should here a clear tone in the blade.  Now I’m sure that some other woodworkers have a better method, and I am always willing to listen to other ideas, but for now this is the method I use.

Regarding build up of sawdust, the design of the blade can help with that. Better bandsaw blades use what is known as Skip tooth or skip design, where every other tooth is pointed in the opposite direction.  There is a trade off with this design, mainly a wider kerf, but wider kerf will help eliminate sawdust build up in the cut, which helps you achieve better resawing capabilities. Some bandsaw blades are now being coated with silicon to aid in movement of the blade through the wood. 

My bandsaw is equipped with a Kreg Bandsaw fence, which is really great for everything but resawing.  As you resaw stock, you normally will be watching the po sition of the blade, to your desired cut line. If the blade starts wandering to right, you need to be able to move the back end of the stock to compensate for the blade movement. If you had a conventional rip fence in place, you don’t have the ability to adjust the tail end of the stock.

The best method is to have some kind of pivot point that would allow you adjust the tail end of the stock, while at the same time supporting the stock.  Thankfully, the folks at Kreg, offer an inexpensive Resaw Fence that easily attaches to the rip fence.  You want to have the apex of the resaw fence to be in line with the blade, and positioned just forward of the leading edge of the blade.  Both adjustments are easily made with a rip fence and resaw fence setup like this.  However if your band saw does not allow you to attach a resaw fence to its rip fence, then you can make a separate resaw fence.  This is a good use for that scrap lumber hiding in the corners of your shop.  The only difficulty in a shop made resaw fence is how you would position it.

As a Christmas gift last year my wife gave me a great tool that easily solves that issue, a Magswitch magnet . This ingenious product allows you to make your own jigs such as the resaw fence and then easily position then where you want them. To lock your custom fence into place all you have to do is turn the know on top of the Magswitch, which energizes an internal magnet.  To remove your jig, simply turn the switch to the opposite position, which releases the magnet. 

So now you have the blade set to the proper tension, the resaw fence in position, only one more thing to adjust or check.  There are two blade guides on your bandsaw, one mounted directly under the table and the other one is mounted at the top of work area.  The upper one’s position is adjustable up and down depending on the thickness of the stock you are cutting. Within each blade guide assembly are two guide blocks, these ride on each side of the blade. 

These guide blocks need to be adjusted so that they are always in contact with the sides of the blade.  There are several different materials that these guide blocks are made from.  The latest trend is ceramic guide blocks.  Another popular choice is to use graphite guide blocks.  Which ever material you use, these need to be adjusted before you start cutting. 

A couple final words about resawing.  Don’t rush the work, let the blade do the work.  Excessive forward pressure on the tail end of the stock will cause the blade to wander. Also don’t try to do all of your resawing at one setting.  As you work the wood through the blade, the blade will heat up.  This heat causes the blade to stretch, which causes the blade to loose tension.  And that causes the blade to wander.  If you tighten the blades tension while it is hot, the tension maybe too tight when the blade cools off. 

Ok, so now that we’re all set up, let’s resaw our 4/4 stock to 3/8″ thickness.  Once you have the stock all resawed then you’ll want to take it to surface planer to take it down to the final thickness of 1/4″.  I always resaw to a thicker dimension then my final thickness. The act of resawing,  even when things are set up correctly and you do everything correctly, can result in a surface that undulates up and down slightly.  Also bandsaw resaw blades do not produce a very smooth cut, there will be a lot of saw marks.  So if my resawed thickness is on the proud side of my desired thickness, I still have material left that I can plane off.  If I attempted to resaw to the final thickness, I wouldn’t have wood left to make corrections with. 

Once the stock is milled and sanded, it’s off to the table saw to be sized for insertion into the slots of the cope and stick rails and stiles we made yesterday for this nightstand.  I think that enough for now, how about coming back later for the next part of this project.