When turning a bowl, I frequently have tearout on the inside end grain. I use a 3/8" bowl gouge, which I try to keep sharp, plus a 1/2" roundnose scraper. Obviously, I need suggestions on preventing the tearout or how to best get rid of it if it does happen.

Tearout on the inside end grain is a very common problem and difficult to prevent. Tearout varies greatly depending on the wood being turned. In general, soft-textured woods, particularly those which are open grained, are more prone to tearout than dense, hard, close-grained woods. Several things can be done to reduce or eliminate tearout. Sharp tools are critical if a relatively tearout-free surface is desired. A freshly sharpened tool should be used to make the final cut because it will produce a cleaner, smoother cut which reduces tearout.

Gouge manipulation will also reduce tearout. Approach the surface of the bowl so the cutting takes place with the flute of the gouge in a position from 1 to 3 o’clock. In this position, the shavings are produced by a shearing cut which will reduce tearout. Use a light cut because the objective is to improve the surface, not remove a lot of wood to shape the bowl. The heavier the cut, the more likely tearout will be increased. Light, fine, shearing cuts with a sharp tool will prevent and remove tearout.

Torn grain on the inside of the bowl can frequently be reduced or eliminated with proper application of a freshly sharpened, heavy roundnose scraper. I recommend a 3/8" thick x 1" to 1-1/2" wide heavy scraper. The scraper has enough mass to dampen vibration, and the large radius allows for better control while making light blending cuts and removing any small irregularities from the interior surface.

Work in the “trailing position.” That is, the scraper should be cutting below the center of the bowl with the handle above the center of the bowl. With the lathe off, adjust the tool rest until the “trailing position” is achieved, then you are ready to make the cut.

The scraper needs to be freshly sharpened with a “burr” on the top edge. To check this, run your thumb across the top of the cutting area of the scraper. You should feel the burr edge. If the surface is smooth and you can’t feel the burr, go back to the grinder to re-sharpen the chisel and establish a new burr edge.

If the approach still leaves some tearout, you can spot sand the area, using a power sander with the lathe stopped. Sand through the various grits until you are satisfied with the surface quality, then start the lathe and power sand the interior of the bowl, using the usual range of grits. This should blend in any slight depression left from the spot sanding and produce a good quality surface.

With my midi lathe, I cannot seem to get on-axis alignment between the headstock and tailstock. The main problem seems to be with the left/right alignment and appears to be due to slop in either the bed of the lathe or the tailstock bottom. For example, wobble is plainly visible while trying to drill with a Jacobs chuck in the tailstock Morse taper. This seems to be common in other popular midi lathes that I have looked at in showrooms. I’d like to attempt making a peppermill, but using a larger drill like a Forstner bit, would be out of the question. Is there any trick or technique to finding and preserving alignment other than buying a more expensive machine?

This is a fairly common problem with many lathes, not just the midi lathes. This misalignment can be caused by several things. One of the most common is dirt or grime buildup inside the Morse taper area of the head or tailstock. Put some solvent such as mineral spirits or lacquer thinner on a clean rag and carefully wipe out the inside of the Morse taper. This area should be shiny and clean. Remove the tailstock from the lathe and carefully clean any grime or grease and dirt from the base of the tailstock. Wipe the lathe bed clean, and if necessary, remove any rust with 400-grit wet or dry abrasive paper. Clean with a dry cloth, replace the tailstock, and tighten loosely. Wiggle the tailstock to check for a secure fit between the bed ways. The tailstock should slide easily but not be sloppy between the ways.

Place a new drive center or 60° cone center in the headstock and tailstock. They should fit securely into the Morse taper in the head and tailstock. Now, slide the tailstock up to within an inch or two from the headstock. Tighten the tailstock to the bed so it is secure, and advance the quill until the points meet. They should match closely. Also, this alignment will suffice for most requirements. If they don’t line up, loosen the tailstock and slide a piece of brass shim stock under one side of the tailstock. This is a trial-and-error process and may require inserting the shim stock in various places until the alignment is acceptable. Brass shim stock is available at machine shop suppliers and comes in various thicknesses. A good thickness with which to start would be 0.003. Once the alignment is acceptable, mark the position and put a little epoxy adhesive on the shim stock, insert the shim under the tailstock, and clamp the tailstock in position. The epoxy should sit overnight. This procedure will usually solve alignment problems.

In a previous “Ask Dale” column, you stated that a safe speed to turn bowls is “D X RPM should equal between 6000 to 9000 RPM.” My lathe motor turns at 1725 RPM. I have a set of step-down pulleys with the following diameters: 3-1/2", 3", 2-1/4", and 1-1/2". Is it possible to calculate the lathe speed with this information?

I prefer to power sand my bowls on the lathe. However, I am having problems with the sanding discs separating from the backing while sanding. I believe that this is a problem with heat buildup. What do you recommend as the best lathe RPM for power sanding to prevent this from happening?