Frequently Asked Questions
Note: Most of the questions below are oriented toward installing butterfly patches to strengthen cracks and to repair imperfections in turned bowls. However most of these questions apply toward flat surfaces as well.
Q. What type of router works best with the system?
A. A laminate trimmer works best. It is smaller and easier to handle than most full size routers. We have had success with the Porter Cable® 7310, however any laminate trimmer or router with a manufacturer supplied adaptor for Porter Cable® bushings will work. The size of the base thru hole must be 1-3/16” with a 1-3/8” rim.
Q. Can you describe the bushing set and router bit?
A. We use the Router Inlay kit with a solid carbide downcut spiral bit from MLCS woodworking (#9177) at www.mlcswoodworking.com. The kit includes the bushing, sleeve, retainer nut, and bit. Similar sets are available from other vendors. Note that the outer bushing sleeve is removed and not used in our process.
Q. Can I use a Dremel-type rotary tool to do the routing?
A. Perhaps, if it can be setup with a base plate and the bushing set. However, we recommend the higher torque and power of a laminate trim router.
Q. Why use a downcut bit?
A. The downward shearing action of a downcut spiral bit helps to avoid tearing of the wood grain at the edges of the recess.
Q. Can you offer tips and suggestions on the routing procedure?
A. First remember that the carbide bit is fragile. If dropped, it will likely break and therefore it is always a good idea to have a spare bit on hand. Make a series of light cuts, about 1/16” or 3/32” per pass, clearing the chips along the way until the desired depth is achieved, the edges are true and the recessed surface is flat. We recommend a final depth of about 3/16” or slightly less. Note that the patch thickness is just over 3/16”, about 0.2”.
Q. On a bowl, do the patches go all of the way through the wood?
A. Not in most applications. The full strength of the patch is realized by adherence not only to the patch edges, but to the flat bottom of the recess generated with the guide template and router.
Q. At what point should the patches be installed?
A. The best time to install the patches is during the final sanding stages of the outer surface of the bowl. Starting with your dried rough bowl blank, turn to the final form and sand down to 150-240 grit. Install the patches, let the glue dry, then hand sand them to the rough contour of the bowl. Then proceed with final power sanding on the lathe.
Q. Can’t I just power sand on the lathe immediately after patch installation?
A. It is possible but if the sander bounces off the proud portion of the patch it can land on another area of the bowl as it turns on the lathe and create a slight depression. This “sander-bounce” effect is avoided by removing most of the proud portion of the patch with a sanding block prior to power sanding on the lathe.
Q. Are there patches that don’t require removing the corner points for the recess?
A. Yes, we also supply “rounded-corner” butterfly patches. Just note this on your order or call to confirm. Click here for more information on rounded corner patches.
Q. What is the easiest way to remove the corner points from the recess?
A. A ¼” chisel with a low angle grind works well. In addition, a slight “V” angle in the cutting edge facilitates a perpendicular cut while holding the chisel at an angle to the recess surface.
Q. What type of glue should I use?
A. We recommend using a quality aliphatic wood glue such as one of Titebond products. CA glue can be used , but although it can be dried instantly with accelerator, it tends to be more brittle and may not hold up as well in the long run.
Q. How can I avoid glue marks or glue stain?
A. After routing the recess, apply a very light coat of lacquer sanding sealer to the surface of the bowl around the recess. Then apply the glue and seat the patch. The sealer will help to prevent the glue from penetrating the bowl fibers and staining the wood.
Q. Can I send you some wood and have patches custom cut from it?
A. Yes. Please call to make arrangements (808) 982-9987.
Q. I need the whole system including the machinery, hardware, template and patches. Can you just send it all?
A. Please call us and we will try our best to help you out.