Andre Martel resides in Saint-Cesaire, Quebec, Canada. He has taught woodturning for nearly 20 years. His specialty is end-grain turning with green wood. After extensive use of a personal version of the super flute Side Ground bowl gouges, ring tools and standard hook tools, Andre began dreaming of a tool with a versatile cutting edge that would be more effective in end-grain turning. He wanted to turn large translucent pieces primarily lampshades. He developed the MHT (Martel Hook Tool) and had it patented and produced. After developing his tool he was invited to a major woodworking congress in Grenoble, France as the international demonstrator. While there he met Jean Francois Escoulen who asked Andre to give workshops to the French professional woodturners. He did this and trained Escoulen, Mailland, Nancey, Bidou, Guillou and sixty other professionals as well as many amateurs. For Andre this was an incredible human adventure and the beginning of many friendships. Presently he offers semi-private and group classes in his own studio besides giving workshops and seminars abroad.

With end-grain turning, approach is completely opposite than in side-grain bowl turning. Andre discussed turning a green goblet with a natural edge and a hollowed trumpet-shaped base. It is turned thin so that most of the wood has been removed. Therefore the remaining thin wall can shrink without splitting. Shrinkage varies in 3 directions, linear (1-3%), radial (3-7%) and tangential (7-15%). This explains why a bowl becomes oval when drying (due mainly to tangential shrinkage). When turning a goblet, Andre hollows the foot or base to prevent it from splitting.

The piece (pear wood) was placed between centers. A tenon was turned on the top part of the piece (tail stock). The piece was removed and the tenon placed in the chuck. The outside of the piece was then roughed with the Side Ground elliptical shaped fluted Bowl Gouge with the tail stock in wood. A shear cut was used.

Then he removed the tail stock and the bottom of the goblet was first hollowed with the SGBG. The MHT was then used to deepen the hollowing and further refine it. The angle of presentation of the MHT is very critical as is the axial movement of the tool. This axial movement is in addition to the lateral movements. A step was left over the final foot, in order to firmly grip without breaking the final foot of the completed goblet. (At this point the interior of the goblet base could be sanded.)

The piece was removed and reversed in the number 2 jaws. The top of the goblet was then hollowed using the upper cut with the SGB Gouge. Again, the small MHT was used to give a final cut to the goblet interior. (The MHT is rotated in order to keep bevel rubbing, as the cut progresses up from the bottom. Lathe speed was about 700 rpm. (When achieving a shear cut lathe speed is not as important as it would be with shear scraping, as even low rev. will leave a clean surface. Sharpening of the MHT is done using a diamond burr (150 grit) inside the curve of the tool and a diamond hone (600 grit) is used both inside and outside to refine the edge. Honing might be done ten times before grinding is again needed. The MHT should never be used with the elbow up. If this is done a severe catch will occur and the MHT may possibly snap off.

The outside of the goblet was then turned. A U-shaped fluted bowl gouge was used. (It is ground like a roughing out gouge and acts like a skew without the severe catches. It is ground at ± 40 degrees.) Goblet wall thickness was determined by both calipers and translucency. The piece was removed from the chuck and re-chucked gently on the final base of the goblet. (Now the wall thickness of the goblet base could be measured as well as the depth of the goblet bottom.) The goblet base was then completed, as was the small bead between the top and base of the goblet.

Andre points to the heartwood of the finished lampshade that doesn't have the translucence of the sapwood.

The upper cut was first used to hollow the shade. The tool rest was at center level. (The action of the tool [gouge] must be carefully controlled at the proper angle [shearing].) The medium MHT was then used always in the horizontal position with lateral movements only to clear the left wall of the piece, the axial rotation otherwise controlling the cutting angle. The upper cut with the gouge travels in the 12:00 to 2:00 positions. Shifting the MHT counterclockwise (axial motion) will give a convex cut. Clockwise will give a concave cut. Andre developed his own tool rest with holes drilled to assist in keeping the MHT in place (mainly when turning away from tool rest). Concrete nails are placed in the holes where needed. Andre does not drill the center hole in a piece. He uses the MHT to form the pilot hole it using a light rocking motion Once the hole is established he can then proceed up the side of the piece on a pull stoke.

The interior was then finished with the large and medium MHTs. As the wall was thinned vibrations increased and thus speed slowed. Sanding could be done at this point using 180 grit.

The outside of the shade was then refined using the bowl gouge. Thickness was checked with the calipers and translucence. The U-shaped bowl gouge was used to get final thickness of about three thirty-seconds of an inch. The piece was then partially removed from the deep tenon and the jaws retightened. This provided more room to work at the top of the shade. A bowl-steady would be quite beneficial at this point. Tomorrow the shade would be ready for sanding.

This completed a GREAT demonstration. For complete details a DVD and VCR will be available in the CMW library in November 2004.

--Bob Gunther

Andre's Website

More Photos of Andre's Demonstration