Wednesday, June 1, 2011

Cutting Bits from Chunks

A previous post featured a large Maccasar Ebony billet that I acquired. Even though this piece is estimated to have been drying for at least 17 years past experience has taught me that it's a good idea to give billets of this type adequate time to acclimate to a new environment prior to processing. Of course the other possibly explanation to why I haven't decided to cut up this piece of exceptional timber is just that. In billet form it is a very formidable looking piece of wood and part of me did not want to alter it just yet. So I've admired it for several weeks and now it's time to cut it into usable pieces for plane making.

There is also another reason I've waited. It's early summer here and for that reason the average daily humidity is higher than it is during the colder months. These are much better conditions for breaking up a billet. Freshly exposed surfaces react much more favorably to an atmosphere that is not extremely dry and this gives the material a chance to react to it's new exposure without having the moisture sucked away from the surface much too quickly.

Past experience has also shown me that it is best to begin the process of breaking down log segments and billets by cutting pieces off the length in increments of 11". If there are checks on the end of the piece then the first piece will probably need to be just a bit longer than 11". This billet was 4.75" thick 6.5" wide and 53" long. Maccassar Ebony has very high specific gravity, yep it will sink in water just like a rock. This also means this piece was quite heavy. It was all I could manage just to hold it on the table of the bandsaw and feed it thru the first cut off it's length. I suffered thru the first cut knowing that every subsequent cut would make the piece lighter. Now that I had my first section cut from the length of the billet it was time to start re-sawing.

At first I thought I would probably need to change to a wider bandsaw blade than the 1/4" wide blade that I normally have on the bandsaw for general shaping of curved surfaces. After all I was about to attempt to re-saw thru 6.5" inches of very dense material. I instead decided to give it try with the 1/4" blade before going thru the trouble of making the change. The blade is a Timberwolf brand blade and I had heard of many people getting favorable results re-sawing with relatively narrow blades of this brand. I was very pleasantly surprised. The blade went thru 6.5" of this material with relative ease. I took my time and made sure I didn't ask the blade to cut at a faster feed rate than it was capable and the results were actually quite accurate.

At this point I stopped to seal the freshly cut end of the billet. Most checks start in end grain and I've found a good coating with a 3 lb. cut of shellac helps keep this part of the billet from drying too quickly.

After a couple of subsequent re-sawing cuts on the bandsaw I had some very nice blanks sized to yield two nested plane totes.

One side of the billet has some noticeable surface checks. This is actually very typical and I'm in no way complaining. Stresses build up in these billets and checks occur. The trick is to figure out how to work around the checks to yield the best material. When laying out my cuts I had this side marked to yield thicker pieces that would be appropriate material for turning knobs and this would also give me some leeway in cutting around the checks.

Now I have many surfaces exposed directly to the air for the first time so I worked quickly to seal the ends and spray a light coat of lacquer on the flat sawn surfaces of the tote blanks. All this in an effort to slow down the effect of being exposed directly to the effects of the atmosphere.

Now these blanks get to rest for a while and if I've done my job correctly the next time you see them they will be plane parts.