Ambrosia Maple Bowl
I recently turned a relatively small bowl from a nice piece of Ambrosia Maple, a wood I have worked with before in larger sizes and which I generally enjoy. Working with Ambrosia Maple isn’t without its challenges and I am not certain that many people realize what the wood actually is and why it is so different in appearance from other maple, or Acer, species, of which there are nine.
What Is Ambrosia Maple?
Ambrosia Maple is not a distinct species within the Acer genus, instead Ambrosia refers to a beetle that infests maple trees, causing distinctive damage. There is no one single species, or even genus, of beetles that cause the ambrosia effect, instead there are numerous such types around the world. The beetles also allow for the entry of fungus, which they are symbiotic with in nature, which causes the typical discoloration of the wood. Maple wood without the ambrosia effect is usually very pale, colorless and without any figure. Ambrosia is, in effect, just another of the several identified figure and color variants of existing Maple species, others of which include, but are not limited to: bird’s eye, curly, quilted, and spalted. Of these variants, Ambrosia most closely resembles the effect of spalting. However, Ambrosia maple may have greater structural integrity than some spalted samples, although arguably, the introduction of the fungus by the Ambrosia beetle can be considered a form of spalting, although one with a specific cause. As is true of any figured or colored sample of maple, prices will be higher to reflect the rarity of the effects and also because it is impossible to know prior to harvest if such effects or figure will be found.
Maple Species
This piece of Maple was almost certainly a piece of Hard Maple, Acer saccharum. I base this identification on the fact that the piece was harvested in the eastern United States, was quite hard, and otherwise has the general appearance of Hard Maple. Geographically, Acer saccharum is an eastern United States wood that is commonly used for turning and other wood working purposes, it is prone to Ambrosia discoloration, and it is characteristically hard, with a Janka rating of 1,450 pounds, which places it in the range of White Oak.
Challenges in Mounting the Blank
Once the piece was cut to a reasonable round on the band saw, I turned it to final round on the lathe between centers as I find this to be more efficient that trying to locate and maintain center with a face plate alone until the piece is truly round. My face plate has a large center hole, which is because of the lathe spindle size, and I find it difficult to hold it perfectly center while screwing it in and this off-center effect causes the loss of otherwise usable material. I have tried multiple methods for correcting this, and turning between centers before face plating is the most effective, although not perfect, solution I have found. On this piece, I still had to re-round even though the piece was round off the centers, since I failed to perfectly center the face plate. I welcome ANY solutions to this constant problem!
Tool Quality Matters
The piece was quite hard and my tools dulled quickly, but since I was using replaceable, and movable, carbide bits in the Easy Wood Tool system this wasn’t difficult to correct. I turned the bottom, including the divot for the chuck and reversed the piece. I drilled a starting hollow using a Forstner bit, but encountered some difficulty as I suspect that my bit, which is part of a twenty-piece set, is of limited quality. Sets, I have discovered, are not really the best value for hard use. The bits tend to be cheaply made, which they would have to be since they sell so many together for an attractive price. I have since found that it is better value to select a size I have specific need for and invest in a good bit, which may well cost as much, or even more, than a set of poor quality bits. Again, the adage that one gets what one pays for is confirmed.
Disaster Strikes
Once the hole was drilled I started hollowing. I can hear a distinctive whine and vibration when turning a blank, especially when working near the edge, when the material is stressing, potentially beyond what it can stand. I heard this, but I think I rushed, which is fatal, and the piece came off the chuck. I stopped the lathe immediately and was not hurt, but the damage was done; the divot had cracked on two sides and I could no longer mount the piece as it stood.
Rescuing the Situation
I was momentarily at a loss and thought the piece might be lost. First I tried to refit the face plate in the hollow I had created, but it wouldn’t quite fit. I tried drilling it out on the drill press with a Forstner bit, but I could not hold the piece steady and then the drill press stalled against the hardness of the wood. I was puzzled and then I thought to try, as a last ditch attempt to save a nice piece of wood, to expand my largest Nova chuck into the hollow. The 100 millimeter chuck, the largest Nova makes, worked! I was able to cut away the damage on the back and cut a new and deeper divot to remount the chuck. Yes, I lost size in terms of height because of this failure, but I still rescued the remainder of the piece which is still of good size.
Final Cuts and Sanding
I was considerably more patient with the hollowing process following this problem and was successful in creating a shape and size that I was happy with. Hard woods are sometimes difficult to sand, depending on how nice a cut is achieved, whereas soft woods tend to cut roughly regardless, with a fuzzy finish, but sand super easy. The cuts were pretty good and sanding was not challenging.
Finishing the Ambrosia Maple
Because the Ambrosia Maple is so hard and completely non-porous, I felt confident that an oil-based finish would just stay on the surface of the wood and might not dry nicely, so I used a nice wax based product, Odie’s Wood Butter, which is a bit easier to apply than Odie’s Wood Wax, which I also use on hard and non-porous woods. I have had good success with these products and use them extensively now.
Final Impressions
Overall, I am pleased with the outcome of the piece and look forward to working with additional pieces of Ambrosia Maple, which I have in stock. I will remember the lesson learned that patience remains an immense virtue and asset in turning, and that when seeming disaster strikes, a little creative thinking and use of existing tools can save the situation when it seems lost.