Teak and Tool Wear
Teak contains silica sand, and it quickly wears down cutting edges on every kind of tool. October 27, 2011
Question
We are just now ramping up our solid wood production and are working on a 300 BF teak job. My planer and jointer use Tersa heads and I can't believe how fast they wear down. I do not know if it is the teak that is doing it or if the Tersa knives do not have the life I was expecting.
Forum Responses
(Cabinetmaking Forum)
From contributor M:
Teak is big time hard on any type of steel tooling. The only thing that stands a chance of holding up to it is carbide. I already know that a set of solid carbide Tersa knives will bring you to your knees the first time you buy then, but you better get used to it if you're going to be doing any amount of solid wood machining. I have machined teak, so I'm speaking from experience. HSS steel won't last any more then a couple hundred feet and then it's shot.
From contributor A:
Teak is really tough on the tooling. The reason is the trees grow mangrove style - in swampy areas with sand. If you look carefully, you will often see white dust in the grain. This is dusty sand. Sand is pretty hard stuff. Apparently harder than M2 tool steel. I bought carbide sets of knives for both my jointer and planer to specifically cut teak. It was worth the investment.
Your Tersa knives will last longer if they are a different, harder, more durable steel. The name means nothing. T3 generic knives outlast name brand m2 by many linear feet.
From contributor J:
Yes, teak is extremely abrasive. It's not all that dense or hard, but it's like running your knives into sandpaper. Cutting it with hand tools requires resharpening every few minutes.
From contributor D:
An 8' teak board through a planer will dull HSS knives by the end of the board. Silica is the culprit. "Saw and sand" is one strategy; carbide or similar harder steel tooling is the other.
From contributor C:
We [Southeast Tool] have found that teak is very hard on tooling also. We have tried some of the coatings on the Tersa knives that we sell and have had mixed results. The longest life has still come from solid carbide so far.
From contributor G:
I got rid of my jointer with the Tersa head for this reason. The high speed steel used in the disposable blades is nowhere near the quality of good solid blades. I built a jig to hone the face of the Tersa blades on a diamond hone and this allowed me to reuse the blades 3 or 4 times before changing for new.
The Tersa blades are great for ease of install, but when you factor in the durability, they are expensive. Teak points out the durability of the HSS blades quite quickly.
From contributor B:
Teak is a special order for me and every time I do I job in teak, I figure on resharpening every machine and hand tool in the shop. As long as this is part of the original job cost, I don't complain. I always try to completely finish all the teak work before moving on to the next order.
Personally, I loath the stuff for what it does to my equipment. I also think it is overpriced and overrated, especially the plantation teak. Glue lines are never fully trustworthy, nor stock availability. (How's that for not complaining?)
From contributor U:
One thing to be mindful of is that there are genuine Tersa brand knives and there are a number of aftermarket knives made to fit Tersa heads. These aftermarket knives normally are sold as Tersa style or Tersa type and are not the real McCoy.
Genuine Tersa brand knives are made in Switzerland and have the name Tersa stamped on the knives. We [Wood Tech Tooling] have seen a wide range of quality in the aftermarket product and have always chosen to offer our customers only the genuine OEM Tersa product.
Just some food for thought in a most competitive and challenging market. Obviously, running teak (as in most exotics and hickory and hard maple as well) mandates the use of solid carbide knives.
From contributor K:
We run genuine Tersa knives in an off brand cutterhead in our Griggio 400 mm jointer. The M42 grade lasts longer than the standard M2, but neither will stand up to teak, and my feeling is neither lasts as long as the resharpenable HSS knives we run in our 12" Northfield, although the quick replacement time makes the Tersa head more popular. If we had a major teak job, carbide knives would definitely be included in the bid.
From contributor G:
I agree completely with contributor K's take on this. We were using the Tersa brand of blades, not aftermarket. The quick change aspect is great but you do change more often than with good quality solid blades. I am interested in the Byrd head but a little gun shy after buying the Tersa and then having to get rid of it.
From contributor O:
Silica, aka sand. Yes, this is extremely hard on all bits and blades. I use my drum sander for surfacing.
