Working with Ipe Wood

Woodworkers air their objections to Ipe, which is heavy, hard, and rough on tools. The Wood Doctor adds a little technical detail to the discussion. March 12, 2014

I'm bidding a job using ipe. How hard is it on steel molder knives?

Forum Responses
(Architectural Woodworking Forum)
From contributor R:
Ipe really is some hard stuff. Not as bad as purple heart, but really hard. Some people are allergic to it (the dust, that is). Itís great for bows. Trying to seal it or glue it is hard due to it being so oily. It dulls any blade it touches.

From contributor U:
I would suggest carbide if you have a lot to do. You could use an endurance coated high speed or some other high quality coated steel on shorter runs under 500 l/f .

From contributor J:
Ipe will dull-down every tool in the shop. Plan on replacing or resharpening every knife, saw and chisel after every ipe order. HSS molder, planer and jointer knives (you name it) will all be blunted immediately. Band saw blades are rendered useless. Carbide tools will take a beating as well.

Ipe is heavy, brittle, notoriously unstable and glue-resistant. It also leaves nasty little splinters which tend to infect and irritate the skin. The fine sawdust is rumored to be both toxic and allergenic.

In the yacht business, ipe is sometimes touted as a viable substitute for teak... This is bull and those who replace teak trim with ipe will learn the truth the hard way (I did).

Ipe is icky but also very beautiful and yes, incomparably hard. The sustainability of ipe (I suspect) is due to its natural resistance to woodworkers. I charge a substantial premium for ipe orders (large or small).

From contributor O:
I recently did an ipe install. It was T&G laid horizontal on a small storefront. All I can think is, never again! The architect that specified it was adamant this wood is superior to all other woods.

Contributor J was, in my opinion, being kind in his well stated assessment. I have worked all domestic and most exotic woods over 34 years of millwork. I have several favorite woods by degrees, but now only one truly awful, despised and useless, bottom of the list hated wood.

I believe Satan's throne must be made of ipe, as it already smells like a blast from Hell.

From contributor D:
I agree on the lack of merit for ipe. The few things it is good for does not mean it is good for anything or everything. The old guys that knew woods all knew what use was good for what wood.

What I find interesting is how those that have no experience with the actual work (as a verb) are the ones that get over-excited by some isolated characteristic and think they are on to some great new thing. This, while the voices of experience get ignored or drowned out.

From the original questioner:
Thanks guys - I've never used the stuff, and that appears to be a lucky break. These are to be the front edge, curved slats for park benches. A shallow C in cross section. We make and resharpen our own molder knives and this will be a custom grind. We added a considerable premium for all that has been said here.

From contributor S:
Devil wood.

From Professor Gene Wengert, forum technical advisor:
As an example, red oak has a density of around 40 pounds per cubic foot, while ipe is around 55 pounds (about 40% heavier). The hardness of oak is 1290 pounds and ipe is 3680 pounds (about 300% harder).

With denser woods, it is important to adjust the knife angles of a planer, as the setting for pine or oak would not be very good - hence, you hear lots of complaints that reflect trying to process ipe like one would process oak. Because of the high density, screwing should use pilot holes that are about 90% of the screw's root diameter. With heavier chips, you also may need to have a hefty dust system.

You also need more power for the planer motor. If short on power, then the feed is slowed which means more rubbing, which means faster dulling.