Over the years I've used a lot of AZ Ironwood for knife handles, it's among my favorite choices. I like that it's hard to grind since it allows me time to make mistakes and fix them and it grinds nearly compatible with bolsters, tangs, and pins to allow me to get a flush fit without undercutting. Then there's the look - wow who can't appreciate the color contrasts, dark lines, and metallic shimmer? I love it!
What I don't love so much is how it doesn't finish as nice as I'd like. It's a tight grained, dense, & oily wood that isn't stabilized, it's natural. Most knifemakers simply sand, buff, and wax and call it good. That's what I did as well but then I started to wonder about how it holds up in the kitchen. Most "custom" knifemaker's knives go from maker to customer and then to the safe - that's it's life. For a kitchen knifemaker we have to expect that our knives will be used, get messed up with oils/grime/acids, and then washed with detergents and maybe even scrubbed with scouring pads. How can we expect a wax coating to hold up and protect the wood in this type of an environment? Ironwood turns dark over time from UV exposure, hand oils, and gets washed out from dish detergents - we need to protect against these problems.
Over time I've had mixed results in finishing ironwood and have found a few things to be true when working this stuff. First is that it should not be over-buffed or buffed hard. In fact, if buffers are used it should be done using a soft buff, gently, and quick because the grain can get easily smeared. I stopped buffing ironwood, preferring to go to higher grit sandpaper instead. Yes some shine is sacrificed by not buffing but I can keep the grain appearance tight. I've also taken on the task of trying to figure out how (if at all) it's possible to seal ironwood using drying oils and this task has turned into a long term experiment since I've had little to no success.
As I mentioned before, ironwood is very dense, tight grained, and oily - it doesn't want to allow anything into or below it's surface. When an oil is applied it ends up sitting on the surface and drying/curing even if it's designed to soak in as many are. For most other woods (even stabilized woods) it's relatively easy to get a smooth build up of oil on the surface by first soaking the wood and then building up the layers but with ironwood (with a surface that doesn't allow penetration) all we get is a build up and this is weak since it's not holding onto anything - essentially the surface build up has got no roots under the surface like we can get with other woods. In every test I've done (with oiling ironwood) I've always been able to scrub away the oil coating using dish detergent. It's a major bummer when this happens after days of rubbing in the coats of oil.
To mention the test/experiments some....what I'm doing is using every drying type oil that I can get my hands on, mixing concoctions, etc. I've been doing this for a couple of years now and only in the last year or so have I seen results that are promising yet not so consistent. I have figured out a few mixtures/recipes that work for most common woods yet ironwood remains troublesome.....until recently.
The knife shown in the pictures below was first finished using the traditional method of buffing & waxing, then it was used and became ugly over time. The owner actually tried waxing per my instructions and then went so far as applying tung oil but it still kept getting uglier. I refinished this handle a few days ago and it's now the first that's been sealed using a new mixture of oils that actually block UV light, waterproof, keeps oily dirt out, and repels acids....all while allowing the look and feel of the wood to come through. The loss of color contrast is the only negative that I can see but maybe over time I can improve on this through tweaking.
I'm going to be shipping the knife back to the customer to have him use it as normal and we'll see where this experiment takes us. I'm hopeful but hey you never know. I'll be sure to post the results when that time comes. I just wanted to share with you guys now what I've been up to. Please feel free to comment, I'd love to hear what you think about the differences between finishes and your opinions on the topic of using ironwood in the kitchen.