Cocobolo question

Ironhorse522 · Jul 31, 2012

I have a custom knife I had made by Dan Harrison. It's a great lil knife with cocobolo handles. My question is the wood has darkened on one side to almost black you can't see the changes in the wood on that one side at all. I know cocobolo changes color with time but I've only had the knife for 3 months and the wood has already changed? Is there anyway to reverse this?

Doug C · Jul 31, 2012

No.
If there is a way to reverse, I hope to hear about it in this thread.

Cocobolo always darkens in my experience.
Exposure to sunlight speeds the process, same with DI.

Doug

HeavyHanded · Jul 31, 2012

I once had cocobolo grips for my Walther PPK. The oils gave me a massive contact rash where they rubbed my side - took 2 weeks to disappear. I washed the grips with denatured alcohol and a rag till they stopped 'bleeding' color and then treated them with mineral oil. They got much lighter in color as the natural oils washed out. I'm 99% certain this is not a great idea for the health of the wood tho it did no long term damage to the grips and allowed me to keep using them without applying a clear coat. They also looked very nice after applying the mineral oil tho quite a bit lighter. They will darken with contact to body oils and ^ sunlight (didn't know that). Hopefully someone with more woodworking experience will chime in.

Robs92XJ · Jul 31, 2012

Do you know if the knife sat for a period of time in such a way that the darkened scale was exposed to sunlight? I doubt it was left outside, but maybe left on a table near a window or something?

I've read about cocobolo interacting with finishes (water-based varnishes and oils) that cause it to durn dark, but if that were the case it should've happened to both handles.

Do you know if the maker used any kind of finish on the scales? It's pretty common to just use the wood bare, buffed and waxed.

Ironhorse522 · Jul 31, 2012

It's stablized I don't know if he put any kind of finish on it. It's weird since the black is only on one side

bgentry · Jul 31, 2012

HeavyHanded said:
I once had cocobolo grips for my Walther PPK. The oils gave me a massive contact rash where they rubbed my side - took 2 weeks to disappear.

VERY interesting! In highschool shop class my teacher told us cocobolo was *hyper* allergenic. That it caused allergic reactions in a lot of people and that continued exposure made the reaction happen faster and more intensely. He was talking about inhaling the dust when sanding it. I had never heard of contact with skin causing a reaction, but it makes a lot of sense, especially on something that is in contact with your body for hours at a time and in a humid environment (under your shirt) and perhaps with sweat as an extra factor.

Brian.

HeavyHanded · Aug 1, 2012

bgentry said:
VERY interesting! In highschool shop class my teacher told us cocobolo was *hyper* allergenic. That it caused allergic reactions in a lot of people and that continued exposure made the reaction happen faster and more intensely. He was talking about inhaling the dust when sanding it. I had never heard of contact with skin causing a reaction, but it makes a lot of sense, especially on something that is in contact with your body for hours at a time and in a humid environment (under your shirt) and perhaps with sweat as an extra factor.

Brian.

I initially had problems with rosewood grips for a different handgun several years prior. It took a few weeks to develop but I wound up coating them with bedliner. Being a little ignorant of exotic woods, I ordered cocobolo grips for my Walther, not realizig rosewood IS cocobolo. This go-round the rash took one day to develop and tookso long to clear up I almost went to the Doc for it. Did some homework and discovered its the oil that causes problems so I washed it repeatedly with alcohol till it lost all its sheen - was basically a real flat, dull, much lighter version of its original color. Worked in the mineral oil and she prettied back up but still much lighter. It had to have made the wood less durable, but cocobolo has some toughness to spare and it never was a problem.

Phydeaux · Aug 1, 2012

I think I remember reading in a book "Know our Woods" by Albert Constantine, that cocobolo is in the same family as poison ivy. I've worked with some when I was in high school, and I did get some skin irritation from it. Consequently I generally try to avoid this wood or i try not to handle it too much.

Ric