Advice and questions on keeping your instruments in top form
I bought my djembe used years ago, and never replaced the skin. Needless to say, it was much in need of a cleaning.

To clean the skin on my djembe without using water, I used orange-oil household cleaner*, and it worked perfectly, with no damage to the skin. Removed the grime and oil, left it much cleaner and sounding better. (a little bit clearer, crisper, rings more vibrantly, less dull and "gummy" sounding)

*:Brand name of the cleaner here in USA is Citrasolv, but probably varies by country.
It's made of food-grade Limonene (from orange peels) and Orange Oil, with nothing else. (all essential oil so it evaporates entirely - beware other products which are not purely essential oil)

It was an experiment, so at first I was cautious, using only a drop or two at a time, but eventually I gained confidence, and was wiping the surface with it freely. I used paper towels to rub the surface, and a spare toothbrush for the scratched and rough spots. I threw away paper towel as it became dirty, using fresh paper and oil to pick up more dirt.
Rough/scuffed areas absorb the oil, so they appear darker until it evaporates. It's not permanent.

Here's a photo soon after I started, (you can see lighter cleaned spots near the rim on the right) and a photo after I did more spot cleanin. You can see the dark marks disappearing, well as the surface lightening. I eventually did the entire surface.
(The dark marks are spots where glue was used to repair scuffs. The glue had been covered in beeswax, which seems to have absorbed grime more easily than the skin itself.)
(I didn't include a photo of the final result, because the sunlight faded rapidly and it's hard to capture the exact shift in hue in different light. Also, the skin is deeply scratched (during shaving?), which is more obvious now that it's clean, so it's not a pretty example to show off the technique's results)
1 - Starting the cleaning process
DSC05327_20p.JPG (55.56 KiB) Viewed 3268 times
2 - After more spot cleaning - marks disappearing, surface lightening
DSC05328_20p.jpg (59.69 KiB) Viewed 3268 times
Interesting. I think this stuff was a bit harder to remove than that because it's an old skin and the surface was polished smooth, a bit shiny, sort of hardened.
I didn't realize it had so much dirt. I was just trying to remove the dark spots, but the surrounding area came up much lighter, so I kept going.

I will replace the skin as soon as I can, but thought I'd share my results since it was surprisingly effective. It's experimental, since I don't know if it will shorten the life of the skin, but I had nothing to lose since it was old anyway.
Isopropyl alcohol works well for cleaning skins, if you feel you must clean the skin. It won't cause any damage and removes dirt and caked-in skin cells quite well.

I generally don't bother removing dirt though. It really needs to build up into a thick layer before it noticeably affects the sound. Usually, my skins break long before they get that dirty.

I just produced a video for youtube where I compare the methods of rubbing the skin with the palms of my hands, which used to be effective in Africa with all the sweat and dust mixing together, and the orange oil method. The djembe that I used to teach for two years now has a small tear and so I thought - what the heck, that's a good opportunity. But both results where so neglegible that I would feel like an idiot to upload almost no result on youtube. I conclude not to bother about this problem any further... :uglynerd:
I agree Michi, it's got to be pretty thick to make a difference to the sound. I'm guessing this had a fair amount of oil in it too, I don't think the dirt alone would impact it so much.

I'd wonder if alcohol might possibly weaken the skins a little bit. I've been warned against it for use on thin wood instruments for that reason, it sort of dries and ages the wood, making it more brittle and fragile. Same for some kinds of plastic and rubber. Of course skin is a different material entirely.
drtom wrote:Maybe your skin wasn't that soiled to begin with
It is much darker in color, to begin with, so you literally cannot see that much of a difference than on a whitish skin. I played it a lot over the past two years so I thought it'll be dirtier. In Africa, there was a thick layer of sweat remains and dust mixed together. Also here I had more results on other skins earlier.
michi wrote:Well, alcohol will be better than water. If used methylated spirits a few times with no ill effects. It evaporates so quickly that I don't think it can do any damage.
I do agree with Michi here. I regularly used isopropyl alcohol to get rid of the fat on my table tennis racket when I used to play. It war very effective and the alcohol removed the fats from the surface quickly and evaporated in no time.
This seems like a good place to insert a related question. If it would be better to start a new thread, please just say so.

How is ink removed from a skin?

I've looked into this and know that several factors must be considered: the type of ink, the depth of penetration, the age of the stain, etc. I've removed fairly small pen marks from the surface of skins, but this one is a monster that was actually spilled and seems to have penetrated to at least some extent if not thoroughly.

The skin is on an heirloom drum of priceless emotional value, and I'm hoping that I won't have to replace it. Maybe someone has some first hand experience with spilled ink and is willing to share.
Ok how'd you get ink on an heirloom drumskin?!
Not that I'm one to talk, with my drumskin that looks like a feral cat used it as a clawing pad.
(There's a reason I didn't show the "after" photo. Maybe I should, just so you can wonder what in the world the person was thinking when they shaved it. It's sliced up something awful.)

Not to be Captain Obvious or anything, but I'd guess that the type of ink is pretty important.
I spilled some japanese caligraphy ink, and it's water soluble, so that would be problematic for a stretched drumskin with a deep stain.
In that case I'd consider covering it with something white, like titanium dioxide (white pigment), mixed into a non-water based glue. (I'd use tree rosin and orange oil, but epoxy should work too)

As for removing it, I've found Orange oil to be a pretty wide ranging solvent, but it doesn't work on everything. I'd assume it would work on sharpie and ballpoint, but I could be wrong. Obviously test it on some paper first, if you know which ink is the culprit.
I have a technique I'll elaborate on, but keep in mind, stains often get worse when you dissolve them, because they spread and look less crisp, so they look more like a huge blotchy thing, instead of a clearly defined mark. (again, captain obvious, but worth a reminder)

The technique is fairly simple: (for fabric, no idea about skins)
Saturate the stain with solvent (whether water, orange oil, alcohol, acetone, whatever is required)
then press it from both sides with paper towel, at the same time, so you're essentially pressing the solvent into the paper towels with pressure from your fingers. Then repeat with fresh solvent and paper towel, as many times as needed/useful. It takes some of the stain away each time. Once will not be enough. Sometimes it eventually removes it all, but sometimes it reaches a point where more repetitions doesn't do any good. It usually does less and less good, so it takes perseverance to get it out 100%.
But this only works if the solvent is the right one, and the material is porous/willing to "give up" the stain. It works for thin woven fabric, but goatskin is very dense, almost like a steamrolled/glued felt, so it might not work very well. Cowskin seems a bit more felty, less gluey, (hence the warmer fuzzier tone) so I'd guess it would worker better on cow than goat, although thickness is a factor too. I did notice the orange oil eventually saturated into the goatskin, but it seemed to go in through the scratches and scuffs, and seep sideways from there, so it might help to rough the surface where the stain is, if you have a goatskin like mine (slick and polished on the top, rather than rough and porous).
Just remember what happened to me though. I went in to remove specific stains, and the surrounding area ended up paler, so I had to clean the whole thing. And then the scratches and scuffs showed up more, and it kind of looked worse afterwards. I saw almost because the stains I removed were very dark, but the scratches don't look pretty either. YMMV, so I say it FWIW.
Unfortunately, bleaching won't work, because anything you might use could hurt the skin.
It's a tough call. If you want to post a pic, I could offer more thoughts on what I'd do. I do understand the urge, I can't resist removing marks from used djeme shells when I see them, crayon, marker, etc, it's gotta go. But the skin is a tough one, so it might not be worth the risk, depending on how bad it looks.
Sorry for the delayed response. Busy, busy, busy. Here's a picture:
inkStain.jpg (643.61 KiB) Viewed 3109 times
That's 12 inches of something other than goat or cow but definitely African.

Thanks for the suggestions BD. I've actually thought about covering the stain rather than removing it. The recent discussion on henna was timely.