I recently found a beautiful piece of yellow fan coral but have been struggling to enjoy it because it smells SO terrible--like a fish market on a HOT summers day!  Please help me get rid of this smell without hurting the coral.
Thanks

There was quite a detailed discussion of this topic on this forum a while back, but I can't find it, so ... First, the ideal treatment. This is how I would do it, but working in a research laboratory I have access to, and familiarity with, chemicals that you may not be familiar with.

There are two possible sources of odor in a specimen like this. If the "holdfast" - the "root ball" so to speak - is attached to the fan, it may harbor a large number of mollusks, marine worms and other organisms, and it may very well be the chief source of odor. I would remove it if it is attached, and just keep the fan with a simple stem at the bottom. If you only have the fan and there is an odor, then it comes from the actual polyps of the seafan.

First of course you need a container big enough to soak the specimen in liquid. I would first soak it in 10% formalin (1 part commercial formaldehyde solution to 9 parts water) for 24 hours or more in a covered container and/or in a well ventilated place, preferably outdoors. This will kill any bacteria, fungi etc. that are growing in the specimen, and will also "fix" the proteins and other perishable substances that are naturally present and are decomposing. The formalin will also "harden" or stiffen the specimen somewhat, so ideally it should be soaked flat, rather than curled in a bucket. Otherwise it may be difficult to flatten later. Then I would rinse out the formalin in a couple of changes of fresh water for a few hours each.  Next I would soak the specimen in a couple of changes of 70% alcohol, preferably ethyl alcohol but isopropyl alcohol will do, at least a few hours each change. "Rubbing alcohol" from the pharmacy, used full strength, will do. Avoid methyl alcohol such as found in gasline antifreeze, shellac thinner, etc. Then lay the specimen out flat and allow it to dry thoroughly in a warm dry place, indoors or outdoors.

OK, all of that having been said, I do not recommend use of formalin by people who have no experience using it. It is kind of nasty stuff, the vapors irritating to eyes and nasal passages, and will make skin exposed to it feel hard. Also some people are sensitive to it and may experience a contact dermatitis from contact with the liquid or even the vapors. If you do use it, wear rubber gloves and work in a well ventilated area.  Alternatively, you can skip the formalin and just soak the specimen in 2 or 3 changes of 70% alcohol as above. As above, "rubbing alcohol" from the pharmacy, used full strength, will do. Alcohol alone doesn't do as good a job as formalin followed by alcohol, but it will usually give acceptable results.  Then dry the specimen as above.

Finally, once the specimen is thoroughly dried, you can spray it with some kind of sealant. A matte spray available at art supply stores (used to fix charcoal drawings so they don't smudge) works very well. I recommend a matte (non-glossy) spray because the seafan looks more natural. You can use something like polyurethane spray, but it imparts an unnatural gloss to the specimen.

Good luck!

P.S. When you have a seashell that smells, Chlorox or an equivalent bleach product is the best thing to use, but don't try this on a seafan or you won't have anything left.  

--Last edited by Paul Monfils on 2008-03-25 04:32:52 --

Wow!!  Thanks.  As you guess, I do not have any experience with formalin, so I think I will stick to the 2nd step for now and see how it works.  Thanks for all the information!

I just realized the earlier discussion of this topic is not on this forum, but on the Shells General Discussion forum on this website.