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This is the dreaded word "formalin"

Community and Forum → Entomological collections → This is the dreaded word "formalin"

Black Coleopter, 13.10.2010 22:26

It's no secret that formalin greatly spoils the material. At the same time, it {formalin} is sometimes used as a fixative. Let's talk about how to correct the consequences of using formalin. How to make insects at least a little softer and more pliable to spreading...

Comments

13.10.2010 22:52, Zlopastnyi Brandashmyg

And what are its advantages in comparison with alcohol?
Probably off-topic, but I don't recommend using formalin unless absolutely necessary. Smelly and, most importantly, toxic. at one time, I burned their hands badly - the consequences were felt for several years.

13.10.2010 23:05, Pirx

I will support you - toxic, and even more so. Classic continuous action biocide. The advantage is that it's cheaper than alcohol and they won't drink it smile.gif

This post was edited by Pirx - 14.10.2010 06: 42

13.10.2010 23:10, Necrocephalus

The main advantage is that it does not evaporate much, and it keeps the material as long as possible without spoiling. I haven't seen a more long-playing retainer.

This post was edited by Necrocephalus - 13.10.2010 23: 10

13.10.2010 23:45, rpanin

It's no secret that formalin greatly spoils the material. At the same time, it {formalin} is sometimes used as a fixative. Let's talk about how to correct the consequences of using formalin. How to make insects at least a little softer and more pliable to spreading...

No way!
What I just did not do, boiled, rotted, kept in glycerin, in ethyl acetate, vinegar, vodka, or what did not help.
A direct path to formalin material, into the trash can.
Likes: 1

14.10.2010 0:31, Proctos

a strong solution of salt and ethylene glycol (antifreeze) holds well for up to 7 days. Insects remain soft and do not fade.
Likes: 1

14.10.2010 14:29, А.Й.Элез

Not entomology, but formalin. Once, in the late 1970s, I had the urge to preserve the snake (it already died with me, so just so as not to throw it away). On sale in any pharmacy was the drug "formidron" (18 kopecks for a hundred-gram bubble), transparent lubricating fluid (from sweaty feet), advised competent people. The composition there was, I remember, almost vodka: forty degrees of alcohol, only water - not all the other sixty degrees, but only fifty, and ten percent formalin, which made the drink unsuitable for internal use. So, I added a little pure alcohol to this formidron (I can't remember the exact dose now), and it's still as good as new in the jar.

14.10.2010 23:01, CosMosk

yes, over the years, the tissues in formalin will "disperse"
and there is a way to return to a soft state (for example, ground beetles), but you just need to specify who knows, I know who, but I can forget to ask...

17.10.2010 13:37, Black Coleopter

A. Y. Elezu: I have a funny story connected with the search for formalin: as a 1st-year student, I needed formalin for soil traps (at that time I still hadn't heard about a mixture of acetic essence with saturated salt solution). I had to spend the whole day going to morgues asking them to sell me some formalin. I didn't buy any formalin from rezeltat, but bought a package of formidron. I diluted it with water and used it as a retainer.
Likes: 1

17.10.2010 16:01, Black Coleopter

a strong solution of salt and ethylene glycol (antifreeze) holds well for up to 7 days. Insects stay soft and don't fade.

I think that it will go well as a retainer for window traps. Will it last a month???

17.10.2010 18:52, Igor1962

once a budgie died and I had formalin-about 1.5 kg. powder put the parrot in a bag and tied it, and hid it, after 2-6 months I don't remember exactly, untied the parrot was like a stone rotting did not touch it.

18.10.2010 20:24, Black Coleopter

What if you add NaOH or KOH to soften it???

21.10.2010 23:40, Aleksandr Ermakov

I use a very weak formaldehyde solution (less than 1%) in cadaver traps. The material (depending on the abundance) is preserved in the summer for 5-10 days. Most of the" right " beetles can be forcibly straightened and dried in the "right" form. Dissection is more difficult, but there are also such successful attempts.
And if you need lye, it's only for the genitals.

21.10.2010 23:44, Aleksandr Ermakov

Formalin is a 40% aqueous solution of formaldehyde.
Formaldehyde is a colorless gas with a pungent odor.

Often, the "water solution" of this "colorless gas" ends up in white flakes that occupy most of the jar. In Sukhoi (?in its crystalline form, this substance is no less caustic and carcinogenic.

21.10.2010 23:58, Necrocephalus

Still, there is one way to soften formalin material. Insects should be boiled in a solution of lactic acid. I don't know how concentrated the solution should be in the optimal version - I think you can choose it experimentally. I had a fairly diluted solution, tried to cook beetles in it (half a minute-a minute) - after such a procedure, they lend themselves to straightening somewhat easier, however, if overexposed, not only the joints soften - chitin can deform.

The white precipitate formed in a formaldehyde solution is a paraform, a low molecular weight polymer. Depolymerized by heating.
Likes: 3

25.10.2010 22:25, Black Coleopter

And where to get a dairy k-tu???

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