I have read several times that steel pins are much better than the black enamelled ones. I just don’t like the look of steel pins, that’s why I have been using black enamelled pins for the last years, but sometimes I can find a tiny bit of rust even know after just three years on the black enamelled pins. It was on a specimen that I rehydrated together with the pin, so it was indeed moist, but still it seems black enamelled pins are really not good. I am using SPHINX black enamelled, size 1, it says in the shop they are steel and rust free but they aren’t.
Which ones would you recommend that really last a life time at least? And if I don’t like the look of blank steel insect pins, and still prefer black ones, can I make them black somehow? Use perhaps car paint to make them black? Any good ideas? I am collecting Zygaenidae so esthetically it looks prettier if the insect pin is also as black as the burnet moths body.
“Use perhaps car paint to make them black? Any good ideas? ”
When you first mentioned this powder coating come to mind, it’s supposed to be abrasion resistant and most important it can be applied as a thin layer therefore not making your pins too much thicker. Only problem is that in order to cure and get the perfect finish with powder coating it requires a high temperature which could harm the spring steel properties of the pin.
So, an alternative method would be blackening the steel using different chemicals to basically convert the surface of the stainless steel to magnetite which is basically rust but it’s black.
You could also try using the same process used for the architectural patina finish which uses a selenium and copper compound, I think this occurs at room temperature so it would be safer than the other options which require input of heat.
Another option would be to electroplate it with another metal that can be anodized to the black coating you’re looking for.
Another process (that may be a lot more difficult to do) would be galvanizing the pin, this would give it a dark grey appearance.
I think I’ve talked enough, there are a few options for chemically darkening your pins, I would suggest for you to take a look at some steel related forums as they sometimes mention processes or blackening or bluing steel, just remember that heating tho pin will result in a floppy wire so the best option would be either chemically altering the coating, or applying a thin coating of paint, but I feel that this last option may not be as suitable as the paint would be weak at he tip of the pin and may start to peel not to mention paint would significantly increase the diameter of he pin. Diluted resin or polyurethane based black coatings may be able to offer the protection and color youre looking for without significantly thickening the pin. And in terms of painting or coating the pins, you will either have the excess coating form a drop at the tip if you hang them tip down which would result in a unusable pin, or if you hang them tip up you will have the coating accumulate at the head of the pin resulting in a thicker head but then the problem becomes how to suspend the pin and coat it completely at the same time one option would be suspending the pins by the head dipping them and using a centrifugal force to remove excess coating but this would be complicating the process. In conclusion, chemically coating the pins would be the best (then again, I am biased as I like chemistry) hope this helps!
It is worth bearing in mind that any treatment of pins should only involve a coating that will not itself react with the inside of the insect that is being pinned. The major problem with pins which can rust is that the rusting process attacks the interior of the insect and may eventually destroy it as a result. Pins which have copper in them, for instance, react with the body causing verdigree, which can be seen as green rust around the point where the pin enters the body. This reaction will eventually cause the rust to spread into the insect's body, and eventually if the pin is made from this alloy it will break, but more alarming is the damage to the insect itself, which may fall to pieces. That is really why stainless steel is the safest type of pin, as this cannot happen with real steel pins.
I thought same ten years ago that stainless steel pins are too shinny, too visible, but in reality ( unless you use black pinning board ) they are less visible than black pins. I have changed all my specimens to stainless within last two years and I am very happy with the final look.
Thanks for all the answers! I will try to set a box of burnet moths with steel pins and see how that looks like, it’s definitely better than having rusty pins.
Yes, You should try and save yourself a lot of time in the future for repining thousands of specimens . I once again had a look on my Zygaenidae and they look great on stainless, black pins stand out too much.
Sometimes I will (for photography purposes) carefully blacken just the head of a stainless pin with an ordinary larger, permanent ink, jiffy marker.... works great to conceal the shiney head against a dark thorax or the black of a beetle's elytra. I suppose before you initially stick the pin through the insect you could blacken the entire pin with the marker, let it dry (takes only a few seconds) & then insert it... Some ink may rub off, but you could carefully re-ink it above & below the specimen. As mentioned earlier, I blacken the heads with black marker, before photographing insects, because I haven't figured out Photoshop yet!!
I too switched over to stainless pins as enameled ones will rust sometimes... humidity should be kept low to prevent rusting (like Adam C's temp & humidity controlled rooms... $$). Using enameled pins in northern, dryer or colder climates isn't too much of a problem, but stainless are essential in warmer,humid climates (especially in the tropics).