EDIT see end of question for updates:
The question came up if this is proper English:
Sorry, I felt the need for a disclaiming for some reason.
And I think it is but some others say it isn’t. I gave a further example to back up my case that that is acceptable with:
“A disclaiming was made by the mayor”
And thus was born the question that you see here. I’m not saying it should be used all the time, but as an occasional usage, is this proper?
Yes yes, the appropriate word to use there would’ve been “disclaimer” not “disclaiming” but disregarding that?
My proof that this is acceptable is the countless number of books I’ve read where I’ve forgotten more than I remember that I’ve read, but I’m certain I’ve seen a literary device such as this used before and not heard a great deal of complaining on it.
So since I posted it was pointed out to me that this is most likely a gerund. If it is indeed a gerund, then is this a proper use of this particular gerund in this instance?
The examples you provided aren’t using the word the right way. I do believe that “disclaiming” is a gerund, however you can’t use it in the way you have it. As you said, the proper way to say it would be “A disclaimer was made”. I think I see why you’re confused. A gerund can be used as a noun, but the proper form would be this:
My disclaiming that the word can be used this way is explained above.
So, yes, you can use “disclaiming” as a noun, however, you can’t make a disclaiming. You make a disclaimer.
From Merriam Webster
dis·claim verb \dis-ˈklām\
1: to make a disclaimer
2 a obsolete : to disavow all part or share
2 b : to utter denial
Examples of DISCLAIM
The prisoner disclaimed any part in the prank
Her spokesperson flatly disclaimed the marriage rumor circulating in the press