This is a tough thread to write and a super-cautionary tale!
I recently bought an Artillery holster in nice shape at a good price,
1917 marked, belt converted, nice supple leather. Had Jerry the holster man take a look at it before I bought it, looked fine, except for some white mold spores.
Asked the best way to "kill" the spores and got instructions:
"Heat oven to 350 degrees, put holster on a cookie sheet and put in oven at 350 for 5 minutes, cut off the heat. Leave in for one hour and take out. Mold will be dead and no harm to the holster."
Simple, just be aware that it may smell up the kitchen a little.
So me, I think well I'll take care of that and wrap it in foil to keep the odor down and prevent it drying out to boot.
WRONG!!
What I did was "boill" the leather , then dry it out! It was shunk, twisted, and hard as a rock, in short RUINED! Only salvageable
piece was the brass stud for the cleaning rod flap.
I'm not posting this so anyone can tell me I was stupid or dumb or anything of the sort, I have already beat myself up enough.
This is to help someone else avoid a potential disaster!
Added by Jerry, lugerholsterrepair:
I asked Don to post this for the reason he has stated..I recommend this procedure to any and all collectors who have a mold problem on leather. My Wife Ellie and I struggled for some time many years ago to find a cure/solution to some molds found on Luger holsters. After much research on mold, we concluded that if enough heat could be safely applied, the mold spores deep down in leather would be killed. We did extensive testing..with old leather parts and pieces that if ruined..would be no great loss. And ruined they were. I had this very thing happen to me when I put leather into an enclosed bag and applied heat.
What happens in an enclosure is that molecular moisture..present in a fairly sizeable quantity in a holster, escapes and condensates inside the enclosed area and turns to steam. Steam is deadly to leather. Just as it is to living skin. I can't tell you the chemical or physical properties that cause it to change..I only know the result as you can see from Don's photo's. Disaster on a grand scale.
The basic heat treatment WITH NO enclosure other than the oven..works with NO HARM to leather. I have done it more times than i can remember. 350 F. for the short period recommended will NOT dry out leather. It often has the opposite effect. Moving and distributing any applications of whatever has been put onto it over the years. I have NEVER had a bad effect yet by placing a holster in an oven at 350, laying on a cookie sheet with no covering whatever.
One caveat comes to mind as I write this..LEATHER. I have NO experience with this procedure for ERSATZ holsters or say, Japanese CANVAS holsters. LEATHER ONLY.
So to clarify this procedure..that I have used with great success to kill some types of mold and completely erase the white mold flowers from the surface.
Preheat oven to 350 F. Place your leather item on a foil covered cookie sheet..foil is just to make the Wife happy. If you are a bachelor a plain cookie sheet is fine. I have never had anything drip off.
Place your cookie sheet with exposed leather on a middle rack. I sometimes use a wooden stick to prop open a Luger top so the heat can reach full temperature inside.
I usually wait a few minutes to make sure the oven has achieved 350 after opening the door..then TURN THE OVEN OFF! Let your leather lay..an hour is usually long enough. The oven will gradually cool but the leather will have reached killing temps through and through. I have found no harm to studs or buckles..One benefit has been to take out your leather while still warm and verdegris will easily wipe off with a terry rag.
As horrible as this experience has been for Don and even myself..I encouraged Don to help us all with an explanation of what can happen..these photo's are tragic..but there IS an explination of why it happened and we should avoid this, learn from this. I wouldn't FEAR my mold killing procedure..just DO NOT ENCLOSE the leather, leave it EXPOSED.
Thanks Don, I know it's a platitude..but your loss results in our gain. Learning is an ongoing endeavor.
Before and after disaster: