This question is directed at our site's tanning guru, but if anone else can help feel free to jump in.
I sent a request for instructions for Lutan-F/EZ-100 usage in the auto tanner and one step in particular glares at me.
You stated that a pre-treatment of skins with Product X..(I forgot the name)...at a ph of 8.0-8.5 followed by pickle and tan.
This is 180 degrees out from everything I have heard and learned about tanning. All other tanning procedures start with an acid solution and never gets above neutral, washing with soaps being the only potential exception.
I hear about pH control during the tanning processes and cautions aboutallowing pH to creep UP into higher ranges. We have been conditioned all along to monitor pH and adjust to lower levels during pickles and to tan at ~ 4.5.
Can you explain the pretreatment theory. Why is the pH so high during this? Won't it cause slippage, especially in questionable capes?
I have heard many good things about EZ-100 and would like to combine this with the A.T. but until I understand this step I feel like I'm following a back country road with no map.
Thanks for your help, Bruce.
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The formula you refer to is one using out Rittels Preservz-it as a pre-tan prior to tanning the piece using Lutan F (N) or EZ-100. This is not a new idea - in fact old time German Tanners call it the "Leipzig Method" and it was used for tanning Alum, and Lutan F (N) skins. It actually raises their shrink temperature slightly, and makes them extremely durable. German Fur Dressers preferred these types of tanned skins.
However - the Germans used Formaldehyde in their formulas - and in ours, we are substituting our Preservz-It product instead. Obviously its substituted because of the carcinity (cancer-causeing) of Formaldehyde. The Preservz-It is a better choice! However, just like Formaldehyde - Preservz-It fixes protein best at a high PH of 8.0-9.0. To raise the PH you must add 20 Mule Team Borax to your pre-tan solution.
In this case, unlike simply pickling and tanning, and never raising the PH above a 4.0, you can safely treat the skins before tanning because of the bonding of the Aldehyde in the fibers of the skin. But it requires the higher PH level to really bond well. An Aldehyde must not be thought of as an alkaline, and the Borax is simply used to prepare the solution for fixation of the Aldehyde.
It will not cause slippage! In fact you will have a very much stronger finished product as compared to simply tanning with Alum, Lutan F (N) or EZ-100.
Now I understand,...I think..*L*...
At any rate I'll use the procedure and see how some skins turn out.
What's an aldehyde?