Paul6000 Report post Posted August 23, 2021 (edited) Hi, I'm having a problem with discolouration of my first leather project. It's a leather sling/safari/campaign style chair made with Tandy's 9 oz Oakleaf veg tan. I gave the seat and arm straps a coat of neatsfoot oil but haven’t got around to doing the back yet. After using it for a couple months, I'm finding that the areas my skin contacts the leather are turning an ugly, grimy grey. I've been hand washing even more than regularly due to the pandemic, so I have a hard time believing that dirt is being transferred from my hands and elbows. It seems more like a chemical thing. I'm totally new to this and had noticed that slicking the edges would often turn them greyish pink but didn’t know if that was normal. So I'm trying to figure out a simple way of darkening it all and thought I'd ask here before putting money towards experiments. I'd be willing to go all the way to black if needed. I'm wondering if the neatsfoot oil is going to be an issue. Thanks, Paul EDIT: just to be clearer, I'm happy that it's getting darker and patinated but want the ugly grey tone to be less noticeable. Edited August 23, 2021 by Paul6000 Quote Share this post Link to post Share on other sites
PastorBob Report post Posted August 23, 2021 I have never worked with "oakleaf" veg tan, but do know if there is no top coat (pro-resist, supersheen, etc.) natural veg tan will absorb the oils from one's body when making contact. It will get darker as you mentioned, over time. Not sure about the greyish color you are speaking of. From the pics it just looks like normal wear marks. What process did you use to slick the edges? Gum Trag? Tokonole? water? Quote Share this post Link to post Share on other sites
Paul6000 Report post Posted August 23, 2021 (edited) Thanks. I didn’t use a top coat, so I guess I should have expected this sort of uneven wear but I'd been hoping it would turn more brown than grey. In person it looks grimy. I've been watching vinegar/steel wool staining on YouTube and wondering about turning the whole thing black. I suppose I'll put some neatsfoot oil on a sample piece and see how it works. I used water to slick the edges. Edited August 23, 2021 by Paul6000 Quote Share this post Link to post Share on other sites
YinTx Report post Posted August 23, 2021 it could be a bit grimy, say hand lotioin or just dirt/grit/grease in general. Try a light bit of saddle soap with a bit of water, work into a sudse, wipe off, let dry see if it helped at all. If there is no seal coat, you could dye it even after nfo. I do recommend a seal coat when you are done tho. YinTx Quote Share this post Link to post Share on other sites
Paul6000 Report post Posted August 24, 2021 Ok, thanks. I’ll try saddle soap and see what happens. Glad to know dyeing is still an option. Quote Share this post Link to post Share on other sites
Lobo Report post Posted August 24, 2021 First comment: That is a very nice piece of work! Second, re: can we dye veg-tan after neatsfoot oil? My response is Yes and No. As others have pointed out, any sealant or finish coat can be expected to interfere with the dyeing absorption. Selection of the dye is likely to be a factor in success. Water-based dyes will be inhibited by the oil in the leather fibers, oil-based dyes are likely to do a better job. Another likely result will be incomplete absorption and probable dye residue transfer from the leather to the user's skin or clothing during contact (not the best result). Finally, veg-tanned cowhide will always be photo-active, responding to ultraviolet and sunlight by darkening (not always predictably or evenly), and oxidation is probable over time. I think what you are describing as a grayish patina is probably oxidation brought on by exposure to light and air. Obviously, the ideal solution is to dye the leather while it remains in the unfinished state and allowing plenty of time for the dye to completely set before continuing with any project. Application of neatsfoot oil also requires a period of time for the oil to "settle" into the leather; it never dries but it does migrate within the leather fibers until it reaches a relatively even saturation. Probably the best product for replacing some of the natural moisture removed by the tanning processes (nasty stuff, lye to remove the hair follicles followed by repeated soakings in tannin-infusions, etc). Neatsfoot oil is rendered from the natural oils of the feet and lower legs of cattle, part of nature's way of protecting the animal's exposed and vulnerable parts from the environment (particularly freezing temperatures); some folks refer to neatsfoot as "cow oil", which is an accurate description. Another passing thought: neatsfoot oil can exhibit oxidation from exposure to sunlight and air, and may be a factor in the grayish patina you are observing. Thorough cleaning (saddle soap may be helpful) followed by a good acrylic sealant may cure the problem. I hope this helps. Quote Share this post Link to post Share on other sites
Paul6000 Report post Posted August 25, 2021 Thanks for the compliment and the in-depth reply. The chair is from a Popular Woodworking video & Chris Schwarz book on Campaign Furniture. Based on what YinTx and you've said, I'll try the saddle soap and if it works, seal it. If not, I'll dye the arm straps black and leave the rest natural, since it seems to be developing a more pleasing, even patina. I'd been planning on blackening the maple cross dowels with some vinegar/steel dye, so black arm straps might look good with that. Quote Share this post Link to post Share on other sites