JazzBass Report post Posted August 17, 2022 We’ve all probably seen the card wallets with a money clip in the center… Although it does indeed seem like a wonderful version of a “minimalist” wallet, the tube of the money clip is affixed by sewing the barrel/spring ACROSS the width of the card wallet- twice. Hmm… These two stitch lines then become the hinges upon which the wallet is opened and closed. Double hmm… isn’t that a recipe for splitting, craking, and ultimate failure over the long term? Isn’t that why we sew along the length of a strap, instead of across its width? Opinions?? I like the design, but have serious misgivings as to the “engineering”. No, I haven’t yet made/tested one, but have had a few requests. My inclination is to believe that a lifetime guarantee would have me replacing every one I make, every 3-5 years. Am I wrong or just paranoid? Quote Share this post Link to post Share on other sites
Dwight Report post Posted August 17, 2022 (edited) I know this is different from what you described . . . but this is how I make a minimalist wallet with money clip. Please note that I don't have a beautiful picture . . . just my original sample . . . My last customer for this brought his very similar one that was seriously falling apart at the seams . . . and he wanted it replaced if possible. His daughter had bought the original one and he just wanted to keep that style because of her tie to him. His was 15 years old . . . May God bless, Dwight Edited August 17, 2022 by Dwight Quote Share this post Link to post Share on other sites
SaintJoy18 Report post Posted August 18, 2022 On 8/16/2022 at 8:16 PM, JazzBass said: Isn’t that why we sew along the length of a strap, instead of across its width? When dealing with straps you are taking into consideration tension, stress and weight distribution. "Lengthwise" stitching will reinforce the leather and support additional strains. By sewing across a strap you are creating basically a perforated tab that can't withstand too much weight and tension. Wallets aren't handling that much stress and weight across those areas so I wouldn't be overly concerned about it. Quote Share this post Link to post Share on other sites
Matt S Report post Posted August 18, 2022 On 8/17/2022 at 4:16 AM, JazzBass said: We’ve all probably seen the card wallets with a money clip in the center… Although it does indeed seem like a wonderful version of a “minimalist” wallet, the tube of the money clip is affixed by sewing the barrel/spring ACROSS the width of the card wallet- twice. Hmm… These two stitch lines then become the hinges upon which the wallet is opened and closed. Double hmm… isn’t that a recipe for splitting, craking, and ultimate failure over the long term? Isn’t that why we sew along the length of a strap, instead of across its width? Opinions?? I like the design, but have serious misgivings as to the “engineering”. No, I haven’t yet made/tested one, but have had a few requests. My inclination is to believe that a lifetime guarantee would have me replacing every one I make, every 3-5 years. Am I wrong or just paranoid? Short answer: yes sewing across a strap does weaken it. Real-world experience of low-strain, low-stakes items means that with a little care in the design and manufacture it's not weakened enough to make any difference in the real world. Look at the countless examples of dress belts, wallets, watch straps and cartridge belts that are sewn the "wrong" way and last for decades in daily use. In stitching across a wallet (e.g. for a spring tube money clip) I would be more worried about stitching too tight to the tube so it strains or deforms, or so loose that it might fall out, or about selecting the temper of the leather, or about a dozen other things before worrying if the leather might tear. Long-winded answer: Engineering in the more general sense is sometimes described as "the art of balancing the ideal with the possible". Making a wallet out of a 1" stack of top quality leather would make it robust but undesirably bulky, heavy and inflexible. The other extreme of folding and stapling a couple bits of garment leather would be frail and stretchy. Hitting the middle ground sweet spot between those two extremes, while also hitting other marks like "subjective aesthetics" and "cost control", is the unwritten goal of what we leatherworkers do. Just as hobbyist and artisanal woodworkers may eschew such modern things as particle board, biscuit joints and CNC cutting, so too do hobbyist and artisanal leatherworkers often eschew things like tubular rivets, edge paint, machine sewing and yes even stitching across a strap. There are circumstances where any of these materials and techniques may be inappropriate. One solution (which works well for the hobbyists, artisans or person otherwise wanting to keep things simple) is to reject them all. "Never sew across a strap" is a fairly foolproof and reliable way to eliminate the potential problem of that strap tearing off. "Don't sew across a strap if it's likely to tear within the projected lifetime and use-case of the item" is a far harder rule to follow because it depends upon a lot more bits of knowledge, which may not be available. Experience (direct or indirect, statistical or anecdotal) starts to fill in a few of those knowledge holes and may provide a different answer. Certain trades tend to err in one direction rather than another. Boatbuilders are very unlikely to use biscuit joints on a boat hull because they're likely to fail in a marine environment and somebody die. So too saddlers may choose to never stitch across a strap because if you do that on a girth/cinch it's under a lot of strain and if it fails somebody could die. Build a coffee table using biscuit joints and it's not only far less likely to fail in its expected use, but if it does the worst outcome is some spilled coffee and a stained carpet. A wallet maker is similarly free to be less strict with their selection of materials and techniques -- no wallet is expected to hold a 200lb man on a 1500lb horse in all weathers at 30MPH. The thing with engineering is, when you have unquantified or hugely variable materials and fastenings, it's difficult to calculate for. Leather is a hugely variable material so there's no specific numbers to plug into things like shear force calculations. We rely on common sense, experience and rules of thumb to develop ranges in which those numbers are likely to fall. The more datapoints we have the narrower those ranges can get but it's really all just an opinion and judgement call. That's why leatherwork is and art! ;-) Quote Share this post Link to post Share on other sites
JazzBass Report post Posted August 20, 2022 Thanks for all the wisdom, folks! Maybe I am a bit paranoid, as it is true that the stitch line is not required to support lots of tension, as in a cinch strap. I’m sure you can see my concern though, as that stitch line is meant to be a hinge, that will be repeatedly be folded on BOTH sides. I’ll just have to make a few, and see how the thickness and temper effect the long term durability. Thanks again for the insight. Quote Share this post Link to post Share on other sites
