Sewn Sling Break Testing Service?

I manage a shop that does all sorts of stuff, climbing is a pretty small department of ours. We do lots of bike service, ski service, gear repair etc. and I've long had dreams of coercing my bosses to offer climbing gear service (resoling, reslinging, the works). Silly little details like no prospect of any profit at all are proving a barrier to getting them to invest in the equipment.... So I've been trying to cobble things together myself.

It's pretty tough to find a dedicated industrial bar tack machine that can handle the thread required for reslinging cams (without spending thousands of dollars, that is) but thanks to a kindly retiring shop owner, I've finally got my hands on one. 

I do face one last hurdle though. I obviously don't want to start reslinging cams for people who aren't me without confirming my slings are strong enough. Does anyone know of a service that will break test slings for me? It's gotta exist out there somewhere.

https://www.theuiaa.org/safety/accredited-labs/

Hownot2 is selling manual break test kits and force meters, exactly for smaller operations like this or rescue workers

Someone please chime in and tell me what's erroneous about my logic here:

You stitch a prototype sling with, say, 5 bar tacks. You pull-test this using a large truck, large tree, tow straps, and a couple of beefy steel lockers. If the the stitching rips, make your next prototype with 6 tacks, etc. Once a prototype breaks away from the stitching, run several replicates with its specs. If it ain't breaking at the stitching, then the stitching is at least as strong as the material you started with.

Another place to have testing done

https://arbsession.com/arb-breaktest-email-1.html 

ACT Labs in Los Angeles is an ISO-9001etc certified shop that does product testing.  They are certified to do both EN and UIAA testing ($$$), or they can do a plain tesile test on the same machienry while charging less.  Since my Dreamlink product doesn't fit tidily into any UIAA or EN standard, I had them do a simple break test and issue me a break test certificate.

IDK about getting UIAA certification for slings you're going to sew onto other manufacturer's cams--you could just have your stitching tested and know it's strong enough, and post the break certificate for customers to see.  Most cams people heve re-slung seem to be past the MFGs stated life span, so the UIAA would already recommend retirement anyway.

Ben Zartman wrote:

ACT Labs in Los Angeles is an ISO-9001etc certified shop that does product testing.  They are certified to do both EN and UIAA testing ($$$), or they can do a plain tesile test on the same machienry while charging less.  Since my Dreamlink product doesn't fit tidily into any UIAA or EN standard, I had them do a simple break test and issue me a break test certificate.

IDK about getting UIAA certification for slings you're going to sew onto other manufacturer's cams--you could just have your stitching tested and know it's strong enough, and post the break certificate for customers to see.  Most cams people heve re-slung seem to be past the MFGs stated life span, so the UIAA would already recommend retirement anyway.

You can't get any sort of certification on a cam re-sling unless you are the manufacturer or their appointed agent, to get a UIAA safety label (the UIAA is itself not a recognised standards agency) you first need a CE certification (so tested to the relevant EN) and the sling is only a part of a cam, the whole thing is tested in it's entirety. CE rules prohibit repairs or modification by anyone but the original manufacturer or their appointed agent who must hold the relevant technical files from the manufacturer.

Jim Titt wrote:

You can't get any sort of certification on a cam re-sling unless you are the manufacturer or their appointed agent, to get a UIAA safety label (the UIAA is itself not a recognised standards agency) you first need a CE certification (so tested to the relevant EN) and the sling is only a part of a cam, the whole thing is tested in it's entirety. CE rules prohibit repairs or modification by anyone but the original manufacturer or their appointed agent who must hold the relevant technical files from the manufacturer.

TBH I don't really care about any kind of certification (although I'm not sure if businesses who actually resling need any certification). I am looking to get confidence in the strength of the slings I sew. Realistically the pathway I have in my head is resling my own gear, resling for friends in the community, get the machine to pay for itself and build some skills, and hopefully convince people that its a valuable service to the community to invest a little in to do whatever it is that needs to be done to resling officially. 

At the moment I just feel like, it's one thing knowing that you're using the correct thread, and the machine is the right kind of machine and all the theoretical building blocks for a strong sling are there, but without getting some real breaking strength data, its just hard to feel good about. I'd be comfortable testing it myself if I didnt have a sneaking suspicion that it'd be cheaper to send it out to a lab somewhere...

I like Logan's idea.

Logan Peterson wrote:

Someone please chime in and tell me what's erroneous about my logic here:

You stitch a prototype sling with, say, 5 bar tacks. You pull-test this using a large truck, large tree, tow straps, and a couple of beefy steel lockers. If the the stitching rips, make your next prototype with 6 tacks, etc. Once a prototype breaks away from the stitching, run several replicates with its specs. If it ain't breaking at the stitching, then the stitching is at least as strong as the material you started with.

That's exactly how I did it BITD before sewn slings were widely available. But,  it wasn't bar tacks. It was linear stitching and parallel rows that I learned from an article by Cal Magnussen (former REI quality dude). I kept track of stitch length, how many passes and stitches per inch.

I stitched the ends of two lengths of webbing and tied the other ends in a water knot. When the waterknot broke and the sewn splice was intact, I was satisfied.

I actually snapped a carabiner in my testing. https://mountainproject.com/assets/photos/climb/108061587_large_1494260507.jpg?cache=1701317972 

Sailrite has some pretty good info on their site. Here is one such article on figuring out how many inches of stitch you need to match the MBS of the webbing you are sewing.

https://www.sailrite.com/How-to-Sew-Webbing-Loops