After too many years discarding punctured tubes, I’ve decided to reuse and repair. Are there any recommendations for good patches for this? My feeling, based on zero evidence is that old-school glue and patch are better than the pre-glued type, but I’d be interested to know what others have found.
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If you do a production line it’s not bad to patch tubes. After patching many tubes (former bike tech), it’s important to clean with rubber cleaner, abrade the rubber, ensure the hole isn’t along a seam, remove the seam around the hole if present, apply glue, let dry until tacky then apply patch and hold together for a period of time. The thinner and more flexible the patch the better.
Repairing a tube while someone is waiting is not worth a shop’s time. I’ll only replace, too much chance of failure and I don’t think techs have the time to piss about with them. YMMV…
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I’ve never had a classic Rema Tip Top glue-and-patch repair fail in use.
The problem with those kits is that if you do one patch every few months the glue tube will dry out long before you use up the patches. As Scott said, doing several at once (invite your friends!) works a lot better.
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I’ve had good results with Rema patches. A couple tips: Glue strength is affected by pressure. I clamp the patch down with a “quick clamp” most often used to hold two pieces of wood together. Second is for the glue tubes that can dry out - put it in a small plastic bag. Put it in two plastic bags! Whatever it takes to ensure there is no circulating air to dry it out. Also you used to be able to buy the glue and patches separately…
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Ive got glue that’s been open for years and is still good, but I do carry two tubes of it in my kit incase. I wont waste my time with the pre-glued ones. I think its too humid over here for them to stick long term.
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I second using a quick clamp to apply constant pressure while everything bonds together.
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Old school Rema style definitely works best. I’ve never clamped, and can’t remember a patch ever failing (and I’ve had tubes with 5+ patches on them). Vulcanising compounds behave differently than adhesives.
As others have said, prep is key, and clamping definitely is needed for TPU repairs.
You can buy extra glue from some bike shops or Decathlon if yours dries out. I squeeze any extra air out of the glue tube and put the cap on tightly which seems to help.
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I very much want to second this point. In my experience this is the single most important step. The glue is initially glossy/shiny and will turn matte once it is sufficiently dried. Only then should you stick on the patch. When doing a roadside repair and you want to just get going again quickly again it’s tempting to just stick the patch on but letting the glue dry is mandatory.
In addition, what I’ve found is that I tend to underestimate the sizes of the patches and then the area in which I’ve applied the glue is too small.
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As far as I am aware, rubber cement is applied and executed much like contact cement. Apply to both contacts to fully dry to the touch and apply the two parts together. I use a commercial Vulcanizing tire/tube cement that is instructed to do this.
As a disclaimer, I run exclusively tubeless, but I went years with successfully patching tubes (shop, not field). The last 12 years tubeless and I can’t imaging still running tubes. Sealant has saved me so many times, I will not consider returning to tubes. If I need to plug/bacon strip a tire (rare) , it usually gets internal patched following the flatting event.
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Stick-on patches were terrible in the 90s (although I lived in a humid area) but my sense is that they still aren’t particularly trustworthy now. Whereas real patches with vulcanization fluid almost never fail.
The only thing I’m wary about is patch + sealant-in-innertube. I haven’t looked into this, but I’ve had patches fail a number of times in this condition, and don’t think it’s random.
(Fresno, california, where I used to live, has tons of goathead thorns some of the year. My first two weeks after moving there, I got five flats. About the same number of flats I’d gotten over a decade in North carolina. Sealant in innertubes solved that.)
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This is my hack. You never lose the hole if you use a twink pen to make a cross-hair. I usually dry the glue over a heater and only pump up the next day. Obviously in the field its different but if I was on a very big trip and was concerned I’d put in my spare tube and patch the holed one incase I needed it. Eg, missed the piece of glass or thorn stuck in the tire. Usually I pump up the holed tube to find where the hole is to check that location on the tire anyway.
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I’ve always used a sharpie to do crosshairs in the same way. Although darker-black doesn’t stand out as well against a butyl innertubes, it’s enough for keeping track of the hole after abrading the area and applying vulcanizing fluid. I just use them to make sure I center the patch over the puncture. But your process with white is a nice extra layer of redundancy.
Thanks to all for your advice. Looks like setting aside a wet evening, proper glue and patches and careful prep / clamping are the way to go. At least until I take the plunge with tubeless …..
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Ive never done clamping myself Martin. Only once did I ever have failures. It was a batch of dodgy cement that was doing the rounds. A long time ago now.
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Hopefully not to hijack…
I’ve figured out how to patch TPU tubes successfully. The self adhesive TPU patches have always failed for me.
In Australia we have Selleys Shoe Fix which seems to work well on TPU. I cut up an old tube to create a patch, spread glue on the patch, apply the patch to the tube, clamp the tube with two pieces of wood either side and leave for a few hours.
My other trick is to use a wooden dowel with a slit cut into it to use as a mandrel to roll the tube up on. I hang the tube from a hook then fit the dowel at the other end and apply gentle tension while rolling the tube up. It’s really effective in squeezing out all the air and getting the tube back to its original packed size.
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Just so I understand, it’s TPU tubes that you’re cutting up for this purpose? And what size dowel is your rolling-up mandrel? I like that idea.
Thirding this (Is that a thing?).
Especially when using a “vulcanising cement” (RTV adhesive), it is imperative to flash off the solvent(s) before joining the surfaces. If the surfaces are joined too early the solvent has to migrate through the rubber, swelling it and weakening the joint by dislocation.
For latex tubes I keep an old tube and cut it to make a patch. Glue it on in usual way and it’s good. Have also done the method of cutting small punctured length out of one to be repaired and rejoining it by overlapping one loose end over the other a bit. That was an experiment really but worked OK too.
Can old butyl tubes be used to patch punctured ones in similar way I wonder? I must try that.
Having said all that I mostly use various brands of preglued patches and have found them to generally work well enough.
… and I never take a patched tube out on a ride as a spare. Just new ones. Folding a patched tube for a saddle pack can start to peel off a patch sometimes. I only use patched for replacements in the home workshop, and at least a day before a ride so can be sure the patch is good.
In the bike shops I’ve worked in I’ve never patched a tube. We’ve always binned them (or put aside for recycling these days). Would need to charge more for time taken to patch than cost of a fresh one and too risky.
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