squirtdad

I have been using sealant in tubes for a while.
The results have been mixed, I have had cases where I am pretty sure sealant has worked but have also had cases where sealant just sprayed out and made a mess (28mm Vittoria corsa tires with conti race lite tubes at 115Psi)

Yester day I got slow flat (32 mm Rene Herse compass Stampede pass with extra lite casing, schwalbe tubes, 30 ml of Caffee latex, 80 psi)

I got off and was about to pull the wheel and put in spare tire, I noticed sealant coming from the sidewall and spun the wheel and found sealant coming out from 2 punctures.

I decided to experiment and got out the mini pump. I pumped the tire up a bit (50 to 60 psi at a guess) and looked at the punctures...where sealant was coming out, wiped sealant away and kept watching
Sealant coming out kept at lower rate......(shoulda taken pics) so I kept watching and wiping in about 10 minutes no more sealant, so I pumped it up to maybe 65 or 70 and made it the 2 remaining miles home

Pumped it up to 90 or and so far seems to be holding

My takeaways

1) sealant works better at lower pressure so use lower pressure and time to let it do it's thing
2) pretty sure is has helped with smaller puncture I did not see
3) flip a coin between putting sealant in a a prophylactic or carrying sealant to use to try to do a fix
4) don't blast away with a co2 cartridge
5) Patience grasshopper
6) may got back to conti tubes as I have had more flats that expected with the schwalbe

dddd

Were the Conti tubes perhaps a little wider in the uninflated state?

Tubes stretch to fill a mounted tire, quite a bit actually.

But a stretched tube wall will produce a bigger hole after being punctured with the same thorn than a less-stretched tube.

As you suggested, sealants work best at lower pressures and smaller holes.

I've wondered myself how CO2 affects the sealing ability of latex versus air(?).

Andy_K 

I'd be curious about this too. I got some Schwalbe tubes recently that are labeled as being suitable for up to and including 700x28s. I'm using them like that and haven't flatted yet (ask again tomorrow), but these tubes are really small. I think the Conti tubes that say 700x25 max are bigger.

4funbikes

I've set a few people up with sealant and have received positive feedback. Most recently, in a fit of experimentation ( or laziness), I repaired a personal slow leak with an ounce of sealant.

daverup 

squirtdad How long had the sealant been in the tube? I've heard that it doesn't last that long somewhere, and wonder when you put it in.

squirtdad

I put it in about 4 to 6 weeks ago.

caffelatex shows this for lifespan of a up to a year in a tube or tubularUsing the recommended quantity for tyre size/type, the expected Caffélatex lifespan is:

• Tubular (or Caffélatex inserted into latex/butyl inner tube): up to 1 year
• UST Tubeless tyre: 2-6 months
• Tubeless-ready tyre: 1-4 months
• Tube-type tyre: 1-3 months

In the impossibility of knowing the specific conditions (kind of wheel/tyre set-up, tyre sidewall thickness and porosities, external temperature and humidity, bicycle storage conditions…), we recommend checking Caffélatex every 2 months, to make sure it’s liquid and therefore ensures its puncture preventive action.
When dry, Caffélatex-sealed wheels are still air-tight, but Caffélatex won’t actively repair punctures.

https://www.effettomariposa.eu/en-us...e-tyre-sealant

squirtdad

I will have to look not sure of the top of my head....