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I had two new tires put on my bike and the LBS used Finish Line sealant.

I have managed to puncture after 5 rides. The tire doesn’t lose much air, but air still bubbles out. My experience with Stans sealant on the previous tires is it did a good job.

I was going to syringe it out the Finish Line and replace with Stans, will this compromise the Stans?

mattnz
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Dugong
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    What kind of bike? Tire sealant is all but worthless on a road bike - the pressure is too high in the small tires used on road bikes. The sealant doesn't stop air from escaping until the pressure is too low for riding. All it does is muck up the tube's valve. – Andrew Henle Feb 08 '21 at 10:48
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    No idea whether those two sealants will mix well, but relying on sealants is always a bad idea; they can never provide serious puncture protection. That is the domain of puncture proof tires: No mess when installing/taking off tires, no problems with sealant unglueing patches, and a puncture rate of about once in 10000km in my experience. – cmaster - reinstate monica Feb 08 '21 at 10:50
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    Are you referring to tubeless sealant or sealant in tubes? Both the previous comments appear to assume the former, the answer assumes the latter – Chris H Feb 08 '21 at 12:54
  • @ChrisH Good point. Given the "puncture" context, tubeless sealant didn't even occur to me. – Andrew Henle Feb 08 '21 at 15:58
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    Finish Line is a company, not a particular sealant. They make several very different kinds of sealant. What is your actual question? – Vladimir F Героям слава Feb 08 '21 at 19:12
  • Finish line is garbage as it has too much glycol and not enough latex. Stans performs okay and has good longevity, but if you’re looking for maximum sealing and aren’t too concerned with longevity, Orange Seal or Bontrager are great options. Stans Race is too aggressive for normal usage. – MaplePanda Feb 08 '21 at 19:45
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    @MaplePanda to be fair, the appeal of FinishLine's (original) sealant is that it doesn't have any latex, so that people with latex allergies can use it. – Paul H Feb 09 '21 at 06:52

1 Answers1

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Yes - mixing sealants will either make no difference, or both will interfere and neither will work.

Start by checking the SDS (aka the MSDS)

Stans: https://www.notubes.com/pub/media/wysiwyg/GIS-004_R3_Stans_Tire_Sealant_SDS_GHS.pdf

Finish Line: http://www.finishlineusa.com/files/Tubeless%20Tire%20Sealant_EU%20SDS_UK%20English_6%20November%202017.pdf

Both are based on Propylene Glycol with Latex embedded as the solid. So there's similarity in their basic makeup - its not like one is oil and the other is water based. However I still would not mix them; Similar in this case means you don't need to dispose of the new tyres.

  1. I would unmount both tyres, pour out the existing sealant and dispose safely.
  2. Then wipe them out with a cloth rag or paper towels. Also wipe down the rims.
  3. Leave to sit open over night to let anything remaining evaporate.
  4. Then reassemble your tyres onto the rim and add you preferred sealant brand as per the instructions.

And consider doing this yourself - no need to pay a bike shop for a simple tyre swap.

Based on that, you may choose to try a couple more months on the original sealant, and go through this process after ~5 months because by then it would need a topup anyway.

Criggie
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    When you've got the tyres off the rims anyway, you could also rinse them before wiping down. This should remove more than just wiping. I doubt it's really necessary with similar chemistry sealants though. – Chris H Feb 08 '21 at 12:56
  • @ChrisH having seen the damage/mess that changing fluids can cause, I'd be replacing the (new) tyres if it was a different chemistry. And any rim strip and the valve. Then I'd clean out the rim with something volatile. – Criggie Feb 09 '21 at 01:34
  • @Criggie Unless you are being sarcastic, changing sealant brands isn’t that bad. As long as they’re both latex-based, there will be no issues. Hardly anyone is going to go throw out a $100USD set of tires and a $20 tape/valve set just because of a sealant change. – MaplePanda Feb 09 '21 at 06:48
  • Just want to add the best luck I've had with sealants across my 7 tubeless wheelsets is a 50-50 mix of Stan's and OrangeSeal. Stan's seems to seal up the sidewall better, OrangeSeal's glitter takes care of the punctures. – Paul H Feb 09 '21 at 06:55
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    @MaplePanda your "both latex-based" is the opposite case to Criggie's and my "different chemistry", so we're all saying similar things: very different sealants - worry lots about what will happen/take precautions; similar sealants - don't worry much at all – Chris H Feb 09 '21 at 08:26
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    @PaulH The best luck I've had with sealants was.... a tube. – Criggie Feb 09 '21 at 09:11
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    @PaulH The best luck I've had with sealants was.... a puncture proof tire. – cmaster - reinstate monica Feb 09 '21 at 09:42
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    @ChrisH Reading comprehension...not my forte today it seems. – MaplePanda Feb 09 '21 at 15:48
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    Tubes and puncture proof tires? quelle horreur – Paul H Feb 09 '21 at 16:20
  • @PaulH Why "horreur"? – cmaster - reinstate monica Feb 09 '21 at 20:13
  • @cmaster-reinstatemonica Mostly joking about how "unfashionable" such things are. But both tubes and puncture-proof tires would suck a lot of the fun out of the types of trails I like to ride. – Paul H Feb 09 '21 at 21:59
  • @PaulH Thanks. Yes, I guess that there may be questions of application involved. My experience is mostly with using my bike as a vehicle for getting everywhere I want within my city. Consequently, my requirements for puncture resistance are relatively high as every puncture means that I'm likely late for whatever I'm riding to. And I was totally fed up with patching tires, sealant not working or unglueing patches when I finally switched to puncture proof tires. It felt like a total liberation to me. – cmaster - reinstate monica Feb 09 '21 at 22:30
  • @cmaster-reinstatemonica Strange. In Portland, OR, I haven't had a single flat on a tubeless tire in several thousands of utility/transportation miles with my stans + orangeseal mix. – Paul H Feb 09 '21 at 22:34
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    @PaulH Yeah, probably there are better sealants out there now than what I had access to fifteen years ago. Nevertheless, the fundamental problem of sealants remains: They don't stop the punctures, they patch them after they form. As such, you will always have sealant and air losses, both of which are somewhat unpredictable since a large hole leaks more of both before the sealant manages to patch it. A puncture proof tire may fail on a big shard, but so will a sealant filled tire on that same shard. The difference is that the puncture proof tire will remain as good as new until it's defeated. – cmaster - reinstate monica Feb 10 '21 at 00:26
  • @cmaster-reinstatemonica For what it's worth, I recently pulled a triangle shaped piece of glass about 1" long and 0.5" wide at it's base from my front tire at a stop light. It was embedded about halfway in. I pulled right before the light turned green (it was a familiar intersection), and the hissing stopped half before I reach the other side of the intersection (this was a 42 mm wide Schwalbe Marathon Supreme, IIRC). – Paul H Feb 10 '21 at 01:00
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    @PaulH and a road tyre would have emptied all its air before that. High volume-low pressure is more suitable for tubeless+sealant. – Criggie Feb 10 '21 at 01:01
  • @Criggie, agree in theory. but in thousands of miles of practice, it just hasn't been an issue for me. – Paul H Feb 10 '21 at 01:02
  • @Criggie and in any case, all you'd need to do is pump it back up after it sealed itself up (as opposed to taking the tire of the rim and replacing the tube) – Paul H Feb 10 '21 at 01:06
  • This is getting well into chat and away from the question, which was specifically about mixing sealants. Let us continue in [chat] – Criggie Feb 10 '21 at 02:26