Are Flat Out, Slime and Stans a scam?

[Gionnirocket]

Slime can clog a tube. So can FlatOut. But to get that result you have to use it wrong. Any time you have tire sealant of any kind inside of a tube, you have to rotate the air valve to the upper half of the arc of its circle (think of the valve as sitting at 1' o'clock. Definitely no more tha 3'o'clock). THEN you put air in or bleed air out.

If you don't do that, the goo can clump near the valve and the act of releasing air becomes the same thing as a puncture. the goo near the valve rushes into it. Clogged valve. BUT knowing this, its easy to never let it happen.

I try not to adjust pressure during a ride and at home I always use a compressor to give a quick blast of air to clear the valve before measuring and adjusting.

 

[chunk]

I think it works, I was getting a flat it seemed weekly from those goat-head stickers, so the last tube I installed, was a tube pre loaded a with slime sealant. So far months later, still no flats, and no problem adding air. The instructions say to add air, have the valve in the 10 or 2 o'clock position to minimize slime getting in the valve, which I've always done. I will use again.

 

[m@Robertson]

Wouldn’t it make more sense to have the valves at the bottom of tire (near 6 o’clock) so any goo can drain out before you put air in?

That’s how I’ve been pumping my tires and have had no issues with tire sealant clogs.

Think centrifugal force. Roll the tire around some and anything on the inside where the valve is gets flung to the outside. From there it rolls away to the bottom of the tire. the valve is somewhere besides the bottom so it stays clear.

 

[K PierreR]

Wouldn’t it make more sense to have the valves at the bottom of tire (near 6 o’clock) so any goo can drain out before you put air in?

That’s how I’ve been pumping my tires and have had no issues with tire sealant clogs.

I have never used it but I have worked at formulation in the coatings industry. The fact that is has propylene glycol in it and the shear volume of the material you are adding to each tire would likely preclude charging with the valve at the bottom of the tire as the best choice.
Flat Out is slightly heavier than water. Charging a 4" fat bike tire adds 470 grams to the spinning mass and that weight can shift.
I suspect that Kevlar is a minor additive fiber as Kevlar would not be my first choice. I view that as more of a marketing tool. Its likely that poly ester and poly propylene fibers make up the bulk of the fiber fill.

 

[AHicks]

The problem with a valve at 6:00 is that it may be sitting in a pool of sealant, especially if it's flat or using some of the amounts people are talking about here. Far better, to avoid the bottom of the stem sitting in a pool of sealant, would be something like 7:30 or 4:30. That's plenty of angle to empty any sealant if you give it a second, and hopefully you don't have near enough in that tube to block the stem from draining.

 

[Rickman1]

The problem with a valve at 6:00 is that it may be sitting in a pool of sealant, especially if it's flat or using some of the amounts people are talking about here. Far better, to avoid the bottom of the stem sitting in a pool of sealant, would be something like 7:30 or 4:30. That's plenty of angle to empty any sealant if you give it a second, and hopefully you don't have near enough in that tube to block the stem from draining.

I’m currently running tubes pre-charged with Slime. I puchased a couple bottles of Flat-Out to use next time around along with some thicker thorn proof tubes. I bought a couple of large 500CC Syringes (included about 2ft of tubing) from Amazon. I will just pour the correct amount in the syringe and “push” it into the tube. Easy and accurate.

 

[AHicks]

With the fleet of bikes I'm keeping up, I generally just buy the larger bottle of Slime. If you look carefully, that bottle has a sight gauge and there are markings in oz. right next to it. Point being, it couldn't be much easier to use as is.

There's also potential to buy smaller bottles with the amount you need all measured out for you. Even if you were to buy a bottle with twice what you need, it's easy to use pretty close to the exact amount needed.

 

[BigNerd]

The problem with a valve at 6:00 is that it may be sitting in a pool of sealant, especially if it's flat or using some of the amounts people are talking about here. Far better, to avoid the bottom of the stem sitting in a pool of sealant, would be something like 7:30 or 4:30. That's plenty of angle to empty any sealant if you give it a second, and hopefully you don't have near enough in that tube to block the stem from draining.

Sorry... didn't mean exactly at 6p more like in that lower half so actually like 4p or 8a.

 

[Tars Tarkas]

I’m currently running tubes pre-charged with Slime. I puchased a couple bottles of Flat-Out to use next time around along with some thicker thorn proof tubes. I bought a couple of large 500CC Syringes (included about 2ft of tubing) from Amazon. I will just pour the correct amount in the syringe and “push” it into the tube. Easy and accurate.

Nothing wrong with accuracy but it's not necessary, in my experience. I usually overdose my tubes by 25 - 50% anyway.

TT

 

[john peck]

Are Flat Out, Slime and Stans a scam? I already purchased Flat Out, but my LBS guy (who assembled my Aventure) said not to waste my time with any of them because the are just a scam, and that I would be better served to buy Tannus Armor or puncture resistant tubes. As an out of shape senior, having a flat miles from my car in Texas could be a serious problem.

Both times, years apart, slime clogged my valve & made the tube useless. I have swbe marathons on
3 bikes, never had a flat.

 

[Tars Tarkas]

Both times, years apart, slime clogged my valve & made the tube useless. I have swbe marathons on
3 bikes, never had a flat.

There's probably no way to get to the bottom of this, and I'm not doubting your experience, of course, but that just doesn't match my experience at all. I overdose my tubes so I would think I'd be more susceptible to valves clogging. I wonder what causes our experiences to be so different? I've used Slime for years in bike tires, wheelbarrows, riding mowers, etc., and never had a hint of a clog.

TT

 

[Gordon71]

There's probably no way to get to the bottom of this, and I'm not doubting your experience, of course, but that just doesn't match my experience at all. I overdose my tubes so I would think I'd be more susceptible to valves clogging. I wonder what causes our experiences to be so different? I've used Slime for years in bike tires, wheelbarrows, riding mowers, etc., and never had a hint of a clog.

TT

Different valve types?

 

[Merle Nelson]

Doesn't Slime dry inside a tire or tube and you need to refresh it every so often?

That's one thing that nudged me toward FlatOut, it supposedly never dries up....

 

[AHicks]

Doesn't Slime dry inside a tire or tube and you need to refresh it every so often?

That's one thing that nudged me toward FlatOut, it supposedly never dries up....

I've never seen any evidence of Slime "hardening" in the years I've been using it.

 

[Merle Nelson]

Okay, my mistake. Thought I read that here.

Hope noone staked life, limb, or reputation on my misguided post in the interim.

 

[Tars Tarkas]

Different valve types?

That occurred to me after I posted. I guess Presta valves are skinnier and that might make the difference. I think Slime is too fluid for that to matter though. I would think even a pretty weak hand pump would provide enough "wind" to blow Slime clog out of any valve though. At least from everything I've seen with it.

I've never kept a tube, in a bike anyway, long enough for the Slime in it to dry out. I change tubes when I change tires, which is rarely more often than about every two years. It's water based, so I think it will dry out eventually. Blaming Slime for drying out eventually would be kind of like blaming tires for dry rotting after a few years in a barn though, in my opinion.

I've had the same (tubeless) tires on my riding lawnmower for at least 12 years. When the tires don't hold air I just add more Slime. That's worked fine so far, even though the tires are well past their "enjoy by" date.

TT

 

[Gionnirocket]

Okay, my mistake. Thought I read that here.

Hope noone staked life, limb, or reputation on my misguided post in the interim.

Slime states that it is effective for 2 years, so I assume it will dry out. Since it is water based I guess you may be able to extend that time frame by adding a few ml of water occasionally.
And on the valves... I did have it foul a schrader. I tried removing the core and cleaning it and the stem with water, but then just replaced the core as I have many on hand and wasn't worth more than a few minutes effort. YMMV

 

[retiredNH]

Slime states that it is effective for 2 years, so I assume it will dry out. Since it is water based I guess you may be able to extend that time frame by adding a few ml of water occasionally.
And on the valves... I did have it foul a schrader. I tried removing the core and cleaning it and the stem with water, but then just replaced the core as I have many on hand and wasn't worth more than a few minutes effort. YMMV

I think your assumption is off a bit. Consider this: For Slime to dry out, the water needs to get from the inside of the tube to the outside. Rubber doesn't let water or water vapor through, so there's no way for this to happen.

I suspect their two year rating is more about marketing and repeat sales than any science.

 

[6zfshdb]

A while back, I cut up an old tube that had contained Slime for over 5 years. It didn't dry out but it was far less viscous (thicker) than new product. It was also interesting to see that the Slime didn't coat the entire tube inside. It was mostly on the outside against the tire tread with very little on the upper surface where the tube rests against the rim. I suppose this is natural considering gravity and centrifugal force.

Tire tubes do lose some air, and the moisture it contains, through slow valve leaks. Some air is also lost through the rubber itself via a process called osmosis. The amount of loss depends on pressure and the thickness of the rubber.

 

[retiredNH]

A while back, I cut up an old tube that had contained Slime for over 5 years. It didn't dry out but it was far less viscous (thicker) than new product. It was also interesting to see that the Slime didn't coat the entire tube inside. It was mostly on the outside against the tire tread with very little on the upper surface where the tube rests against the rim. I suppose this is natural considering gravity and centrifugal force.

Tire tubes do lose some air, and the moisture it contains, through slow valve leaks. Some air is also lost through the rubber itself via a process called osmosis. The amount of loss depends on pressure and the thickness of the rubber.

Rubber inner tubes can be slightly porous to air, true, but not by osmosis, at least not as a chemist would use the term. You might note that for most solids, gas permeability is higher than liquid permeability, usually much higher. But this is a complicated field unless you're a chemist!