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lphilpot 01-22-11 06:20 PM

Pumping up sealant tubes?
I had a sealant tube (not a Slime, another brand) that I tried to pump up and so much of the goo/fibers got into the (Schrader) valve stem that it prevented the valve from fully opening or closing. As a result it made a perfectly good tube unusable.

When airing up a sealed tube, is it a good idea to put the stem at 6 o'clock for a few minutes prior to pumping? How does it take to clear? Or does it matter? Is there any way to prevent sealant in the stem?


fietsbob 01-22-11 07:17 PM

TRY stem at 12:00.

Schrader valve cores are removable and can be replaced.

lphilpot 01-22-11 07:26 PM

Duh, of course - 12 o'clock. I was thinking of the sealant running simply out of the stem, not around to the other side of the tire. :o

I removed the core, which is how I saw it was bent, but I've not picked up another. Usually I tend to have lots of little parts like that around, but you know how it goes: When you need x, you never have it. The stem itself is full of gunk, so I'll have to clean that out before trying a new one.


[edit: I should have originally said, "unusable when I needed it" rather than simply "unusable", since I didn't have a replacement core.]

cruisintx 01-22-11 09:08 PM

I would have thought that having the stem at 3 or 9 o'clock would have let the slime run down better than at 12. And 12 o'clock allows nothing to drain from the stem itself. Now that I think it through tough, I'm wondering if 4 or 8 woud be even better as each of those positions would allow the fluid to not only run away from the stem to the bottom of the tube but it would also allow the stem to drain at the same time.

xizangstan 01-22-11 11:56 PM

I agree with 4 or 8 o'clock positions for the stem. And I try to keep new spare valve cores and caps handy. I get the valve cores in the automotive department at Walmart. Set of 4 with a heavy duty tool for less than $2. I keep an eye on supplies at ACE Hardware or auto parts stores for the metal valve core tool type metal caps. I'm sure they weigh a millionth of a gram more than the standard plastic caps, but I like having valve core tools out on my rides with me.

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