Tubular Glueing- Re-do or leave?

Everything about building wheels, glueing tubs, etc.
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lord_brush
Posts: 300
Joined: Mon Nov 28, 2005 2:34 pm

by lord_brush

So I have a Conti Competition tubular that’s been stuck to my carbon DA50 rim for a few (3), years. Not been used since 2015, but am now going to be back on racing. Question is…..the tub is well n truly stuck fast- no signs of glue degradation, and I can’t pull it off without a considerable amount of force. Used Vittoria Mastik. Should I be looking to re-glue this as good practice, or if the bond seems secure, should I just leave??
The right to bear arms is slightly less ludicrous than the right to arm bears. (Chris Addison)

sungod
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Joined: Fri Dec 24, 2010 9:37 pm
Location: it's raining, it must be uk

by sungod

if it's stuck firm i'd leave it, but do check all the way around and on both sides, old exposed mastik dries out and goes brittle/powdery, any sign of that and i would reglue

alcatraz
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Joined: Mon Aug 29, 2016 11:19 am

by alcatraz

Could heat reactivate the glue and soften it up a bit?

If it's hardened, can't it cause a tear in the outer casing?

I don't use tubulars. Just curious to learn more.

/a

sungod
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Joined: Fri Dec 24, 2010 9:37 pm
Location: it's raining, it must be uk

by sungod

i always assumed the glue gets brittle as volatile compounds escape over time, if that is the cause then i think heating would make things worse

exposed glue does it much faster, so it's the edges where any problem will show up

a good glue job can exceed the strength of the bond between carcass and basetape, or even the basetape itself so that it tears, but both can be fixed if the tub is being removed to be patched

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dj97223
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Joined: Sun Nov 06, 2005 7:27 pm

by dj97223

The glue does not last forever, but if it is stuck, it is stuck. Keep an eye on it, however (which I do regardless of age of the glue). Deflate the tire completely and check for gaps between the rim edge and the base tape, and for any separation between the tire and the base tape. Small separations between the tire and the edge of the base tape can be repaired with Barge cement without removing the tube.

If you are not careful removing the tube, then you can separate the tire from the tape. I use a plastic tire lever or a round screwdriver shaft and wiggle it back and forth under the tube up to the valve stem.

Oh, and I doubt heat will help adhesion, though I've read of some people using it to help remove old glue from a rim. Never tried that myself.
“If you save your breath I feel a man like you can manage it. And if you don't manage it, you'll die. Only slowly, very slowly, old friend.”

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lord_brush
Posts: 300
Joined: Mon Nov 28, 2005 2:34 pm

by lord_brush

Well, I ended up removing it seeing as I was glueing a new tub onto the other wheel. OMG, it really was stuck FAST!
The right to bear arms is slightly less ludicrous than the right to arm bears. (Chris Addison)

UpFromOne
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Joined: Wed Apr 08, 2009 5:23 am
Location: Olympic Nat'l Park, WA

by UpFromOne

I was gonna say, the last 2 posts from yours OP, are spot on.
Any powdery edges can be touched up with a careful addition around the rim/tire interface, but if the tire feels stuck good, it usually is. If you can tear off the tire laterally, it was definitely not a good glue job.

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