Tub gluers - curing time for glue layer

arturo_belano

Whenever I've glued CX tubs, I usually set aside the rim / tyre overnight between layers to cure - this seems to be pretty standard, before a final layer on the rim just prior to mounting. This guy in the vid below, however, is doing the whole show in abar an hour, with little curing time. Does anyone have experience of this method? Because just firing the whole thing on in an hour is very appealing.
He's a pro mechanic, so is presumably drawing from a lot of experience and not just talking bollox. But it does seem at odds with most other approaches.

https://www.youtube.com/watch?v=okqs-3HgU4U

cycleclinic

not long I have mounted tubs inflated then rode without dying or the tub rolling. Best left over night though.

VamP

Don't get me started...

arturo_belano

VamP wrote:

Don't get me started...

Start me off son.

I'm not talking about curing the final thing - I think it's pretty unequivocal that leaving the mounted tyre for 24 hrs minimum strengthens the bond and is a good idea. I mean leaving each layer to cure overnight, is that necessary?

VamP

The curing time for each layer does affect the overall strength of the final bond. Many say that you should leave it overnight, but I think 4 or 5 hours between layers is good enough.

Every season early races there's a load of rolled tubs in evidence. I think rushing the gluing process is a contributory factor for many of these, although the main culprit is unresolved mismatch in curvature of rim and tyre. If you have a mismatch you need to use tape to bring centre of tub in contact with rim. Another chief cause, particularly for carbon rims, is contaminated rim. Give it a good clean with acetone before putting the first layer on.

Finally, a lot of people don't do quality control. Once my glue jobs are dried, I deflate the tyres and wrestle with them for 5 to 10 minutes all the way around on both sides, looking for any weak spots.

Rolled tubs are really annoying. Much better to glue properly and have peace of mind.

arturo_belano

VamP wrote:

The curing time for each layer does affect the overall strength of the final bond. Many say that you should leave it overnight, but I think 4 or 5 hours between layers is good enough.

Every season early races there's a load of rolled tubs in evidence. I think rushing the gluing process is a contributory factor for many of these, although the main culprit is unresolved mismatch in curvature of rim and tyre. If you have a mismatch you need to use tape to bring centre of tub in contact with rim. Another chief cause, particularly for carbon rims, is contaminated rim. Give it a good clean with acetone before putting the first layer on.

Finally, a lot of people don't do quality control. Once my glue jobs are dried, I deflate the tyres and wrestle with them for 5 to 10 minutes all the way around on both sides, looking for any weak spots.

Rolled tubs are really annoying. Much better to glue properly and have peace of mind.

Thanks mate, good to hear your experience. I did in fact roll a tub last race, hence the question.
Think the rim cleanliness might have been my problem, actually, as I was quite methodical with the gluing. I'd used loads of white spirit to clean the previous glue off, and just gave it a cursory acetone wash afterwards.

tgotb

I generally tend to leave the old glue on, so long as it's sound. My method with new tyres/rims is 3 separate layers of glue on the rim and one on the tyre, minimum 12 hours to cure between each, and then one more on each when I glue them. If the rim's had a tyre mounted before, I skip those 3 layers or maybe just do one more. I don't think there's any benefit in stripping off multiple layers of sound glue, only to replace them again.
+1 for quality control!