Puncture repair-why allow for glue to dry?

dinneenp

Hi,
When repairing a puncture-apply glue, leave dry & then apply patch.
Why do you leave the glue dry? Does the patch have an adhesive that sticks easily to a dry glue?

Also, some say to apply several layers of glue, allowing it to dry before applying the next layer of glue
What are the thoughts on this?

Thanks,
Pa

07Lapierre

The glue is wet so it doesn’t go solid in its container. Once you apply the glue to the tube, it reacts with the air and the chemical that keeps the glue from sticking evaporates.

Or something like that I believe.

dinneenp

07Lapierre wrote: »

The glue is wet so it doesn’t go solid in its container. Once you apply the glue to the tube, it reacts with the air and the chemical that keeps the glue from sticking evaporates.

Or something like that I believe.

But you could apply the patch quickly, while the glue is still not fully dry. But you're meant to wait till its fully dry. I'm wondering why, normally you attach something to glue before it dries...

mrcheez

dinneenp wrote: »

But you could apply the patch quickly, while the glue is still not fully dry. But you're meant to wait till its fully dry. I'm wondering why, normally you attach something to glue before it dries...

When attaching two things using glue as a bridge then you stick them together when the glue is wet so that it holds them in place.

In the case of the patch, the glue acts as a sealant rather than a glue for the patch, so you need to let the "sealant" dry before you apply the air-tight patch.

Timberrrrrrrr

Applying the patch to the glue while it's wet means it takes longer to dry as the air isn't getting at it, the patch can also slip off the surface you want it.

Applying while its semi dry means it is stickier when applied and will stay in place better.

07Lapierre

Suggest you try it. Next time you have to repair a tube, apply the patch quickly and see what happens. My guess is it’ll be fine at first, but over time (a few weeks) the patch will eventually lift resulting in a slow puncture.

80j2lc5y7u6qs9

dinneenp wrote: »

Hi,
When repairing a puncture-apply glue, leave dry & then apply patch.
Why do you leave the glue dry? Does the patch have an adhesive that sticks easily to a dry glue?

Also, some say to apply several layers of glue, allowing it to dry before applying the next layer of glue
What are the thoughts on this?

Thanks,
Pa

Long time since I did it but you don't leave it dry completely do you. Isn't it still slightly sticky to hand when you apply it?

Tony04

dinneenp wrote: »

Hi,
When repairing a puncture-apply glue, leave dry & then apply patch.
Why do you leave the glue dry? Does the patch have an adhesive that sticks easily to a dry glue?

Also, some say to apply several layers of glue, allowing it to dry before applying the next layer of glue
What are the thoughts on this?

Thanks,
Pa

Ive always put the patch on immediately after gluing and never have had an issue

07Lapierre

Derek Sticky Violoncello wrote: »

Long time since I did it but you don't leave it dry completely do you. Isn't it still slightly sticky to hand when you apply it?

That’s correct... it should feel sticky.

velo.2010

Cyclesuperstore are doing 4 Conti race tubes for 20 euro ATM.

Mav11

I find the self adhesive patches from halfords to be excellent. Never had an issue and no messing with glue.

magicbastarder

i guess what you're waiting to allow dry is just the solvent to allow the glue to be workable, it's not actually a functional part of the glue itself.

07Lapierre

Slightly off topic but do people still repair punctures nowadays? I thought it was just me. (I wait till I have about 10 punctured tubes and I go out to the garage and fix them all )

magicbastarder

that's what i did. recently repaired six tubes, discarded two or three as not worth fixing. i puncture rarely enough that it took me several years to get to the 8 or 9 tubes.

cletus

Glue has water in it to prevent cohesion inside the bottle (that's why it doesn't set or go off in a sealed container.)

Allowing the glue to get tacky or "go off" let's the water evaporate. That just leaves the glue polymers, which is what causes adhesion.

You can apply the patch before it goes off, but it's easier to get good adhesion if you wait

eeeee

07Lapierre wrote: »

Slightly off topic but do people still repair punctures nowadays? I thought it was just me. (I wait till I have about 10 punctured tubes and I go out to the garage and fix them all )

I do the same and repeatedly. Those with only one patch can go back in the front of the road bike, 2+ patches live on the back. No patches in the track bike.
Infinite patches in the commuter (up to 6 in the old commuter )

crosstownk

If you allow the vulcaniser to cure for a minute or so the patch will stick and stay in place. Wet vulcaniser can result in the patch sliding about on the tube.

I repair tubes. I don't see any point in binning a tube that can be easily repaired. It takes less than 10 minutes to patch a tube. Even latex tubes repair easily.

Another thing to bear in mind is that the small tube of vulcaniser will go off after time once it's been opened. It may be hard and useless the next time you need it.

I've gone tubeless on one bike so hopefully that'll be less patching.

eeeee

How do you repair a latex tube? I always thought they were unrepairable? I have only seen them be completely blown to pieces when they fail.

crosstownk

eeeee wrote: »

How do you repair a latex tube?

Exactly the same as a butyl tube. They take a patch readily. Some reckon a latex tube repair is better than a butyl repair.

I haven't had any blow out but I have had pin prick punctures caused by shards of glass.

Wishbone Ash

Tony04 wrote: »

Ive always put the patch on immediately after gluing and never have had an issue

:eek: Pure luck I'd say - normally that's a disaster

07Lapierre wrote: »

... (I wait till I have about 10 punctured tubes and I go out to the garage and fix them all )

For me that would mean a visit to the garage every 10 years or so!

crosstownk wrote: »

...I repair tubes. I don't see any point in binning a tube that can be easily repaired. It takes less than 10 minutes to patch a tube. Even latex tubes repair easily.

Another thing to bear in mind is that the small tube of vulcaniser will go off after time once it's been opened...

You've sort of answered your own question. As it goes off, it just easier to buy a new tube than waste money on repair kits.. If I know in advance that I'm going to do a long ride (i.e. a 200/300 audax for example) I'll buy a puncture repair kit in case I get more than 2 punctures on the ride. Otherwise I just use a new tube on normal rides. That said, I use puncture resistance tyres so it's not really an issue.

crosstownk

Ah but the satisfaction of repairing and reusing is important! Less throwaway and more recycling despite the inconvenience.

Latex tubes are significantly more expensive and therefore worth repairing.

Wishbone Ash

crosstownk wrote: »

Ah but the satisfaction of repairing and reusing is important! Less throwaway and more recycling despite the inconvenience.

Latex tubes are significantly more expensive and therefore worth repairing.

Fair enough. I rarely pay more than €3.50 for a tube and probably buy about one or two annually so repairing them isn't really a priority.

I've a slow one on the rear driver side in the car that needs to be looked at tomorrow. Why don't we put sealant in those? Too wide so that we'd need too much to be effective?

Also when did thay start charging for Air at petrol stations, cost me a euro earlier and they didn't have the chart of pressures I remember them having from my youth :mad:

crosstownk

[Deleted User] wrote: »

I've a slow one on the rear driver side in the car that needs to be looked at tomorrow. Why don't we put sealant in those? Too wide so that we'd need too much to be effective?

Also when did thay start charging for Air at petrol stations, cost me a euro earlier and they didn't have the chart of pressures I remember them having from my youth :mad:

While you can’t fill your car tyre with a prophylactic sealant (that I’m aware of) you can get sealant for car tyres. Most new cars come with a sealant and compressor repair kit rather than a spare wheel. It’s a temporary repair so you’ll still need a proper puncture repair. There are also run flat tyres.

Your recommended tyre pressure is on a sticker somewhere - usually inside the fuel filler flap or on a door jamb.

Man with broke phone

cletus wrote: »

Glue has water in it to prevent cohesion inside the bottle (that's why it doesn't set or go off in a sealed container.)

Allowing the glue to get tacky or "go off" let's the water evaporate. That just leaves the glue polymers, which is what causes adhesion.

You can apply the patch before it goes off, but it's easier to get good adhesion if you wait

What if i told you glue goes dry when it reacts to water vapour in the air.

crosstownk

crosstownk wrote: »

While you can’t fill your car tyre with a prophylactic sealant (that I’m aware of) you can get sealant for car tyres. Most new cars come with a sealant and compressor repair kit rather than a spare wheel. There are also run flat tyres.

Your recommended tyre pressure is on a sticker somewhere - usually inside the fuel filler flap or on a door jamb.

Yeah thats exactly where it is when i went looking for it when I got home, on the fuel flap (haven't had a car puncture in quite a while as you can guess) on the tyre it only gave the max which was 51psi

The flap did indeed have a handy chart hidden as it was inserted backways by a previous owner.

dinneenp

07Lapierre wrote: »

Slightly off topic but do people still repair punctures nowadays? I thought it was just me. (I wait till I have about 10 punctured tubes and I go out to the garage and fix them all )

It was the first ride on my new Canyon road bike and all. No idea if it's a better tube than a standard one but also get a sense of achievement at repairing your first tyre (in years)

cletus

Man with broke phone wrote: »

What if i told you glue goes dry when it reacts to water vapour in the air.

I'd say that you could very well be right, I'm very often wrong on a wide array of topics, and if my (mis) informative statement on the sticky topic has caused anyone to improperly use, apply or store their glue, or resulted in harm, alarm or the subsequent spreading and dissemination of said misinformation, then I duly apologise

*Edit* Even though I admit to being wrong about many things, it still irks me, so I went and had a quick Google. It appears you are correct...and so am I.

Mechanical adhesion results from water(as a solvent) evaporating from the glue polymers, creating van der Waals forces

Chemical adhesion, in cyanoacrylate (super glue) occurs when it reacts with water vapour.

The glue in your patch kit is a vulcanising fluid. It allows for a chemical bond between the rubber of your tube and the patch that happens once the solvents evaporate. These solvents are not water, but more volatile compounds like acetone or toluene. As to whether they require the presence of water, as in the case of cyanoacrylate, I haven't been able to establish yet, but it doesn't appear so

cletus

[Deleted User] wrote: »

I've a slow one on the rear driver side in the car that needs to be looked at tomorrow. Why don't we put sealant in those? Too wide so that we'd need too much to be effective?

Also when did thay start charging for Air at petrol stations, cost me a euro earlier and they didn't have the chart of pressures I remember them having from my youth :mad:

The emergency tyre sealant that now gets supplied instead of a spare wheel has its own issues. Normal practice is (or has been) to replace the tyre, as the resultant foam inside the tyre renders the tyre unrepairable. Tyreweld, a company that makes such sealant, say that it's water based and can be washed out before repair, but anecdotally at least, I've heard replacement is the only option

Irish_peppa

Deleted User wrote: »

I've a slow one on the rear driver side in the car that needs to be looked at tomorrow. Why don't we put sealant in those? Too wide so that we'd need too much to be effective?

Also when did thay start charging for Air at petrol stations, cost me a euro earlier and they didn't have the chart of pressures I remember them having from my youth :mad:

Pre charging for air, the amount of times i visited garages where some scrote had damadged the air pump or abused it and put it out of action was unreal. Since they started charging the 1 euro i cant recall the last time I visited a garage with a broken or out of order air pump. SOME People will abuse/have no respect for what they get for free. Sad but true.

magicbastarder

Man with broke phone wrote: »

What if i told you glue goes dry when it reacts to water vapour in the air.

as cletus mentioned, there are different types of glues. CA glue does cure rapidly when exposed to moisture in the air; IIRC it was invented as a battlefield glue for gluing wounds closed more quickly than stitching, and was activated by the moisture in the wound.