Tube repair failures !! I just don't get it !!
 

I've repaired more inner tubes with patches than I can remember !! One or two have failed but 99% have stayed on for 1000's of miles of no problem riding..

Right, me and my mate James are in Tanzania and suddenly (as if by magic), all our patches are falling off as are our repairs !

We have repaired the same holes time and time again. (6 flats in 24 hours in the baking heat is NO fun I can tell you).

The patches just wont stay on the tube... I have used three different brands of patches, glue etc. The same stuff I use at home with no issues...

Any ideas ??????

What I do to repair is.........

1. Thoroughly clean the contact area. Scrape away any old glue etc. Roughen it up with sandpaper etc.

2. Apply rubber solution to patch area and allow to go tacky for about 30-60 seconds.

3. Press on patch and apply pressure, working in the patch.

4. Waiting 5-10 mins.

The patch will hold on for a couple of hours or a hundred miles then start leaking and sometimes fall off.

I just don't get it !!! All I can think of is that it's the heat but my repairs lasted in 49c Sudan !! Can anyone think of a flaw in my practice or have any other info ?

I know patches are only meant to be a temp repair but on our trip, one spare tube is a luxury (and they have holes in too).

Cheers in advance, Ted

I clean with petrol between #1 and #2 and I never touch the rubber solution with my (dirty) fingers.

What kind or tubes do you use? Some brands are more or less impossible to patch.

Quick thoughts:,
could the patches have perrished in storage, exacerbated by the heat?
Is the tyre slipping round, pulling off the patches?
Could you try a repair late at night, when it's cooler incase the heat is drying the rubber out too quickly.
In Morocco the tyre repair shops put the patch and tube in a press while it cures.
Good luck

Ted, I agree with Alibaba on this one, a cleanish rag with a little gasoline on to remove any silicone from the mould when the tube was made or the inner of the tyre is essential...... try the gasoline trick, after all, what ya really got to lose?

Also try to let the glue 'set' up a little more...i like to leave it for about 2 or 3 mins to get very tacky, nearly dry, this makes it more like an impact adhesive..( remember the patch is also 'sticky' when you peel the film off...... then put the tube against something firm like a book and really press hard on the patch ( OK, Ok im teaching you how to suck eggs here...sorry)

Good Luck!!!

hello Ted
 

Hi Ted,

so you made to Tanzania on your expensive rear tyre ;-)

very good.

my first thought of your problem was:

the glue is old (the tube has been open for too long) so the new patches wont stick anymore.

but this wont explain why the old patches (that you put on a long time ago) would also come off.

I stoped using this TipTop (in the green box) patches after one came off with the heat in Australia - but I would still carry them for emergencies (always with new glue every six months or so)

As you know, most of the places in Africa that fix tubes dont use this patches, they cut up an old tube to make a patch, use their own glue and enough heat to *glue* and press them together. I never had one of this patches come off.

my advise: take the tube to a local tyre fixing place and ask the guy to take all the TipTop patches off and fix the holes with his method (make him clean the tube with petrol-or do it yourself). watch him and if you dont trust his job, go to another place.

At Alibaba:

*What kind or tubes do you use? Some brands are more or less impossible to patch.*

I have never heard of this, which brand do you mean?


Ted, enjoy your trip and ride safe
Greetings from Brazil
Mika

Hi Ted,

"Roughen it up with sandpaper etc."

You've planted that 'etc' where a whole lot of other stuff should be.
What do you use for roughening up? I long ago gave up with the stupid bits of paper you find in the repair kits. I use a cut-up fairly coarse (don't remember the grit No.) sanding band used on floor sanders.
And rub until every trace of moulding mark, embossed pattern or seam mark has gone.
That leaves a lot of powder and grit in the surface of the rubber.
AliBaba says to use petrol, which sounds pretty good. I never do, but give the surface a thorough flicking, not rubbing, with a clean cloth. Like you're dusting the Crown Jewels......

Either way you need to get rid of all that dust without further contamination. (But I'm sure you know all this anyway).
Then proceed as you describe.

But there's one other item that I use that's missing, and may be important when you're in a hot place.
The hotter it is, the more 'sticky' or 'tacky' will be the surface of the patch and the inside of your tyre. If the two stick together just lightly and you're not on the smoothest of roads, then the patch will be disturbed. (You probably know all this as well).
So use plenty of talcum powder, or something similar.
My advice, always have plenty in your puncture toolkit, and use it lots!
Imperial Leather works for me!

Hope that helps.
Enjoy Tanzania, for me it was a great place.

If you do not have access to "talcum powder" you can use any of the following.......

Grind up a "tums" between two spoons

look under your feet! NO not inside your socks, under you, yes, that's it! dirt..when dry dirt has various size particles, i have often used very dry soil or dirt as talc, just make sure it is very very very fine, and wipe off any "big" bits.....

powdered soup/drink/even powdered coffee

After all... all you need is to stop the adhesive from sticking to the inside of the tire... even an opened up tissue or paper napkin will work!

above all........ stay calm, and THINK "outside the Box"

M

All of the above.

One possible idea (I've never patched a tyre at 49C), the patches and the tube will have started to re-vulcanise at these temperatures for extended periods (starts at about 40C in natural and buna rubber hoses). This makes a "shiney" surface the glue can't flow in to to get a grip and ages the rubber making is brittle and hard. Fresh patches and keep them as cool as you can IMHO will help.

Andy

Good advice--after all local tyre shops do fix punctures several times a day and know what works.

What they actually do is to vulcanise it. Basically they cut a small piece of rubber to go where the hole is, then a larger piece of rubber to go over the whole area, use some sticky stuff to hold it in place temporarily, then place it between plates under pressure and heat the whole thing up using contacts and a battery. The heat fuses the pieces of rubber to the original tube.

Cost of the vulcanisation in Morocco is typically something like 30p per patch. The pic below shows me praying to help the process along.

Ted, you missed the "praying" part off your list. It's obviously the important final step!

at tim: very good picture

so, Ted, now you know what you did wrong. But dont forget the compass (or gps) to get the direction right.

Enjoy
Mika

WOW !! Thanks for all the great feedback..

Well, on the side of the road, I just roughen the area up with sandpaper or a rough stone etc. To get rid of all of the "shiney" or the old glue. Its dry rough rubber by the time I apply the glue..

I don't think it's the glue. It's been new, old, European, Ethiopian etc etc. The patches have been a variety too.

I think it's something to do with the heat and the patch RE-vulcanising. The patch is sometimes sticky, leaks then reseals itself. REALLY anoying.

The long days in the heat get the tubes literally, TOO hot to touch. It's unbelievable.

The local repairs have failed too. They use old rubber and contact adhesive as people have said.

I'll deffo try the petrol trick too. Nice one !


For now, we have new tubes in and they're holding.

Keep the ideas coming. It's very interesting :thumbup1:

You have to wait much longer until the solution is completely dry.

...just a silly thought, could it be the humidity? Is it a dry heat or are you in an area with high levels of humidity? Could the moisture be finding it's way into the glue/curing process and causing the problem?
Have you tried using artificial heat to accelerate the curing process and disperse any moisture !
good luck
K

I'd also wait a minute or 5...