tube patch 'blows a bubble' then pops

[email hidden] (larry english) wrote in news:abbf1007.0308130750.38efd665 @posting.google.com:

Quoted message said:

several times, i have had a tube patch 'blow a bubble' at the edge of the patch, then the
bubble pops.

Sounds like the patch wasn't bonded properly the first time. Use the sandpaper in the patch kit to
carefully clean the entire patch area. If you're using a glue-on type patch, make sure you use
enough glue to cover the entire patch area (and a little more).

In article said:

several times, i have had a tube patch 'blow a bubble' at the edge of the patch, then the
bubble pops.

Is it perhaps possible that you got a "snake bite" puncture (two parallel small slits due to
"bottoming out" on a hard bump) and only noticed one of 'em? The patch might coincientally barely
cover the second hole, and be likely to fail over time.

If not, the first suggestion is right on. The reason most people can't get patches to hold is that
they don't sand enough. I use a sanding drum in a Dremel tool, which requires a little bit of
practice to avoid destroying the tube. It has been claimed in this group that any sort of
hydrocarbon solvent that removes the glossy sheen from the tube will be sufficient, but that
approach won't remove the ridges and other embossed patterns in the tube that always seem to be in
the area of the puncture.

A properly applied Rema patch will not fail.

Art

Something isn't sticking right...

If it's a glued patch sand the tube, apply "glue" (actually vulcanizing fluid) and LET IT DRY, then
put the patch on and hold it in place with firm pressure for a few seconds.

Sanding is important when using quickie pre-glued patches, too.

Mike Yankee

(Address is munged to thwart spammers. To reply, delete everything after "com".)

(larry english) may have said:

several times, i have had a tube patch 'blow a bubble' at the edge of the patch, then the
bubble pops.

it;s almost like an orange bubble gum bubble.

the patch had been on there for weeks, it wasn;t fresh.

what causes this?

This used to happen to me years ago whenever I got in too much of a hurry fixing a puncture that was
adjacent to a molding ridge in the tube's surface. If the area around the hole wasn't completely
flat, the patch had to be clamped under a fair amount of pressure while the glue bonded..and then it
eventually failed anyway. I learned to make use of the sandpaper to remove that ridge before
applying the glue. I also learned that a diamond-grit coarse nail file can come in handy at such
times; it stays sharp a lot longer than sandpaper. Modern tubes don't seem to be as heavily
afflicted with the surface features that I used to see, so the need for buffing is less than it was
back then...but not entirely absent.

Quoted message said:

can you patch over a patch?

I wouldn't recommend it, for a variety of reasons, not all of which apply at the same time.

Quoted message said:

this is even worse - the corner of a patch, which of course is even more likely to leak.

I have seen little or no difference in the results obtained with round vs square patches, and can't
recall that corners of square patches were prone to any more problems than anywhere else. I'd say
that location has more to do with the likelihood of a patch failing than anything else. My
experience has been that the number one least successful patch locale is adjacent to the stem; if I
get a leak there, I trash the tube and throw a new one in.

--
My email address is antispammed; pull WEEDS if replying via e-mail. Yes, I have a killfile. If I
don't respond to something, it's also possible that I'm busy.

Arthur Shapiro said:

Quoted message said:

several times, i have had a tube patch 'blow a bubble' at the edge of the patch, then the
bubble pops.

Quoted message said:

Is it perhaps possible that you got a "snake bite" puncture (two parallel small slits due to
"bottoming out" on a hard bump) and only noticed one of 'em? The patch might coincidentally barely
cover the second hole, and be likely to fail over time.

I'm with you on that. The symptom points directly at that. However, it might be worthwhile to review
the FAQ patching item.

draco.acs.uci.edu8b.1.htmlOpen ↗

Jobst Brandt [email hidden] Palo Alto CA

In article <[email hidden]>, [email hidden] (larry

english) said:

several times, i have had a tube patch 'blow a bubble' at the edge of the patch, then the
bubble pops.

it;s almost like an orange bubble gum bubble.

the patch had been on there for weeks, it wasn;t fresh.

what causes this?

Inadequate prep with the sand paper or not allowing the glue to dry before putting the patch on
comes to mind (from my own mistakes).

Quoted message said:

can you patch over a patch?

I do regularly.

Tom Gibb <[email hidden]

Werehatrack said:

(larry english) may have said:

several times, i have had a tube patch 'blow a bubble' at the edge of the patch, then the
bubble pops.

it;s almost like an orange bubble gum bubble.

the patch had been on there for weeks, it wasn;t fresh.

what causes this?

This used to happen to me years ago whenever I got in too much of a hurry fixing a puncture that
was adjacent to a molding ridge in the tube's surface. If the area around the hole wasn't
completely flat, the patch had to be clamped under a fair amount of pressure while the glue
bonded..and then it eventually failed anyway. I learned to make use of the sandpaper to remove
that ridge before applying the glue. I also learned that a diamond-grit coarse nail file can come
in handy at such times; it stays sharp a lot longer than sandpaper. Modern tubes don't seem to be
as heavily afflicted with the surface features that I used to see, so the need for buffing is less
than it was back then...but not entirely absent.

Not sure that I'd agree with this. I've had no problems at all with ridges or texture as long as I
carefully sand all of the mould release off of the tube (no shiny or non-jet black places where the
patch goes), get glue everywhere and let it dry well (very important), and press the patch firmly
all over -- repeatedly to make sure that I didn't miss any places.

David

[email hidden] (Arthur Shapiro) wrote in message news:<[email hidden]>...

Quoted message said:

In article <[email hidden]>, [email hidden] (larry

english) said:

several times, i have had a tube patch 'blow a bubble' at the edge of the patch, then the
bubble pops.

Is it perhaps possible that you got a "snake bite" puncture (two parallel small slits due to
"bottoming out" on a hard bump) and only noticed one of 'em?

possibly.

Quoted message said:

The patch might coincientally barely cover the second hole, and be likely to fail over time.

If not, the first suggestion is right on. The reason most people can't get patches to hold is that
they don't sand enough.

i thought i read somewhere that the point was just to rough it up a little.

i didn;t think you had to grind it flat.

though it makes sense that ridges are going to cause a problem.

this one wasn;t near a ridge though.

wle.