Punctures. How to mark the hole?

[mikeymo]

So, repaired a puncture today.

Managed to find the hole, and marked it with a Sharpie. But by the time I'd roughened the surface with 800 grit W&D, used Isopropyl alcohol to clean it, 3 layers of glue, etc., as per...

https://www.tenerife-training.net/Tenerife-News-Cycling-Blog/how-to-patch-an-inner-tube-the-right-way/

...it was difficult to see where the actual hole was.

Is there some of technique to mark the hole, that will survive the cleaning and leaving-the-glue-till-tacky process.

Thanks.

[Jdsk]

Yellow wax crayon in the kit. Four marks forming the corners of a square which has the hole at the centre (or any other pattern that you prefer) far enough apart to not be removed by the sanding and glue.

(In practice I often do it by eye and memory using tube position and markings, but if you want to label this method works fine.)

Jonathan

[mikeymo]

Yellow wax crayon in the kit. Four marks forming the corners of a square which has the hole at the centre (or any other pattern that you prefer) far enough apart to not be removed by the sanding and glue.

(In practice I often do it by eye and memory using tube position and markings, but if you want to label this method works fine.)

Jonathan

Ah, I see.

I'll ask for my money back, no wax crayon in my kit!

Daughter is doing an art course, she's bound to have something suitable.

Thanks.

[tatanab]

Don't bother about it. For cleaning/abrading you know where the hole is because you can see it or hear it. Adhesive is applied to a larger area than the patch. if you cannot see the hole any longer, a little air in the tube will cause the covering of glue to burst or bubble at t just that point so you see where to centralise your patch.

[Psamathe]

Note the distance from the valve (approx or hand spans or a broken twig, etc.).

Ian

[mikeymo]

Don't bother about it. For cleaning/abrading you know where the hole is because you can see it or hear it. Adhesive is applied to a larger area than the patch. if you cannot see the hole any longer, a little air in the tube will cause the covering of glue to burst or bubble at t just that point so you see where to centralise your patch.

That's an idea, thanks.

(though I am following the "suck all the air out" recommendation in the linked web page. Probably pointlessly)

[PH]

I mark a large cross in biro, larger than the area to be cleaned, I can se where they would intersect even though I can no longer see that.

[elPedro666]

Also use the excessively large X marks the spot method, but with the wax crayon thingy, so when you've lost the centre of the cross you're still able to visualise it. Although generally I'd hope that the hole is in the middle of the area you've prepped! [emoji6]

I'm a trendy consumer. Just look at my VOG-L09 using hovercraft full of eels.

[drossall]

Don't bother about it. For cleaning/abrading you know where the hole is because you can see it or hear it. Adhesive is applied to a larger area than the patch. if you cannot see the hole any longer, a little air in the tube will cause the covering of glue to burst or bubble at t just that point so you see where to centralise your patch.

+1

[GideonReade]

No need for an "X", only need one line. 'Cos the hole is always right on the seam!

[sjs]

I mark a large cross in biro, larger than the area to be cleaned, I can se where they would intersect even though I can no longer see that.

Never thought of that, but I do make biro marks far enough away not to be affected by the abrading and near enough so that I can estimate the centre with good enough accuracy

[kylecycler]

I'm almost embarrassed to ask, I should know, I've repaired countless punctures, but I've often had the same problem as the OP - am I the only person who finds that the yellow crayon (even when you have one), doesn't necessarily work? Does it help if you rub it against a rough surface first? I got another one out of a box of crayons but it didn't work either.

I think I might have tried a Tippex pen once but I've forgotten whether it worked or not (or even where it is now!). I think it did, though.

[Jdsk]

I'm almost embarrassed to ask...

No need. Ignorance is very rarely a problem as it can be solved by knowledge. Stupidity is a different matter. : - )

It's a good bet that whenever someone asks this sort of question there's a whole load of others who'd like to know the answer too.

Jonathan

[gregoryoftours]

Yep big cross hairs with a biro means you can still see exactly where the puncture is even after roughing the area up and spreading the cement. I only repair punctures at home or at the end of the day when touring so I'll have a pen handy.

[peetee]

Find the hole and press the tip of you finger on it. Where the bulge is on the flip side make a mark (if you want - I don’t bother). Put your thumb on this and your foot through the loop at the other end of the tube pulling it tight and grasping the tube in your fist. You can now efficiently rough up the tube in the right place ready for the glue and patch.