How to Patch your tube!!

A tube patch either holds for years or lifts in a fortnight, and the difference is almost always surface preparation and cure time. Les Walters works through the whole repair in the video, including the two bits most home repairs get wrong.

Les Walters on properly repairing a tube bladder — 4 minutes 48 seconds.

This follows on from how to locate a leak on your tube. If you have not pinned down where the air is going yet, start there — a good repair on the wrong spot fixes nothing.

What you need

• A pen or marker
• Very coarse sandpaper — 40 or 60 grit
• Vinyl repair glue
• A patch kit
• Sticky tape
• Padding — a foam buffing pad, sponge, or any soft springy rubber
• A heavy weight, around 20 kg
• Methylated spirits and a clean rag or paper towel

Patching the bladder, step by step

Mark the hole before you do anything else

Draw a couple of lines marking the centre of the hole so you can find it again once the area is sanded and covered in glue. Confirm it is the only leak while you are at it — there is no point patching one hole if there is a second.

Place the patch and draw around it

Sit the patch over the hole and draw a circle around it on the bladder. That circle is now your working area: everything inside it gets sanded, and everything inside it gets glued.

Sand back to matte with coarse paper

Use very coarse sandpaper — 40 or 60 grit. Work over the whole circle until all the gloss is gone from the PVC. Removing the gloss is what lets the glue key into the vinyl; a polished surface will not hold, which is why fine paper is the wrong tool here.

Scuff the patch as well

Do exactly the same to the back of the patch — scuff it until the gloss is off. It is half the bond and it is the half people skip. Mark the top side of the patch with your pen while you can still tell which way up it goes.

Clean both surfaces

Wipe both the sanded circle and the back of the patch with methylated spirits on a clean paper towel or rag. This lifts the sanding dust and any oil off your hands. Acetone can be used with care, but metho is the easiest to work with.

Glue inside the circle

Apply the vinyl repair adhesive evenly inside the drawn circle, working in a circular motion for coverage, and make sure it gets into any creases. Some adhesives go on one surface, some on both — gluing both surfaces makes it less likely you miss an area. Read the instructions that came with your adhesive rather than following any guide blindly, this one included; they are not all the same.

Position the patch and tape it down

Lay the patch inside the circle, lined up with your marks. Then run sticky tape over the top. The tape does two jobs: it holds the patch exactly where it needs to be, and it stops the glue squeezing out the sides and sticking to the weight you are about to put on it.

20 kg on a foam pad for 24 hours

Put something soft and springy over the patch — a foam buffing pad, a good sponge, any soft compliant rubber — so the pressure spreads evenly across the whole patch rather than pressing on one spot. Then put roughly 20 kg on top of that. Leave it for a full 24 hours while the glue sets into a permanent bond, and do not inflate the tube before that 24 hours is up.

After the 24 hours

Take the weight and the tape off, put the bladder back in its cover, and inflate it as a test. Our guide to inflating your tube correctly covers doing that properly — and the habits that stop the next leak, since heat in the sun does more damage to tubes than anything sharp.

Common questions

What sandpaper do I use to patch a tube?

Very coarse — 40 or 60 grit. You are trying to remove all the gloss from the PVC so the adhesive can key into it. Fine sandpaper polishes the surface instead of roughening it and the patch will not bond properly.

Do I need to sand the patch as well as the tube?

Yes. Scuff the back of the patch until the gloss is gone, exactly as you do on the bladder. The patch is half the bond surface, and leaving it glossy is one of the most common reasons a repair lifts.

How long does tube patch glue take to cure?

A full 24 hours under weight. Do not inflate the tube before then. Shorter cures under pressure are the other common reason a patch fails.

How much weight should I put on a tube patch?

Around 20 kg, sitting on a foam pad or sponge so the pressure is spread evenly over the whole patch rather than concentrated in one spot.

Can I use acetone instead of methylated spirits?

Yes, with care. Metho is easier to work with and less likely to cause you problems, so it is what we use.

Why do I need to tape over the patch?

Two reasons. It holds the patch in position while the glue grabs, and it stops any glue that squeezes out the sides bonding to the weight you have sitting on top.

Do I glue one surface or both?

It depends on the adhesive — read its instructions. Where both is an option, gluing both the bladder and the back of the patch makes it less likely you leave a dry spot.

What if I cannot find the hole?

Work through our leak-finding guide first. Most of the time it is a cross-threaded Boston valve rather than a puncture, and soapy water will show up anything too small to hear.

Related guides

• How to locate a leak on your tube
• How to correctly inflate your tube
• Resource Centre — fin settings, fit guides and the rest of the how-to videos.

Shop the gear

• Tube repair kits, pumps and accessories
• Ski tubes

Not sure whether yours is worth patching or replacing? Send us a photo and we will tell you straight.