Re-patch with different style of patch kit?

Question

I have an inner tube that I previously patched with one of those sticker patch kits, but the puncture was on a seam, and now the air was leaking out around the edges of the sticker.

I want to re-do the patch with a different patch kit, using vulcanizing fluid. What should I do to prep the site for the new patch?

I've already peeled the sticker off, but there's glue left behind, and I'm worried about how the glue will interfere with the vulcanizing fluid and or liquified rubber. Do I need to get all the glue off? If so, how should I do this?

Answer 1

Answer Yes, it's possible to repatch, and a good idea. Sticker patches are temporary, proper patches will last the life of the tube.

Method: I'd buff the area of the tube well using coarse sandpaper or the metal abraider tool in many patch kits. The purpose is to remove the outer layer of butyl rubber and leave exposed some fresh stuff. It will take off the remaining adhesive too. Buff a generously large area around the hole.

Then apply your fluid. Spread thinly over the whole buffed area.

Then go away for 5-10 minutes Failure to let the fluid "set up" is a common cause of patching failures.

Then stick a patch on top - not a sticker-patch either. Center it over the puncture hole, and press down firmly. I use a roller to push it home,

Finally, test-inflate till the tube stretches a little. This will cause the clear plastic backing to peel up for easy removal. Leave it inflated for an hour and after that time, if the tube is still firm, then it is a good patch.

I've carried stickers for years but rarely use them - they're only for when the spare tubes run out and I normally carry two. However stickers are good for helping others who might have different sized tubes and are stranded because of lack of preparedness.

If the patch doesn't work, you can try again by peeling the failure off and doing over, but tubes are consumables and there's definitely a point where you give up and use a fresh one.

Answer 2

I've had to do this before. I had decent luck using alcohol and a rag followed by sanding to get the adhesive off, but it was still left with some tenacious gummy residue. I used hot water and concentrated dish soap to scrub that off, let it dry, and then it was clean enough for light sanding to get it the rest of the way to where you want for a vulcanizing patch. There's presumably a solvent that can quickly obliterate the adhesive without hurting the rubber, but I have no idea what it is.

Answer 3

You need a razor blade, a piece of sandpaper to remove the mold release (don't use the cheap cheese graters that come with some poor patch kits), vulcanizing glue and the patch.

Firstly, remove the old patch. If it's a glueless patch this should be easy. If it's glue type patch, see "removing patches" here: https://www.sheldonbrown.com/brandt/patching.html

Secondly, cut the seam away near the place where you put the patch using the razor blade, carefully to not worsen the puncture. The tube should be completely seamless in the area where you intend to patch.

Thirdly, remove the mold release from the to-be-patched area from the tube using the sandpaper. Make the sanded area slightly larger than the area where you put the patch.

Fourthly, spread put vulcanizing glue with your finger around the area where you put the patch, making it slightly larger than the patch. Wait for it to slightly dry so it looks like a gel and not a liquid. Close the glue tube so that you push the glue at the tip by compressing the tube so that there will be no air bubble and then while compressing the glue tube to keep the air bubble removed, put the cap on.

Fifthly, remove the aluminum foil behind the patch so you have a patch on the transparent plastic only with no aluminum.

Sixthly, press the patch on top of the area you want to patch.

Seventhly, hold the edges of the patch and spread the patch and the tube to see if there's perforations that cause the plastic on top of the patch to spread into two pieces. If you don't see an opening crack in the middle of the plastic, you need to make the perforations yourself with the razor blade. Make a short half centimeter long cut in the middle of the plastic, carefully to not puncture the patch. Then spread the patch and the tube together. You should see that the cut spreads from the middle to the edges of the transparent plastic. You have now a patch on top of which there are two rectangular pieces of transparent plastic. Remove them starting from the middle of the patch.

It is important to note there doing the seventh step correctly is necessary. If you try to remove the transparent plastic from the side, the patch WILL lift. It will cause a poorly patched tube with a slow leak.

Now that you have a patched tube, put it away and hope you don't need to use it in the next 24 hours. It takes 24 hours for the glue to fully dry. The initial short wait was not enough for that. If you try to use the tube in the 24 hours, or if you do the seventh step incorrectly, you will have a slow leak. However if you carry only one spare tube and have to patch in the field, a very unlucky day with two punctures means there's no other option than to risk having a slow leak by using the patched tube in the 24 hours after patching.

The best patch kits (Rema Tip Top) used to have a perforation in the middle of the transparent plastic. Probably to save cost, it has been removed today at least in Rema Tip Top kits so you need to create it using the razor blade.