I thought I did a good job applying a patch to my tube. The air stayed in for a few minutes and then it all came out. Do you folks have any tips on how to apply a patch? I'm not sure what I did wrong!

surface prep is the important beginning.. I keep a piece of cloth backed metal prep "sandpaper" in my kit.

then the 'self vulcanizing' fluid is applied, let the solvent portion evaporate. the red part of the patch should merge well

remove any voids by stretching the patch and tube as one.

Let the "glue" dry completely before applying the patch. If you don't, it won't hold.

Don't try to substitute contact cement for the "glue" (vulcanizing fluid) that came with the patch kit.

As fietsbob noted, clean and scuff up the surface area around the puncture.

The only time I've had a patch fail was when I was impatient and didn't let the fluid dry.

Sand the area around the puncture using the sandpaper , apply the glue, let it dry, apply patch , your done .

Almost. Resist the urge to touch the glue to check if it is dry. The oils on your fingers can interfere with the bonding process.

My patch kit came with rubber cement, is that not as good?

I assume that whatever is in the kit is fine.

I'm no expert on glues / vulcanizing fluids - but I've tried to use regular DAP/Weldwood contact cement before and it didn't work for me. Maybe it was user error though.

It will work but it's not the best solution. "Rubber cement" is just bits of rubber dissolved in a solvent. It will stick but it's only an adhesive. Better patch kits (Rema Tip Top) use vulcanizing fluid which contains an accelerator in the fluid and a rubber forming compound on the patch (the red part of the patch). The accelerator reacts with the compound on the patch to form new rubber bonds...not in the adhesive "stick to it" sense but in the chemical bond sense. It's not just an adhesive but it forms new rubber which more permanently bonds to the tube than just plain rubber cement would.

Rema patch kits cost a little more than the Sunlite but they work more reliably and more permanently. It's worth the extra cost.

Or forget about the sticky kids stuff and use Park glueless patches like I do. Scuff the hole area, inflate the tube to it regular size, press on the the glueless patch, and hold it tight for maybe 10 seconds, and you are good to go.

I am running tubes that have Park glueless patches are more than 2 years old.

+1 on Rema Tip Top

After I've applied the patch I squeeze the tube really hard between my palms for a couple of minutes. You can feel the heat of the vulcinization process. I imagine this helps, but have no proof other than that my patches always stay on!

+∞ on Rema Tip Top patches. They work reliably, they're inexpensive, and they last practically forever. I've got some tubes that were probably patched a few decades ago that still hold air. And some of the guys in the Classic & Vintage forum are probably riding on Rema patches older than I am.

...although, with that said, the Sunlite patch kit should probably work, too, so long as you're prepping properly. Sand the tube around the hole, apply glue or vulcanizing fluid, let it sit 'til dry and tacky, then remove the patch's foil backing and apply. If the patch has a clear plastic film, consider leaving it in place so you don't peel up the patch trying to remove it. Install the tire, inflate, and ride.

I have a Park patch kit, $2US; had to fix a flat last month for the first time in a decade or so. I followed the directions in the kit, walking away from the tube while the fluid dried (time passed faster this way), and it worked perfectly.

About how long does it take for the glue to dry?

A few things I've learned... the hard way:

1. It's better to carry a spare inner tube and, if I get a flat while riding, to swap the tube, ride on, and fix the other one later on, at home.
2. After waiting for the glue (vulcanizing fluid) to dry -- and I mean waiting the full seven minutes -- I apply the patch and clamp it under moderate pressure, in a vise, for thirty minutes.
3. Once I release the newly-patched inner tube from the vise and peel off the plastic "cover", let it cure for 24 hours, before testing and using it.

These might seem "over the top", but they've proved to be true. Of course, YMMV.

it takes three to five minutes. I bought my patches in Bulk. Got 100 of them and a can of Green Slime rubber cement for patches and tubes. The can comes with a brush. It has saved me a lit of time and trouble because I no longer have to be super stingy with the glue. I sand the whole area bigger than the patch. I apply glue to an area bigger than the patch. I haven't had a failure since getting the bulk kit. I now will sometimes patch a tube twice maybe even three times before switching to a new tube.

My routine is:
1. Sand the area
2. apply glue using the tube tip to spread it (no fingers.)
3. wait LOOONG time for glue to dry
4. remove backing from patch and carefully place over hole.
5. there's no second tries for placement; if you mess up, start over now!
6. firmly roll/press the patch into the glue and let sit another LOOOONG time.
7. after a zillion years, it's OK to remove the plastic from the other side of the patch, but usually I leave it on and reassemble the tire.

Like everyone else says. I also only use the Rema patches. On the road I wait about 5 min for the "glue" to dry. I have a set of those plastic "sport" levers and use one of the levers with the red "holder" as a backing to press down on the patch after applying it. At home I let the glue sit for half an hour or more while doing something else. Someone suggested using one of those tools for rolling in screen splines; I had one in my toolbox and I started using that at home, really going over the applied patch in different directions (in particular along the mold seam) and that seems to really get the patch on tight. I've never bothered removing the "cellophane" plastic on the top of the patch.

Note that the Rema patches have 2 versions like Touring TT01 and TT02. One (forget which) has more of the round patches. I've never had a need for the oblong patches on road tubes. I probably have twenty of them in one of the Rema green boxes left over.

scott s.
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If the hole is along a seam/ridge in the tube, I sand it down smooth before patching.

Don't forget to find the cause of the hole before putting the tube back. One piece of glass can cause many flats.

Which Rema type would you recommend on a MTB?

Over the decades of patching hundreds of tubes on bikes (and cars back in the day) the main reason I have found that patches don't hold is that the inner tube surface was not prepped properly. Those metal scratchers that come in cheap kits don't work. Regular sandpaper is ok. Usually the sandpaper that comes with a good kit is pretty good to (albeit too small though). I use a small swatch of emory paper from a roll of plumbers sandpaper. Hey, it's what I have on hand. The main thing is it's got to be sandpaper. Oh, I don't know, 100 grit maybe? If you have a Dremel tool, the little sandpaper drums are awesome and make for a fast prep job! We used to use an air sander in the old filling station I worked at. Ummm, be careful to not burn through the tube....

Rough up the area all around the hole. That roughed up area needs to be a good bit bigger than the patch one intends to use. Now, rough it up some more. A little more, ....just a few more strokes. Look good? Nice and clean? Darker than the surrounding rubber? Ok, now give it a few more strokes with the sandpaper. Ok, now apply the rubber cement. Use the stuff that comes in the kit or, like me if you're at home, get an 8 oz can of vulcanizing fluid at the auto parts store. It has to be glue that comes in a patch kit or is used for patching tubes. Let glue dry completely (as previously stated and this is important for the reasons given).

Now apply a SECOND thinner coat of glue. Yup. Let dry and slap the patch on and use your pump head or the bottom of a CO2 capsule to really rub the patch on. Sprinkle a little bit of dirt on the patch (or talc if you have it) and mount back on the bike. The dirt and talc keep the patch from adhering to the tire.

Here is another tip that I figured out over the years: If you partially inflate the tube (oh, maybe 1/3 full of air) AFTER you apply the second coat of glue and slap the patch on that inflated tube, the tube tends to not distort so much once it's inflated all the way when on the wheel. I don't notice this on my mountain bike but on my 23c tires on my road bike if I don't do this I do notice sometimes a bump where the patch is. If you put a patch on an un-inflated tube and inflate it, watch what happens. Yep, the tube stretches around the patch. That's what makes that little bump on the tire.

I'll be perfectly honest here though. I use the Park self-sticky patches out on the road. Same deal though, you have to really rough the tube up good or those won't stick for long either.

Why the Park patches instead of regular patches on rides? Because I don't have to worry about a small tube of glue hardening up. I just slap a patch on and go. And as a previous post said, the Park patches do last a long time if put on right.

Sorry for the dissertation on patching but it really isn't that hard as long as you follow the good advice given on this thread. And yes, I buy Rema patches too...the 100 box...because I live in the desert where we have a lot of thorns.

That sort of kit works great and will make permanent patches. I've used similar for decades without problems unless I mess it up (sloppy, impatient).

Just follow the directions. Sand an oversized area, apply the glue, wait for it to dry, apply the patch.

Look at Youtube if you are uncertain.

I agree. I've been using glueless patches for over 15 years, maybe closer to 20 years, and in all that time I only had one patch fail.

HOWEVER, I've never had to inflate the tube to it's regular size to make a glueless patch work. All I do is buff the tube of an area slightly larger than the patch will cover, carefully peel the patch off the backing so as to touch only the smallest area possible (just a corner), apply the patch dead center over the hole, then as firm as you can you press the patch onto the tube for 30 seconds then look at the patch and if you see a section that looks cloudy press that area again for 30 seconds.

A glueless patch will hold for the life of the tube if done correctly but they do not work on latex tubes. I've had as many as 15 glueless patches on a in use tube that was 5 years old. They also will hold on a deflated tube used for a spare for a long time, so long it will outlast the tube.

Not all brands of glueless patches are good though, I use the Specialize Fatboy patches, but the Park is also good, they may be made by the same company? All other brands I would stay away from.

I think I probably wasn't rubbing hard enough when sanding (The tire should look different after sanding the area, right?)

DON'T rub too hard or you'll rub right through the tube! You just want to take the "shine" off, which when that happens it's actually roughing up the tube slightly, you should not see small groves cutting into the surface of the tube, that means you're rubbing too hard. Again just lightly sand it just enough to take the shine off the surface of the tube.

morgothaod,
Do not you have steps to follow on your kit or glue? Usually there are and they are the best for the glue.

I have patched tubes using similar kits and just pieces of another tube in combination with glue for rubber. I never had a problem with the patch.
But I always press the patch overnight by something really heavey like bed. Couple of times i tried to put tube in the wheel and pump it up to 58 PSI right after patching and it worked well too.

I hope it was just a bad luck for you and you will not have this problem any more.