Eli_Damon

I have read several threads about patching tubes using rubber cement and bits of old tubes. I am not especially interested in this for its own sake since I don't get punctures very often. However, I would like to make other stuff by gluing pieces of old tubes together. I tried to glue some pieces of tube together but it didn't work. Can any of you figure out what I did wrong? I sanded the shiny coating off of the rubber surfaces. I spread some Camel type C universal cement that I got from an auto parts store onto the surfaces. I waited for it to dry. Then I stuck them together. But they don't stay stuck. How can I make them stick and become a single, continuous piece of rubber? Thanks. Eli

jjciiijs

I am not sure about the cement you used, but here is the proceedure, which could be used with rubber cement or JB weld. You know, rubber cement works great.

clean rubber (acidtone is fine)
scuff rubber (kill shine)
clean rubber
cement
add light presure until dry.

bmorey

That's acetone (dimethyl-ketone).

BCRider

Art store rubber cement isn't the stuff you want. I'm not sure what the stuff is that we use for patching but it is more like the old solvent style contact cement but not as smelly. But if you can still get the old style contact cement then it'll work fine.

Either way regardless of which you use the tube with the hole and the section of old tube both need to be scuffed well to get under the surface skin. And really unless you can see that it is contaminated with something there's no need to clean it with any sort of solvent. Just use some coarse sandpaper or the little cheeze grater that comes with patch kits then straight on with the glue. Let dry until it is dull and only has a slight solvent smell compared to the wet glue smell. Then squeeze together for a few seconds and you're done.

DannoXYZ 

Rubber cement IS NOT the same kind of stuff as vulcanizing fluid. Some cheapo patch-kits (or people) use rubber-cement and it does work. But only barely, which will work for 90% of patch jobs. But rubber-cement just glues the rubber patch on. At any later time, you can peel that patch off cleanly.

Vulcanizing fluid actually chemically fuzes the rubber together. There is no longer a separate layer between patch and tube, they are one. If you try to peel off a patch that's been applied with vulcanizing-fluid, you'll end up tearing the patch or tube. There's no way to separate the two.

The other thing you want to work on is technique. You need to sand and scuff off ALL of the shiny surface of the tubes. There's a mould-release compound on the surface that'll prevent the vulcanizing fluid from acting on the rubber. If you watch how the auto-mechanics use the Camel patches, they use a die-grinder with wire-brush on the tyre to remove the shiny surface down to deep black. Not just scuff it up to grey, but remove the top layer completely.

And you do want to be careful about the amount and timing of the application. Don't use the tip of the tube to apply the glue and smear it around, you'll contaminate the tube. Also you end up with way too much fluid that's applied in streaks with thin and thick spots; some of which have already dried for too long. Instead, drop a corn-kernel drop into the centre of a sanded spot. Then use the other mating piece (or patch) and use that to smear the glue apart evenly. This gives you fast application time so all parts of the gue will have the same "air" time. And it gives a nice even layer. Wait 30-45 seconds and press the parts together. Do not move for 60-seconds. And then let it sit for a couple hours.

Grand Bois

The point of the sandpaper or cheese grater is to remove contaminants, not to roughen the surface. The proper solvent will work even better.

https://www.sheldonbrown.com/brandt/patching.html

G piny parnas

ya,vulcanizing fluid--- you have to melt/fuse tubes together--- and many come with silicone powder( contaminate) and why are we doing this anyway? and ..... I dont want to fuse my tubes together?