Super strong glue for plastics

[Veloo]

Anyone know of a glue that makes plastic as good (or better than) as new?

Frame pump mount cracked.

Handy for other things too, of course.

[rnhood]

The maker should just send you a replacement. No big deal. But I'd be looking at another pump if it were me. If it broke once then it'll probably break again.

[Black Dog]

JB- Weld plastic epoxy. There is nothing stronger. BTW, I have tried every type of glue, nothing comes close.

https://image.dynamixse.com/fit/300x450/webp.q80.png-lossy-85/https://dynamix-cdn.s3.amazonaws.com/jbweldcom/jbweldcom_802318292.jpg

Here is a test of various plastic glues and epoxies.

https://www.google.ca/url?sa=i&url=https%3A%2F%2Fwww.youtube.com%2Fwatch%3Fv%3Ddj tKXkTqPUI&psig=AOvVaw2iHnz0HLPtmX4O-lXPQmJG&ust=1595892981871000&source=images&cd=vfe&ved=0CA0QjhxqFwoTCLCugOqK7OoCFQAAAAAdAAAAABAN

[Veloo]

Where have you found this BD?
Crappy Tire has red and black but not yellow.

[Bentley]

Amazon has it. Appears the color is tan, not yellow

Ray

[Black Dog]

Where have you found this BD?
Crappy Tire has red and black but not yellow.

The red and black is more or less the same. Different cure time is the difference. I use the Red and Black. It sets in 15 minutes and is easier to work with since it has more open time.

[wallymann]

Anyone know of a glue that makes plastic as good (or better than) as new?

i dont think such a thing exists, especially if you have limited surface-area available to bond.

if you have a larger area to bond area and aesthetics dont matter too much -- adhesives can work because and can work even better if you can reinforce the joined bond with something mechanical like rivets or screws.

[Veloo]

Thanks.
Does a tube have much shelf life or does it tend to dry up like Krazy Glue after the one application?

The red and black is more or less the same. Different cure time is the difference. I use the Red and Black. It sets in 15 minutes and is easier to work with since it has more open time.

[p nut]

My pump mount cracked earlier this year. I just used super glue and sprinkled baking soda on top of it. Instant bond and is holding so far.

[weisan]

You would be surprised a lot of these frame pump mounts are interchangeable. I got a bunch of them from the co-op, they all work the same way, you pop the pump into the holder and it's really just the velcro strap that is holding it tight so it doesn't fall off.

[alancw3]

JB- Weld plastic epoxy. There is nothing stronger. BTW, I have tried every type of glue, nothing comes close.

https://image.dynamixse.com/fit/300x450/webp.q80.png-lossy-85/https://dynamix-cdn.s3.amazonaws.com/jbweldcom/jbweldcom_802318292.jpg

Here is a test of various plastic glues and epoxies.

https://www.google.ca/url?sa=i&url=https%3A%2F%2Fwww.youtube.com%2Fwatch%3Fv%3Ddj tKXkTqPUI&psig=AOvVaw2iHnz0HLPtmX4O-lXPQmJG&ust=1595892981871000&source=images&cd=vfe&ved=0CA0QjhxqFwoTCLCugOqK7OoCFQAAAAAdAAAAABAN

I would agree. jb weld is the best and like the poster I have tried them all. nothing comes close to jb weld. personally I like the 5 minute set time one.

[Tony]

Methylmethacrylate is what you what in a two part glue. It bonds certain types of plastic on a molecular level. Not all plastics can be glued, some need to be welded.

[JAGI410]

Thanks.
Does a tube have much shelf life or does it tend to dry up like Krazy Glue after the one application?

I just finished the 2 year old tube I had in my garage. As long as put the cap back on quickly, it'll be fine for a while.

[duff_duffy]

Just an FYI, some Epoxy’s may change color over time. Used the JB epoxy on tub a while back, looked great at first but turned yellower over time where the epoxy was still visible. Just an FYI if some leaks out or is used as a bit of filler (my crack did not come completely together some of this filled in gap).

[benb]

That JB Weld is $8

It might be more expensive than a new mount for the pump from the manufacturer.

Only thing with Epoxy is the long set time means you better have a clamping solution for the part, which might be tricky with a little pump mount if you're not in the habit of doing stuff like this.

[voir dire]

The JB Weld 24-hour cure is the best, but on a small surface like a pump bracket where the glue must stay only within the broken area, and which can't even be clamped let alone pinned, nothing will be as good or better than the original molded plastic. That joint will always be fragile and will eventually crack again. A new bracket might be the better option.

[Black Dog]

Thanks.
Does a tube have much shelf life or does it tend to dry up like Krazy Glue after the one application?

Long shelf life. The syringe seals well after each use. Very well designed. I have about 7 separate uses out of my current syringe over the last year.

[Mikej]

What about a solvent like PLASTRUCT?

[Tony]

I would just weld it. Use a heated spoke with a flattened tip and knead the two sides together. Use a zip tie as a rod to fill any voids.

[Clancy]

My pump mount cracked earlier this year. I just used super glue and sprinkled baking soda on top of it. Instant bond and is holding so far.

Why the baking soda?

I’ll pile on the praise for JB Weld, good stuff.

[jemoryl]

There are really two ways to bond plastics: glues like epoxy (e.g. JB Weld) and chemicals which fuse the plastic together. The latter often used for polycabonate: clamp the items together and introduce the solvent which fuses the two parts together. Or, if you ever made model cars or airplanes, polystyrene fused together with toluene based 'glue'.

Epoxies usually hold out well if you don't mix the two components. Sometimes I prefer individual tubes rather than the syringe thingie for just this reason.

[Veloo]

Lezyne describes the material as a "composite matrix frame pump mount".

[2LeftCleats]

Does the JB Weld stand up to heat? I’ve tried a couple different glues for a plastic light fixture, but the heat of the bulb caused failure.

[jemoryl]

Does the JB Weld stand up to heat? I’ve tried a couple different glues for a plastic light fixture, but the heat of the bulb caused failure.

Most epoxies don't hold up to heat very well. But when you say heat, I'm not sure this would be an issue for a bike application. We used to mount optical components on a table with 5-minute epoxy and then use a heat gun to soften and remove - quite hot.

[Veloo]

Came across this vid as I'm searching for the J-B Weld Plasticweld syringe which no one seems to carry in Toronto.

May be other out there vids with similar tests.

https://www.youtube.com/watch?v=djtKXkTqPUI

[Veloo]

Whoops, didn't realize BD already posted this.

Came across this vid as I'm searching for the J-B Weld Plasticweld syringe which no one seems to carry in Toronto.

May be other out there vids with similar tests.

https://www.youtube.com/watch?v=djtKXkTqPUI

[spank]

I would just weld it. Use a heated spoke with a flattened tip and knead the two sides together. Use a zip tie as a rod to fill any voids.

+! or a soldering iron that you don't care if you get melted plastic on.

[Bob Ross]

or a soldering iron that you don't care if you get melted plastic on.

When I was a kid in the early 1970s I had a "hot knife" for modifying all the plastic model cars I built. It was essentially a soldering iron with a removeable/replaceable Exacto Knife blade for a tip. Nowadays I think of a use for one maybe once a year...but if it were any more frequent I'd definitely try to find one. I presume such a tool is still made?

[voir dire]

Does the JB Weld stand up to heat? I’ve tried a couple different glues for a plastic light fixture, but the heat of the bulb caused failure.

I have used the 24-hour cure (grey color, 2-part) JB Weld for exactly that situation, repairing a broken plastic lamp housing, with 100% success.

The housing holds not only the bulb but also the 3 "arms" for the heavy shade, so it is under constant stress. The tabs that held the "arms" broke off when the housing fell and cracked. The JB Weld has held up perfectly, at least over 5 years now, with hot 100W incandescent bulbs which are on all evening every day since it is a lr lamp, for much of that time (the new ES LED bulbs are much cooler). No issues at all, still solid as a rock.

[fmradio516]

had an incident with the mountain bike the other day and broke my Hammerhead GPS mount. I have replacements but theyre kinda lightweight and idk if theyd hold up to the heft of the Karoo.

Got some of the JB Plastic Weld and did my worst. Very messy but i dont care.

Also, warning, this stuff is pretty thin compared to other epoxies and regular JB weld. Comes out fast.

Will find out in a couple days if it holds up. Not sure how only a 30 minute cure could be...

https://i.imgur.com/P96N8hb.jpg?1
https://i.imgur.com/od7HI7c.jpg?1

[weisan]

.
https://i2.wp.com/sydneysabre.com/wp-content/uploads/2015/07/kill-bill-pai-mei.jpg?ssl=1

[Mark McM]

As it happens, I've also got a job to bond plastic to plastic. I have a set of old, but still very comfortable, Sidi road shoes. The plastic heel cups have become unbonded from the sole, and I'd like to rebond them. I don't know what type of plastic the heel cup is made from, but I'm pretty sure the sole is Nylon (its not a carbon sole). The rest of the upper is still well attached to the sole, but if the heel remains free, the part of the upper still attached will soon pull away from the sole.

An ideas what adhesive would work best here? Since the heel cup aren't perfectly the same shape, I suppose what ever adhesive is used will probably need to fill some space at a few points.

[Tony]

As it happens, I've also got a job to bond plastic to plastic. I have a set of old, but still very comfortable, Sidi road shoes. The plastic heel cups have become unbonded from the sole, and I'd like to rebond them. I don't know what type of plastic the heel cup is made from, but I'm pretty sure the sole is Nylon (its not a carbon sole). The rest of the upper is still well attached to the sole, but if the heel remains free, the part of the upper still attached will soon pull away from the sole.

An ideas what adhesive would work best here? Since the heel cup aren't perfectly the same shape, I suppose what ever adhesive is used will probably need to fill some space at a few points.

I think something like Lexel would work, maybe also Aqua Seal depending on the plastic