Better adhesive than JB Weld?

[Bizarro Lois]

I'm repairing the gas gun I made to go with my husband's Sandman costume. The body of the toy gun, pvc pipe and the nozzle on the end were all attached JB Weld. It held just fine through the entire convention, but he dropped it on the last trip to the car - the nozzle flew off and the stuff holding the pipe to the gun cracked to the point that I could just pull it apart. Did I do something wrong? Or is there something that would be sturdier when I reattach the pieces?

 

[Bradleyfett]

Plastic Welder by Devcon may be what you need if you can get a good glob of it on the break in a place where it won't be visible (on the inside?)

M

 

[exoray]

PVC is funny lots of adhesives have a hard time grabbing onto it, this why it's usually solvent bonded vs glued...

I second the plastic welder, it is an epoxy but it also has solvents in it that etch the surface of the plastic for a better bond...

 

[Funky]

I have to agree, epoxy is the way to go. Superglue and even JB Weld will get brittle after time. 5 minute epoxy is a solid "weld".

 

[Bizarro Lois]

Is this plastic welder stuff available at Lowe's or Home Depot? If not, I might have to hot glue it on if we decide to dress for Baltimore Comicon. Would pvc glue work?

 

[runnriottt]

Belzona is what you seek... Its awesome. Expensive, but will last until doomsday.


http://www.belzona.com/

 

[jackdoud]

Is this plastic welder stuff available at Lowe's or Home Depot? If not, I might have to hot glue it on if we decide to dress for Baltimore Comicon. Would pvc glue work?

PVC glue will only work if all the parts are PVC. Devcon Plastic Welder is available in all major hardware stores that I've seen. 5-minute or 2-ton epoxy would also work but I'd sand the pvc a bit first.

 

[Bradleyfett]

Ace Hardware carries Plastic Welder.

 

[thegreatgalling]

I have used 5 minute epoxy to glue a stack of six or so HEAVY metal washers. The stuff IS like metal. There is also 24 hour epoxy, but I am way too impatient for that.

Typically with epoxy, you get two tubes and have to mix a bit of the two substances on a seperate surface before applying. Just warning you that it is nasty to get on your fingers and it can smell like something fierce.

I like epoxy because of its versatility, as it basically bonds nearly anything to nearly anything:

"Bonds some metals (including stainless steel, brass, aluminum, carbon steel and cast iron) and some plastics (including ABS, acrylic, polycarbonate, PVC and nylon). Also good for glass, wood and ceramics."

 

[thegreatgalling]

After making sure, it appears that JB Weld IS technically a 5-minute epoxy.

I have never used JB Weld so I cannot compare, but I can vouch for Devcon's epoxy. I use the one that seperates the two parts into seperate tubes.

 

[SD Studios]

Here are the "rules of thumb" (or is it rule of thumbs"?) :lol

For PVC, you want a solvent-based adhesive. Epoxies don't stick completely to PVC. They will certainly "grab", but the designed-bond-strength of the epoxy won't be reached on PVC. If it is subjected to shock, it will fail very quickly.

PVC is specifically designed to NOT let things stick to it, that is why they use it for plumbing applications. And cheap jackets. Pleth-uh.

"Gray" type 2-part epoxies are almost always stronger than "clear" types. Especially in metal-to-metal applications.

The strongest epoxy adhesive (that civilians can buy) is PC-7. It takes 3 or 4 days to reach maximum strength, but if you look at the specs (tear/ tensile/ compressive/ grab-strength/ etc) it has the highest numbers.

JB Weld is a close second. The slower-cure version is ultimately stronger than the 5-minute, but not by THAT much.

There are more "serious" adhesives and epoxies that you can buy from resins material suppliers, but those are overkill for (most of) the kind of stuff we do.

 

[Noeland]

The trick to using the JB stuff (I use JB quick) is making sure the surfaces have tooth. A smooth PVC pipe isn't going to work, you have to use a rough sand paper to scratch it up, and then take something sharp and dig some scratched into the area where the adhesive will go.

I always back up any kind of adhesive with screws if I can too.