plastic welding

does any one know how to plastic weld I fixed a gas tank buy melting the surface and smered it back how is plastic welding really done. :)

I had a old 96' kx80 that had a cracked tank and my dads freind plastic welded it. He said the way it works is they have this gun that blows super heated air on the plastic basically melting it and then you gun squirts more super hot plastic out onto the heated up spot so that they kind of mix together and become one. Sounded pretty cool.

A plastic supply house usally will weld plastic.

Jetser is right they just use a souped up blow dryer. Just make sure the plastic rod is the same material as the tank.

MY Makita Heat gun came in a kit with a nozzle to concentrate the heat, and a couple of different types of plastic welding rods... PVC and ABS types...

Basic principle is to heat the plastic, and feed in some filler material... sames as welding metal...

Practice on an old fender first... I use the heat gun for getting out the white spots on the plastic, and have welded some kids toys together... Just take your time on the tank... clean and degrease the area, and even use a dremel to make a small channel to allow the filler to flow deeper into the crack...

Good luck,


I think I'd splurge for a new tank. Haven't you read the posts about the WR and more recently the XR that spontaneously ignited and burned to the ground?

For less than $200, I wouldn't even take the chance.

Ditto on replacing the tank suggestion.

Why take a chance of burning up your bike if the weld fails? :)


If done right I doubt it will fail. The guy that did mine does this on giant underground pipes that are under lots of pressure. I think they were like water mains and things like that, those have to be tough and cant bust otherwise its not good. As long as it is done by someone who knows what their doing.

The only way to really know what you are doing is to know what the original base material composition of the tank is. Otherwise, you don't know for sure that the additional material you are adding will be compatible with the original tank. It may hold for a while but it may also fail at some point as well.

Your plastic pipe welding example doesn't fit this situation. You are refering to a guy who is welding a known base material with the compatible additional material spec'd out by either a PE or the company that sells both products.

I'd still just get the new tank. There are used one's on this site all the time.

If you decide not to get a new one, I'd call your insurance company and check what fire/theft insurance cost. That way when you spontaneously burst into flames, you can at least get a new bike. :)

XR4 Barbeque

WR426 Fire

WOW im am definetly not on a roll today. Thats the second time Ive got burnt because I didnt know all my info :). In other words very good point, didnt think about that. Insurance I do know is a good idea no matter what. My friends dad's bike got stolen a while back and now he doesnt have a ride no more.

I can tell you from experience that plastic welding eventually fails and is not worth the risk when it comes to a fuel tank. Sorry buck up. :)

No problem. I learn more off of all you guys on this site than I could ever contribute.

OT: By the way, my buddy and his brother just bought new GasGas trials bikes. Said they are sweet and there is a dealer about 45 miles away from me. I'll have to check them out.


I have several years experience with plastics. Not particularly "blow molding" as I think is the process in which the tanks would be made, but injection molding.

Much of the physical properties of a plastic part have a lot to do with they way they are formed. Much of the strength comes with the material flowing in one direction much like wood is stronger against the grain vs with it. This is more true for amorphous materials not crystalline materials that most of our motorcylcles parts are made from. Then its more a matter of how the part cures and the amount and size of crystal strutures that are formed. You would loose that in a "welded" section.

Most if not all plastic parts now produced have the material in which they are made from molded onto the part somewhere. Its for recycling purposes. Most of our bikes plastic parts are made from PP (Polypropolyne) so the argument that we don't know what the base resins is not true.

I still would not even think about welding a fuel tank holding 2.4 gallons of highly flammable material and mount it on a bike that I ride through rough terrain. Looking for trouble.


Vmax you should check out and give the GasGas a ride. They are really sweet bikes. Im loving mine, cant get enough of it. Got all the trickest stuff on em Ive ever seen. Be careful though if you test ride one you just might get hooked on it. Ive heard the new 450's are pretty good. If ya ride one post it up and tell us what ya think.

Look at my picture. Don't ever attempt a repair.

'nuf said.

Look at my picture. Don't ever attempt a repair.

'nuf said.

Hokie smokes- Start kicking dirt!!

My stock WR426 tank does not have the material which it is made from molded into it.

I agree that a lot of the newer plastic parts being produced today have this information near the recycle symbols. Many parts still don't so I'd still argue that someone who portrays themselves as being capable of doing this job could easily screw it up. Either by choosing the wrong material or not doing the job correctly. It's just not worth it.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now