Plastic Welding

JimS · Jun 7, 2020

Can anyone recommend a plastic welding tool? I have a couple of 2000 gallon plastic water tanks to weld. Any tips on the process would be appreciated too.

560Dennis · Jun 7, 2020

Might try the mfg. that made it, they would have run into this ? Where I d start , not ever done it before .

MarkB_MI · Jun 7, 2020

Harbor Freight has several different tools. I tried the cheapest one, which is basically a big soldering iron, and was unhappy with the results.

You do need to figure out what plastic you're dealing with so you use the right filler. Some plastics are easier to weld than others. Check the recycling code on your tanks; they're probably HDPE (#2).

Stephen Newell · Jun 7, 2020

I bought a Weller model 8200 soldering iron. It comes with a flat blade for plastic welding. Plastic welding works real well for getting loose parts in place but doesn't offer much strength. I usually get what I'm working on put back together with welding but then roughen the area around the weld and coat with epoxy for plastic and put fiberglass cloth into the epoxy. It needs something to reinforce the break to last. My first project was a bumper cover on our car. I welded it back together, smoothed it over with body filler and painted it and a couple of months later it started breaking apart. I repaired it again the same way a couple more times and it kept breaking until I went over the back side with the epoxy and cloth. It then stayed together even when the car was rear ended again and broke in other places than where I repaired it.

Janicholson · Jun 7, 2020

90% of the bulk tanks are polyethylene. It is probably the easiest material to weld there is. The process is heat dependent. Too much, and the plastic changes structure, blackens and oxidizes, loosing strength. too little and the material really is not joined. Deep root welding it important in this case to prevent weld failure. Cutting a groove with a sharp utility knife if the material is 1/4" thick, or thicker. is needed to assure depth of weld penetration. The filler rod is used to both stir and fill at the same time. The plastic stays hot a long time, and will burn, and stick to your skin making a real serious 3rd degree burn, don't go there. Practice on similar material if you can, and be patient. It is no harder than working with a oxy acetylene setup welding steel. The tool is almost always plunged into the depth of the weld . Watch some YouTube on it before starting. Make sure the stress that caused the cracking is eliminated, the weld will not likely be stronger than the original. Once you develop some heat control, and fill stability go at it. Jim
One simple kit

Material

rew1953 · Jun 7, 2020

I have a MAC plastic welder. It is the old style that looks like a soldering iron with a wide foot and hole to insert a filler rod. It works extremely well if you do not try to go too fast. Too much travel or wrong heat setting can cause the work to become fluid and a collapse of the weld. I have repaired radiator shrouds,washer fluid reservoirs, and antifreeze overflow reservoirs with great success. I have found that using a lower melting point plastic than the Work produces the best results. I have even repaired leaking plastic gas cans and my personal favorite is a Plano tackle box I dropped out of the truck and busted the plastic lid pretty severely. I guess the new technology is a hot air welder, but I have not tried that.

37 chief · Jun 7, 2020

I have welded plastic a lot. In my previous job in a printed circuit board factory. Hot air gun is the best for deep penetration of the plastic. Try an area not related to the leak, to get the feel of what you are doing. Make sure the rod you are using is comparable to what you are welding in a area also not related to the leak. If you don't have the correct rod. I have cut a small strip from somewhere on the material you are welding if you can find an edge not important. Just don't be in a hurry. Works for me. Stan

rlp in Co. · Jun 7, 2020

This is what I used. I couldn't find the tip but it is only a piece of heavy wire bent with a flat tip a inch wide.I cut inch wide strips of 1/4" rabbit wire a then press the wire into the plastic with the hot tip. I tried a heat gun but it is too wild! You can easily melt a big hole fast! You need the big soldering iron to have enough heat. Press the rabbit wire deep into the plastic but not clear thru. After the strip is imbeded, melt some plastic of the same type over The top. On the finish side, I took a small pencil type soldering iron. and melted and smoothed the crack. I have a Kawasaki 400 Bayou that a buffalo had used for his play toy. It was VERY badly damaged! Cracks and broken off pieces everywhere! The fenders are all back together and maybe stronger than before. I still have one brace that I have to straighten and weld back on before I put the fenders back on. If a person had seen it before, you would not have believed it could be fixed!

Untitled URL Link

wore out · Jun 7, 2020

Have any of you guys tried a "hot stapler"?

https://youtu.be/1VN6lxdC9LY

rlp in Co. · Jun 7, 2020

I have no idea how that link got onto my reply. My phone does stuff all by itself! I had posted that a long time ago and apparently my phone had in memory somewhere. That post got proofed about ten seconds after I posted! Wonder how long this one will last?

Plastic Welding

JimS

Member

560Dennis

Well-known Member

MarkB_MI

Well-known Member

Stephen Newell

Well-known Member

Janicholson

Well-known Member

rew1953

Member

37 chief

Well-known Member

rlp in Co.

Well-known Member

wore out

Well-known Member

rlp in Co.

Well-known Member

Similar threads