Soldering Plastic

[mkr7734]

Had a chance to do something new today. I pitched a large log into the back of the Gator CX when it was below O and cracked the plastic bed. So I went into town to the body shop and asked what kind of glue they use on car bumper covers because this plastic looks to be the same or very close.. The guy said we don't we solder them up. Solder them up I asked??? He said sure. He said if it is black plastic it is easy, if it is yellow plastic your out of luck. So I asked him how he does it. He said just get a old solder iron with the big blade and heat it up and melt it into the crack and weld a bead of extra plastic in as you go along. I said sounds good I have one of those solder irons, do they sell the plastic filler because I don稚 have any extra plastic to fill it with. He said hold on and he went and got a old broken inner plastic fender well and said just cut some strips out of this and give it a try. It works great and I learned something new today. :thumbsup:

 

[Luke'sScreenName]

And....
Pictures?!

 

[mkr7734]

And....
Pictures?!

Not much to show but I took some shots for you. I just wanted to fix the crack so I did not grind it smooth or anything but he told me you can work it out if need be like they do on bumper covers. I pushed hard on it and it seems to be as strong as new. Far as I can tell. This old Gator CX is over ten years old and has more than 1,800 hard hours on her so I just wanted to seal up the cracks.

 

[dickfoster]

Had a chance to do something new today. I pitched a large log into the back of the Gator CX when it was below O and cracked the plastic bed. So I went into town to the body shop and asked what kind of glue they use on car bumper covers because this plastic looks to be the same or very close.. The guy said we don't we solder them up. Solder them up I asked??? He said sure. He said if it is black plastic it is easy, if it is yellow plastic your out of luck. So I asked him how he does it. He said just get a old solder iron with the big blade and heat it up and melt it into the crack and weld a bead of extra plastic in as you go along. I said sounds good I have one of those solder irons, do they sell the plastic filler because I don稚 have any extra plastic to fill it with. He said hold on and he went and got a old broken inner plastic fender well and said just cut some strips out of this and give it a try. It works great and I learned something new today. :thumbsup:

I have never tried to solder plastic but depending on the type of plastic I suppose you could do that too. I'd likely try a heat gun with a fine focus tip instead of a direct contact hot iron.

I have also used Mar-hyde 3310 which is a two part flexible compound made to repair plastic bumpers. It's good for urethane, polyethylene, polypropylene, ABS and most other automotive plastics. I used it to modify some urethane fender flares. I mixed in a little black plastic dye while mixing the two parts. Then used the pasty compound to fill the v grooved cracks and spaces.
After it set up, I sanded and buffed and you can't tell from 6 inches away that it wasn't made that way. It's easy to tool, sand and buff after it cures. I took the added precaution to fiberglass the back sides for more structure.
After about 12 years it still looks as the day I did the work and it's still holding up.
You can also paint the stuff.
Instead of fiberglass I suppose one could also try some gorilla tape on the back side.

 

[davesl708]

I will have to try that. My plastic grill on the BX cracked at the bottom.

 

[ruffdog]

I had a critter gnaw a hole in my Speeco wood splitter fuel tank a few years back. I bought pliable epoxy that is ok for gasoline use and tried that. It lasted about 2 years and I always kept the fuel lower than the repair (top corner). I did buy a new tank but thought about fixing the old one first. The tank seemed like a UHMW type plastic so I used black plastic strips (filler rod) made from a oil jug. Yep, just get your soldering iron and start melting it together and smoothing it out. It worked great and I bet it will be a permanent repair. (it has been 2 years now) If you have something yellow to fix, just use yellow jugs. Just heat it past being soft (so it will stick together) but not too hot so you are burning the plastic.

 

[PILOON]

I also have had decent results using hot glue gun sticks.

 

[dickfoster]

I also have had decent results using hot glue gun sticks.

Hot glue is really styrene, the same stuff used to make coffee cups and coolers.

 

[k0ua]

I have been soldering plastic for about 50 years. It can work well, or it can get away from you pretty quick with a rapid melt thru. Also don't breath the fumes. But as I said, it can work well if you are careful.

 

[Trials]

If you don't care what it looks like: To repair plastic motorcycle fenders, we just drill a whole series of holes along either side of the crack and then stitch it up with zip-ties Frankenstein style. it holds really well compared to plastic welding and looks kinda bad-a**.

 

[mkr7734]

I try not to be a hack, that said, yeah, we all do. I did do the other area in the bed that had cracked 6 to 8 years ago. That fix was a hack. I had to remove what I had used but the way he said to do it was melt all the way through adding the plastic as you penetrate the thickness of the plastic and it will be good. MY second repair is much better with the iron hotter and the filling process better. I may get this yet. As for now I think my bed is fixed. :thumbsup:

 

[Ed of all trades]

Thanks MKR and others. I have heard of it but never tried it. Will keep it in mind, might need it one day. Ed

 

[STx]

I got one of these (Urethane Supply Company 5700HT Mini Weld Model 7 Airless Plastic Welder - - Amazon.com) last year to repair the plastic fenders on my TC40DA after tearing them up pretty badly. It did a fine job and was certainly better than the $1,200/ea that it would have cost for new fenders. The nice thing about this kit is you can set the temp based on the plastic type and it includes the filler material for different plastics. I found that preheating the area with a heat gun helped the job go much faster.

 

[Harlan B]

Look on You Tube. Lot of good videos on plastic welding

 

[David_Kb7uns]

Harbor Freight has 2 plastic welding gun kits, one using compressed air and the other with a built in blower motor. They also have a selection of different types of filler rod available.

Plastic Welding Kit

Plastic Welder & Welding Kit

50 Piece Plastic Welding Rods


David

 

[CalG]

As mentioned in one of the posts above, Drill and zip tie "stitches". But then use zip ties as filler rod while you do the plastic weld (it's not soldering, it's WELDING ;-)

Build up a healthy bead so the repair is at least as strong as the original, plus, you can file/sand/grind the bead down smooth if you want.

cheers

 

[Tractor Seabee]

If you are an O/A welder the hot air torches like HF has work good with little learning curve. I have even done overhead beads on RV tanks. You need to keep the filler rod ahead of the hot air stream and use it to keep the molten area fom sagging.

Ron

 

[Eric Salop]

If you want while away a few happy hours, I can recommend having a go at melting back to watertight a length of 2" mdpe pipe that was playing hide and seek in long grass and then found by a mower.

 

[alchemysa]

I posted on this subject a couple of years ago. Plastic soldering is an incredibly handy thing to know about. Most often I will also strengthen the soldered joint with hot glue. My only failure with the hot glue was when I used it to strengthen a soldered repair on a black poly wheelbarrow tub. In the sun, the black plastic absorbed so much heat the hot glue melted again.

http://www.tractorbynet.com/forums/related-topics/292114-do-yourself-plastic-repairs.html

 

[Tractor Seabee]

One caveat: mixing different types of plastic filler into the joint will probably fail unless their composition is in the same family. For pipe we used to cut narrow rings off same type pipe and use that for filler rod.

Ron