Anyone welding plastic?

[Super Mech]

Today I had to repair a small hole in a BMW X5 fuel tank. I tilted the car on the
lift so the front was higher than the back and the fuel would stay at the rear. I then took a regular soldering iron and started to soften the plastic and work it over the hole. I have to say it worked perfectly!

I am now interested in looking into plastic welding techniques and the different kinds of welders and rods. Anybody do this?

 

[MarkG]

I'm happy you lived to tell us about it! :O

The closest thing I've ever heard to 'welding plastic' is model cement. The polyureathane glues (like 'PL Premium) might work too----who knows. They stick tenaciously to everything else!

 

[Bobhdus]

I used to weld a lot of PVC, Teflon, and CPVC. Some were sheets, others were Pipe used in industrial applications. It works extremely well, and if done right, can be safer than glues or adhesives. My welder was made by Seelye, and had the built in air compressor. It was a lucky buy and I bought it for $125 on eBay, all it needed was the heating element replaced, $40, and it works great. New would have cost about $990. You can buy rod in about any color and for any thermobond type plastic. Thermoset is not weldable. Check out Seelyes website. They have great videos on YouTube. There are many hot air style welders like mine, then there are a lot of hot iron types too which can work well too. Good luck! Check out burn chart to use ID plastic here http://www.seelyeinc-orl.com/pdf/burn-chart.pdf and Seelye website here http://www.seelyeinc-orl.com/index.html

 

[trackwelder]

This is the kit I have. It has paid for itself at least 20 times. I have repaired radiators, bumper covers, atv fenders, even the skimmer on the pool with the kit. Not sure about repairing a gas tank unless it was empty and purged with argon. Here is the link to kit I use
http://www.amazon.com/dp/B000GKDMHW/?tag=atomicindus08-20

 

[Bobhdus]

This is the kit I have. It has paid for itself at least 20 times. I have repaired radiators, bumper covers, atv fenders, even the skimmer on the pool with the kit. Not sure about repairing a gas tank unless it was empty and purged with argon. Here is the link to kit I use

http://www.amazon.com/dp/B000GKDMHW/?tag=atomicindus08-20

The Fiber Flex universal rod that comes in your kit looks interesting.... Have you tried it?

 

[trackwelder]

The Fiber Flex universal rod that comes in your kit looks interesting.... Have you tried it?

It does work well. I like to fuse the broken item using just the parent plastic material. This creates a divot perfect for melting in some stainless reinforcing mesh. Then if the type of plastic is unknown using the Fiber Flex has always worked for me. This kit has saved my *** so many times its one of my favorite tools.

 

[kerrynzl]

I use a hot air gun to do repairs,
But also have experience with "wedge welders" and High frequency welders for PVC welding.

 

[CJM8515]

I have the harbor freight one, its like a giant soldering iron. Has worked well over the years. I have used the urethane supply one (friend has), way better but damn $$$ vs the HF job.

The fiberflex rods are the best and about all I use.

 

[Hammer1963]

I have been using the welding kit offered by Urethane Supply for 20 plus years. Wide variety of plastic rods that will repair most any material. A very versatile and affective product. I believe the later kits may include an instructional video as well. If not, YouTube most likely has some offerings. If you have any questions, send me a message.

 

[TimeWarpF100]

10yrs ago I had a plastic spoiler on my 1969 low mile 428CJ cougar that was cracked. Straight nice spoilers were a 1000.00 plus if you could find them.

At the time I bought a plastic welder for 800.00. Used it only a few times after that. If one is looking would consider selling it. Came with a couple boxes of different plastic rods and instructions how to tell what plastic you were working with etc

10 yrs later the spoiler still looks perfect!

 

[Monkey Milk]

10yrs ago I had a plastic spoiler on my 1969 low mile 428CJ cougar that was cracked. Straight nice spoilers were a 1000.00 plus if you could find them.

I thought the original spoiler's were 2 piece fiberglass? Prone for cracking in the middle where they were joined.

 

[TauntDevil]

I have welded a few 240sx gas tanks using a regular solder iron. Only once did one catch on fire but I always pull the tanks to find the leak being that they are difficult to get too.
Not sure what caused the fire being that there was no fire or anything. Maybe just the heat of the solder or something.

 

[Guster]

Repaired a bumper and fender mirror mount along with a few other bits using a large old electric soldering iron that I made a few different tips for. I do a lot of welding and brazing repair too and plastic turned out easier than I thought it would be.

 

[countryroad82]

In my line of work plastic welding is a staple. But since I'm a cheap a$$ when it comes to buying certain tools I use a soldering iron for most of my repairs to join 2 pieces together like brackets and such. Another method I use is a hot staple. If I have the room to do it anyway, most of the time it's used when I put a bumper cover back together or a headlight bracket. But once again I haven't let go of the cash for the proper tool, I use a set of vise grips, a hot staple, and a propane torch. Heat the staple up to glowing red, set it in halfway through the plastic, hold it still as it cools, and BAMOO! After setting a couple staples inline with a rip or tear, grind them down, spray some paint on the **** poking up, flip it over, and finish the pretty side. It's a great fix for those cars that the owner doesn't want to pony up the cash (or insurance company) for an older vehicle, I really wouldn't do it for something newer, unless it was mine lol.

 

[zkling]

Yes, unfortunately it is a plastics world we live in. I bought my kit used, can't remember the name off the top of my head. A true hot air welder is so much nicer than a soldering iron or other hot surface contact method. The HF offerings are really not that bad for these. Realize, like metal not all plastics are weldable, but most non toy or household junky items are weldable.

 

[Super Mech]

I want to thank everyone for the input. Because this will be something new for me I just may give the HF hot air welder and soldering iron type a try. I can see that knowing how to successfully weld plastic can be a great money and labor saver.

 

[CJM8515]

My only complaint about the HF one (soldering iron type) is the tip gets SO hot it tends to sorta bend. If pushed and not taking your time Im sure it would snap right off. Otherwise it has worked well for me.

 

[Ed ke6bnl]

I made my own plastic welder from a $2 really old soldering I bought the other day at the swapmeet 150 watt is what it checked out to be. I the cleaned up the copper tip and cut up a a this piece of Stainless sheet about 1.25 x .5 and silver soldered it to the copper tip and it works great. the first one I used to fix a 8 in crack at the bottom of my RV 120 gallon water tank and it has held for over 2.5 years. Just go back from a trip of 4000 mile with 1/2 full tank of water that we never used and no leaks. I leave a welder in the trailer and the rod.
I even have one of those expensive plastic welders with heating element with air regulator that I did not get to work as well as the homemade one. like seen on the Seelye site will part with it for $75 + shipping

 

[Super Mech]

My only complaint about the HF one (soldering iron type) is the tip gets SO hot it tends to sorta bend. If pushed and not taking your time Im sure it would snap right off. Otherwise it has worked well for me.

Yes I did read that in the reviews. If I get it I will use the router speed control that they sell(already have one) to control the heat.

 

[Guster]

But once again I haven't let go of the cash for the proper tool, I use a set of vise grips, a hot staple, and a propane torch. Heat the staple up to glowing red, set it in halfway through the plastic, hold it still as it cools, and BAMOO!

That reminds me - using fine stainless or brass mesh is another nice way of adding reinforcement to a large crack or tear that you are fusing back together. Sinking the mesh into the surface on the back side of the crack before adding material over it. Works very well.

Lots of great examples of this on Youtube.

 

[countryroad82]

Guster, yup thats another one of my little tricks depending on how large of an area I am repairing. Lots of those tricks I have stored in my pea brain for fixing some junk!!

 

[Ed ke6bnl]

That reminds me - using fine stainless or brass mesh is another nice way of adding reinforcement to a large crack or tear that you are fusing back together. Sinking the mesh into the surface on the back side of the crack before adding material over it. Works very well.

Lots of great examples of this on Youtube.

Stainless and brass is great but for some non critical jobs at home I use metal screen door material, cheap and works fine and galvanized rust resistant.

 

[Guster]

I have lots of fibreglass and want to try using that instead of metal mesh sometime too.

 

[Ed ke6bnl]

I have lots of fibreglass and want to try using that instead of metal mesh sometime too.

will the fiberglass melt before it gets imbedded in the plastic?? I guess I can go try it out

 

[TimeWarpF100]

I thought the original spoiler's were 2 piece fiberglass? Prone for cracking in the middle where they were joined.

Early ones were plastic

That's why you will see near impossible to find a 1969 that is not warped

1970 they went to fiberglass

 

[TimeWarpF100]

I have needed my plastic welder a few times since the move over 4 yrs ago now, but could never find it when it was needed.

Now that things are finally getting organized finally have it where I can find it.

A few pics of my unit. It has a heat source and a air compressor built in. Works quite well. Never had much luck welding plastic with the cheap units.

If anyone wants it send a PM. It lists for close to a grand.

A few different models avail. The ones with heat source and air compressor work the best.

 

[Guster]

will the fiberglass melt before it gets imbedded in the plastic?? I guess I can go try it out

Neither composite reinforcements like glass, carbon or aramids should melt at the temperatures required to weld plastics. It is a lot cheaper and easier for me as I always have composite reinforcements on hand. Finding s small piece of stainless mesh usually requires a trip to the local dollar store to pillage their kitchen utensil stock.