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Plastic welding


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Anyone done any plastic welding? (Not much use on a defender of course)

There seem to be kits around varying from ebay specials at £50 through to sealey at £120 then the pro models around £500.

Guessing the cheapo will be useless, has anybody used the sealey model?

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I do alot of plastic welding with just a gas powered soldering iron, i repair lots of motor bike panels, bumpers and plastic wings etc

Some plastics weld and others burn!

I tend to trim off elsewhere you can't see of the bumper etc i'm welding too using it as a filler rod.

The most important thing is to make sure you remove all traces of paint back to the plastic to be repaired as paint and other substances can make the weld brittle.

Hope this helps

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I've done quite a bit but not with the equipemtn you mention. It can be a bit of a black art but the type of plastic and it's age are both factors.

All plastic have plasticisers in them to some extent and these evaporate with heat, so the paret plastic will embrittle as will the filler.

Using an oddcut is a good idea because you can be assured it's campatible with the same coeficient of expansion.

I've used hot air guns, these heat both surfaces and if you are using it the filler rod which is then pushed in and rollered to drive it home. You can also weld on a hot-plate to join 2 flat surfaces but on squeezing them together ou loose a little length.

I've used a soldering iron but TBH it's too hot and oxidises the plastic, you don't want that.

What are you trying to join? a solvent cement might be more appropriate and you can make a filler paste with offcuts or shavings dissolved in the solvent.

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Some bumper repairers will use a heating tool (like a soldering iron) to push a metal mesh into the back surface of the bumper in order to bridge the gap. The plastic is a bit too thin for succesful welding without some form of reinforcement, you also risk distortion of the bumper surface due to stress which will look bad on a painted bumper.

SMART repairers can also use a spray that gives the peened finish of a self-coloured plastic bumper to respray repairs.

Also be careful what plastic you use to make the console, PVC for example can emit some nasty by-products.

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The joint must be clean of the compounds that plastic producers use to free the material from molds and processing equipment, and the pieces forming the joint must be properly beveled and have a good fit.Speed tip welding method is a much faster welding technique and with practice can be used in tight corners.

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  • 3 weeks later...

i do alot of plastic welding on polyethylene. we use if for landfill applications mostly.

we use both tackers (heat pencil ones) and extrusion guns, which blow hot air through a nozzle and have automatic wire feed. bit like these


we use the fusion 3 c's and the welding pen s. ext guns cost around 4k tackers (welding pens) are around 1-1.5k

if you want any thing making mate just send me a pm with measurements etc and i will see what i can do. we use 5mm- 100mm sheet and pipe from 25mm to 2000mm diameter

oh we make speed boats as well, rescue boats and fish farm boats

hth scott

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I would like the boat making please, how much?


a small 4 meter rescue boat is around 8grand. thats not including motor(s)

tbh it may sound alot for a plastic boat, but these have been tested to the extreme. they have been dropped from a height of 10 meters from a crane onto concrete with no real damage, just scratches etc. each cell is blocked from the next with a blank, we join them using compound mitres and butt welds on large omicron machines. they join the ends of the pipe by trimming the ends, heating the clean ends under pressure, then ejecting the heater and fusing the ends together. this weld is just as strong ast the pipe itself, maybe even a bit stronger. http://pipesystemsdivision.fusionprovida.com/Site.fusion?intPage=227

i have actually made a few snorkels out of 63mm sdr17.6 pipe (approx 5mm wall thickness) as there near on indestructable. you can put the pipe into a vice and close it as far as it will go and bend it 30 to 40 times before it will show signs of splitting. its brilliant stuff. ive been trying to get the directors to look at making them using injection moulding etc as they would be 10x stronger than any other snorkel out there.


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Snorkels aren't injection moulded, they are rotationally moulded.

thanks for that. to be honest i dont think it would matter either way.

whats the pro's with rotationally moulding them over injection moulding?

i cant really see any, or i may not be looking into it like you.


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