Plastic Welding

[Daydreamer]

I need to replace the water tank. Its in the aft cabin in a locker under the berth and would need to be a very specific shape and size. Polypropylene sheet is easy enough to obtain and wekding torches are cheap enough on Ebay. Can anybody advise on whether its reasonable proposition to fabricate one.

 

[30boat]

I wouldn't even try.

 

[rob2]

I watched the guy from TekTanks welding up a tank at the SIBS. They use some kind of induction torch with a filler rod - it's not just melted together! Without the specialist equipment, I don't think you'll achieve a reliable product.

Rob

P.S. If I'm wrong, let me know how to do it! I could do with some new tankage...

 

[electrosys]

I once watched a guy with what looked like 'a hot-air gun with a fine nozzle and a length of tig filler wire', weld some grey pvc superstructure onto a RIB. Looked dead easy.
But then again, watching a pro playing a concert grand also looks dead easy.

Even with a few years of metal welding under my belt, if I wanted to take up plastic welding, then I'd buy some kit, and work on scrap plastic for a couple of days until I developed the hang of things. But if I wanted to do just one job, then I'd get someone who already has the experience to do it for me.

BTW - you'll also want to use potable water-quality plastic.

 

[ean_p]

its very very easy , though not economic for just one tank. The equipment is a hand held hot air gun 100 squids plus off ebay and a nozzel to suit filler size(dependent on base material), though it can be done without the speed nozzel by freehand a little like gas welding again using the hot air gun. material to use of choice is high density polyethylene at about 70 squids for a 2000 x 1000 sheet in 9/10mm, though polyprop' can also be used as its a little cheaper

 

[2Tizwoz]

I've only used the Leister tool similar to this one http://www.youtube.com/watch?v=I2pQKPxZMd0&p=D7211DAB82C56930&playnext=1&index=27

It's a much easier process than welding metals. The tools available on ebay for prices far more within reach than the original Leister which I bought secondhand, look very similar and presumably achieve a stable controlled air temperature.

The biggest problem which would be my concern would be designing the tank and welds, if potable water is the purpose, so as not to create potential nooks and crannies which could harbour bacteria.

I would attempt it.

 

[Daydreamer]

Yes Thanks for the replies. It does indeed look like a realistic proposition.
I might even come back and tell you all how I get on

 

[emearg]

Well Day Dreamer.....I would be very interested to see how you got on as I am thinking of welding up my own plastic water tank as I cannot get a tank off the shelf to suit, so would be looking to fabricate and weld my own tank then it would be a custom fit in my locker.

Graeme

 

[David2452]

I have called people in to weld bosses on to tanks for dip tubes and the kit they had was a bit more sophisticated than a £100 hot air gun and a bit of plastic stick, the guy who does it says even he has failures that have to be repaired when he constructs tanks. Like so many things, it can be done, but easily and by somebody who has not done it before is another question.

 

[Bikerwookie]

If you can gas weld aluminium you can weld plastic if you have the kit. It is prone to many types of failure though. Practise does not necessarily make perfect. Try some butt welds and then try destroying them gives you an idea of how difficult it can be. Low penetration, lack of filler and too much heat are just the start of it.

Worth a shot in my opinion if you have the time.

 

[sarabande]

I have a Leister Traic Hot Air Gun for welding farm tarpaulins to shape. Works brilliantly on polyethylene and other thermosetting plastics to make small boxes from those cheap white food cutting boards in Poundshop.
.


See their website and l oads of youtube stuff.

http://www.leister.com/en/index.html

http://www.youtube.com/watch?v=ztQ05wDsqfY


It's not rocket surgery, but your first few attempts will be dodgy.


Training course availabvle from Leister.

 

[Graham_Wright]

I need to replace the water tank. Its in the aft cabin in a locker under the berth and would need to be a very specific shape and size. Polypropylene sheet is easy enough to obtain and wekding torches are cheap enough on Ebay. Can anybody advise on whether its reasonable proposition to fabricate one.

Have you considered flexible tanks?

 

[wee_niall]

i repaired out poly tank with the plastic welding rods from ebay and a wee butane block torch/soldering iron thing - seems to be holding still but i'm not sure how well a complete tank would work

 

[emearg]

Thinking of buying a plastic welder, Triac AT welder, the smallest in the range from leister.

Now for the Billion dollar question could I buy some plastic sheets 8mm or 10mm thick and make a custom water tank for my sadler 32. The one reservation that I have is that nobody seems to have welded 8mm or 10mm plastic sheets to make a water tank and nobody seems to have used the Traic AT welder to do it. When ever you see the professionals doing it they have the heavy duty welders and when ever you see any videos of people doing demos with the Triac AT they are only welding 4 or 6mm sheets , so is the Traic AT heavy enough to make proper welds in 8 or 10mm thickness that are structurally sound enough to not leak.

Has any one ever used the Traic AT welder to make a water tank????

Are you going to get the correct degree of weld penetration in 8mm to 10mm sheets to ensure a water tight tank????

Could I get away with using thinner sheets???

You would have though that if people had used the model to make tanks then there would be loads of demos on utube, there aren’t so does this mean that no one has done it.