repairing a plastic boat.

[gordmac]

My Plastimo PRD has a couple of cracks in it that would be better fixed, Is it possible to glue polyethylene or does it need to be welded? If the latter any way of doing it without proper equipment and what to use for a filler? Worst case, any cheap plastic welding equipment about?

 

[prv]

Not tried myself, but everything I've read suggests it's a welding job. Nothing will stick long-term to the waxy and slightly flexible surface.

Pete

 

[bikedaft]

chewing gum didn't work

 

[GrahamHR]

My Plastimo PRD has a couple of cracks in it that would be better fixed, Is it possible to glue polyethylene or does it need to be welded? If the latter any way of doing it without proper equipment and what to use for a filler? Worst case, any cheap plastic welding equipment about?

Bonding to PE; it's like the holy grail. Welding is your only option. It can be very succesfull.

 

[TradewindSailor]

You could patch it, but it is unlikely to be pretty:

Drill out the end of the cracks so they don't continue.
Put release wax over the area.
Wet out some 0-90 stitch mat with resin. Use a thickness suitable for the damage.
Let it cure ... and then pop it off.
Clean up both surfaces with acetone, mek, or alcohol
Put mastic under the patch and use blind rivets to hold it in place.

Unfortunately the plastic is probably already UV degraded, so it is unlikely to last.

 

[Lakesailor]

Apparently the material that is used for milk containers is very good for welding polyethelene. A hot iron bar, big soldering iron or careful use of a good, controllable, blowtorch can do the deed.

 

[bikedaft]

Apparently the material that is used for milk containers is very good for welding polyethelene. A hot iron bar, big soldering iron or careful use of a good, controllable, blowtorch can do the deed.

thanks

 

[Iliade]

Maplin do a gas powered soldering iron which has the hot air attachment for welding plastic

http://www.maplin.co.uk/p/pro-iroda-solderpro-70-gas-soldering-iron-kit-n13ar

 

[Searush]

Anyone tried "Mr Sticky's polybonder" designed for Pe "welding"? It appears to recommend heat treatment to the damage first so that the bond will take place. Enough heat to make the surface go shiny, but not melt it.

I have just bought an HDPE sit on kayak with splits in it & will report back in due course. Lots of "How to" videos on the Interwebby wotsit if you look. Hot air guns (paintstripper guns) seem to be the weapon of choice, I shall be using a butane blowlamp as it is what I already have in the garage. There is a superficial sliced cut that I shall practice on first. If I can lay that down flat & sealed I will feel confident to tackle the impact cracks.

The white plastic milk bottles are HDPE 2 are suitable for welding, but may be liable to UV degradation in time. You can buy coloured HDPE2 "welding rods" of the appropriate material off e-bay for very little cost & you stand a chance of getting a similar colour repair. The other trick is to buy fine mesh alloy flyscreen to heat (carefully!) & push into the repair as reinforcement. Most repairs are not pretty & I've not seen an "invisible" one yet, but they all claim to be "workmanlike" and "strong enough".

 

[Searush]

Maplin do a gas powered soldering iron which has the hot air attachment for welding plastic

http://www.maplin.co.uk/p/pro-iroda-solderpro-70-gas-soldering-iron-kit-n13ar

or you can buy a hot air gun off amazon for 1/3rd of that price.

 

[Searush]

Been doing a bit more research & it seems that HDPE 2 softens at 300deg & you can get heat guns with settings at 300 deg &/or 600deg (presumably for paint stripping or de-soldering). HDPE does not go liquid so it should not run away, but can catch fire.

 

[Lakesailor]

Did the armadillo die?

 

[Searush]

Rusted up on the hard drive somewhere.

Thought you might like a change.

I found it in a charity shop for 3.99 & decided my 37 year old son might like it. The sound effects still work, which gave me a bit of a surprise when they went off unexpectedly.

 

[gordmac]

Some useful information, thanks guys.

 

[CAPTAIN FANTASTIC]

Apparently the material that is used for milk containers is very good for welding polyethelene. A hot iron bar, big soldering iron or careful use of a good, controllable, blowtorch can do the deed.

+1 but use a hot airgun or a commercial hairdryer

 

[nigelmercier]

Maplin do a gas powered soldering iron which has the hot air attachment for welding plastic...

Cheaper on Amazon: http://amzn.to/1qryWHG

The Iroda Solderpro 70 Gas Soldering Iron Kit is a great tool to have on board; handy for soldering, heat shrink, rope cutting ...

 

[Lakesailor]

+1 but use a hot airgun or a commercial hairdryer

Interesting. I've not had reason to weld plastic and am surprised a hot air gun is ....erm...hot enough. Mind you, they can set fire to wood so perhaps I am underestimating them.

 

[nigelmercier]

Mind you, they can set fire to wood so perhaps I am underestimating them.

But that's only Fahrenheit 451

I have certainly melted plastic with mine, normally when I didn't want to. Variable power & speed is a must, like this one: http://amzn.to/1oosdJs which says 550°C

 

[Lakesailor]

But that's only Fahrenheit 451

I hear you Ray.

 

[Searush]

Interesting. I've not had reason to weld plastic and am surprised a hot air gun is ....erm...hot enough. Mind you, they can set fire to wood so perhaps I am underestimating them.

I've been looking into this, many HAG are designed to operate at two nominal heat levels; 300deg (suitable for HDPE plastic welding) and 600deg (suitable for paintstripping). I am currently trying to decide if I want to spend 16 quid on one rather than just guess the heat with a gas blowlamp.