[Peter Blackburn]

I have a Ninja that has developed a crack inside the water tank.

On the Ninja there are two hinged brackets mounted at the back of the water tank. This enables the machine to split for maintenance.
To prevent the screws penetrating the actual casting of the water tank, 4 small domes have been moulded to accommodate the screws, they can be seen in side the tank at the back.

The crack is on one of the domes and is filling the cavity where the screw is, it is then dribbling out from the screw on the hinge at the back of the machine and dripping everywhere.
What can be done?

Cheers
Pete   

[John Kelly]

Not conversant with the Ninja. However a couple of things you could try other than purchasing a new tank.
Try filling the hole with Plastic Padding Leak Stopper, re-fit the screw before it sets. This might work, however it is hard to get anything to stick to polyprop.
You could also try welding it (carefully) using a soldering iron. You need to find a scrap peice of the same type of plastic and melt this onto the damaged area. If you just try to melt the existing plastic it will just shrink and make it worse, you need to add additional material.

[calmore]

What sort of material is it?  Glass fibre would be easy enough to repair. Is it Polypropylene (Like washing up bowl plastic)? If it is it will probably have a small triangular recycling logo stamped in it with the letters "PP" alongside/in the middle.

You can buy various glues/fillers in RS that'll stick Polypropylene.

[calmore]

Here's a document that helps you identify the type of plastic used: www.lincolnshire.gov.uk/upload/public/attachments/540/PlasticID.doc

If you can find out what it's made from you stand a good chance of finding a product to repair it.

[Cloverleaf]

It's polypropelene.

Enquire at a local plastic injection moulding company to see if they have a sonic welder.
This is tool that simply has a piece of steel that vibrates at many thousands of times a second, creating heat.
This will melt the plastic localy to seal the crack permanently without causing carbon contamination.

The crack was probably due to a defect or weld line not sealing properly when it was made.

I would avoid temporary repairs like plastic padding etc, once it's welded you can forget about it.

Just takes a moment to weld. Then you can clean their foyer for free 

[Peter Blackburn]

Hi guys,
Thanks for the replys, the Ninja is made of - Lightweight high density polyethylene (HDPE), if this helps.

Cheers
Pete

[Cloverleaf]

HDPE is still the same to weld as PP

John

[Adam Young]

Araldite It. Epoxy Resin was made for this.

Regards,

Adam.

[Adam Young]

But it will still break under stress

A

[calmore]

From memory a hot glue gun will stick HDPE very well.

[Ken Wainwright]

Pete

As long as the structural integrity is sound, and you are only looking for a semi-permanent repair, I have successfully used Fernox LS.X in cases such as this on both GRP and poly-cases. Repairs have lasted me for years.  It's a silicone type sealant, can be used in water immersed situations (bath type sealants can't), comes in a toothepaste type of tube, and is quick and easy to use. It's in a yellow carton and can be found in the plumbing section of your local DIY store.

If you are looking for a totally permanent repair, the other advice given here should be pursued.

Safe and happy cleaning
Ken

[CARPET KNIGHTS]

Take it to a car body repair garage and have them plastic weld it. They do it all the time on bumper repairs and so on!

Cheers Goron

[Peter Blackburn]

Thank you Ken!

Superb advice regarding the Fernox LS.X, the leak is now well and truly plugged.

Imagine a pint glass full of your favourite beverage, now imagine putting that glass to your lips and drinking it. After you have finished it imagine that I paid for it.

I'm from Yorkshire, so that's the best your going to get unfortunately.

Thanks again Ken
Pete

[fletch]

Hi yah Pete,
I've also got a Ninja that has devoloped a leak  aswell  sounds very similar to yours, I wonder if there is a faulty batch outthere
                             Regards.

[Ken Wainwright]

You're welcome Pete.

I can't manage a whole pint, would you mind if I just had a half 
You know what we're all like south of the Mersey

Another great product for use on cracks and for repairs is Milliput putty.  It's a two part epoxy putty and dries very hard. Will cure underwater and can be drilled, cut, sanded etc.  It's not suitable for flexible mouldings like the Ninja case, but I've used it on GRP where it doesn't flex and on other components.

Safe and happy cleaning
Ken

[Matt Lindus]

They Always leak!!!