Hole in plastic water tank

I have a 60 lt black plastic caravan water tank under the chassis of my vehicle and it has a hole about the size of a 10 cent coin. Unfortunately I can't remove it so I need to repair it in situ. Has anyone got any ideas, as it is for drinking it needs to be non toxic.

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Reply By: Bushranger1 - Sunday, Feb 26, 2012 at 20:53

Sunday, Feb 26, 2012 at 20:53
G'day John,
Pretty sure those ABS plastic tanks have to be repaired by plastic welding.
I repaired my canoe made of the same plastic with a soldering iron & some strips of ABS plastic.
I don't believe there is an adhesive that will do the job but maybe someone else knows of one if it is available.
AnswerID: 478770

Reply By: gbc - Sunday, Feb 26, 2012 at 21:13

Sunday, Feb 26, 2012 at 21:13
Try to get some ferropre from the local plumbing supplies.
AnswerID: 478773

Reply By: Member - Serendipity(WA) - Sunday, Feb 26, 2012 at 22:40

Sunday, Feb 26, 2012 at 22:40
I repaired mine with some plastic water tank repair putty I bought from SuperCheap autos. Works like that metal cement but is made for plastic water tanks.


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AnswerID: 478782

Follow Up By: John Russell - Monday, Feb 27, 2012 at 08:13

Monday, Feb 27, 2012 at 08:13
Thanks for the replies, will try the repair putty or Ferropre before I take the soldering iron to it. The hole is already about a 10 cent coin, don't need to make it bigger.

FollowupID: 754312

Reply By: Rangiephil - Sunday, Feb 26, 2012 at 22:59

Sunday, Feb 26, 2012 at 22:59
Good luck!!!
I tried plastic welding on the 1MM hole worn in mine and ended up with a 10MM hole. the problem is , is that if it has worn through , then the plastic all around the hole is wafer thin.
A new tank is only about $85 AFAIR from Caravans Plus online, depending on the model.

Regards Philip A
AnswerID: 478786

Reply By: Peter_n_Margaret - Monday, Feb 27, 2012 at 08:57

Monday, Feb 27, 2012 at 08:57
Is the tank black?
If it is it is almost certainly made from Polyethylene and the only sure way to repair it is to have it hot air welded. Easy job for a specialist. Very difficult without a proper hot air welder. Small holes or cracks are a soldering iron repair possibility.

If the tank is custom made and white it is probably made from ABS.
ABS can be solvent welded with MEK, but the patch MUST be ABS also.

There is also a small possibility of it being custom made from Polyethylene. This is another hot air weld only material.

In all cases the patch MUST be the same material as the original tank.

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AnswerID: 478803

Follow Up By: John Russell - Monday, Feb 27, 2012 at 18:01

Monday, Feb 27, 2012 at 18:01

Yes the tank is black. Any idea around Geelong who could do the job re hot air welding?


FollowupID: 754376

Follow Up By: Peter_n_Margaret - Monday, Feb 27, 2012 at 20:16

Monday, Feb 27, 2012 at 20:16
Look in the yellow pages under ''Plastics fabricators''. They are likely to have welding facilities.

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FollowupID: 754384

Reply By: Member - DAZA (QLD) - Monday, Feb 27, 2012 at 09:25

Monday, Feb 27, 2012 at 09:25
I once repaired a plastic tank a long time ago with out bogging or welding ect.

The hole was similar to a 10 cent diameter.

I used a Toggle Bolt and a Flat Stainless Steel Washer with the bolt hole the same diameter as the toggle bolt and a Fibre Washer.

You could use a Rubber Seal Washer from a plumbing store.

Check with your local hardware store if you don't know what a Toggle Bolt is.

Very easy fix.


AnswerID: 478808

Reply By: blown4by - Friday, Mar 02, 2012 at 23:57

Friday, Mar 02, 2012 at 23:57
Q Bond
AnswerID: 479243

Reply By: Tim the tool man - Thursday, Mar 08, 2012 at 13:16

Thursday, Mar 08, 2012 at 13:16
Hi all,

Just wanted to provide some good information about "plastic welders" for anyone who has an interest.
Firstly, when we talk about "welding" of plastics - it is possible to effect true molecular welding - but you will never achieve this with a soldering iron. You need to have equipment that is specifically designed to meet worldwide welding standards. Using the following tools, you can achieve extremely strong WELDING of plastics.

Hand-held plastic welders:
The hand-held plastic welding tools provide a precisely controlled jet of Hot Air, which can be set to a specific temperature for welding all thermoplastics. These are by far the most commonly used tools for plastics fabrication and repair welding today.

So what do you need to consider before buying a Plastic Welder ?
Here is a list of things to take on board prior to purchasing your first plastic welder.

1. Quality -
DVS compliant ?
Equipment should be selected that complies with worldwide welding standards, as set by the German/Swiss welding/joining society (DVS). This means the welding equipment is manufactured to meet ideal parameters as required to ensure strong, structual, molecular welding.
CE compliant ?
In general equipment manufactured in Europe (Switzerland / Germany) will carry the CE mark. CE marking is a key indicator that a product complies with EU (European Union) legislation. CE marked products conform to very high standards of manufacture, safety, performance and quality - CE marked products are bought by professional users as they are the most suitable for industrial & commercial use. (Beware of cheap chinese equipment !! In China the CE symbol has been alleged to stand for China Export or China Engineering - because some Chinese manufacturers apply a very similar marking to their products. As Chinese exporters have used the CE logo incorrectly, the matter was raised at the EU parliament in 2008, and the Commission decided they will look into trade-marking the official CE logo - and are in discussion with Chinese authorities to ensure compliance with European standards. So in simple terms - if you pay peanuts, you'll get monkeys)

2. Back up & Support -
Make sure the supplier offers back up and support. Applications advice, spare parts & technical service is usually offered by the quality equipment suppliers. A good supplier will carry a full range of equipment, accessories and even consumables - eg. Plastic Welding Rods. These suppliers have generally been in the business for many years and so will have the knowledge & experience to best support you.

3. Warranty -
High quality welding tools are usually covered with a warranty. In Australia & New Zealand, Techspan brand plastic welders are supplied with a limited 2 year warranty.

4. Temperature Control -
A critical part of the plastic welding process is ensuring your welding temperature matches the welding temperature of the particular material to be welded. As different plastics weld at different temperatures, a welding tool with precise electronic temperature control is essential. In general temperature control is built-in to the welding tools. Some models even offer LCD displays, where you can set welding tempertures accurately on the screen. These models are commonly referred to as 'Digital' models.

5. Built-in Blower -
The most common plastic welding tool is fully self contained (Techspan model Rion) - meaning that the blower is built-in to the welder. These tools are by far the most portable and easy to use. Some models dont have built in blowers - compressed air can be used to provide the required airsource to such models, however use of compressed air can be very expensive and must be 'clean & dry'. Pressure must also be be controlled to suit the welding tool airflow specifications. Compressed air flow characteristics are also not as ideal as the fully self contained models with built-in blowers.

6. Accessories & Nozzles for Plastic Welding -
The welding tool will require some specfic accessory nozzles in order to effect correct welding techniques. To ensure you have all the right nozzles for your welding application, we recommend you buy your plastic welding tool in KIT form.

Techspan have put a great deal of emphasis on providing 'easy to find' equipment specification, training videos and more online. The latest Techspan website is packed with all the information you'll need.

Online Store: Now you can View, order & purchase our vast range of Plastic Welding Tools online 24/7.
Visit www.plasticweldingtools.co.nz

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Visit www.youtube.com/user/TECHSPANONLINE

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Visit www.facebook.com/Techspan

The above is only one of our recent 'tech tips'. To view the whole series of 'tech tips' on welding plastics, go to the following link >>

Also, here is our full Instructional Plastic Welding Video >>

I am also happy to take any direct queries covering the plastic welding process, should you care to email me..

Tim the tool man
E tim@plasticweldingtools.com.au
AnswerID: 479883

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