Sealing a water tank

Philip,

I in my job use Silicon sealant which I have used to seal in my case Bulkhead water fittings on a round sank successfully and it puts up with the heat of water over 100Deg C so will be ok. If you are in Bedfordshire area you can have a tube.

Martin P

Philip Carter wrote:

Thanks for the tip and the offer. I live up in North Yorkshire, so now that I know that works I`ll nip down my local B & Q.

Phil C.

All silicone sealers are equal - but some are more equal than others! Have a look around the stock at B&Q to get the right one, but you might do better if you tried a plumbers merchants. The best (and most expensive) is Sikaflex which I have used to seal gurt holes in boats, caulk clinker hulls from stem to stern, seal water tanks with big splits in them, repair rusty pitted holes by applying it to a sheet of hardboard & parking the tank on top. Etc, Etc. It's good stuff, but the cheaper "bathroom sealer" varieties tend to be a bit flopty bunny ;o))

Don't buy more than you need, I've never yet found away of stopping the set silicone from creeping through the whole tube once it has been opened & exposed to the air & it's not specially cheap. I did slow it down by recapping the tube underwater............

Regards,

J. Kim Siddorn,

The stuff we use come from Italy and a part used one can sit in my van for weeks between uses and will only require the plug removed from the end of the tube. I must admit mine is of industrial quality and seals the chamber of large industrial washing machines whose operating temps are normally

82Deg C @ 2.5 Bar working pressure but if the machine throws a wobbly can exceed 110 Deg C @ 2.5 Bar pressure. If anybody wants a tube and I have my Van at a rally you are welcome to ask.

Mart> All silicone sealers are equal - but some are more equal than others!

That certainly makes the job sound simpler and quicker than it used to be, the last boat I caulked was done using a mix of putty, white lead paste and LM grease over twisted caulking cotton. I only wish that the people who fitted my shower last December had used something half as good as Sikaflex, perhaps that would have avoided the waterfall we now have in the hall below for the second time in eight months.

I've found Fernox to be good. For the uninitiated it is a silicon sealer that can be applied to wet joints and will withstand reasonably high temperatures (central heating pipe work etc.) Most plumbers merchants do the stuff and sometimes even B&Q do it.

Alternatively, you could use a panel beating technique to produce flats in the cylinder around the holes. The plastic washers should do the job then.

Mark

Sikkaflex is (generally) polyurethane rather than silicone. Their silicones are no more equal than anyone else's (and expensive), their _good_ stuff is the PU. There's nothing else up to the job of gluing the ally panels onto Range Rovers! OTOH, the PU has a poor shelf life once opened - it's a bit of a one-job tube.

I wouldn't use silicone. It's a screwed flange, so you want elastic and slightly sticky, more than you need the gap-bridging of silicone. I'd use the inevitable Hylomar (good fits) or Oyltite stick (bad fits and bodge repairing).

OTOH you could just pop down the plumbers merchants and get a curved washer set for round tanks :-) I know. I'm a spoilsport......... ttfn Roland

A good bulk head fitting will pull the tin work flat also, the silicon just makes sure.

Martin P

you could use a panel beating technique to produce