Identify plastic glue

I hope this post is not too far from model-making and may be relevant to it, even though the term being worked on is not a model.

thanks in advance for any advice you can give,

I am overhauling a water-tower. (Www.waterrower.co.uk) Th rowing machine has a doughnut shaped hard clear plastic water tank 50cms in diameter which is in two halves (Top and bottom) glued together. The lower half has a lip the other half sits in.

I need to glue the two halves together. The glue needs to bond and fill then1mm gap between the top half and the lip.

When I separated the two halves the old glue came away as a pliable strip of glue about 1mm in thickness. The strip had a smooth feel.

The water rower website sells a glue kit which fits in a standard tube squeezer (like you use for going round Shower tiles just . It’s a two part solution which comes with two cartridges and a tube like a hypo which mixes the two parts of the glue and applies it as a liquid which runs into the gap and quickly becomes viscous. It sounds like something very tricky to do with a standard applicator.its also £35 and they’re out of stock.

Can anyone identify the type of glue? Or alternative solutions? I’m thinking of using straightforward araldite, but I’m not sure if araldite is waterproof when dry and I don’t know if the bond needs to be flexible when dry - does plastic expand and contract much with temperature?

Any advice would be much appreciated.

cheers!

Adam

I think that you'll have to identify the plastic specifically

I would have thought that a standard sanitary silicone rubber sealer would work perfectly and come apart again if need be

araldite might be a problem with coming apart easily

Evo do their “sticks like s*** “ adhesive which sticks almost anything and is waterproof but again difficult removing it at a later date

Thanks Roy! That is going to be difficult - it would be better if we knew. I would describe it as similar to hard plastic drinking bottles, maybe 2mm thick. It’s nearly 20 years old and apart from a few scratches it is undamaged. Dirt washes off. There were some paint splashes which chipped off without damaging the surface.

What do you think of the suggestion to use rubber sealant?

thanks again,

Adam

if the old sealant peeled off, it clearly wasn'y solvent welded. The two part glues with mixing dispensers are typically epoxy or acrylic. Epoxy is not normally flexible so an acrylic is more likely. A two part silicone i also possible. For something readily available and durable I'd suggest a good quality clear RTV silicone. This may take some time to set fully so not so suited to a production environment hence their use of a two part product which are typically faster setting. At least with RTV you can remove it without damage.

Robert G8RPI.

Sikaflex is a very strong bonding sealant. It is used in the auto industry for sticking body panels on. I have used it a lot in the past. We used to bond Spoilers & side skirts on custom cars with it. Once on it's never coming off. Sticks plastics & steel.

Another is the silicon sealant used for building fish tanks , plastic & glass. Never comes off once cured .

Steve.

A fish in the internet suggests the tank is made of polycarbonate. The dispenser shown on the web is is for a two component syringe with a static mixer nozzle attached.

Epoxy might do the job but you might never get it apart again.

I would have guessed it was a clear two component addition (platinum) curing RTV silicone. Shouldn´t attack the polycarbonate. Anything with a solvent in, is a no go. A clear sanitary silicone would probably do the job. Put a blob somewhere out of sight and see if you can get if off again.

However I had a look at this German site (https://www.poolpowershop.de/waterrower/glue-kit) and it helpfully has the supplier details of what they are selling for the job. It turns out to be an electronics grade; unfilled, room temperature fast curing; two-component polyurethane adhesive is designed for the adhesion and potting electronics.

Dick.

That is fantastically helpful and many thanks for the advice, which I now need to go through and see what I can obtain. 🤗👍🏼