Sealer

Using the numbers as a template - draw around them .

Remove the numbers .
And tricky as it is try to roughen the inside the numbers with some fine sandpaper.
I've done it with discs of sandpaper on a old very small and circular container .

Take some coarser sandpaper and roughen the back of your numbers .

Blow away the dust .

And on a dry day -apply the glue and apply .

You need to hold it on for as long as you can stand .
When dry and set varnish is a very good idea !

Good luck !

I was going to suggest Yacht varnish.

Try Sticks Like Sh*t by Evostick.

Good tip Merlot. I have never used no more nails and will keep it in mind. I use a very small amount of GG to stop it oozing out which works very well.
I second yacht varnish as the best sealant I have used.

As far as I remember glue needs to be applied to a clean surface , so sticking the numbers back on involves cleaning off the old glue from both surfaces before re gluing them , then use a stronger adhesive

I think you would be better off improving the adhesive before sealing the numbers. Yacht varnish is very good for weather protection but won’t prevent them falling off.

merlotgran

Are you looking for something to stick the numbers on before sealing them? If so you need two separate products.

The numbers are supplied with an adhesive on, albeit a not very strong one.
I am looking for something to place over the top so they cannot be picked off.
Thanks

Are you looking for something to stick the numbers on before sealing them? If so you need two separate products.

Gorilla glue dries to a creamy colour. No More Nails dries clear.

Kalu

Gorilla Glue

Does this dry clear?

Elegran

Surely that 1 is a 4 ?

The 1 fell off already. The 4 is in the process of falling off

Have you tried Screwfix?

Surely that 1 is a 4 ?

Gorilla Glue

YouTube is your go to for this information.