Adhesive

When it comes to making crafty containers or sticking magnets to cache containers, adhesives become important.

Maccamob contacted Selleys for their recommended product for poly plastics, and was advised that "none of the Selleys adhesives will adhere to Polypropylene or Polyethylene". Check their individual product data sheets on line if you're not sure.

Many of them are also not water resistant in outdoors situations. Selleys actually referred them to Loctite for a suitable product.

Loctite 770 Activator/Polyolefin Primer is designed for "difficult to bond substrates which include polyethylene, polypropylene, polytetrafluoroethylene (PTFE) and thermoplastic rubber materials". You can read more about it, and suitable adhesives to go with it, in the Loctite PDF.

Loctite 406 seems to give the strongest bond with polypropylene, which is what most plasic cache containers, such as Sistema, are made from. Loctite PDF The stuff is a bit pricy though.

Many geocachers have had success with Selleys Liquid Nails.

Bear_Left recommends that if possible, go for mechanical fixing (i.e. bolts and nuts or screws into something) and seal the holes with silicone or lashings of hot glue. Not as pretty as adhesives, but much more secure. Washers to spread the load under the head of the bolt and the nut are also a good idea, as they might 'pull through' eventually.

Energizer61 suggests if you're wanting to stick Poly to Poly, go to an Electrical or plumbing wholesaler, ask for Conduit (at the electrical wholesaler) or Stormwater (at the plumbing wholesaler) solvent cement. Works particularly well.

The type Engergizer61 uses is "Type N Solvent cement" Made by Vinidex designed for non pressure applications, the other type is "type P" designed for pressure pipes etc, which may be better if you are looking for a totally waterproof seal. If you know any electricians/plumbers, ask them if they've got a sample (most would have half empty bottles rolling around in the van everywhere).

Read the instructions (the first thing it say's is "Solvent cement jointing is a trade skill & should be executed by appropriately qualified persons") & you shouldn't have a problem. More info here; Vinidex