A big part of why my ePipe project is stuck is that unlike most of the high-end mods currently out there, I cannot use all-metal construction, which means my mechanical connections have to be based on glue. In fact, the biggest metal part in my design is the top cap, a metal disk.
The problem is that Propylene Glycol breaks adhesives down, badly. Superglue, hot glue, rubber cement (natural or synthetic), none of it lasts long once the liquid starts dripping into it. The only thing I've found that can stand up to it is two-part epoxy, and only if the surfaces are porous (metal that doesn't have significant corrugations won't hold). And epoxy is a bit of a pain to work with, in addition to the fumes I'm having to balance out the curing time of the epoxy against the amount of bits I need to assemble in one throw and how long I have to wait before moving on to the next. And if I get too much epoxy smeared onto the pipe body, getting it off without ruining the wood finish is a pure ......
Gorilla Glue works great and seems immune to the breakdown, but I can't use it anywhere it will be visible because it foams up and looks ugly. I've tried some exotic (and really too expensive) industrial adhesives (most of which didn't work any better), but the long list of handling warnings and looking up some of the ingredients makes me iffy about selling a product built with them.
Does anyone here have any ideas for adhesives that can bond wood, plastic, and metal, do it reliably and without being too toxic for a home workshop, and stand up to the de-bonding effects of PG? I've *found* a solution, using Gorilla Glue where I can and epoxy where I can't, but it makes assembly a very fiddly multi-stage process.
How much trouble have other had with PG breaking down their mods? Or am I just being too aggressive about testing and stressing my pipes?
--Dave
The problem is that Propylene Glycol breaks adhesives down, badly. Superglue, hot glue, rubber cement (natural or synthetic), none of it lasts long once the liquid starts dripping into it. The only thing I've found that can stand up to it is two-part epoxy, and only if the surfaces are porous (metal that doesn't have significant corrugations won't hold). And epoxy is a bit of a pain to work with, in addition to the fumes I'm having to balance out the curing time of the epoxy against the amount of bits I need to assemble in one throw and how long I have to wait before moving on to the next. And if I get too much epoxy smeared onto the pipe body, getting it off without ruining the wood finish is a pure ......
Gorilla Glue works great and seems immune to the breakdown, but I can't use it anywhere it will be visible because it foams up and looks ugly. I've tried some exotic (and really too expensive) industrial adhesives (most of which didn't work any better), but the long list of handling warnings and looking up some of the ingredients makes me iffy about selling a product built with them.
Does anyone here have any ideas for adhesives that can bond wood, plastic, and metal, do it reliably and without being too toxic for a home workshop, and stand up to the de-bonding effects of PG? I've *found* a solution, using Gorilla Glue where I can and epoxy where I can't, but it makes assembly a very fiddly multi-stage process.
How much trouble have other had with PG breaking down their mods? Or am I just being too aggressive about testing and stressing my pipes?
--Dave
