aga - 5-11-2015 at 12:27
Is there any reason why the Silvering process would not work on PVC ?
Specifically i'd like to silver the inside of the pipe to make a light-guide for Sunlight.
annaandherdad - 5-11-2015 at 13:57
I don't know but when I was making mirrors I made boxes lined with paraffin to hold the silvering bath. This was with the Brashear process. Turns
out some of the silver stuck to the paraffin as well as the glass. Glass has to be extremely clean to get a good coating, and I don't know if that's
possible with pvc.
The problem of a light ray in a gently curved, reflecting cylinder is an interesting one. It involves two adiabatic invariants. Note that the
intensity gets multiplied by 0.95 or some fraction on each bounce. If it takes a large number of bounces, there won't be much light left.
aga - 5-11-2015 at 14:23
Thanks for that aahd.
The pipe i had in mind is quite 'dusty' so i suspect that silver would not adhere very well no matter how well it was cleaned.
Time for Plan J instead.
careysub - 5-11-2015 at 18:31
Almost certain to not work.
PVC is a very low surface energy material (just twice that of Teflon) and to get anything to adhere to it it should be flame treated - passing a
propane flame over. It just takes a moment, and the surface turns dull (that is how you know if you did it successfully).
Flame treating the inside of a pipe would be a little tricky.
And I don't know if the activated surface would stay activated while arranging for the silver to precipitate.
Twospoons - 5-11-2015 at 20:01
Flame treatment might be tricky, but i think plasma treatment using an atmospheric pressure dielectric barrier discharge might work well - foil on the
outside and drag a wire around the inside.
I made a low pressure plasma treatment system that worked a treat for getting glue to stick to LCP, another notoriously difficult polymer to bond to.
homebrew plasma cleaner
I've used a similar trick to make a plasma cleaning 'wand' from a glass tube - one wire inside, and another spiral wrapped around the outside.