Posted by Dave on February 18, 2005 at 11:59:22:
In Reply to: Re: ZRC Cold Galvanizing Compound. posted by PHK on February 18, 2005 at 04:12:32:
My own personal opinion is this stuff is worthless compared to hot dip galvanizing.
When something says "95% zinc BY WEIGHT", I would really like to know, ok, so since zinc is a very dense and thus heavy elemental metal, now, how about by VOLUME? If I were to find out if is 30% zinc by volume, I would not be the least bit surprised. Any character can take a paint and put ultrafine zinc powder in it.
When they suggest 2 coats at 1.5 mils each, totaling 3 mils, which is about the thickness of a human hair....sorry, the first time you drag it across that tank finish eating rock or hard surface with an edge, it IS going to scratch to the core material surface after all, it only needs to scratch as deep as the average human hair. Hot dip galvanizing can easily add close to ten times the thickness of 3 mil spray on zinc particle bearing paint, and unlike paint, it forms an elemental bond with steel rather than a mechanical bond as in paint.
For all the time it takes to prep a tank, clean it, then spray it, and for how inexpensive hot dip galvanizing is, I personally wouldn't bother with doing anything mickey mouse, but hey, what the hell do I know!
I will guess your local professional dive store has the right contacts, and I know SSA in Montclair has a contact wherein I have seen their work on several CCR cylinders and the work looks quite competent.