[VAC] Re: Blackwater Tank Repair

["Jason Guynes" <jguynes@xxxxxxxxxxxxxxx>]

Well, I had pretty much decided that my tank was polyethylene and resigned
myself to purchasing a new tank.  However, after checking out the site that
Chris suggested, http://www.urethanesupply.com/index.htm, (thanks Chris!) I
ran a few tests and now know that it's definitely not polyethylene.  The
site has a chart that lists the characteristics of most plastics.  The most
telltale characteristic about polyethylene is that if you grind it, it
melts.  My tank sanded easily and the grinder produced no discernable
melting.  Further, I tested it for adhesion with epoxy, marine epoxy putty,
and JBWeld and everything stuck to it.  All of this makes it seem like ABS.
If so, it's easy to repair - even though the cracks are extensive.

That being said, I'm planning to make the repairs -- since they are so
easily made-- and I'm also planning to look into getting a new tank.  Being
new to this, I'm told that 6 gallons is fairly minimal for a blackwater
tank.  Since I prefer places without hookups, I may need something larger.
I'll reinstall the repaired tank if I have too, but since I now know that
replacement tanks can be made to order and have some good leads on places
that do good work, I'll probably try to get a larger tank made that extends
into the adjacent closet.  I'd also like to install a graywater tank for the
sinks -- I don't think I can rig anything for the shower.

Thanks everyone for all the help.

Jason Guynes
'65 GT