Re: Please recommend custom tank makers
What thickness, and are you talking just a rectangle, or does it have compound shapes?
The most expensive I have seen was a highly complicated V berth tank, that had 14 sides due to it being specced to exacally fit into the curve of the hull as it came up from the centerline, as well as being structual enough to take the place of the normal boards that would have supported the V berth. Including three access plates, three pickups, and four returns it ran just over $5,000. This included preassure testing, shipping and duties. And was made out of 1/8 inch titanium. I tried to figure out the volume, but got lost trying to break it into pieces to figure out the volume. But suffice it to say that the tank weighs in at 65lbs.
A much more reasonable 85 gallon rectangular tank (45"x35"x12") made from 1/16" sheet ran just over $2,500.
I would really have to price it since both of these are old quotes, and prices have come down since then. But I would just roughly guess a 24"x20"x12" would be in the $1,000-$1,200 range. But I wouldn't want to be held to those numbers because the specific design could radically change the cost. That rediculously complicated one for instance had every edge double welded, and it had an insainly amount of welds due to the number of panels. A simple box where we could use a break machine to bend the corners, and just have to weld one seam would be a lot less expensive, just because of the man hours difference.