quote=cummings66]I'd say go for the HP100 tank myself. The weight difference in the water is a wash,..... [/quote]
Excellent advice.
I'm looking for another old PST made tank for Sherwood or Genesis to match the one I have now. I paid $75 for my HP100 with valve, but I had to hydro and vis it which cost another $33. I'm not willing to spend more than $120 to $130 myself for an old tank, but I would spend more on a newer one.
Yep. I'd agree and say he should go for the HP 100, as long as it's not the Japanese make, which I believe had significant problems, according to my LDS. The Japanese version also had a taller boot and stood taller- not desirable, in my book.
The PST HP 100 is very popular here in New England. HP 80's aren't as popular and are harder to sell around here.
I've bought about 15 or more PST HP tanks in the past 10 years, some to sell, some to keep as a "fleet" of 8 or 10 for camping/diving trips to places where there were no fill stations. I loved the 100's, but have switched to mostly 120's now.
Around here (NH, MA, ME), the going price for a PST HP 100, with most of a hydro left on it, runs between $150 to $200, regardless of age, believe it or not. Current visual wouldn't be expected here. You did very well to have gotten yours for $75 plus a hydro, I think. In 10 years of buying, I only found about 4 around the $100 price. Had to be the first caller on those, for sure!
No matter what, get it vis'd before you buy if you can. Din tanks are easy to find rust in them because it seems the threads can hold water after a dive and if you don't blast it out or let it dry and the dive shop neglects to do it, you may find water getting in the tank during a fill and you could have rust in it. Especially the angled DIN valves you find on Genesis and Sherwood tanks.
I think your word of caution to get a visual is good advice for the OP, and it's quite likely that the tank will have some small amount of rust in it, but that's common and rarely reaches the level of being a problem. Usually doesn't even require a tumble.
My tanks will occasionally get minor rust in them even with my good care to blow out the valve after diving, so I don't know if the angled valve is the issue as much as occasionally damp fills from the dive shop, such as when it's close to filter change time for the shop.
Most of the tanks I bought were 5 to 10 years old when I bought them and I expect them to pass hydro for a few decades more. Most had slight rust inside. None required a tumble to pass inspection, although I made my own tumbler and cleaned them all up.
I'd say the OP should ask a knowledgeable local diver to look it over with him, then probably buy the HP 100 and feel pretty happy about the tank and the price (if it's PST). He should check eBay prices on these tanks, too. They run pretty high, even for older tanks. They're very popular.
Dave C