Firstly Steve, we have just sussed here in NZ and currently a re-galv with spinning costs about 60% of new 10mm (3/8") chain, good chain. By spinning I mean straight out of the galv bath the put it into a centrifuge and spin the excess off. It is worth spending the bucks to do that. That's chain at the old price, see further down.
Patrick - your chain doesn't look that bad from what I can see in that photo
. Nice shape, nice weld zone, can't see any big wear and while I can't pick up any stamps I'd say it probably is a well made chain. Rust wise again not to bad mostly. Bit hard to see if those couple of extra rusty bits a flaking or not though. I'd say that unless those bad bits are flaky I'd check out a galvaniser for the cost to get it done. If the chain needs blasting before galving it may push the price up a bit.
I'd also allow for a test afterwards. As you mention you have no history
on the chain it could be well worth it for the peace of mind. Getting it proof tested shouldn't be too hard unless you are in the middle of no where. Suss a company who does commercial
crane type gear
, they usually have test beds.
Here is a specific bit on regalvanising chains you may like to read. This site is in NZ so not a lot of point shopping
there I'd say, the freight would be nasty. Also those are metric chains and if you are US based you'll probably have imperial sizing, it does make a difference.
Do I Regalvanise or not and what pitfalls could there be? - Chains, Ropes & Anchors :: The Maritime Bondage Specialists
The basic things to look for are wear, anymore than 10% of starting diameter will get knocked back by a survuyor on a commercial
boat. Check where the 2 links meet each other, that's the highest wear zone. Recreational don't have any rules I know of, here at least, but if it's getting close to 20% I'd be a bit nervous personally.
Flaky rust. Usually means the chain will need bead or sand blasting before re-galv and in blasting can often take the diameter down more than you expect.
If the chain has already been re-galved a couple of times I'd be nervous or at least make sure it is proof loaded afterwards.
Whatever you do move fast. The price of Zinc is going up like a rocket and the price of steel
even faster. 2 big manufactures we deal have both said their raw material costs have gone up over 40% in the last 2 months. So any new supplies of chain will be going up in price a lot and shortly.
Hope that helps. Ask any questions you may or I've forgotten, I'm good like that.