So I bet some of you have been wondering just what happened to the S&G cells over the past few weeks. Well, just after the last apparently successful run and before the data publishing was able to be live again, the active cell was loaded with not 1, but 2, 400L class Celani wires and test loaded with Hydrogen. We got 25% loading on the first attempt which is awesome. What was not so good was that there seemed to be some serious failures in contacts and wiring and the cells have laid dormant whilst awaiting repair.
The good news is that Nicolas has put aside the time to give them a little TLC, actually, they have been in intensive surgery lately.
The failure mode was the same on both cells:
- water got into the copper - electric wire connections and these got corroded (outside the cell)
- mechanical stress on the electric wire caused them to fail
So whilst it might be simpler to understand these experiments over the other ones we are doing, the whole immersing them in water brings its own complications!
So Nicolas had to:-
- Replace one of the passthroughs, that accounted for 4 electrical connections, on each cell.
- Perform complex surgery to remove the 353ND epoxy and replace the ceramic passthrough.
- Re-build the electric wire connections which are now reinforced with Belzona 1111 (super solid stuff).
This has now been fixed for both cells. With these corrections and modifications, it is expected that the issues encountered will not cause problems again.
The hard part will be to remount every thing on the active cell without damaging the valuable Celani's wires which still have a high loading. Currently, the wires are still mounted on the 3 mica parts, but this subassembly is presently dismounted from the cell.
Nicolas says he is waiting for a roll of Block constantan (0.2mm) that he has been using to seal the glass fiber sheath on the copper wires (inside the cells). Without this, it will be to risk for the active wires.
He hopes to finish reassembling everything this Thursday.
Then we'll restart test, with LIVE data, potentially as soon as this weekend.
In the meantime, if anyone has any protocol suggestions or practical points for us to ensure we incorporated, we would really appreciate if someone could sift though the discussions of the last run and pick out the gems of ideas that were put forward.
We are likely to set the cells up in a way that allows them to readily reach a steady state rather than over insulate them and we have some good previous data to go on that will enable us to hopefully start at a point that is closer to steady state, however there is potentially more and better active material in these cells than before, so it could be an exciting run.
Oh, and we'll have an ambient sensor.
UPDATE#1 - Repair done, getting ready to fire up
Nicolas managed to repair the feed-thoughs on both the cells, without damaging the highly loaded 2 400L class Celani wires in the active cell. The electrical wire connections are now reinforced and should not exhibit the same failure mode when immersed into water.
He is reconnecting both cells to the HugNetLab boards. And plans to restart testing from this Friday afternoon.
He says that he is not certain that the cells will sustain vacuum correctly, I guess we will see.
The Teflon gasket seat on both cells might need to be reworked too. But this should be easy to do if it is needed. See a few shots from the re-build.
The S&G following a very successful loading of 2 X 400L Celani wires in the active cell was found to have a major failure point. This has now been repaired and reinforced and we think it is about time they get fired up for a live run!
Taking learning from the previous run, we have a better idea of where the start point in terms of Pin for the active and control should be and there will be logging of ambient!
Otherwise, pretty much the same BUT - the Active and Control will switch positions!