Aaron's blog

I was reading some discussion about the AeroPress recently and many people were describing their process.  There are some people who love their coffee in a very precise way!  My process is probably close to the ultimate in laziness (80% of the quality for 20% of the effort).

I use a vacuum mug that is probably 16 oz. capacity.  Over time I have become able to eyeball how much water in the electric kettle will result in the mug being almost full.  So I fill the kettle to a little over the top of the "0.5L" text and start it.  While it heats, I put the filter and grounds (a couple heaping teaspoons of cheap stuff) into the AeroPress.    As the kettle heats up it starts making noise.  After about 10 seconds of noise it is the temperature that will result in an easily drinkable cup of coffee immediately after brewing.  So I take the water and poor it over the grounds, slowly at first so that all the grounds become wet and then rapidly so that they get mixed up more.  If I don't wet all the grounds then some of them tend to stay floating on the surface.

About 70% of the time I do some mixing with the paddle that comes with the AeroPress.  Coffee drips out the bottom and as the water level lowers I add more water, sometimes stirring more.  I let it drip and keep adding water until the kettle is empty.  Then it is time to press; I go all the way to the bottom and squeeze the last bit out of the grounds.  I'm not sure if that is recommended!  If I overfilled the kettle a little this is when I will find out, as coffee dribbles over the edge of the mug.  Then I pop the puck of grounds into the trash, rinse everything, and wipe it down with a paper towel.

Some places where I am probably losing quality:

• In that discussion many people rinse the filter to avoid a paper taste; I don't do that.
• It is very common guidance for any brewing method that the water should be heated to just under boiling.  My water is significantly cooler than that.
• Many people optimize some sort of blooming process; I just go for the full immersion of the grounds right away.
• I squeeze the juice out of the grounds into the coffee cup and I'm not sure that is a good idea.

I was recently helping someone with a transition from Dropbox to SharePoint/Teams/OneDrive for Business.  They were running into issues with filenames.  As an all-Mac business there were many files they had created with colons in the file or folder name.  Windows doesn't allow those characters and SharePoint does not appreciate them either.

Some Googling suggested that downloading a ZIP of the Dropbox folder might solve the problem.  I found that when I extracted the ZIP the offending files were just missing.

I ended up creating a droplet on Digital Ocean and syncing the Dropbox folder to it.  Even though it was 20GB and 14,000 files, the sync only took three or four minutes!

Then I set about carefully renaming things.  Thanks to StackOverflow I mainly worked with variations of this command: find . -type f -name "*:*" -exec rename -n 's/:/-/g' {} + It renames all files that contain a colon by replacing that with a dash.  If you have directories that contain a colon then it will fail to rename those.  Run again with -type d to rename those.  Remove the -n to actually make the changes; with -n it just tells you what it would do.  Append | wc -l on the end if you want to count how many issues you have.

Towards the end I was just using find . -name "*:*" to do final checks.  And I checked all the invalid characters.  Some of them require \ as an escape character; for example find . -name "*\?*"

Then you may find out other odd things.  For example, file and folder names cannot start with a space.  find . -type f -name " *" -exec rename -n 's/\/ /\//' {} + can help with that.

For the actual sync I setup Dropbox and OneDrive for Business on the same machine (enable long file names).  Then I used robocopy /MIR to copy files into the OneDrive folder.  After my first run of that, OneDrive started syncing as expected.  Then it got upset about some filenames, which is when I realized that there are additional characters not allowed in SharePoint that are OK in Windows.  It offered to fix those, replacing the characters with an underscore.  Then I found out about the spaces issue and fixed that back on the Linux droplet.  After Dropbox synced I ran robocopy /MIR again to put in those new fixes.  A significant problem with this method is that OneDrive for Business changes the filesize on some Microsoft filetypes so if you have a large amount of those types of files it might cause difficulties.  After the initial robocopy the magnitude of this issue can be quite reduced by using the /MAXAGE parameter to limit the files that it copies to the last few days.

For entertainment tonight we played trivia via the VHF radio. There were about 15 teams playing.

The host read four questions for each round on the radio and we submitted our responses for each of the five rounds in a Google Docs form. At 5 points per question and a bonus point for signing up early we were in the middle of the pack with 31 points going into the final question. We wagered two points!

The final question asked who performed the song that was played at the beginning of the cruisers net this morning.  The cruisers net is also a VHF affair which consists of announcements, comings and goings, buy/sell/trade, and requests for help.  The host typically plays snippet of a song at the beginning of the program.  Of course no one knew that it would be a question in trivia that night, and based on the scores we heard I don't think anyone got it right.  It was '39 by Queen.  Pretty interesting that Queen wrote a folk song like that.  Betting only two points paid off and we tied with one group for third place!

In other business, everything except essential services was shut down yesterday in the Bahamas. It turns out most things that we care about ARE essential services...groceries, gas, water, laundry, and shipping parts (our steering needs some maintenance). And restaurants are doing take-out if we really want some fried food. No big social events is one of the few significant changes for us. And our friend Daniel is not coming to visit for a week as planned (it is interesting that he technically could, but it would be unwise).

We still plan to be in Georgetown until well into April, but that could easily change. Ideally tourism would be encouraged again by then and we would see a few more places on the way back to the US sometime in May. If we want to go back to the US anytime, we are able to, and stopping at Bahamas islands along the way for essential services is OK too.

In this post I will document the Seawater Pro watermaker that we installed one year ago.  It currently makes 15 gallons per hour here in the Bahamas at about 850 PSI membrane pressure while consuming about 850 watts.

I ordered and installed the system in March 2019, probably total installed cost was about $3,100 and a solid week+ of learning, working and running to hardware stores.

• $2,575 to Seawater Pro.  It looks like this $2395 item currently in their store is basically what I got.  I would really recommend getting the "remote control" version which is basically a pretty panel to put the controls and gauges in, but it is $400 more and you have to draw the line somewhere.
  • Base system price was $1,595
  • $699 for the DC motor and brass pump upgrade
  • $39 for the SW30-2540 membrane (an upgrade? I see they retail for more like $200 online?)
  • $80 shipping and some tax were the remainder
• Additional costs rough estimates (one year ago by memory!)
  • $250 for plumbing odds and ends not included "in the box"
    • Boost pump is far from high pressure pump
    • Had to split air conditioner sea water intake (do not run AC and watermaker at the same time)
    • New dump overboard through the hull for salt water output
    • New input into top of water tank
    • Valves to direct product water overboard or into water tank
    • Misc. to get house water to the system for flushing
  • $250 for wiring
    • About 30 feet of 2AWG marine wire
    • Circuit breakers
    • Compression lugs, heat shrink, looming, etc.

What the operating process looks like, plus notes about a few steps that we skip:

1. Ensure needle valve is open (unrestricted).
2. Ensure product water valves are set to flow overboard and put that dump hose out the v-berth hatch. (usually skip this and just dump straight into water tank...20 seconds of 2,000 TDS water is quickly diluted by the following hour or two of usually 100 TDS water)
3. Turn on salt water boost pump.
4. Verify that the pressure gauge before the salt water high pressure pump shows higher than 0 PSI (usually skip this, depends on cleanliness of sea water in the area).
5. Turn on salt water high pressure pump.
6. Tighten needle valve over about 20 seconds to bring pressure to 750-850 PSI, observing GPH meter rise to 15 GPH (or more, or less).
7. Turn on the TDS monitor and observe it drop from around 2,000 to under 200.
8. Open product water valve to water tank, and then close the one that dumps overboard. (usually skip this)
9. Put away overboard dump hose. (usually we don't dump any water so skip this)
10. Run for a long time, typically one to two hours.  Monitor both low pressure and high pressure gauges every 20-30 minutes, and also listen to the sounds of the system for interesting changes.
11. Loosen the needle valve slowly over 20 seconds to bring high pressure to 0 PSI.
12. Turn off high pressure pump.
13. Turn off boost pump.
14. Flush system with fresh water. This ideally would mean doing something with the garden sprinkler timer but I haven't gotten that to work so I flip open a valve under the settee. (usually we skip this)

So basically we are doing two "naughty" things.  We don't dump the initial product water overboard, but the math on dilution is quite convincing to me that it doesn't really matter, the water tastes fine, and we are generally healthy.  And we don't flush with fresh water after running, but the system performance does not seem significantly degraded.  Perhaps we will need to replace the $200(?) membrane earlier than the 5-10 years that people normally get out of them.

Our system has a 12V high pressure motor.  At operating pressure this alone seems to draw about 800 watts (65A at 12V), with the boost pump drawing the other 50 watts.  For our 4x 100Ah 12V lithium iron phosphate (BattleBorn) battery bank this is no problem.  It may not work so well on smallish lead-acid battery banks, in which case using a generator and 120V AC pump would be wiser.  If we run the generator our battery charger can put out about 90A so it can charge the battery a little in addition to keeping up with the watermaker draw.  But mostly we get enough solar from our 1100 watts of panels to keep up with the fairly liberal demands of the two of us.

That's it!