Being a Southern boy (in my second childhood) who likes to have pun in the sun, I'm posting this in the general discussion forum rather than a tip or business or ID posting.
Previously I asked questions on Antminer S9 bitcoin machines. Let me tell you, it isn't easy money like busting the piggy bank for pennies. I have dismantled about 450 and not a single physical bit coin was stuck to the circuitry. I should have known, as nothing rattled when I shook them.
I'll give a general rundown of the procedure I developed. The first batch of about 170 machines took me on and off about 12 hours to process until I established my routine. Now I cando the Kandu in half the time, if I don't stop for a nap, or see a nice flinty rock and decide to knap.
I stand the units on their head (it didn't work well when I left the machines upright and stood on my head). Each unit has two fans, one on each end, so the problem is telling the head from the tail. When I post the pictures, you will see the difference. The one end, remove the fan and the boards slide right out, if you have disconnected the wiring connectors from the control board.
Instead of removing the fan's four screws, I remove the four #2 phillips screws from the sheet metal plate the fan is attached to. I toss the fan into the bin to go for shred at a local yard at 8 cents per pound.
With the fan removed on that end, the three hashboards slide out easily. The hashboards with heat shields on both sides weigh 2 pounds each, or 6 pounds total. Chris said the boards with heatsinks are "midgrade all day and all night".
Having removed the hashboards with their protrucing connectors, I then remove the control board, which appears to be a high peripheral requiring about six boards to weigh a pound..
Next, I stand the antminer on the half shell on the clean end and remove the fan from the other end. I hate to throw away perfectly good fans into the shred bin, but there just aren't many fan dancers around anymore (Fan dancers of the olden days, made a man feel hot instead of cooling him off)
Last, I slide off the extruded aluminum cover that protected the control board.
All that remains is the empty extruded aluminum shell of what once was a mighty bitcoin maker: 2 pounds of fancy scrap, affectionately known as 6163 or something like that at the recycling yard. The boys who play recycling games in the big leagues and have a stadium franchise in Chattanooga Tn surprised me with a $1.01 per pound payout on the extruded aluminum..,
As of now, I am on the positive side moneywise. Recovered initial cost, and pocket a bit of return, and still have another pallet of 120 to strip.
Then comes the hard part: Do I take the roughly 2000 pounds of boards with heatsinks (uncleaned) to Boardsort as is, or remove the heatsinks for local sale? The boards from each machine make a stack about four iinches thick, double the volume of the "clean boards" which means a larger capacity vehicle (not really, since I already had a pickup truck load ready to bring, so would need a bigger vehicle already) Bring the unclean boards to board sort would pay $3 for the six pounds of boards in each unit. Stripping the heatsinks for local sale would net $1 for aluminum, and the diminished boards (in the math of Dollar General, 3=2) @ $1.50 per pound, you figure it out. The total money is about the same: it just means cleaning the boards means I miss some nap time, or if I see a pretty flinty rock, wait, I already used that one.
So far, I haven't devised an easy, efficient way to remove the heatsinks without disturbing the chips (some pop clean, others tear the copper layer. I've tried some methods suggested on this forum.
With the extra hour of darktime we were granted last Sunday when the clocks ran backward for an hour, just like the Mississippi river in the earthquake on the New Madrid Fault in 1811-12 ran uphill to create 'Reelfoot lake" I did some cogitating and contemplating.
In my experience in the building trades, I learned it is easier to tear something down if you know how it was put together. That, combined to with the admonition from Sunday School days where the wise man said a proverb, which I paraphrase here, "Go to the Antminer, thou sluggard. Consider their ways and be wise."
So, I shall be watching videos during naptime or is that knap-time, to learn more than I want to know about hashboards and how they grow.

You are awesome. I really enjoy reading the stories you tell. I think I may be on the other end of tn from you in the Memphis area. My local yard gives me motor rate for fans. You might be able to get a few more Pennie’s for rock hunting that way. Thanks for all your inputs.

Thanks for the compliments. A good compliment lasts longer than a mere monetary tip, but I will take a sample to the big boys and see if they will beat the shred rate.

Dozin' Dave woke up from his cat nap in the recliner, since the recliner was not the "Catnapper" brand and managed to view a few You Tube videos (not a single "Me-ow Tube" in the lot) and so far, only found information from repair type persons who are attempting to put Humpty Dumpty back together again, rather than make scrambled eggs from the remains.
It appears that a dedicated desolder-er can remove a heat sink in about twenty seconds. Quick, easy, right? Yes for one sink. But suppose one has a total in excess of 192,000 heat sinks? Definitely not going to finish before breakfast this week.
After taking a mental break from "board sorting" to remove electronic clutter piled in front of the rock polishing machinery, I discovered a funny hair dryer I had hauled in with some boxes of stuff given by a friend as cleanup after an estate sale. Yep, the manly hairdryer was a heatgun, as recommended by Lost.
A quick test on a hashboard showed that indeed it only takes a few seconds to melt the solder/soften the glue and let the heatsink fall free. (note to self: don't do this project barefooted, anymore)
I think I can speed the process by heating hotter and allowing the waste heat from a single sink be deflected to the surrounding sinks. By current calculations, I should be able to finish in the year 2323, rather than the first projected timeframe of year 2525 (will AI still be alive?).
But, it still seems the best idea is to resign myself to delivering the ton or so of boards to Boardsort with the heat sinks still attached.

If you have a sunny spot or have a heater running already for the cooler months you could stage the next set of heatsinks to allow them to warm up before you hit them with the real heat.

_________________
Here to learn more so I can recycle more
My grades are my own opinion and not an official grade from Boardsort

I always enjoy reading your "rambles" (when I'm at work and the day is dragging on). I wonder if you could get under those heatsinks with a chisel or putty knife and tap the sinks off?

Btw, post some pics of you knapping projects! I don't know any flint knappers in person anymore, but I do follow some on the social medias.