On these hash boards, one side has regular extruded aluminum, that is aluminum colored. These knock off easily, when struck from the ends s having a black pad/film over the tiny chip. The otherside has slightly smaller chips that look like they are chrome or stainless steel shiny. These are glued/ soldered directly onto a traced design of gold. These are hard to knock loose, and occasionally rip the copper layer. All of them will pop off with a hard blow with a hammer, removing the entire column or most of it with one or two blows. If struck from the side, they tend to hang tight and bend the heat sink rather than popping loose.

Just talking to myself.
Just talking to myself, but you are welcome to listen in while I ruminate. What I have to say probably will never have any relevance to any board you may encounter other than hashboards.
If you have read my posts on the search for an easy method of knocking off the 120 heat sinks from each board, you know I jumped in headfirst without checking the depth of the water. Belly flops and headfirst dives didn't get many boards cleaned. So, the past few cold frosty days gave me a chance to cool my fevor and contemplate. The boards did clean easier when they had been out all night in 22 degree weather, but Pinky, Pointer, Tallest and Ring complained that the cold made them all thumbs, barely able to function.
So I agreed to move the set up indoors. Got my vise on a stand, right beside my rock saw, so I can clamp in a rock, and listen to the music of diamond blade singing a lovely rock tune. And while the saw is sawing, I can be whacking aluminum heat sinks (I know some of you don't believe in double tsk-tsking, that I should concentrate on one job at a time.)
Once indoor with my setup sitting there all sat-up, , I grabbed a two pound sledge to beat the holdtight off the board. Quickly I realized that was a lot of work and hard to control. It just so happened that there beside the work area was a drywall 8 inch blade(been so long since I did construction that I have forgotten what it is called.)
I grabbed it, put a board on the vise for solidity, and tried to chop down. Didn't work. So, I held the board in my left hand, and since I had another hand left over, I held the drywall knive by the handle, like it was a hammer (a really narrow hammer) and with the board tilted a bit vertically, whacked the columns of heatsinks, which popped right off. In five to ten seconds, one side of the board was clean, and the heatsinks collected in a plastic tote.
The sinks on the other side of the board are a bit more difficult, so for now, I am doing the easy off side.
It no longer seems like an endless project. I think I can clean the 1800 boards on one side in only two breakfasts, if I skip my minimum daily requirement of naps.

Not only am I talking to myself: I'm replying to my own comments. In less than half an hour, I had a plastic container, also known as a garbage can, with 60 pounds of extruded aluminum clips, or about 40 bucks at local prices.

Reading the post before last, I started imagining you as Genie from the animated Aladdin movies. (Think it was your choice of saying ruminate) so now your voice is Robin Williams' in my head.
¯\_(ツ)_/¯

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

I had Deadpool in my mind.

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Lostinlodos, do you use this careful method when cleaning boards for scrap or just ones you are repairing?

I rarely have to deal with anything like this. Either way. And I’d pass in a repair of this type. The work involved is extreme (you can’t freeze and heat boards you intend to fix). You’re manually removing each chip one by one. And in reality something like this is designed to use until dead. Not be fixed along the way.
The labour cost for such a repair is more than buying a new board.

For scrap… freeze it, heat it, bang off as many sinks as I can with a punch and hammer.
Takes about 10 minutes per board. Sometimes less.

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Halfway to nowhere, and resting up before I start back.
Glad I wasn't born old and poor: I've had to work hard to increase my poverty, but I'm working on spending my first million faster than it is coming in. I always thought I would be dead or rich before age 30. Wrong on both counts.
I gave up on finding an effortless way to clean one inch size heat sinks from the antminer hashboards and gritting my toothless gums (too old and poor to get those $40,000 dentures ((or even the 2 grand affordable cheapies)) ), I spent 3 or four hours for hours on end (not really, just four or five days) whacking the heatsinks off one side of the boards (the larger heatsinks that had a black pad/glue/solder.
With patient persistent and patience, I learned that it matters which end you whack from, but you don't know which end on which board until you give the first couple whacks. Sometimes, striking a sharp blow with the drywall trowel blade from the connector end makes half of them fall off. Other times, it knocks a few off, along with the tiny black pad, and tears the green coated copper, taking the tiny chip and a bit of copper with the heat sink. Striking the same board from the other end was also unpredictable, as it could knock half of the 60 heatsinks with one blow, or just a few, knocking some cleanly and others with the board rip attached. Some few boards that had gotten left in a tote with rainwater for a few days cleaned easily.
No hope of making any of my stories short, but I wound up with 850 pounds of extrusion/aluminum...it brought the low end of the price range since it had the contamination where it was attached to the board. But since I could collect about 50 pounds per hour, I was making a wage about equal to that of a french fry fast food cook.
With the sinks removed from one side, the boards are still midgrade at Boardsort. With the uncleaned other side, there is still about 1600 pound, but the volume has shrunk by about 3/8, or maybe 3/7, not real good at estimating fractions, since I can't see the whole thing.
Since cold weather finally went south, or came south, and Boardsort is on Holiday Hours, looks like I will have a few weeks to slowly process the other side of the boards for coin. the side with the more compact heatsinks are soldered on with no black pad. Most will pop off with a harder blow, but some will sticktight and bend rather than pop. Probably half of those will clean easily enough, and then the rest brought in as midgrade.
Since my mental capabilities have done a polar reversal, from fast learner/slow forgetter to fast forgetter/slow learner, it took a couple tries for me to figure out that knocking off the sinks in a gravel driveway made for difficult pickup of the ones which got away, and missed the tote/tub I had catching them.
Hitting the sinks was almost like hitting a baseball, except a heatsink wasn't coming at you at 90 miles per hour. But the hitting was the same. A downward chop toward the bottom of the sink resulted in a grounder which was caught by the shortstop. A straight level swing made a line drive which mowed down several more in its path. A chop angle up toward the top of the sink could knock one out of the park.
Don't you just hate it when a story just ends, without any summation or conclusion, or even a moral exhortation such as, young man, stay away from hashboards, as you see what they did to me.

I’m loving this.

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