I just checked out some Shafhauer blocks. The becket has a total of an inch of 14 gauge stainless, at 95,000 psi, tensile strength 7500 pounds. My blocks , if given an inch wide 3/16th aluminium becket at 45,000 psi, have a tensile strength of 8437 lbs. The 3/16th inch shackle s on a Shafhauer block has a tensile strength of 1655 per side, for a total of 3311 lbs, the weakest point . While the bearing is super strong, a chain is only as strong as its weakest link. One can easily go wider on the becket on my blocks, which I usually do, something you can't do on a commercially made block. What they sell is what you get.
Checked out some Harken, Lewmar and Schafer blocks. Only tiny bits of metal holding them together, especially the beckets.
I don't anticipate any similar calculations from Steve ( Smackdaddy ) . Just more adolescent jeering .
Sigh. It doesn't take adolescent jeering, Brent. Just facts.
From your enlightening treatise:
BS Yachts Marketing Program
+++++++++Here is my first post on the blocks after I finally found the photos.++++++++++++++
Finally! I found those pics of the $2 blocks Brent was talking about
Make your own block and test it. It only takes 20 minutes and $2 worth of materials.
The cheeks of a sheet block can be easily jig sawed out of 3/16th aluminium scrap. Some use spacers which can be made out of pipe , on the becket end, to space them the same as the width of the sheave. I prefer to leave the two cheeks attached by a strip of 3/4 inch wide aluminium, then bend it 180 degrees to make the becket. These cheeks should be sanded very smooth and well rounded to eliminate chafe.
Then it' s simply a matter of running a 3/8th ss bolt thru the sheave to make up the block.
You can make up sheaves by running a hole saw thru a sheet of plastic , such as a cutting board. Micarta, salvaged from electrical panels makes even better sheaves which will last several lifetimes. Black plastic is far more UV resistance , if you can find it.
After hole sawing it out, you put a carriage bolt thru it and put it in a drill chuck. Then you use a vise and machine the groove in it , using the drill like a lathe.
You can use a spacer to make a double block, or put different sized sheaves in line, like the yachtie blocks.
While I think bearings are a gimmick , if you insist , you can make the hole in the sheave a half inch wider than the bolt, then stack bits of 1/4 inch rod , made out of any material you like, around the pin and viola, roller bearings.
I have made a single block this way, using only hand tools in 20 minutes, a far stronger and more reliable block than most of the super expensive "Yachtie " blocks people get conned out of large sums of money for. A billionaire can't buy a better block for any amount of money. It takes less time to build one than it takes to travel to the ship swindler and buy a block .
Yet another of many examples of how building your own produces a far better product than the cheque book delivers.
Last edited by Brent Swain; 10-17-2011 at 04:35 PM.
I assume these are from his own boat - which starts to give some small indication of its condition. I guess we all have different measures of "perfection".
As you can see, they are in perfect condition, with zero wear or corrosion after 29 years , and many Pacific crossings. If you want "shiny" you can do it in minutes with a brillo pad on a grinder. That has never been a priority for me. I prefer to concentrate on structurally and functionally sound. I have no interest in impressing anyone but the practical.
Thanks for posting these Smack. They make my point.
I then offered to buy one of his blocks for $11 (half the price of the $22 Garhauer, and 500% more than his cost to make it) and test them both to destruction as he's laid out below in the next post. Still no luck.
A friend sailed to New Zealand and back, with stock "yachty" style blocks. They had black anodized aluminium cheeks with stainless straps over them. The corrosion between the SS and the aluminium swelled the cheeks tight against the sheaves, causing them to freeze solid, in such a brief, one year trip. That is the kind of perfectionism Smack advocates. As long as it has a brand name on it, it must be perfect. My blocks have had no problems in decades . That is my definition of perfection, not decorative priorities over reliability. I still see those failed blocks for sale in yachty stores ,for high prices, for those "knuckleheads "gullible enough to judge marine hardware by the price tag and it's decorativeness. I see some lewmar blocks with 1/4 inch stainless shackles with 1/4 inch pins, and flimsy plastic cheeks , for $40 each.
How does the high price tag and brand name make plastic and tiny shackles stronger than the amount of metal holding my blocks together? How dose the tiny amount of stainless around the shackle pin get strengthened to more than the amount of aluminium in the beckets on my blocks, by adding a brand name and high price tag? They give the safe working load at 900 lbs, a fraction the strength of the half inch line going over it. I believe all blocks, cleats and mooring bitts should be stronger than the biggest line that will be used on them. That is simply good seamanship ( unlike what Smack advocates|)
You can easily make a strength comparision between my blocks and commercially made blocks . Just tie a loop of rope around a tree and the other end to the becket of one. Then tie another loop of half inch Dacron around the two blocks and tie the other becket to the back bumper of a car, with lots of slack . Then get in the car and put the pedal to the metal, and see which one breaks first. If your theory holds, then you believe that mine will break first, and you will be out 20 minutes and $2. So why don't you try it? Because you know full well that your commercially made block wont stand a hope in hell!
What is your theory on that? Or do you simply believe that mother nature is kinder, and more gentle, to materials which look like something out of a blister pack from a yachty store?
Didn't know mother nature was that consumer biased .
I’m still waiting for my BrentBlock so I can do the test he lays out above. So far - he hasn’t delivered.