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Old 01-13-2018, 06:48 PM   #1
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Claw Modified

To me the Claw is about the most interesting anchor we use. Have you ever wondered about the tall vertical part of the shank? Or the twisted side flukes?

I noticed on at least one of Steve's (Panope) vids of Claws that the anchor breaks out butt first .. not straight out as would seem natural. The back end of the Claw frequently pops up vertically. This can be seen on Steve's Anchor Setting Videos post #118 5:2 on the timer.

Many times I've heard others on TF say they thought the Claw lacked fluke area and it's performance was consistantly lows a result.

I took my 22lb Claw to the weld shop w directions to modify it to have far less tendency to pop up at the back where the shank and fluke meet. Also I gave more area to the center fluke and provided much greater sharpness both at the tip and on the side. The side needs minimal resistance to allow the anchor to rotate to a fully set vertical position. That is w the shank sticking straight up. This is the only way all three fluke tips get buried.

All the additions are 1/8" steel.
I think it has as much fluke area as the 33lb Claw but only weighs about 24lbs.
Just gave it a second coat of paint but haven't tried a set yet. I'm worried it won't rotate and stand up straight. Helping to that end is the fact that all added weight is very low on the fluke but the add ons aft of the original fluke may inhibit the anchor rotating and standing up. Hope to get out and try it in a week or two .. or so. Later I want to set it close to shore (on an incoming tide) where I can see if the anchor sets straight up.

Comments ?

The last pic came off my i-pad and I forgot it takes pics upside down unless you take them upside down.
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Old 01-13-2018, 07:08 PM   #2
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Your persistence is a force to be amazed by.

My first reaction was that the flattening of the pointy bit up front would inhibit penetration of the bottom, but on second thought, when the anchor hits bottom it flops onto one side or the other and the sharp corner of the flattened bit would dig in.

Looks interesting, and would certainly increase the amount of sucking muck here on the west coast the anchor holds onto.
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Old 01-13-2018, 08:11 PM   #3
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Eric, I'm a fan of claws. Please give us the lowdown on how these mods worked after you've tried it for a while. Maybe your design will be the next big thing.
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Old 01-13-2018, 09:32 PM   #4
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Thanks Ken and Murray.
Haha if it’s a “big thing” I’d be quite supprised and lucky too.
The aft added surfaces are set at 10 degrees. I wanted some angle up to reduce the tendency of the Claw to break out vertically and add some holding power as well. With more angle I think it may pitch the shank up but more likely I think is would encourage impacting mud. I’ve already thought about some holes like the ARA anchors. Perhaps vent holes and more angle up is the future.
Murray yes the center fluke needs to be sharp on the side edges and the tip as well. I used the chisel tip inspired by the Max brand anchor and my experimenting w the XYZ anchor.
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Old 01-14-2018, 05:49 AM   #5
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Eric,
If you keep adding steel, you will soon have a Super MAX Anchor or a "look alike." Just kidding. Anxious to hear how it sets and holds. Good luck.

Steve
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Old 01-14-2018, 05:51 AM   #6
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Some thoughts:

These anchors are difficult to get right. I have seen tests comparing the original Bruce claw anchor to the almost identical Lewmar claw. The Bruce sets much more easily than the Lewmar. Don't know why. Apparantly the geometry is critical.

When the "claw" pops out, it is because the force levers the back up against the more fixed point. That is probably why you added the back flukes. They may not work as well as you hope because they will be surrounded by disturbed soil and may not have much up force resistance. But some is better than none every time!!

I do admire your persistence.

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Old 01-14-2018, 09:44 AM   #7
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Eric
I would be interested to know if you can differentiate the holding ability by mud or soil type. Seems to me that at one extreme in soil density you may have a winner but at the other extreme the original may be lots better. I don't know how you would get that information in a reliable manner. Have you done any of that kind of differentiation in previous modifications? Or with previous anchor comparisons?
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Old 01-14-2018, 11:14 AM   #8
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Steve,
My attempt to make it better is based on increasing flike area and thus holding power. This 22lb Claw is aimed at becoming a better anchor and a lighter anchor than my 33lb Claw. So I’m adding weight to the 22 but increasing it’s fluke area. As long as the 22 dosn’t become a 34 Im ahead of the game.

David,
Yes they seem to be much a mystery. But Steve (as in Panope) pointed out one of the two most interesting and few differences in the Claws. That is the shank angle or more properly the rhroat angle .. as evidenced by the shank angle. Steve put a gaggle of anchors up on top of his boat cabin and drew attention to the angle of the Bruce and the Lewmar (I belive) Claw pointing out that the Lewmar had a very noticeably wider angle. So w a given shank angle the Lewmar has a considerably wider throat angle so the fluke will be more vertical .. or less horizontal. This is akin to the angle of attack of the wing of an aircraft compared to it’s fuselage. And most of us know when the angle becomes too great the wing stalls and fails. I belive much the same happens w the anchor fluke.
Obviously w the fluke horizontal holding power is limited to only the drag of the blade moving through the bottom .. like a knife. But when the angle of attack gets too great as in to vertical a fluke the anchor either holds or heads for the less dense bottom material .. up. Most or all anchors will have very loose just plowed up bottom material on top of the fluke. Easy to push up and out of the way. In the case of the Claw the large amount of plowed up material on top of the fluke creates enough resistance to hold most boats in begin conditions. But if the wind picks up and there’s more tension on the rode the geometry of the shank and fluke pins the fwd end of the shank to the bottom. So instead of comming straight out like most anchors the shank end diggs in like goat feet and the fluke pops up vertically. See Steve’s vid at “Anchor Setting Vidios post #118”. Perhaps the Rocna did this before they added the abruptly turned up trailing fluke edge.
So by adding constderable fluke area aft of the stock anchor I hope to have created a Claw that will much more often stay buried and keep holding. To do this I reasoned very little up elevator (in aviation terms) or just up angle or perhaps no angle would be required. I settled on 10 degrees. And David you’re right the loose and highly disturbed substrate on top of the fluke would still become a pushover (pun intended) and there would be little or no gain. This is not a condition unique to Claws though. But the lower throat angle and the increased fluke area aft may work together as a plus.
David your “because the force levers the back up against the more fixed point.” .... the more fixed point being the tip of the shank that is plunging fwd at or into much harder more or less undesturbed seafloor. You got it is the way I see it.

Keith,
Yes the Claws are notorious for dragging in mud as I recall. Other anchors have shown great holding power in fairly hard bottoms but failed dramatically in real soft mud compared to other anchors. No anchor is perfect at both extremes but all of us seek the widest range of solid performance. The Rocna failed in the really soft Chesapeke Bay mud but performs well in more typical “mud” as evidenced by many TF members. We should always be suspect of products that perform in one extreme exceedingly well. The old addage that one should have 3 or 4 anchors aboard for different bottoms still applies but w newer anchors less so than w older anchors.
And Keith yes I have had a big surprise making a tip mod on my XYZ Extreme anchor because the tip was very wide. See pic. I thought it would or may set half of the time but was expecting worse. Used it extensively on an Alaska to Puget Sound trip and was nearly shocked to find it set easily every time. It also held in a 50 knot gale so that anchor with a good rock anchor should cover all bases. But that’s two anchors and on occasion will obviously require retrieving and deploying #2. That would, however cover a very wide range of bottom performance possibly or probably exceeding the range and holding performance of any one anchor.
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Old 01-14-2018, 12:35 PM   #9
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Eric, you keep on tweaking that work of art until it does what you want it to do for the specific bottom at hand....(hand-made "Tinkerer of the Month Award is on it's way to ya!).

As long as you adhere to a few basic laws of metallurgy when dealing with cast iron (pre and post heat treatment), anything you stick on the base anchor that shows improvement during trial and error testing, is as good if not better than something conceived from hundreds of hours in front of a CAD program! In my former life, we designed and fabricated many specific-use, long-handled tools to work on nuclear fuel assemblies under 20' of water. Most of the initial design drawings were sketched on the back of a rubber PC glove!

Years back, I modified a 40lb "China Claw" that was one of the anchors on my 40' sailboat, by welding a down-turned "pointed tooth" on the tip. I called it my "Bird Island" anchor, after a favorite anchorage near the Matagorda Ship Chanel Jetty, that is sometimes frustrating to set a hook. The extreme current in this area keeps all the soft material swept from the bay floor, leaving a hard packed sandy clay. The original Claw or my Danforth would require at least several drop-drag-retrieve-repeat exercises before you could find a chink in the armor of this bottom that an anchor could catch on and start digging in. The tooth solved this initial bite issue, and the claw dug in like an Alabama tick! Only problem then was breaking that puppy out of the hard clay...but we never worried about dragging!

Nowadays on the trawler, a 65lb Mantus and a F37 Fortress works for everything we encounter on the Texas coast.

Happy welding!
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Old 01-14-2018, 03:06 PM   #10
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Luke,
Steve on Panope did a very similar mod on the Supreme.
His luck was far worse than yours.
But his “tooth” was different too I’m sure.
Spent 1/2 hr looking for the posts on his mod but couldn’t find. Sorry.

So if I ever get tired of modifying other designs I may look you up w your tooling exp.


Re what I was saying earlier I wrote some time ago on Steve’s setting vids this;

“Re the bruce/claw I don't think any of us really understand it's dynamics. I had thought I'd "figured it out" several times only to turn my back on the theory and adopt another. It's got some very positive features and it's quite different from any other anchor. All the while I have this sneaking hunch that w the right modification it could be at least a top performer. But no one has figured that out yet if indeed it could be done or if there is any mod that would transform the anchor.”
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Old 01-15-2018, 08:56 PM   #11
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Luke,
Spent some more time going through "Anchor Setting Videos" by Steve of the SV
Panope. Found the part about modifying the Supreme w an appendage probably a bit like your "tooth". It's on page 27 post #524.
I don't know why it didn't work but it probably "hooked" the bottom too much pitching the anchor up into a very high angle of attack. Kinda like "stubbing" your toe. One may be able to say the anchor stalled.
Hope you enjoy the copy.

PS,
I'm going to expose my lack of metallurgy knowledge. Are you assuming or do you know .. are the Claws made out of Iron? You refer to that and I was under the impression that they were cast steel. Except the Bruce that is forged per dock talk. Is there even such a thing as cast steel? I thought there were problems welding iron. The guys at the fab shop just did it and didn't mention that it was a bad idea or was difficult. Since you seem to know about such things .. what's up?
Also do you (or anybody else) know if the Claws shank can be cut ("in half") and welded back together w reasonable strength?
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Old 01-15-2018, 11:01 PM   #12
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Yep...the extension to the anchor in post #524 was different than what I added to my "China Claw". I modified that anchor before the advent of camera phones, so don't have a picture. The "tooth" that I welded on was shaped sort of like the triangular tip of a CQR anchor, and pointed downward approximately 25 degrees.

Regarding the base metal of the anchor, I don't have a whole lot of faith in the metallurgy of these knock-off anchors... However, they are probably closer to cast steel than cast iron. The way I usually test metal is to hit it with a grinder and watch the spark length and color. Red sparks that are shorter in length usually denotes cast iron. Yellow/whitish sparks that are longer usually denotes some grade of steel. Either way, when welding to a cast metal, especially something thicker than ~3/4", preheating to around 250 degrees is the norm in most welding procedures I've seen. This is usually followed up with some sort of post-weld heat treatment to prevent warping/cracking. Probably not an issue with the mods you've made, as the "mud palms" you added won't likely see enough structural stress to challenge the heat affected zone of the weld.

Regarding cutting/welding the shank... Yes, a weldment can be performed that is as structurally sound as the base metal... IF the proper procedure, filler material, and welder skill is used. However, this is getting into the structural components of the anchor, so beyond this point, there be dragons!
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Old 01-16-2018, 05:57 AM   #13
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I had always understood that the Bruce was forged steel and the Chinese made Lewmar was cast something. Given that you "welded" to it then it probably is cast steel not iron which is not weldable. I put weld in quotes because it could have been brazed with a bronze filler metal but that should be easily noted due to the color.

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Old 01-16-2018, 10:22 AM   #14
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Thanks Luke,
I assumed your extension or add on was more of an extension ahead of the end of the ctr fluke. Whereas Steve G’s add on was attached to the bottom of the ctr fluke underneath the parent metal. Both adds but one underneath and one out front. Rex of ARA is keen on turned down “toes” on fluke tips.

Thanks re the weld/metallurgy response. I was thinking of the preheating complication but I was making a $200 mod to an $80 anchor so was rightfully concerned about the cost. So when they didn’t say anything I didn’t say anything. And I assumed as you do that the after mud palms would be under very light load. They knew it was an anchor (Bob the welder is a boater) and I asked for a higher carbon steel for the fwd fluke extension than mild steel but I don’t know if they remembered or complied w that.
I remembered the spark tests but have/had no idea what color to look for. You’re close enough to this stuff to carry it around in your head .. good. Thanks.


David,
Given that it was undoubtably (at this point) cast steel and there is absolutely no gold colored bronze rod evidence visable. FYI my parent 22lbClaw is not a Lewmar .. I may have said Lewmar as my 33lb Claw is. The 22 is a no name Claw w nothing other than “22lb” being on the side of the shank. I would have modded my 33lb Lewmar but the throat angle was so great and I’m convinced the narrower or shallow throat angle is much preferable. I’m also convinced the shallow throat angle is the main reason the Bruce Claw is known to be superior. The forged bit is just icing on the cake ... just my opinion. Thanks for your response.
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