Primitive Archer
Main Discussion Area => Bows => Topic started by: Selfbowman on November 16, 2025, 06:51:53 pm
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I got this black locust stave from Jim Hammer. I felt that it was real dense so I did a couple of one inch cubes and weighed them then did a float test. Here are the results. They both weighed .54oz. Pics of float test.
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Barely buoyant.
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Pic of locust.
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Not trying to be a smart *** but is that good our bad ? :)
Pappy
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Pappy the black locust is as dense as Osage. In the bowyers bible Osage specific gravity is .82 so if I’m right here 18% of the cube should be above the water line. On black locust the specific gravity is .69 So 31% of the cube should be above the water line. It seams that both wood types are very dense. This could be some very good black locust because of its density. I might be all off here not knowing what I’m talking about. So if I am please correct me. 🤠🤠
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Ok just thinking I decided to check the moisture in both woods. The Osage was6% and the locust was 10%. So the black locust moisture may be affecting the float test. Need a smart guy!
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Arvin, you’re talking above my pay grade, but as always I’m following along and I’m sure like always will learn from your experience.
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Ok I made a white pine 1” cube it weighed.36 so lighter than the black locust. Specific gravity was .45 in the Bible. Here is the float test . Could not get it to float right but more above the water line. Not as dense .
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Arvin, is that tap water or pure distilled water? That does make a difference in float height.
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Ok I made a white pine 1” cube it weighed.36 so lighter than the black locust. Specific gravity was .45 in the Bible. Here is the float test . Could not get it to float right but more above the water line. Not as dense .
Assuming the dimensions are very close to 1 cubic inch, thays pinr block is .62 sg. Im starting to question the accuracy of that list in the TBB.
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You need to oven dry the samples for hours down to 0% water content if you want to get an accurate reading, that´s why Tim Baker suggested a small narrow sample - like a 1/2 inch diameter dowel with square sides. I think Tim mentioned 4 hours oven time for a small sample.
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You can also dry samples in the microwave but I’ve had some pieces pop and fizzle quite a bit. (lol)
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Tap water sleek. Ryan your funny. I think that the weight being the same tells us a lot. I’m going to build it to the spec of the Osage bow that has two records and see what I get.
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Pappy, there is some pretty good evidence that the denser the wood is for its species, the better it works for bows. Say, if the average density of a species of tree is .600, then a sample coming in at .700 is likely to make a better bow and one coming in at .500 will need a collar and a leash because it's gonna be a dog.
I know in my experience I have made a couple green ash bows that shot so badly you didn't need a chronograph to measure the speed of the arrow, you needed a CALENDAR! Both staves came from a tree that was super lightweight.
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If the sample is an accurate 1" cube and the moisture is at 10% you have a piece that is around .8 sg. Same as osage. Pretty common for black locust. If it does not chrysal black locust can make super fast bows. From the woods, I tested black locust had the lowest hysteresis. Funny thing is that woods low in hysteresis also tend to chrysal. Good luck.
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Steve would 69” be long enough? It’s 2-3/8 wide at fades.
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Black locust can be your best friend, or your worst enemy when it comes to building a bow with it. Early on, and a lot my tillering fault the first black locust log I cut staves from either broke on the back , or ended up with belly frets. 2nd log I found laying along side the road with no center in it. It was dense as h111, and to heavy to carry to my truck, so I split it on the spot. I got 4 nice bows from that log. No frets, and no broken backs. Thought I had it all figured out. 3rd log was a bust too. Just like any other wood. Some logs are good for bow making ,and others not so much with in the same species.
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Steve would 69” be long enough? It’s 2-3/8 wide at fades.
I would say yes, In the past I have always made them too narrow and a bit shorter. Very fast wood. I think your dimensions should be ideal.