How do you drive bronze screws into oak?

I think a good trunnel wood would be black locust. Immensely strong, hard and extremely durable. It is in the US a common tree.

Black Locust | The Wood Database (Hardwood)

What I don't get is why this tree is not more commonly used. It is used for fence posts on farms in rural Virginia. Maybe the cost, but I think it should be grown and harvested like other trees.

Comments: Black locust is a very hard and strong wood, competing with hickory (Carya genus) as the strongest and stiffest domestic timber: but with more stability and rot resistance.

Pricing/Availability: Black locust prices can vary depending on location, but prices should be moderate within its natural range. Those living in the eastern United States can expect prices to be comparable to white oak. In other areas where the lumber has been imported, the prices can be much higher.

Sustainability: This wood species is not listed in the CITES Appendices, and is reported by the IUCN as being a species of least concern. Furthermore, the species has become very widespread, and is even considered invasive in some areas. [1]

On my Dad's Virginia farm in the west part of the state, the black locust he cut down, their stumps never rotted. Or lets say 20 years later they look about the same. He bought 30 acres decades ago near Blacksburg VA, and cleared some land for horses.

 

Got a decent tight fit for the white oak lower piece. Plan to glue it in maybe tomorrow.
With it in place, looks like the flowing curve of the keel is an excellent match to the original build



Need to get some more jacks for the gluing



The rear curve is a 7" disc
I shaped into the wood using these tools sitting on the ground on a rug. The forward cut is at 45*
Those 24 grit zirconia grinder discs, never wear out. I bought 50 and am still using the same one, and I have used it a lot. It easily shapes wood, it is a wood eater, and skin too. I got a few finger cuts from the spinning disc. But they are mostly healed now. This is my first grinder. A Porter Cable, nice trigger lock.

To get out the high spots, I used my jigsaw. As in cut the old keel wood with the new oak pressed in place. Using jacks you can set the space needed to use the jigsaw. IT takes some skill to fit in new wood to a close tolerance, Close fit means less glue needed, another plus.

 

I agree with Black Locust.
I've a feeling that in Norway in 1952 it was not readily available, and those old fish boats were probably
never expected to last for more that ~30 years.
William Atkin specified Black Locust for all kinds of things in many of his designs, such as shaft logs, cleats, and chocks.
In that old fish boat even the fastenings for the futtocks for the double-sawn frames were Hard Pine.
You should have seen what we went thru bending 2-1/4 Fir planking around the canoe stern.

 

Yeah, people are short sighted in many things in life, not expecting things to hang around as long as they do.
And then it is good enough, and I won't live that long too.

 

I put one of my 50 ton jacks under there to get a tight fit.
It is now glued in, hopefully never to come back out.
Used 4 hydraulic jacks, next thing is to install some bolts.


Oak is strong but it still can bend.


I guess I won't need any screws. The bolts are at the ends and in the middle

I might put 2 long screws at the aft end going up at a slight angle. OEM did that where skeg keel sections meet, although I dont know what the point is of doing that.
It will have a 2" thick worm shoe, and I can overlap joints with solid wood.

The bow end with a 45 angle, there are 2 bonze bolts in the ends of each wood section about 7" apart.
The aft end of the glued in board has a bronze bolt 4" from the end.

I did glue in 14 trunnels in the upper board, but again who knows why they are needed.
I hope it stays good and solid. I made 1/4" white oak dowels. And drilled 1/4 " holes.
Oak has a tensile strength of 9000 psi per square inch.

9,000 psi (~62 MPa)
The ultimate tensile strength of Oak Wood is approximately 70 MPa1. Oak has a tensile strength of 9,000 psi (~62 MPa), making it a great choice for projects that require strength and durability2. It can be strength graded from D18 up to D40 using the BS EN 338 classification system3.

 

Today I put in the bolts and dropped the jacks, and it is perfection.
Very happy. I measured the angle on the keel bottom along the length and it is averaging around 0.5 degrees so very flat, as in flat enough.

Pretty good considering I used circular saw to cut out the bad keel, grinder sanded and power planned some of it. It just worked out, like it often does for me. Of course have had failures, which I why I have to fix this borer damage. I hate worms.

 

Showing pics of what the borers did to that section of white oak keel skeg in maybe 3 or 4 years. I broke it up and burned it on our deck outdoor chiminea. Surprisingly, it took a lot of time to catch fire. I thought would go fast with all the holes, but no. I wonder if 54 years in salt water did something to the wood. I would start the fire all around this wood, and the fire constantly went out and the wood was untouched. I had to build a fire with scrap pine wood and then it did burn.



you can see not much left here.

 

How boring! ( As in "hole"... ha, ha, ha. )

Nicely done SD.

 

Probably most of the volatile wood compounds had been leeched out of the wood, assisted by the holes, leaving salted cellulose; maybe like how lightening struck wood won't burn easily. I suppose even poisonous woods would eventually be rendered palatable to worms if soaked long enough. I wonder if they like creosote. If only you could train the worms to put holes where you actually want them.

 

Didn't Larry Pardey use creosote on the underwater planking of Serrafyn?Not sure how easy it is to find real creosote these days.

 

Creosote - Wikipedia https://en.wikipedia.org/wiki/Creosote
Talks about various creosote types.
We eat wood based creosote, frequently used on meats.

The good stuff, preserving wood, coal based creosote is regulated use.
Government regulators always seem to target the solutions that actually are highly effective to prevent their use.

 

Used to get coal based creosote from farm suppliers, for pre-treating fence posts in termite prone areas. I've had thumping headaches from just the fumes when painting it on, so eating it wouldn't be fun for worms you'd think. Black tar would present a thicker layer of yuk to deter them, like used on the old sailing ships before copper sheathing. The road making stuff which has to be heated to apply would be best maybe. But messy even when cold and hard. Any small scratch and they'd be in there again though.

 

The best trunnel woods in the US are black locust, osage orange and live oak. All very strong and rot resistant.

If there is a good reason that black locust is not readily available in the US, it is because the trees don't grow straight enough for large scale lumber production. Black locust is a commercial lumber in Hungary. The Hungarians selected for much straighter trees than the wild ones in its native range. The cultivar developed for lumber in Hungary is shipmast locust. Black locust is not widely available in the US and is considered an invasive species in some Midwestern states. The wild type spreads rapidly by suckering forming a thicket. The shipmast is not so fast spreading unless it is injured or pruned and is a valuable lumber tree in Europe. There is a source for shipmast locust in Trumansburg, NY, but availability is very limited.

It is sold for decking and appears to be an excellent choice. Compare Black Locust Decking vs Alternatives https://robidecking.com/compare-hardwood-decking/ Trunnels are available in WI from https://www.midwestblacklocust.com/dowels-pegs-trunnels

 

Where my Parents owned 36 acres near Blacksburg VA, there are many of these trees, lots looking like this, very common and some more scraggly.
An excellent wood to use for many things. And does grow decently fast.
We used to go to Turman's lumber to buy red oak fence boards, and they cut large amounts of red oak, which does not last and never saw any Black Locust there. Some white oak. Maybe the red oak was cheap!
Wood Products - Turman Lumber

Black Locust Tree: Types And Pictures - Science Trends

The black locust tree, or Robinia pseudoacacia, is a deciduous tree found throughout the southeastern United States, as well as in South Africa, Europe, and Asia. The tree is native to the southeastern United States, but it has been transplanted to other areas of the globe such as Australia, Pakistan, China, Canada, India, Europe, South Africa, Asia, southern South America, and New Zealand.

The black locust tree is a deciduous tree of medium-size, and it is sometimes called false acacia. Various types or cultivars of the tree can be found in the US and around the world.

 

Black Locust very nice tree, flowers, that some people don't like because they are considered invasive. The tree fixes nitrogen right from the air so grows in poor soils
Identify Invasive Trees - Black Locust