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NJeff
03-16-2001, 02:27 PM
I am looking for 3/4" X 1 1/2 " silicon bronze strapping to shore up some cracked frames where sistering is not practical. Have found “tobin” but not silicon bronze. Any help would be appreciated.

NJeff
03-16-2001, 02:27 PM
I am looking for 3/4" X 1 1/2 " silicon bronze strapping to shore up some cracked frames where sistering is not practical. Have found “tobin” but not silicon bronze. Any help would be appreciated.

NJeff
03-16-2001, 02:27 PM
I am looking for 3/4" X 1 1/2 " silicon bronze strapping to shore up some cracked frames where sistering is not practical. Have found “tobin” but not silicon bronze. Any help would be appreciated.

reddog
03-17-2001, 05:18 AM
Hi;Not being a metals expert I may be off base but why can't you use the tobin bronze?I know that LF Herreshoff speced tobin bronze for keel bolts and hull strapping on some boats.
Other members have mentioned a place called Atlas Metals.I believe they have an ad in WB magazine.
Good luck;Earl

reddog
03-17-2001, 05:18 AM
Hi;Not being a metals expert I may be off base but why can't you use the tobin bronze?I know that LF Herreshoff speced tobin bronze for keel bolts and hull strapping on some boats.
Other members have mentioned a place called Atlas Metals.I believe they have an ad in WB magazine.
Good luck;Earl

reddog
03-17-2001, 05:18 AM
Hi;Not being a metals expert I may be off base but why can't you use the tobin bronze?I know that LF Herreshoff speced tobin bronze for keel bolts and hull strapping on some boats.
Other members have mentioned a place called Atlas Metals.I believe they have an ad in WB magazine.
Good luck;Earl

Bob Cleek
03-17-2001, 01:03 PM
If my Altzheimer's isn't acting up today, Tobin bronze is an old tradename for silicon bronze, as is Everdur bronze. Tobin's fine. On the other hand, have you considered sistering or overlaying with epoxy laminated strips? Just a thought. Problem with strapping a frame is that you are filling it with more holes and the stresses are transferred at each fastening rather than across the whole face of the frame to be repaired... an advantage with epoxy repairs.

Bob Cleek
03-17-2001, 01:03 PM
If my Altzheimer's isn't acting up today, Tobin bronze is an old tradename for silicon bronze, as is Everdur bronze. Tobin's fine. On the other hand, have you considered sistering or overlaying with epoxy laminated strips? Just a thought. Problem with strapping a frame is that you are filling it with more holes and the stresses are transferred at each fastening rather than across the whole face of the frame to be repaired... an advantage with epoxy repairs.

Bob Cleek
03-17-2001, 01:03 PM
If my Altzheimer's isn't acting up today, Tobin bronze is an old tradename for silicon bronze, as is Everdur bronze. Tobin's fine. On the other hand, have you considered sistering or overlaying with epoxy laminated strips? Just a thought. Problem with strapping a frame is that you are filling it with more holes and the stresses are transferred at each fastening rather than across the whole face of the frame to be repaired... an advantage with epoxy repairs.

Moray MacPhail
03-18-2001, 04:40 AM
I had a customer asking the same sort of question, and after some digging found out that Tobin Bronze is in fact a type of brass. I don't know why LFH thought it was good stuff, because either silicon bronze or phosphor bronze will last much longer.

There is an excellent, but quite technical, review of metals on
www.kastenmarine.com, (http://www.kastenmarine.com,) and I've put one in as plain English as I can on www.classicmarine.co.uk (http://www.classicmarine.co.uk)

Moray MacPhail
03-18-2001, 04:40 AM
I had a customer asking the same sort of question, and after some digging found out that Tobin Bronze is in fact a type of brass. I don't know why LFH thought it was good stuff, because either silicon bronze or phosphor bronze will last much longer.

There is an excellent, but quite technical, review of metals on
www.kastenmarine.com, (http://www.kastenmarine.com,) and I've put one in as plain English as I can on www.classicmarine.co.uk (http://www.classicmarine.co.uk)

Moray MacPhail
03-18-2001, 04:40 AM
I had a customer asking the same sort of question, and after some digging found out that Tobin Bronze is in fact a type of brass. I don't know why LFH thought it was good stuff, because either silicon bronze or phosphor bronze will last much longer.

There is an excellent, but quite technical, review of metals on
www.kastenmarine.com, (http://www.kastenmarine.com,) and I've put one in as plain English as I can on www.classicmarine.co.uk (http://www.classicmarine.co.uk)

NJeff
03-19-2001, 09:44 AM
reddog, thanx. this is the info I was looking for previously in building/repair. Tobin was recommended but i was not sure it was appropriate and was advised that it is also called “naval brass” . But if it is good enough for Nat H, it’s good enough for me.
Bob, It is marvelous to see you back! I am doing several sisters on other frames but one has a but block on one side and floor timer on the other, and another frame is cracked just above the garboard. Re the stress factor, i would think that the thu bolts would hold the bronze tight to the frame and would help share the stress with the bolts.
I have more questions re fasteners for the above and will post them back in building/repair.

NJeff
03-19-2001, 09:44 AM
reddog, thanx. this is the info I was looking for previously in building/repair. Tobin was recommended but i was not sure it was appropriate and was advised that it is also called “naval brass” . But if it is good enough for Nat H, it’s good enough for me.
Bob, It is marvelous to see you back! I am doing several sisters on other frames but one has a but block on one side and floor timer on the other, and another frame is cracked just above the garboard. Re the stress factor, i would think that the thu bolts would hold the bronze tight to the frame and would help share the stress with the bolts.
I have more questions re fasteners for the above and will post them back in building/repair.

NJeff
03-19-2001, 09:44 AM
reddog, thanx. this is the info I was looking for previously in building/repair. Tobin was recommended but i was not sure it was appropriate and was advised that it is also called “naval brass” . But if it is good enough for Nat H, it’s good enough for me.
Bob, It is marvelous to see you back! I am doing several sisters on other frames but one has a but block on one side and floor timer on the other, and another frame is cracked just above the garboard. Re the stress factor, i would think that the thu bolts would hold the bronze tight to the frame and would help share the stress with the bolts.
I have more questions re fasteners for the above and will post them back in building/repair.

reddog
03-19-2001, 03:21 PM
NJeff;
Just heard back from a company called Diversified Metals.Apparently Bob's memory is spot on and "tobin bronze" is silicon bronze.Guess LFH knew what he was about after all.
All the best.Earl

reddog
03-19-2001, 03:21 PM
NJeff;
Just heard back from a company called Diversified Metals.Apparently Bob's memory is spot on and "tobin bronze" is silicon bronze.Guess LFH knew what he was about after all.
All the best.Earl

reddog
03-19-2001, 03:21 PM
NJeff;
Just heard back from a company called Diversified Metals.Apparently Bob's memory is spot on and "tobin bronze" is silicon bronze.Guess LFH knew what he was about after all.
All the best.Earl

Frank Wentzel
03-20-2001, 08:48 PM
I just saw a corrosion table in "Metal Boat Quarterly" that said that Tokin bronze (and marine bronze) contains 39% zinc.
www.kastenmarine.com/mbqMetRef.pdf (http://www.kastenmarine.com/mbqMetRef.pdf)

This would make Tobin bronze very prone to dezincification in salt water. Of course, unlike modern alloy practice there were no ASTM standards for alloy compositions in times past. So it is difficult to say what a given foundry might produce under a given alloy designation.

As to Captain Nat's boats and the materials he used. He obviously did not intend to build disposable boats but if you look at the history of most of the boats he built you will find the original owner rarely kept them more than a couple of years. He was not building with our preoccupation with preservation in mind.

Frank Wentzel
03-20-2001, 08:48 PM
I just saw a corrosion table in "Metal Boat Quarterly" that said that Tokin bronze (and marine bronze) contains 39% zinc.
www.kastenmarine.com/mbqMetRef.pdf (http://www.kastenmarine.com/mbqMetRef.pdf)

This would make Tobin bronze very prone to dezincification in salt water. Of course, unlike modern alloy practice there were no ASTM standards for alloy compositions in times past. So it is difficult to say what a given foundry might produce under a given alloy designation.

As to Captain Nat's boats and the materials he used. He obviously did not intend to build disposable boats but if you look at the history of most of the boats he built you will find the original owner rarely kept them more than a couple of years. He was not building with our preoccupation with preservation in mind.

Frank Wentzel
03-20-2001, 08:48 PM
I just saw a corrosion table in "Metal Boat Quarterly" that said that Tokin bronze (and marine bronze) contains 39% zinc.
www.kastenmarine.com/mbqMetRef.pdf (http://www.kastenmarine.com/mbqMetRef.pdf)

This would make Tobin bronze very prone to dezincification in salt water. Of course, unlike modern alloy practice there were no ASTM standards for alloy compositions in times past. So it is difficult to say what a given foundry might produce under a given alloy designation.

As to Captain Nat's boats and the materials he used. He obviously did not intend to build disposable boats but if you look at the history of most of the boats he built you will find the original owner rarely kept them more than a couple of years. He was not building with our preoccupation with preservation in mind.

Allen Foote
03-21-2001, 10:24 AM
I deal with Atlas metals in Denver. Good people. http://www.atlasmetals.com

[This message has been edited by Allen Foote (edited 03-21-2001).]

Allen Foote
03-21-2001, 10:24 AM
I deal with Atlas metals in Denver. Good people. http://www.atlasmetals.com

[This message has been edited by Allen Foote (edited 03-21-2001).]

Allen Foote
03-21-2001, 10:24 AM
I deal with Atlas metals in Denver. Good people. http://www.atlasmetals.com

[This message has been edited by Allen Foote (edited 03-21-2001).]

Bayboat
03-24-2001, 10:02 PM
You might think about this as an alternative to strapping and thus weakening the frames (also, bolts through the frames and planking will leak eventually, no matter how carefully they're installed):
About 20 years ago I did a frame repair job on a 36' Alden sloop. Some of the frames had double curves. I installed white oak laminations on the siding, 1/8" thick so they would bend easily, laid in resorcinol with a few bronze anchorfast nails in each as they were laid down. Where I could I covered the whole frame. Otherwise I went as far as I could on either side of the crack. This does minimal damage to the frames. The frames were sided 2" and molded 2-1/4". The laminations totalled about 1" thick, increasing the molding to about 3-1/4".
They're still there. This way you don't have to get alongside a frame for sistering. You might have sticker shock over the price of that bronze. This way you don't need it. If you do indeed use bronze, 3/4" seems a bit thick for the job. With frames that are sided 1-1/2" I would think 3/8 would be plenty strong enough.

Bayboat
03-24-2001, 10:02 PM
You might think about this as an alternative to strapping and thus weakening the frames (also, bolts through the frames and planking will leak eventually, no matter how carefully they're installed):
About 20 years ago I did a frame repair job on a 36' Alden sloop. Some of the frames had double curves. I installed white oak laminations on the siding, 1/8" thick so they would bend easily, laid in resorcinol with a few bronze anchorfast nails in each as they were laid down. Where I could I covered the whole frame. Otherwise I went as far as I could on either side of the crack. This does minimal damage to the frames. The frames were sided 2" and molded 2-1/4". The laminations totalled about 1" thick, increasing the molding to about 3-1/4".
They're still there. This way you don't have to get alongside a frame for sistering. You might have sticker shock over the price of that bronze. This way you don't need it. If you do indeed use bronze, 3/4" seems a bit thick for the job. With frames that are sided 1-1/2" I would think 3/8 would be plenty strong enough.

Bayboat
03-24-2001, 10:02 PM
You might think about this as an alternative to strapping and thus weakening the frames (also, bolts through the frames and planking will leak eventually, no matter how carefully they're installed):
About 20 years ago I did a frame repair job on a 36' Alden sloop. Some of the frames had double curves. I installed white oak laminations on the siding, 1/8" thick so they would bend easily, laid in resorcinol with a few bronze anchorfast nails in each as they were laid down. Where I could I covered the whole frame. Otherwise I went as far as I could on either side of the crack. This does minimal damage to the frames. The frames were sided 2" and molded 2-1/4". The laminations totalled about 1" thick, increasing the molding to about 3-1/4".
They're still there. This way you don't have to get alongside a frame for sistering. You might have sticker shock over the price of that bronze. This way you don't need it. If you do indeed use bronze, 3/4" seems a bit thick for the job. With frames that are sided 1-1/2" I would think 3/8 would be plenty strong enough.