When Did Old Town start using Diamond Head Brass Bolts for seats and thwarts?


Enthusiastic about Wooden Canoes
I'm doing a restoration on a 16' Charles River Old Town with a serial number 33608, built in 1915... Was surprised to find counter sunk steels bolts were used to attach both the seats and thwarts. The canoe has open gunwales. I think the seats are replacements of the originals but the thwarts appear to be original... I am also doing a restoration on another 16' Old Town.. 80382 which was built in 1924. The diamond headed brass bolts are evident in the 1924 model. Is it possible the counter sunk steel bolts are original? The flat head steel bolts themselves are unique as the heads are round and flat with no screwdriver slots...have never seen anything like them before. My limited experience tells me that the original Diamond head brass bolts were replaced at some point in favor of having smooth gunwales from stem to stern. If that is true I will replace them with home manufactured replicas of the original diamond shaped brass bolts.. Is there any history out there to show that the steel bolts could be original? Harold
Is there any history out there to show that the steel bolts could be original?

Yes, all indications are that the diamond headed bolts were first introduced around 1922 so both of your canoes probably have original bolts. Feel free to reply here if this doesn't answer your questions.

Benson... Thank you.. You guys and this forum are absolutely amazing.. The original bolts were all so badly rusted they had to be cut off to remove them. Me thinks I will take some solid brass Toilet Flange Bolts with flat heads, do a little grinding to reshape the heads and use them as replacements. They are installed with a wood plug as a coutersink so they are invisable and no one will be able to tell the difference, until another twenty or thirty years goes by and someone else undertakes another restoration with the canoe and finds them easy to remove...No Rust!
Just my opinion, but flange bolts are larger in diameter than typical seat bolts. Typically Old Town used # 12-24 bolts and other manufacturers used #10-24.
With an inwale that is 100 years old, I would not use a a standard 1/4-20 or 5/16-18 toilet flange bolt in an inwale of that age. I believe it is too large in diameter and may at some point compromise strength.
When I have encountered this in the restorations in my shop, I have plugged the original hole (if it was bad)with a dowel, then redrilled and countersunk the hole and used a 10-24 silicon Bronze carraige bolt.
10-24 Bolts up to 6" in length are available at Merton's.
Rollin and Jamestown have 4" 10-24x4 silicon bronze seat bolts.
Bottom line, IMHO, don't use anything over #12 bolt in an inwale...they are fragile...especially if they are 100 yrs old.
Dave... You come to the rescue again... The bolts I took out are 10-24 and 3/16" in dia and the brass flange bolts are 1/4" with 20 threads to the inch. Merton's is all new to me. It is great to find a source for this kind of thing... I didn't realize that the old bolts were nothing more than small carriage bolts, but finding them commercially in bronze is great... Thank you.. Hope to see you May 28th at the Spooner WI Canoe Heritage Museum Boat Show. This particular canoe is promised to my son when it is finished but will have it for show along with the 1918 BN Morris I finished last fall. Harold.