Rebuilding bottom on 57 OffShore
Posted: Tue Nov 28, 2006 6:44 am
Hi All,
Some of you may have seen the recent Ebay auction for a 1957 Thompson 18' OffShore, located in Saranac NY. Well- I'm the fool that brought 'er home.
If you didn't see the auction, the listing is still there with some pictures:
http://cgi.ebay.com/ebaymotors/ws/eBayI ... 761&rd=1,1
Number on transom is V 71044
This boat has some great attributes- most of which are above the waterline. The mahogany is in super shape- seats, windshield, decking, coaming, all need sanding and varnishing but are in pretty good original condition. The hardware is all intact and in good shape.
As for the hull, the plywood planking seems sound, but below the waterline things get wacky. The line of the keel waves up and down where it has sat on the trailer rollers, and the hull heaves up where it sits on the 2x4 stringers on the trailer. The ribs from about the dashboard to the stern have significant rot on their bottom halves, and there are patches and strips of oak that previous owners have put in to try to stabilize things. The success of those efforts has been limited.
Due mostly to the condition of the ribs, I believe I need to rebuild the bottom of the boat. Once in my garage, and flipped onto a cradle, my plan is to remove the garboard planks, and maybe two or three more planks, remove the keel, keelson, sisters etc.. and take out all the bad ribs. Then replace keel assembly (white oak, I know, I've got a great local sawyer), ribs, and reattach planking. I don't think I can scarf in rib extensions in a lot of cases as the rib is bad right from the keel to the turn of the bilge.
Questions:
When disassembling, is it better to try to take things apart mechanically (dig out filler and unscrew the screws, pry the nails) or cut the fasterners (maybe a hacksaw blade between the planks) and push the remaining bits out. Any suggestions?
What is the proper order for reassembly? I have built lapstake canoes, where the ribs are inserted after planking, but from reading here it seems the ribs are fastened to the keel sisters? Which means the ribs would have to be in, then planking goes on. That could be difficult in this case.
Thanks for any suggestions- and for all I've learned so far just reading about everyone's experiences. This is a great resource!
I'll see everyone around,
Dave
Sandwich, NH
Some of you may have seen the recent Ebay auction for a 1957 Thompson 18' OffShore, located in Saranac NY. Well- I'm the fool that brought 'er home.
If you didn't see the auction, the listing is still there with some pictures:
http://cgi.ebay.com/ebaymotors/ws/eBayI ... 761&rd=1,1
Number on transom is V 71044
This boat has some great attributes- most of which are above the waterline. The mahogany is in super shape- seats, windshield, decking, coaming, all need sanding and varnishing but are in pretty good original condition. The hardware is all intact and in good shape.
As for the hull, the plywood planking seems sound, but below the waterline things get wacky. The line of the keel waves up and down where it has sat on the trailer rollers, and the hull heaves up where it sits on the 2x4 stringers on the trailer. The ribs from about the dashboard to the stern have significant rot on their bottom halves, and there are patches and strips of oak that previous owners have put in to try to stabilize things. The success of those efforts has been limited.
Due mostly to the condition of the ribs, I believe I need to rebuild the bottom of the boat. Once in my garage, and flipped onto a cradle, my plan is to remove the garboard planks, and maybe two or three more planks, remove the keel, keelson, sisters etc.. and take out all the bad ribs. Then replace keel assembly (white oak, I know, I've got a great local sawyer), ribs, and reattach planking. I don't think I can scarf in rib extensions in a lot of cases as the rib is bad right from the keel to the turn of the bilge.
Questions:
When disassembling, is it better to try to take things apart mechanically (dig out filler and unscrew the screws, pry the nails) or cut the fasterners (maybe a hacksaw blade between the planks) and push the remaining bits out. Any suggestions?
What is the proper order for reassembly? I have built lapstake canoes, where the ribs are inserted after planking, but from reading here it seems the ribs are fastened to the keel sisters? Which means the ribs would have to be in, then planking goes on. That could be difficult in this case.
Thanks for any suggestions- and for all I've learned so far just reading about everyone's experiences. This is a great resource!
I'll see everyone around,
Dave
Sandwich, NH