I am using the staple-less method described in Canoecraft for a Bob's Special. I've used finishing nails to hold the strips to the molds for the central molds where the gunnels will cover the nail holes, but I haven't permanently attached the strips to the molds toward the bow and stern. At first I was clamping the strips near the gunnels to the molds while I put more strips on top, but after a while I took the clamps off.
All of the strips on the centre molds are flush with the molds, but the strips near the gunnels on the bow and stern molds pull away by up to 1/4". The strips nearest to the newest strip on the bow and stern molds don't pull away at all.
I've only set one strip at a time and I have hammered in the wedges fairly firmly. My problem likely comes from hammering the wedges in too hard, though if anyone else has any suggestions on how to avoid this, please let me know. Should I fix this problem by somehow bringing the strips back to the molds before working any farther? I'm worried that this will add stresses to the boat that will come back to bite me in some other way. Should I just leave things be and chock it up to a quirk of my boat when it's finished?
I've attached a picture of one of the worst offenders.
Help! Strips Coming Away From The Molds
Help! Strips Coming Away From The Molds
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Patricks Dad
- Posts: 1476
- Joined: Wed Oct 13, 2004 1:11 pm
- Location: Warrenville, Illinois
Re: Help! Strips Coming Away From The Molds
From your picture it looks as though if you put some pressure on the outside of the hull, it would lay nicely on the form across it's length (at least as far as the picture shows). What if you just push the hull in at the gunwale location (does the rest of the hull fall into place?)?
I'd suggest you pull it in using one of a few different approaches.
You could glue a small block to the hull and put a small screw through it into the form to hold it in place (drill the hole for the screw before gluing it to the hull). You can sheer it off later easily when you are ready to remove it. Use this technique in a few places as need to keep the hull on the forms.
Or you could try to put a couple drops of hot glue between the form and the hull to hold it in place (if you have celophane tape on the form it may pull off however).
You could also put a strap (ratchet clamp or very long cable-tie) around the hull to keep the strips (current and future) against the hull
When you take the hull off the forms, you may experience some spring-back which will (partially) defeat this strategy but you will at least have more confidence that future strips you put on from here-on are more likely to follow the original hull design.
When you take the hull off the forms, you can cut a short strip for each station which matches the intended beam for each station and help hold the hull in shape while you measure for seats, thwarts, yoke and decks which will do their part in ensuring that the beam is correct in the final product.
Enjoy your build!
I'd suggest you pull it in using one of a few different approaches.
You could glue a small block to the hull and put a small screw through it into the form to hold it in place (drill the hole for the screw before gluing it to the hull). You can sheer it off later easily when you are ready to remove it. Use this technique in a few places as need to keep the hull on the forms.
Or you could try to put a couple drops of hot glue between the form and the hull to hold it in place (if you have celophane tape on the form it may pull off however).
You could also put a strap (ratchet clamp or very long cable-tie) around the hull to keep the strips (current and future) against the hull
When you take the hull off the forms, you may experience some spring-back which will (partially) defeat this strategy but you will at least have more confidence that future strips you put on from here-on are more likely to follow the original hull design.
When you take the hull off the forms, you can cut a short strip for each station which matches the intended beam for each station and help hold the hull in shape while you measure for seats, thwarts, yoke and decks which will do their part in ensuring that the beam is correct in the final product.
Enjoy your build!
Re: Help! Strips Coming Away From The Molds
i'm also building a bobs special, and i used the stapeless method outlined in canoecraft.. more or less. i wanted the strips to be a bit more secure against the forms, so i also used flat stretchy straps as pictured in my thread:
http://bearmountainboats.com/phpBB3/vie ... f=1&t=4028
at the end of the day i think you will find that it will not be a perfect match to the forms once it's been glassed, but when you install the center thwart it all kinda works out.
http://bearmountainboats.com/phpBB3/vie ... f=1&t=4028
at the end of the day i think you will find that it will not be a perfect match to the forms once it's been glassed, but when you install the center thwart it all kinda works out.
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Rod Tait
Re: Help! Strips Coming Away From The Molds
I would try to get the strips back tot he molds now before you proceed. After more strips are attached, it will become more difficult to push the strips to the forms as the extra material will have no where to go. You might try to add a bit of dry heat in the form of a heat gun to soften the wood and push back into place, then add some hot melt glue as already mentioned to hold it to the forms. It will be more difficult as you progress up the sides to keep strips onto the forms, especially in the ends, so I pre-bend the strips with the dry heat to conform to the shape before I commit to glue.
I have been adding some videos of the process of wood strip building to my blog on my web site and if you look at the one on stripping a kayak hull, you will see some pre-bending taking place.
I have been adding some videos of the process of wood strip building to my blog on my web site and if you look at the one on stripping a kayak hull, you will see some pre-bending taking place.