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| Pine Stock planed to thickness |
Stock:
We chose kiln dried, clear Yellow Pine to build the frames. Yellow Pine is a traditional boatbuilding wood and extremely durable, cheap too at $1.33 a board foot. It's grown here in my state and makes sense to me. 4/4 stock was chosen over 8/4 because we intend to laminate the frames with half lap joints for assembly. They will be glued and screwed together. I plan to encapsulate both frames and hull with epoxy on the inside "overbuilding" with the use of fillets and fiberglass tape at the seams for added strength and water resistance if it did find its way down there. I may change my mind on this point, however, it may be money well spent at least below the waterline.
Milling and Cutting:
We started with rough sawn clear 1" x 6" x 12's, my wife and I milling them down to 3/4" final thickness, then ripped them down to a full 4" width. As cramped as my shop is it helped having my wife catch the boards on the off side as they were fed through on both the planer and the table saw. This would be impossible to do myself on the jointer with its short bed. We have done this so many times, with thousands of board feet of lumber under our collective belts that we didn't have to go over a game plan on how to separate the pieces as we made 6 to 8 planer passes, each being flipped each time.
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| Typical Frame - Station 6 |
The leftover strips will serve as cleats and scrap to be used as needed. I made the decision to add the additional height to the bottom chord as needed to create a level sole ("boat speak" for floor). I thought its was easier to make them all 4" high instead of custom cutting a series of widths for each station.
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| Frames cut and stacked - awaiting assembly |
I then proceeded to cut these to length slowly and methodically working my way through the prints as each cut was a slightly different angle, and was measured from either real or projected end points. I stacked these into bundles so they wouldn't get mixed up (past learning experience paying off here) and taping them together for future assembly.
Assembly:
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| 316 Stainless Shark Screws |
I agonized (maybe not agonized) over the decision of what to use for both fasteners and glue for frame assembly. Traditional choices would be silicon bronze fasteners and epoxy glue. I understand the idea of using these fasteners and glues for boats that spend their lives in the water and will see themselves immersed for extended periods. The Redwing will not. The reality is that she will spend most of her life on a trailer in a covered building and her bilges will be pumped or drained every time she is used. This didn't mean that I was interested in using white Elmer's and sheet rock screws, but I did settle on different choices for several reasons.
For glue, I settled on PL Premium by Loctite available at most big box stores. I read through a lot of literature and suggestions by experienced builders and it shows great promise as a highly water resistant adhesive that exhibits great strength and bonding properties. Its available in convenient caulk tubes, can be capped at night (I use a stubby screwdriver) and has low VOC's (fumes). I must be clamped extremely well as the foam out has no strength. This was no problem as my fasteners would provide the clamping pressure needed. Speaking of fasteners... I made the decision to stick with Stainless Screws in this application for a few reasons:
- Cost - about a third of what silicon bronze costs.
- Intention to fully encapsulate the frames.
- Use of 316 Stainless vs. 304 which is more resistant to saltwater chlorides, the real culprit with pitting and corrosion.
- Reasons mentioned above.
I ordered the screws (#8 x 1-1/2") from Manasquan fasteners and when they arrived was boxed by Simpson Strong Tie (marked as dock fasteners for saltwater). They are a high-low thread which are purportedly harder to back out and they drove well. Only available in Phillips drive I was worried that they would cam out but I had no such trouble. They drove well without predrilling on all but the smallest of pieces. I intend to use them when it comes time to attach the plywood to the frames, patching them with an epoxy and microballon slurry before covering with Xynole fabric and epoxy.
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| Ready for clamping (screwing) together |
Assembly was pretty straight forward. I laid the pieces out to check for proper fit and alignment and had to trim a piece or two along the way. I would then just lay a generous pattern of PL down and using pencil marks drawn during the check for alignment, I would begin screwing the pieces together adjusting them along their length in pairs spaced 6" to 8" apart. The squeeze out was satisfactory and I cleaned it up along the way with a putty knife and scrap board. I kept everything I needed in a tote close at hand to limit the amount of time I spent hunting for tools and such.
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| Note the chine (corners) and limbered (horizontal) notches |
Set aside to cure, I managed one frame per night. I would sand and clean up the previous night's frame and mark and cut the chine slots that will tie all frames together once secured on the Strongback. I also "limbered" up the frames. In other words I used a hole saw to cut a half moon notch in the bottom center of each frame. The purpose is to allow water that may find its way into the bilge a path to gravitate to the lowest point of the boat where I will mount an automatic bilge pump. I will leave station 20 and 2 unlimbered so as to provide a solid bulkhead fore and aft. I'll foam fill the forepeak below the anchor locker and mount a second bilge pump behind station 20 to handle any water that finds its way into that part of the boat.
6-10-2014 UPDATE...
The final few frames forward are a little different in their form and function. These are at Stations 2 and 4 at the very front or forepart of the boat. You can see how they narrow and grow taller toward the front as the hull curves up and in to the stem or sharp edge of the boat.
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| Frames 2 and 4 Construction Plans |
They are different because the top part of the frame is a closed arc that forms the front deck of the boat ahead of the cabin or small projection with the round portholes in the picture on the "Concept and Design" page.
I had intended to get back to the lumber supplier for more pine to build the arched tops but hadn't had the chance and didn't want to waste a weekend. I had some white oak sitting around from a past project and decided to use it as it is a very suitable boat building wood and is very strong. I thought it may serve well here with the combined weight of the cabin resting on it, as well as, a crew member standing on it while working the anchor.
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| Template for Station 2 (half of arch) |
Here you see my marking the oak with a template that I made by plotting the arch full size, gluing to a cheap piece of Masonite hardboard and sawing out. Paper stretches too much and is fairly fragile. It won't hold up too long in a shop environment. I used a square to align the center line, then flipped it over to do the other side using the square flipped over as well.
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| Station 4 inside edge sawn |
This was followed by cutting out the two part frames (overlapping butt joints like the rest of the frames) with a jigsaw. I could have used a band saw with even better results but the jig saw answered well enough for this fairly small task on 4/4 stock. If I attempted anything thicker the bandsaw would have to be used because of the tendency for a jigsaw to veer at an angle when cutting a curve. I did get a little of that but would sand them off together for an even edge.
Once cut I glued them up using Titebond III PVA adhesive and screwed them together to clamp and cure for 30 minutes or so.
HANDY TIP ALERT #1
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| From the middle to the edge |
One tip on gluing up and one I learned building saddles and it's a simple one... Always glue from the inside of the part to the edge, not from the edge to the middle. From the edge to the middle only scraps off the glue on the boards edge, however, brushing from the middle out will leave the glue sitting at the edge of the board. This saved me a lot of nasty leather edges which are as important to saddle making as tight joints are to woodworking. Now, I'm not one for extreme neatness in glue ups and honestly am very generous with the glue. I keep a bucket of warm water handy to immediately scrub and sponge and don't mind a healthy squeeze out along the edges. But I hate to "scrape" the brush off as I spread glue across the surfaces being coated.
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| Assembled Frame Deck Beam |
Okay, back to assembly. Here is the part screwed and glued and needing a wipe down. Wipe with lots of water. Glue left on the surface will prevent finish or subsequent glues from adhering. You won't hurt the wood I promise. You'll notice that the top board stops short the width of the overlapping frame portion. Once they had set for a while I used an oscillating belt sander (present from my wife many years ago, Thank you Wife!) to dress the edges even and to take the variances in the two cuts.
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| Assembled Station 4 Frame |
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| Stations #2 & #4 |
I then proceeded to assemble them using the PL Premium adhesive that was used on the other frames checking diagonals for squareness. Limbered up and notched as the rest of them were was the final step and we were ready to start mounting these on the Strongback. Check that process out on "Setting the Frames" page. Thanks!
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