Preparing the temporary frames – our comedy of errors.

We made use of some great weather early September (yikes – really running behind on writing this blog), to set up the temporary frames and attach the boat frames to them. A spare 18 mm MDF sheet on top of our garden table was our worktable for this work. It provided a large, flat area and access for clamps all round.

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Sunny workstation. The small plywood parts were a makeshift solution for dealing with the slightly too long screws. Yes, one of the standups in the wrong way round. One of many small mistakes made here.

We had already cut MDF to the required dimensions based on measurements taken from Sheet 2 of the plans. Using a sliding bevel, we copied the angles for construction of the temporary frames from the same sheet.

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Sheet 1 of the building plans was taped down flat on the large MDF sheet we used as makeshift worktable.

We included the additional vertical supports close to the centre of the frames, as recommended by the class association. These significantly stiffen the temporary frames up, provide support and can help with alignment. If they are installed correctly. We recommend adding them, but take care to leave enough space from the centreline to allow for the wood strips on the outside of the girder to slide it. We didn’t so had to saw them off again. Yet another little error we made in this step.

The next step was attaching the boat frames to the temporary frames. This is a bit of a faff, but worked well once we figured it out:

  1. Start with either port or starboard frames and working through all stations before doing the other side.
  2. Align and centre the temporary frame to the baseline on Sheet 1 .
  3. Clamp the temporary frame in this position.
  4. Use a collection of small squares to line the boat frame to match the corresponding positions on sheet 1 (the plywood frames are the full MDF thickness above the sheet, so this is essential). I would recommend using the inward corners of the stringer and chine cutouts as well as the edges that line up with the girder as orientation points.
  5. Hold the plywood frame tightly in this position, while screwing it down to the temporary MDF frame. This is where an additional pair of hands is very convenient.
  6. Check that nothing moved while putting in the screws. Chances are it did.
  7. Once all frames for one side are glued up, clear the table and flip Sheet 1 to attach the other frames for the other side.

As always, taking your time and working carefully pays off here. We did a lot of double checking.

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A first glance, note that the MDF framing isn’t clamped down yet.

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The “demi frames”. Notice that the additional vertical supports would snug right up to the girder. This isn’t good. Leave at least 10mm space here. 

Once the all the framing was done, we couldn’t resist balancing them on the building frame (some many different types of frames in this post … too confusing for me), to get a first real feel for the hull shape.

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Mockup of the hull shape. A good eye will spot our final and most frustrating error in this step. Yes, the frames are all on back to front, because we installed them on the MDF the wrong way round. *sigh*

We only noticed that we installed the plywood frames the wrong way round on the MDF frames when we started fixing them to the building box. After some back and forth we decided to leave them and pay close attention that when we fastened them, the ply wood was in the correct position. Annoying but less hassle than redoing it all. The frustrating bit is that we had two frames that were initially installed the right way round, but we ‘corrected’ them.

In the end, this was a step that had me really worried initially, but it was quite simple. We did manage to make a series of mistakes, but that was down to our paying attention to the wrong things. No lasting harm was done and we hope that we now have filled the required number of errors to ensure the rest of the build goes smoothly (yeah, right …).

 

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Getting our bearings

It took a bit longer than expected to get our bearings again and work out where we left off in detail. The girder was pretty much finished prior to moving from London, and is just awaiting a set of four bolts to strengthen the daggerboard case. As I never posted anything on that step, here is a quick run through it.

Time warp back to 2015!

We bolted down the port side of the girder on the building box. Then we glued the straight doublers down first, to add stability before bending the curved bits into place.

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Laying out the internal framing on the girder

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Gravity clamping. Never thought that old book would be useful again 😉

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Removing a bit of excess epoxy. Gotta love a rebate block plane.

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More gravity at work.

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Adding the curved doublers. Note the small blocks screwed down to hold the curve.

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Girder ready to close.

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Closing the front bit.

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Front section closed. The aft section has the first three coats of epoxy on the dagger board case region, to ensure an extra thick, smooth coat. The rest was then sealed before glueing down.

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Last polishing up.

 


I should mention that we ran into some issues while glueing up the last bits, once again based on errors in the CAD plans we used for the CNC routing. I cannot stress enough to use the class association provided CAD plans, not the ones held by 4th Dimension in Bristol. In the case of the girder one of the large lightening holes was off, making it necessary to shift the position of the diagonal bearer running up to the mast foot.

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The relevant detail on the plans.

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Notice the diagonal bearer doesn’t quite reach to the top. Quite a bit of filleting involved in making sure it is stable.


 

With the girder near finished, it was time to pack everything up for the move to Sussex, but not without some fun and games:

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Aaaand pretending it’s already a boat, prior to packing it all up.

Fast forward back to late Summer 2017:

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Starting up again. And scratching our heads to remember the details.

But we figured it out 🙂

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Frames and the cut and prepared MDF strips for the temporary framing to mount them.

More to come very soon!

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Back at it. Really!

I clearly remember the discussion on the Y&Y that I was having with Dave regarding building a Farr 3.7. I was in mild panic about the required woodworking skills. At the time Dave told me not to fret, you learn the woodworking on the way and the bits you can see don’t come to the very end (in my words).

Four years later (heavens, does time fly), I have fully caught the woodworking bug, but D. put down her foot three weeks ago and the message was clear: “The boat build is happening. Now!”.  So, a workbench, several small boxes, a benchtop bench, two Japanese toolboxes and an in-progress saw bench later, the boat build is now back on track. I mentioned that I got a bit carried away with the woodworking bit, didn’t I?

The first step was setting the build frame up again. Luckily, we seem to have stored everything good enough and nothing has warped.

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Building frame back in action. Only the lid missing at this point.

 

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Getting back to it.

The past year has brought many distractions from the Farr building. Once it was clear that we would be moving out of London (yay!), we finished the girder, but stopped the build at that point, so that the project could be comfortably moved.

Now, our boat kit has been relocated and the new ‘workshop’ (still a garage, but with water and power this time) is being set up.

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The ‘set up’ has brought on another distraction. After going back and forth, I decided to tackle the workbench issue. Properly.

The “workbench issue“: While very convenient, the foldable workbench we have been using is a bit too low for me. More importantly, all the workbench options I have been able to find and try are simply too light to properly plane on them. Which will become an issue once we get to the point of making scarf joints for the hull panels.

The solution: Build a workbench. Make it fit, make it heavy enough and then use it.

Easier said than done. But not nearly as difficult as I imagined it to be. After some reading, I settled on a Nicholson-style (or “English”) workbench. I also let myself be convinced that with a little fore-thought, vises are not necessary. There is a ton of material out there to help. I did not follow an existing plan, but based the design on ideas that had been proven useful in the past. Andy Margeson’s Oregon Woodwork blog was probably the most influential reading for me. I also found Richard Maguire’s video series on the topic very helpful.

The final joining up of the separate elements, as well as flattening the top are still ahead of me. But I did a dry fit already, to make sure that everything goes together smoothly and because I really wanted to see what the finished bench will look like.

Legs glued up.

Legs glued up.

Dry fitting aprons on legs

Dry fitting aprons on legs

Preparing the legs for a lap joint. Part 1.

Preparing the legs for a lap joint. Part 1.

Preparing the legs for a lap joint. Part 2

Preparing the legs for a lap joint. Part 2

Preparing the legs for a lap joint. Part 3

Preparing the legs for a lap joint. Part 3

Glueing up legs and aprons

Glueing up legs and aprons

Dry fitting without the top (and the bears)

Dry fitting without the top (and the bears)

Dry fitting the whole thing.

Dry fitting the whole thing.

If the Farr comes together as accurately as the bench has done, we would be thrilled. Fingers crossed!

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Finishing the frames

It seemed that we were close to having the frames finished once all the doublers were added. As it turns out, that was a very naïve idea. The sealing and coating of the frames took more time than we had anticipated. We had both underestimated how rough plywood after the first epoxy coat is and the amount of sanding that is needed to smooth this out at least a bit. But first things first:

We chose to simply use epoxy for sealing and coating the plywood. No solvents added, as these supposedly mess up the physical properties of the epoxy. We used a foam roller (the thin polyurethane ones from WEST) for the larger areas with a 1 inch foam brush for getting into the corners and harder to reach spots, finally tipping of with a 3 inch foam brush.

The Gougeon Brothers book recommends at least two layers of epoxy. They suggest expecting sanding to remove one layer, so a total of three layers should be the minimum laid up. As this is a dinghy that won’t stay in the water for days on end, we decided to go with this recommendation. After all, we don’t want to weigh the boat down with additional layers that don’t serve any function. So we applied the initial layer, tipped it off and let it cure for about two hours. After the initial cure we added a second layer (‘tacky on tacky’). This we let thoroughly cure (at least three days).

Coated frames spread out and waiting for epoxy to cure.

Coated frames spread out and waiting for epoxy to cure.

The result is surprisingly rough, mainly due to swelling of single wood fibers. We washed the frames with plenty of water and a “Scotch Brite” pad to remove any potential amine blush. As we didn’t like the roughness, we sanded the frames with 80 or 100 grit paper (both seemed to work fine). We were not trying to achieve a perfect finish, just to remove the small spikes and roughen the surface for more efficient keying in of the final epoxy layer. The third and final layer was then applied in the same manner. The result is nice and shiny with the color of the wood coming out really nicely.

Finished frames waiting to be mounted on the building jig.

Finished frames waiting to be mounted on the building jig.

A few small things at the end:

  • We paid particular attention to get the endgrain efficiently coated.
  • The first coat was probably more akin to one-and-a-half, as the first epoxy to be laid down is immediately taken up by the wood.
  • It is worth wiping the surface of the frames with a paper towel drenched in acetone after the sanding step to remove finger prints.

The last point is also the first entry on our new “Notes” page, where we collect the small lessons we learned the hard way.

Finally, I can’t help wonder if using a dedicated sealant such as Eposeal isn’t worth the additional cost. If anyone has comments on that, I would love to hear them.

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Back at it

Once again, it has been a longer time since the last post. Which doesn’t mean we haven’t been working on the build. Once the weather turned warm enough for epoxy to reliably cure, we jumped back into the workshop and have now finished the frames and are close to finishing the girder. In parallel we are sorting some bits and pieces for the next steps. The biggest part of that will be building a steaming box, so that we can steam-bend the stringers, chines and gunwales.

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Catching up.

I have been tardy. Not with the boat work but with writing. In contrast to the impression this blog gives, we have made some progress over the past weeks.

All the frames are now doubled up where needed. The transom was still a bit more work, as doublers for the side decks needed to be shaped and mounted as well.

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First glueing steps for transom doubler.

Transom all doubled up.

Transom all doubled up. Frame 1 is peaking out underneath, just waiting to be sealed with epoxy.

We have also faired the doublers to the frame shapes (not all the sawing, etc. was perfect so a few bumps needed to be smoothed out). The main lesson learned while doing that is that a spokeshave is amazing for tight curves, but when it comes to not so tight convex curves, a block plane is just sooo much nicer. In general I have to say that the block plane has been a great investment. It is getting constant use.

Everything is now ready for us to seal and coat the frames and then it’s back to the garage and on with the girder. While progress has been a bit slow, it feels like we are moving towards a major jump ahead.

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