Monday, March 2, 2015
Excuses To Delay Fairing!
After my initial bout with fairing, I got a bit gun shy. I didnt want to make any mistakes fairing the structure. Was that really it, or was it because I am not thrilled with this part of the boat build?
Well, I think its a bit of both, probably more on the not so thrilled part. Anyway, after having gotten part way finished with the starboard side, I was at a point where I was going to have to tackle the sheer at frame 4. This is the first part of the sheer where the curve towards the bow starts. Its the same with the chine. From this point forward, fairing is going to be more challenging and I am not quite ready mentally to tackle this.
Also, the sheer forward of this point is going to have quite a bit of material removed because of the angle downwards of the frames. The "Boatbuilding With Plywood" book by Glenn Witt states that it is often necessary to add additional material to the inside of the sheer between the frames in this area.
A perfect excuse to stop fairing!
So the sheer in this area has a curve which means that any material added here will also need to conform to that curve. I had some remaining sheer lumber left over, but not enough to do all the reinforcing. More on that in a minute.
I cut as many pieces as I could from the leftover sheer material to fit in these spaces. I left them long so that when the wood was bent, there would still be enough material. The reinforcements need to go from one frame to the next. A total of six pieces would need to be added. I had sheer material enough for four.
What I also had was some leftover scrap from two years ago when I cut out the frames. This scrap was 3/4 inches thick and I needed 5/8" thick for the sheer reinforcement. A few months back I had experimented with my table saw on how to cut thin slices off of wood. I was planning on using this technique to get the wood down to 5/8 inch.
The technique is simple really. You take a piece of wood at the correct thickness and place it between the table fence and the saw blade. The fence is cinched up to the wood. You can then run the thicker lumber through the saw and it is thinned down to the correct thickness.
Before I could do that, I had to get a usable piece out of the scrap, which was oddly shaped. I needed a straight edge on on side of the scrap in order to eventually cut the piece to the same width as the sheer material. I simply drew a straight line on the scrap through the widest portions allowing enough material on one side of the line for the necessary width. Then I clamped a wider board on top. This wider board already had a straight edge on two sides. One side was lined up with the drawn line. The other side would run against the fence and allow me to make a straight cut on the drawn line. The fence was set at the same distance as the wood clamped in place.
Im sorry I didnt take any pictures of this particular process, so I hope my description is adequate. Once I had the wood to the correct width, I applied the technique for getting it to the correct thickness. This left me with sufficient material for the two additional sheer reinforcements.
The reinforcements were bent using steam over cinder blocks and using a ratchet strap to perform the bend. The following photos illustrate this process. The trick here was to get the bend sufficient enough to conform to the sheer when I glued it into position.
Gluing was performed in a similar manner to the second sheer lamination done a few weeks ago, namely using clamps.
After the bending was performed. I would temporarily clamp the wood to the outside of the sheer and draw a line to indicate the angle I had to cut the ends to match up to the frames. I would then cut outside of that line at the same angle and then gradually adjust it inward, testing the part on the inside of the sheer until it fit the way I wanted it to fit.
The end result after several days of steaming and gluing was six reinforcements glued between frames 4 and 5, 5 and 6, and 6 and the breasthook. The next two photos show before and after shots of the sheer between frames 4 and 5
This next photo shows the additional thickness.
Between work, steaming the wood, waiting for it to dry sufficiently, gluing up the parts , and waiting for the epoxy to cure, I managed to avoid fairing for a week.
But alas, I knew that I had to get into it or the boat would never be finished. So three days ago I started back up on fairing.I got the sheer faired from the aft end of the boat up to frame 4 on the starboard side as well as the remaining area of the chine in the same stretch of boat.
The piece of plywood is used to simulate the skin that will eventually be applied. I am pretty sure that when I start fitting the real skin, there will be additional fairing required so Im just trying to get close at this point.
So far most of the fairing has been sanding the chine and sheer down to the same angle as the frames and then blending the area in between the frames to get a nice flat area to attach the skin. Forward of frame 3, the sheer starts to curve and the area to be blended increases as you get closer to frame 4.
To give myself something to guide the sanding by, I drew a curve from frame 3 to frame 4 on the sheer, gradually widening it to match up to the area already sanded down at frame 4. You can make out the line on the sheer in the last photo. The sheer is then sanded back at an angle to this line from the outside, leaving the bottom of the sheer essentially intact.
What I was trying to achieve is an angled surface on the curve that matched the angle that the skin will mount to the chine and sheer at. You can see that in the next photos.
Finally, today, I started repeating the process on the port side aft of frame 4. I still have more work to do here.
To illustrate one final point, the next photo is shot looking down on frame 4. You can see that the frame needs to be faired to match the chine on the left of the photo. The other frames forward of this are even more dramatic in the amount of material that needs to be removed.
Needless to say, the forward area of the boat has many angles and curves to consider while fairing and I intend to go slow in this area. So updates to the blog may be a bit farther apart for awhile.
Until next time, take care.
Well, I think its a bit of both, probably more on the not so thrilled part. Anyway, after having gotten part way finished with the starboard side, I was at a point where I was going to have to tackle the sheer at frame 4. This is the first part of the sheer where the curve towards the bow starts. Its the same with the chine. From this point forward, fairing is going to be more challenging and I am not quite ready mentally to tackle this.
Also, the sheer forward of this point is going to have quite a bit of material removed because of the angle downwards of the frames. The "Boatbuilding With Plywood" book by Glenn Witt states that it is often necessary to add additional material to the inside of the sheer between the frames in this area.
A perfect excuse to stop fairing!
So the sheer in this area has a curve which means that any material added here will also need to conform to that curve. I had some remaining sheer lumber left over, but not enough to do all the reinforcing. More on that in a minute.
I cut as many pieces as I could from the leftover sheer material to fit in these spaces. I left them long so that when the wood was bent, there would still be enough material. The reinforcements need to go from one frame to the next. A total of six pieces would need to be added. I had sheer material enough for four.
What I also had was some leftover scrap from two years ago when I cut out the frames. This scrap was 3/4 inches thick and I needed 5/8" thick for the sheer reinforcement. A few months back I had experimented with my table saw on how to cut thin slices off of wood. I was planning on using this technique to get the wood down to 5/8 inch.
The technique is simple really. You take a piece of wood at the correct thickness and place it between the table fence and the saw blade. The fence is cinched up to the wood. You can then run the thicker lumber through the saw and it is thinned down to the correct thickness.
Before I could do that, I had to get a usable piece out of the scrap, which was oddly shaped. I needed a straight edge on on side of the scrap in order to eventually cut the piece to the same width as the sheer material. I simply drew a straight line on the scrap through the widest portions allowing enough material on one side of the line for the necessary width. Then I clamped a wider board on top. This wider board already had a straight edge on two sides. One side was lined up with the drawn line. The other side would run against the fence and allow me to make a straight cut on the drawn line. The fence was set at the same distance as the wood clamped in place.
Im sorry I didnt take any pictures of this particular process, so I hope my description is adequate. Once I had the wood to the correct width, I applied the technique for getting it to the correct thickness. This left me with sufficient material for the two additional sheer reinforcements.
The reinforcements were bent using steam over cinder blocks and using a ratchet strap to perform the bend. The following photos illustrate this process. The trick here was to get the bend sufficient enough to conform to the sheer when I glued it into position.
Gluing was performed in a similar manner to the second sheer lamination done a few weeks ago, namely using clamps.
After the bending was performed. I would temporarily clamp the wood to the outside of the sheer and draw a line to indicate the angle I had to cut the ends to match up to the frames. I would then cut outside of that line at the same angle and then gradually adjust it inward, testing the part on the inside of the sheer until it fit the way I wanted it to fit.
The end result after several days of steaming and gluing was six reinforcements glued between frames 4 and 5, 5 and 6, and 6 and the breasthook. The next two photos show before and after shots of the sheer between frames 4 and 5
This next photo shows the additional thickness.
Between work, steaming the wood, waiting for it to dry sufficiently, gluing up the parts , and waiting for the epoxy to cure, I managed to avoid fairing for a week.
But alas, I knew that I had to get into it or the boat would never be finished. So three days ago I started back up on fairing.I got the sheer faired from the aft end of the boat up to frame 4 on the starboard side as well as the remaining area of the chine in the same stretch of boat.
The piece of plywood is used to simulate the skin that will eventually be applied. I am pretty sure that when I start fitting the real skin, there will be additional fairing required so Im just trying to get close at this point.
So far most of the fairing has been sanding the chine and sheer down to the same angle as the frames and then blending the area in between the frames to get a nice flat area to attach the skin. Forward of frame 3, the sheer starts to curve and the area to be blended increases as you get closer to frame 4.
To give myself something to guide the sanding by, I drew a curve from frame 3 to frame 4 on the sheer, gradually widening it to match up to the area already sanded down at frame 4. You can make out the line on the sheer in the last photo. The sheer is then sanded back at an angle to this line from the outside, leaving the bottom of the sheer essentially intact.
What I was trying to achieve is an angled surface on the curve that matched the angle that the skin will mount to the chine and sheer at. You can see that in the next photos.
Finally, today, I started repeating the process on the port side aft of frame 4. I still have more work to do here.
To illustrate one final point, the next photo is shot looking down on frame 4. You can see that the frame needs to be faired to match the chine on the left of the photo. The other frames forward of this are even more dramatic in the amount of material that needs to be removed.
Needless to say, the forward area of the boat has many angles and curves to consider while fairing and I intend to go slow in this area. So updates to the blog may be a bit farther apart for awhile.
Until next time, take care.
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