Skipjack Kathryn by Mahuna - FINISHED - 1:32 - Based on HAER Drawings

[EdT]

Looking great as always, Frank.  You can certainly tell that structurally she was built for the bay and not the horn.  Beautiful clean work.

 

Ed

[GuntherMT]

16 hours ago, Mahuna said:

Thanks Brian.

 

I'll be around all weekend. Stop by if you're in the area.

 

Next weekend or today?  I've got strep throat so I am not going anywhere this weekend while the penicillin does it's thing.

[Mahuna]

Hi Brian - sorry to hear you're not well.  Get better soon.

 

Unfortunately I meant today and tomorrow.  We leave on a road trip on Thursday morning - going places that are a little less warm than here.

 

I'm hoping to have Kathryn's hull planking finished before we leave.

[Mahuna]

6 hours ago, EdT said:

Looking great as always, Frank.  You can certainly tell that structurally she was built for the bay and not the horn.  Beautiful clean work.

 

Ed

Thanks Ed.  Even though they're not ocean-going, it's amazing to think of the kind of beating these old skipjacks take during the winter oyster season.  This photo is from a book on working skipjacks and it shows Kathryn in 2016, some few months after the recent rebuild.  All of the plank seams show - needing a new paint job already!

 

[Mahuna]

Part 24 – Hull Planking – Preparing the Chine

 

I was able to develop a workable approach to installing the chine.  First, some background:

 

All of the cross-sectional drawings in the HAER documentation show the rounded chine and also show the frames as rounded at the chine.  One drawing, from Page 6, actually depicts the planks used in the chine area and shows them cupped around the frame.

 

                        

 

I had not been able to determine an approach for making this type of chine plank for the model.  I have been in contact with one of the people who worked on the Kathryn rebuild, and he told me that during the rebuild the chine planks were installed as thick planks and then were planed to form the rounded chine.  Looking through photos from the rebuild, it can be seen that the chine area of the frames was made flat, rather than rounded, so that flat planks could be used for the chine.

 

                        

 

The frames that were installed on the model have the rounded chine, so these needed to be modified to allow flat planks to be used.  The first step was to line off the chine using drafting tape, and then to mark the upper and lower boundaries of the chine on each frame.

 

                        

 

Using the marks on the frame, a sanding block was used to flatten the chine.

 

                        

 

The following photo shows the model with all of the frames flattened in the chine area.  The chine in most of the frames is the same width, but this decreases for the last 6 or 7 frames approaching the stern.

 

                        

 

Thick planks were milled for the chine.  Although the documentation indicates that 3 planks were used in the chine, I decided to use a single plank to simplify the construction.  The planks were lined out on each side to allow beveling the sides of the plank so that the hull planking could sit flush with the chine.  The chine planks are significantly thicker than the hull planking that will sit next to the chine.  This will allow the chine planks to be rounded after all of the hull planking is installed.

 

A compass was used for lining out the planks.  The metal point was reversed so that the compass would ride along the side of the plank and give a consistent width of the line.

 

                        

 

The planks were lined out for the bevels on each side.

 

                        

 

The bevels were then cut into the planks using a stump cutter in the rotary tool, followed by some final sanding.

 

                        

 

                        

 

The chine planks would need to be bent to fit properly.  I decided to install the planks as short sections that were pre-bent to fit the respective location.

 

Bending was performed by soaking the piece of chine in boiling water, and then using a plank-bending tool to form the shape.  The tool was held vertically in a bench vise.

 

                        

 

                        

 

All of the pieces required for a side were made before any was installed.  The pieces were labeled for sequence and direction.

 

                        

 

The following photo shows the port side chine after the initial installation of the chine pieces.  It can be seen that a lot of subsequent shaping is required before there would be a fair run of these planks.

 

                        

 

The following photo shows the starboard side after some initial shaping, and the port side awaiting shaping.

 

                        

 

Both chines have now been installed and shaped for their final configuration

                        

 

                        

 

                        

 

                        

 

Next up is the installation of the hull planking for Kathryn’s sides and bottom.

 

Thanks everyone, and Happy Fathers Day to all the Dads (and Grandfathers) out there!

 

[russ]

That is a good solution to difficult problem. We had vessels down on the Gulf Coast with a hard chine, but I am not sure if they shared this particular characteristic. Very interesting feature.

 

Russ

[Mahuna]

Hi Russ:

 

Thanks!

 

Most skipjacks have a hard chine, bottom planks laid in a herringbone pattern, and are built without true frames.  Kathryn and a small number of others was built with traditional frames, longitudinal bottom planks, and a rounded chine.  The construction process between the two styles is very different.

[russ]

I think most of our hard chine vessels down here were built upside down.

 

Russ

[Mahuna]

9 hours ago, russ said:

I think most of our hard chine vessels down here were built upside down.

 

Russ

Hi Russ.  My understanding is that the hard chine boats are built the same way on the Chesapeake.  Kathryn was likely built in a more traditional manner - upright.

[Mahuna]

Part 25 – Hull Planking – Side Planks

 

After a full day in the shop the hull planks have been installed on Kathryn’s sides. 

 

This went very quickly, but I have to admit that the reason for the speed is that I didn’t spend any time laying out the planking, spiling, or generally taking a lot of care in how the planks look.  Since Kathryn will be painted I decided to simply get the planks in place and then to finish the sides by scraping, sanding and a liberal use of wood filler.

 

Normally I would focus on one plank at a time, but in this case I was able to install a strake on each side without much trouble.

 

                        

 

Most of the clamps in the photo are micro needle-nose clamps I was able to find at Menards.  Their length allowed me to clamp all the way down to the bottom strake.

 

                        

 

They’re priced very reasonably, even with shipping and handling.  Here’s the link for the clamps.

 

            https://www.menards.com/main/tools-hardware/hand-tools/clamps-vises/wolfcraft-reg-micro-needle-nose-clamp/p-1444439537678-c-9135.htm?tid=5859562028242466227&ipos=1

 

When the planking was completed, but before sanding and filling in the spaces Kathryn looked pretty rough.  But after the initial cleanup she’s starting to look pretty good.  Here are some ‘before’ and ‘after’ photos>

 

                        

 

                        

 

                        

 

                        

 

                        

 

                        

 

There’s still a lot of cleanup needed before painting.  I’ll be installing the bottom planks next, and then will spend some time rounding the chine and getting the hull ready for painting.

 

Thanks Everyone!

[russ]

The planking looks pretty good.

 

Please eyeball the sheer strake on the starboard side. It is probably the camera playing tricks with me, but it looks like there is a hump along the edge of the deck at the first plank butt. Probably a bad angle for me, but please have a look and make sure.

 

Russ

[Mahuna]

53 minutes ago, russ said:

The planking looks pretty good.

 

Please eyeball the sheer strake on the starboard side. It is probably the camera playing tricks with me, but it looks like there is a hump along the edge of the deck at the first plank butt. Probably a bad angle for me, but please have a look and make sure.

 

Russ

Thanks Russ - I see what you're referring to and I'll check it to morrow.  I haven't finished all of the fairing work, and there is still some future construction above that sheer strake (planksheer, railings, etc) so I think it will work itself out.

[Omega1234]

Hi Frank

 

Flattening the chine line must've been a fair deal of work, but, oh, so worthwhile now that it's done.  

 

You know what?  Something that has also struck me is just how shapely the hull is.  Low, flat, with a broad beam, a lovely sheerline and a lovely stem, she looks 'fast' even whilst she's stationary.

 

Nice.  Very nice.

 

Cheers

 

Patrick

 

 

[Mahuna]

Thanks Patrick.  Kathryn is considered one of the faster skipjacks in the Chesapeake Bay.  One of the the things that made me want to build the model is her beautiful lines - I hope I do her justice.

[druxey]

Looking lovely, but I think Russ is correct. Hopefully it's an easy fix.

[HIPEXEC]

Looking real nice!

[Mahuna]

12 hours ago, druxey said:

Looking lovely, but I think Russ is correct. Hopefully it's an easy fix.

Thanks Druxey.  Russ is correct, and the fix will be fairly easy.  I'll be spending some time looking for other areas to correct before painting.

 

10 hours ago, HIPEXEC said:

Looking real nice!

Thanks Rich.  Welcome back.  This week will be a good test of the new A/C for your shipyard.

[Mahuna]

Part 26 – Hull Planking – Bottom Planks

 

There was a comment by Russ in the post on side planking, indicating that there seemed to be a problem in the starboard sheer strake, where the top of the strake had a bulge in it.  This was a correct observation, and thanks to Russ for pointing it out.

 

I think that this type of feedback is one of the real values in starting a build log.  Other modelers can sometimes see things that we can’t, possibly because we’re too close to our model.  I know many people are hesitant to point out issues lest they seem critical, but I welcome this kind of comment – it helps me become a better modeler.

 

I could also see the bulge in the starboard sheer, but I wanted to make sure the correction didn’t cause an issue in the opposite direction.  I also wanted to find any other issues in the run of the sheer.  So I ran chart tape along the sheer, trying to make sure it ran fair regardless of what the sheer actually did.

 

                        

 

The tape did point out the problem that had already been discussed, but it also showed a couple of other areas with the same type of issue.  The following photo shows a similar issue on the port side.

 

                        

 

These issues were corrected by careful sanding, using a hard sanding block.

 

The most difficult part of the bottom planking was bending the garboard strake over a fairly short distance.  The HAER documentation indicates that with the fore-and-aft bottom planking there is no need for staving or a chunk forefoot, and the garboard plank is twisted at the forward end to meet the stem.  This can be seen in the photo on page 238 of ‘Chesapeake Bay Sailing Craft’ by Robert H. Burgess.  It can also be seen in the following photo of Kathryn taken prior to the recent rebuild.

 

                        

 

However, the forefoot was changed during the rebuild, since staving was used instead of twisting the plank.

 

                        

 

Since the model is following the construction shown in the HAER plans, the garboard strake needed to be twisted to the required shape.  After soaking the plank in boiling water it was clamped in place.  A hair dryer was used to accelerate the drying time, and the plank was left clamped until it cooled completely.

 

                        

 

When the bottom planking was completed the chine needed to be rounded to its final shape.  A scraper for this purpose was made from a piece of steel. 

 

                        

 

Using this scraper made shaping the chine fairly straightforward.

 

                        

 

Kathryn still needs more sanding and scraping, followed by priming, before painting can begin.  The outer stem and cutwater also need to be installed and shaped to match the lay of the planking.  The following photos show the current state of the model.

 

                        

 

                        

 

                        

 

                        

 

Hmm - after loading the prior photo I see what looks like an issue with the port side of the sheer strake - it seems to flatten a little.  I'll need to check the model and see if this needs correction.

 

 

                        

 

                        

 

We leave tomorrow for a fairly long road trip (hopefully to cooler temperatures!) so Kathryn will be put aside for a while. 

 

Thanks everyone!

[HIPEXEC]

Have a great trip! This heat is intolerable.

[Mahuna]

Thanks Rich.  I guess the only good thing about the heat is that it makes a great excuse to stay in the shop all day.

[druxey]

Looking more elegant each time you post, Frank. Glad you could correct the run of the sheer. BTW, how do the sheer strakes fair into the stem?

[Mahuna]

Thanks Druxey.  Here are a couple of photos I took of that area.  The top of the sheer strake is at the same height as the top of the cutwater, so it looks like the thicker sheer strake is feathered in to the outer stem.  I think the area above that is actually the log rail and then a covering for the top of the knighthood.  In the photo it looks like a slight bulge that   The width of the aft edge of the outer stem is the same as the hull planking, then tapers forward to the width of the cutwater.

 

 

 

And here's a photo that shows the same area during the rebuild.

 

[russ]

The starboard sheer line looks fantastic. The port looks very good with the one issue you noticed. I see it. Not sure what is causing it. However, the model looks great. The method for carving the chine is a good one. I will file that away for future reference. Good work.

 

Russ

 

 

[MEDDO]

Love the full size pictures for reference.  It's a great comparison.

[Mahuna]

3 hours ago, russ said:

The starboard sheer line looks fantastic. The port looks very good with the one issue you noticed. I see it. Not sure what is causing it. However, the model looks great. The method for carving the chine is a good one. I will file that away for future reference. Good work.

 

Russ

 

 

Hi Russ - thanks.  And thanks again for your vigilance - keep it up!  I checked out the model from a lot of different angles, and don't really see any issues with the port side - very strange.  I'll keep looking when I'm back to work on it in a week or so.

[Mahuna]

2 hours ago, MEDDO said:

Love the full size pictures for reference.  It's a great comparison.

Thanks Michael.  The photos come in very handy - I don't think I'd be able to get the same results with only the HAER drawings.  I'm glad I was able to spend a little time on Kathryn when she was docked in Deal Island a couple of years ago - although I wish I had taken photos of some other items that I hadn't thought of at the time.

[Elia]

Frank,

 

I've been following along, hitting the the 'like' button alot.. and just have to pipe up to say your hull framing, planking, and fairing are superb.  Very very sharp work.  I find Kathryn's hull framing and planking a fascinating alternative to what I've seen on other Skipjacks. 

 

Elia

[Mahuna]

2 hours ago, Elia said:

Frank,

 

I've been following along, hitting the the 'like' button alot.. and just have to pipe up to say your hull framing, planking, and fairing are superb.  Very very sharp work.  I find Kathryn's hull framing and planking a fascinating alternative to what I've seen on other Skipjacks. 

 

Elia

 

Thanks Elia - Kathryn's framing is unique among skipjacks.  There were only a few built like Kathryn and she's the sole survivor.

 

[usedtosail]

The model looks fantastic so far. Very nice framing and planking.

[popeye the sailor]

every time I come in lately,  I get stuck in the kit forum........I've finally gotten the chance to see what going on in here today.   I missed a lot Frank......catching up was fun though    man,  you made a lot of progress.....the inner nad outer hull is looking great!   outer planking superbly done.......really very nice!