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

[Mahuna]

Thanks Popeye.  Some skipjacks have a pulley mounted on the side wall of the hatch just in front of the cabin, but Kathryn's aft hatch seems to be too far inboard for that configuration.   

[EdT]

Lovely work as usual, Frank.

 

The tackle looks much better now.  One thing to keep in mind: the length of the tackle itself should be somewhat longer than the required length of travel to raise the centerboard to allow the full travel without the tackle becoming block on block.

 

 

 

Ed

[Mahuna]

Thanks, Ed.  Yeah, I measured the centerboard travel and tried to allow that and more in the tackle movement. 

[Mahuna]

Part 59 – Pushboat Davits

 

Kathryn has a pair of fairly complex davits for carrying the push boat, or yawl boat. The davits are still configured as they were during the HAER survey, but recently the color has changed.  When I first saw Kathryn in the fall of 2015 after her recent rebuild, the davits were painted an aluminum color – probably with Rust Oleum paint.  Then when I visited in the fall of last year, I found that they had been changed to a glossy black.

 

The HAER drawings show a lot of the details of the davits, and the photos in the book “Working Skipjacks of Deal Island” also show a lot of the details.

 

The following are a few photos of the davit configuration.

 

The first is from the HAER files, taken at the time of the 1995 survey.  It doesn’t show a lot of details, but it does indicate that the aluminum color was used back then.

 

                        

 

The following two photos are from 2015, and show a little more of the details.  The forward part of the davit is not straight, but is configured from two separate pieces.  There is a cleat arrangement in the forward third of the davit.  This cleat is used for tying up when Kathryn is docked.  

 

                    

 

There is an electric winch attached to each davit, aft of the cleats (I still haven’t decided whether I’ll try to duplicate this feature).  Aft of the winch there is an angled configuration on the top of the davit, presumably to provide additional strength.

 

                        

 

The following two photos are from 2017, after the color change.  There are two uprights under the angled configuration, one of which is vertical and one is angled towards the push boat.

 

                        

 

There is another support that runs from approximately the center of the transom out to the davits.

 

                        

 

Construction of the davits started with the development of a jig that would hold the main pieces at the appropriate angles.  The jig was made from Corian, and grooves fitting the dimensions of the davits (3/32 square brass rod on the model) were cut on the milling machine. (Please ignore the lines that look like hatches – they’re from a different jig.)

 

                        

 

The brass pieces were cut to length and the appropriate angles were shaped using a disk sander.

 

                        

 

The pieces were held in the jig using miniature machinist clamps.  The large clamp on the left is used to hold the jig steady, and the alligator clip on the right is part of the resistance soldering setup.

 

                        

 

The following photo shows the davit frames after soldering.

 

                        

 

The cleats needed to be fabricated next.  A small jig was made from some square brass rod, to ensure consistency of the shape.

 

                        

 

1/32 brass rod was softened by annealing and then was pressed into the jig to achieve the desired shape.

 

                        

 

The bottom of the cleats was flattened with a file to ensure a solid connection to the davit.

 

                        

 

                        

 

                        

 

Pieces of scrap brass of the proper thickness were used to allow clamping of the cleat without distorting its shape.

 

                        

 

After soldering, the legs of the cleats were cut to final length and the ends were shaped using a file.

 

                        

 

The angled brace was made next.  A jig was made from wood scraps for each side (two jigs required because the soldering heat might deform or destroy the jig).

 

                        

 

Two pieces of 3/64” round rod were held in the jig (the ends had been shaped to an angle that allowed the two pieces to fit securely together), and a piece of 3/64” square rod was used as the upright.

 

The following photo shows the jig being held for soldering.  The jaws on the right are from a vise grip, mounted in a bench vise and holding the jig.

 

                        

 

This soldering step formed the triangle shape and the upright as a single piece.  The piece was then cut down to the final size, using a rotary tool.  After sizing and shaping, the piece was soldered to the davits using the following clamping arrangement.

 

                        

 

The copper alligator clips are holding the legs of the triangle in place, while the middle alligator clip is keeping a wet piece of paper towel over the previously made solder joint to keep it from loosening.  The alligator clip on the far right is from the resistance soldering setup. Each leg of the triangle piece was soldered to the davit using this setup.

 

                        

 

Sockets are needed on the davits to securely hold the different uprights that will be part of the final installation.  These sockets were made from 3/32” square tube that had one side ground off, and cut to 3/32” pieces.

 

                        

 

Some of these sockets will be added to the davit in the area of existing solder connections.  The use of a wet paper towel as above isn’t practical because of the proximity of the socket to an existing solder connection, so a different approach to protecting the existing solder connection was needed.

 

There is a product called ‘Kool Jool’ that I found a while back on a jewelry supply site. Its intended use is to prevent the heat from soldering affecting stones set in a piece of jewelry.  I had not previously used the product, but I thought this might be a good solution to the problem.

 

                        

 

The following photo shows the soldering setup with the Kool Jool protecting the previous connections.  A strip of scrap wood was run through the opening in the sockets, and this allowed holding the sockets in place.

 

                        

 

The product worked very well – there was no loosening of the existing connections.

 

                        

 

There are still some decisions that need to be made about the davits on the model.

 

            Will the electric winches be on the model?

 

            Will I add a pulley that can be seen on the underside of the davit?

 

            Most importantly, how will the davits be colored to match the aluminum color?

 

So I’m not sure what will follow next – continue work on the davits, or set them aside and work on something else while I work out some issues.

 

Stay tuned to find out!

 

 

[popeye the sailor]

davits look great Frank!   

[Mahuna]

17 hours ago, popeye the sailor said:

davits look great Frank!   

Thanks Popeye.  Still lots of work left on them.

[Mahuna]

Part 60 – Pushboat Davits cont’d

 

In the last post, I mentioned that there were still some decisions that needed to be made about the davits on the model.

 

            Will the electric winches be on the model?

 

            Will I add a pulley that can be seen on the underside of the davit?

 

            Most importantly, how will the davits be colored to match the aluminum color?

 

I decided that the winches should be on the model, since they were present during the HAER review and I had already decided that the model should look like Kathryn looked during the review.

 

I did add the pulleys for the same reason.

 

And, after some internet searches on painting brass, I found some good information from a couple of model railroading forums, and I found some Tamiya paint that would provide the look that I wanted.

 

First – the electric winches.  By the way, I noticed in the ‘Working Skipjacks’ book that there are photos of the pushboat being hauled by the crew without using the winches.  I got in touch with Kathryn’s owner and asked him why this was so.  He said that even though the winches are supposed to run off battery power they often don’t work – probably because of water getting into them.

 

The following is a photo of one of Kathryn’s winches.

 

                        

 

Using the length of the winch measured from the HAER drawings I was able to estimate the various dimensions of the winch using this photo.  I actually made two sets of winches - I needed to make the second set because the first set wound up being to fat. Most of the following photos showing the winch fabrication are actually from that first set, but the process was still basically the same.

 

The final set of winches were made from 3/16” brass rod, and were ½” long.

 

The first step was to reduce the top end of the rod to the dimension of the drum on the top of the winch (1/8” on the model).

 

                        

 

A center drill was then used to hollow out the drum. The cutting area of the center drill includes a sloped shoulder that can be used as a countersink.  This served to hollow out the drum in a cone shape.

 

                        

 

                        

 

The drum is concave, and a round file was used to get this shape.

 

                        

 

                        

 

There is a flange just below the drum, which is used to mount the winch.  This flange was cut using the parting tool.  Most of the cuts on the winch were so small that this was the tool used for most of the cutting.

 

                        

 

The body of the winch is the thickest part, so this was separated out next.

 

                        

 

The middle of this body area is narrow, and there are a number of bolts visible.  The middle of the body was reduced. 

 

                        

 

 

Drilling holes for inserting simulated bolts was unsuccessful (broken drill bits), so grooves were cut into the rings of the body so that small rods could be used to simulate the bolts.  This was done on the rotary table of the milling machine (held vertically).

 

                        

 

The bolts were made using .0195 brass rod, which were soldered in place.

 

                        

 

In the above photo the Kool Jool mentioned in the last post was used to protect solder connections.

 

The following photo shows the finished winches.

 

                        

 

Painting, along with installation of the davits, will be covered in the next post.

 

Thanks everyone, for the likes and comments.

 

Edited May 19, 2018 by Mahuna

[Mahuna]

Part 61 – Pushboat Davits cont’d

 

The brass parts of the davits were painted because it was very difficult to get a uniform light color using the JAX Flemish Black.

 

The painting process consists of the following steps (any handling of the brass parts is done while wearing latex gloves to keep from getting body oils on the brass):

 

First, clean the brass part by soaking in lacquer thinner for 30 minutes.

 

Next, scrub the part with soapy water and rinse thoroughly.

 

Then soak the brass part in white vinegar for an hour or so. This slightly etches the part to provide ‘tooth’ so the paint will adhere.  Rinse the part thoroughly after this step.

 

 

Paint with a primer – Tamiya grey primer was used for this step.  Let the primer cure overnight.

 

 

In the above photo, the winches are held in place by two-sided tape.

 

Paint with the final color.  I used Bare Metal in a spray can from Tamiya.  Again, let the paint cure overnight.

 

 

As a final step, I sprayed a coat of Dullcoat on the parts.  This helps protect the finish, and eliminates any glossy appearance.

 

After all of the parts were painted, the davits were ready for installation.  A jig was used to ensure that the davits were set at the proper angle as shown in the HAER drawings, and that they extended far enough to properly support the pushboat.

 

The first photo shows a drawing, glued to thin plywood, that was used to lay out the davits.

 

                        

 

The jig shown in the following photo was used to support the davits.

 

                        

The jig was made so that a crossbar would support the ends of the davits at the appropriate height, and the wood pieces extending forward from the vertical post ensured that the jig was at the proper distance from the outside edge of the cap rail.  The weight at the base of the jig ensured that the jig was held in place during the assembly process.

 

Two small seats were made to support the forward end of the davits at deck height.  These seats were made from 1/8” square brass tube with 1/32” posts for insertion in the deck.

 

                        

 

                        

 

The davits were epoxied into the deck seats and the aft ends of the davits were clamped in place.

 

                        

 

A perpendicular strut holds each davit in place.  These were epoxied to the aft ledge and to the forward bracket on the davit.

 

                        

 

Another vertical strut slants from the aft bracket on the davit to a point adjacent to the perpendicular strut, and was epoxied in place.

 

                        

 

Finally, diagonal struts were epoxied from the middle bracket to a point adjacent to the pushboat bumper.  (The epoxy shown in these photos was later cleaned up and painted over.)

 

                        

 

The electric winches were hung from brackets that had been made from 1/8” brass angles milled to take the round body of the winch.

 

                        

 

The new pulleys can be seen just aft of the winches.

 

Finally, a crosspiece connects the two davits.

 

                        

 

A ‘lazy board’ is installed on top of the crosspiece.

 

                        

 

                        

 

A good friend from the Chesapeake area told me the name of the board: 

“As usual no one knows why, but one old timer told me if you felt lazy you could lie down on it [pretty precarious perch I think.]   (there is a photo somewhere of a guy doing that.)  Another said it provided a lazy-man's way to get in and out of the push boat.  He did not tell me the non-lazy way.”

 

This completes the installation of the davits, although some cleanup of the epoxy and some painting touch-up still remains.

 

This was a fairly complex installation that I was concerned about, but I’m pleased with the results.  I’m not sure when I’ll hang the pushboat from the davits – I still need to decide whether to make my own blocks or to use commercially available ones (likely from Syren) for the rest of the rigging.  Meanwhile, there is quite a bit of metalworking still ahead – including the propeller for the pushboat.

 

Thanks everyone!

 

 

 

 

[usedtosail]

Those winches and davits look great. Good job!

[Mahuna]

Thanks Tom.  I'm happy with the progress.

 

 

[Mahuna]

Part 62 – Pushboat Propeller

 

I decided to go ahead and try my luck at making a propeller for the pushboat.

 

An image search on the web gave me lots of choices. After importing a photo of a propeller into CAD I traced the outline of one blade and marked off the position of the blades.

 

                        

 

5 small pieces of .010 brass sheet were glued together using Ambroid glue.  When the stack cured the drawing of a blade was glued to the stack of brass sheets and the shape of the blade was then cut out using a jewelers saw, followed by final shaping using a rotary tool and files.  The stack was then separated into individual blades by a brief bath in acetone. (Sorry, no photos of this process).

 

The shaft of the propeller was made from 3/32” brass rod, with the forward end reduced to 1/16” to fit into the keel.

 

                        

 

The slots for the blades needed to be cut into the shaft at 120 degree intervals, and at the same time the slots needed to be made at an angle of 24 degrees off center.  

 

The 120 degree intervals could be achieved by mounting the shaft in a collet held by a six-sided indexing block mounted on a milling vise, and repositioning the block for each 120 degrees.  

 

The 24 degree cut would be made by using a rotating base for the milling vise.

 

The following photo shows this setup.

 

                        

 

I planned to use a .010 slotting saw sitting vertically and mounted on the mill.  When I tilted the mill head to a horizontal position, however, there was not enough clearance under the mill’s head assembly for the mill vise to travel. Fortunately, when I had purchased the used Sherline setup a few years ago, one of the items included in the purchase was something called a Horizontal Milling Conversion (which I never thought I’d need).  This allowed me remove the column and the head assembly from the X-Y table, which provided plenty of clearance for the work.

 

                        

For soldering the blades to the shaft, the indexing block assembly was held in a bench vise and soldered using the setup shown in the following photo.

 

                        

 

The propeller was cleaned and polished.

 

                        

 

And was then blackened with JAX Brown-Black applied with a brush.

 

                        

 

After drilling an appropriate hole in the pushboat keel the propeller assembly was glued in place using CA glue.

 

                        

 

Thanks everyone!

[GuntherMT]

Great work on the setup to make the propeller Frank, came out great!

[Mahuna]

Hi Brian - great to hear from you.  Yeah, it sometimes takes much more time to come up with the right setup than it takes to actually execute the milling - but it's worth it!

[cog]

Do you take orders?

Marvelous propeller. Do you leave it blackened or will you give it another colour?

[thibaultron]

Great work on the propeller! All your machining is top notch!

[popeye the sailor]

super job on the davits and winches........ a very nice bit of metal work.   looking at the picture of the winch,  I can see why he had such a poor review of them

note the rot hole in the bottom housing.......surly due from water getting in there     actually.......looking at this particular winch......it looks more hydraulic,  than electrical.   you did a super job imitating them.   the prop look very nice as well     wonderful progress! 

[Mahuna]

8 hours ago, cog said:

Do you take orders?

Marvelous propeller. Do you leave it blackened or will you give it another colour?

Thanks Carl.  I'm leaving the prop as is.  I think the only other look I'd want would be a bronze color.  And I would take orders, but I don't think you'd like my hourly rate!

 

1 hour ago, thibaultron said:

Great work on the propeller! All your machining is top notch!

Thanks Ron.  When I first got the machining setup I was pretty intimidated by it, but now I'm enjoying the challenge.

 

Hi Popeye - thanks for the kind words.  You're right about the winch - they don't look like they're in very good shape.  I'm pretty sure they're electric - in some of the photos I can see how the electric cables run to them from the batteries.

 

[usedtosail]

Beautiful prop, Frank. When you rotate the index block in the vice to drill the second and third slots, how did you set the same depth to the saw blade as the first cut? I am very new to machining, as you can probably tell.

[Mahuna]

Good question, Tom.  The rod was held by a collet mounted in the index block, so essentially this combination was one solid workpiece.  I tried aligning the back of the index block with the back side of the vise by eye, but this wasn't very accurate.  I wound up holding a parallel bar against the back side of the vise and sliding the index block back until it touched the parallel bar.  This gave me the repeatable position of the cut.

Edited May 23, 2018 by Mahuna

[usedtosail]

Nice. Thanks Frank.

[HIPEXEC]

Frank, you are a master in art of model ship building. Excellent work.

[Mahuna]

Thanks, Rich.  But I'm not a 'master', just a modeler who's trying to get better.

[Mahuna]

Part 63 – Dredge Rollers

 

Kathryn has dredge rollers that are configured like the typical skipjack’s rollers.  The supports for the rollers are fairly complex, and I decided to model them as close as possible to the actual supports.

 

The forward support is constructed so that it wraps around the aft part of the forward railings, and the top of the support is slightly lower than the top of the railing.  The axis of the roller fits into a notch in a plate on top of the support, and there is an extended piece that prevents the roller from slipping out of its support.

 

                        

 

The aft roller encases the entire railing configuration, and the axis of the roller fits into the front of the support.  At the top of the aft support there is a slanted piece that supports the vertical roller.

 

                        

 

Each of the supports has an inboard triangular brace.

 

                        

 

                        

 

On the model, the main part, or body, of each support was made the same way – as a single piece folded over to encase the rail. First, an appropriate sized piece of brass strip (1/8” x .025”) was scored where the folds would occur.

 

                        

 

These scores were used to register a small triangular file that was used to open up the scores.

 

                        

 

After annealing the strip it was clamped in the vise and bent, then hammered, to make a 90 degree bend.

 

                        

 

The strip was then clamped to a 5/32” x 1/8” square tube (the width of the rail is 5/32”) and bent and hammered.  This corner wound up being slightly rounded – probably unavoidable.

 

                        

 

The workpiece was then held in a jig made of Corian, and the base was soldered onto the body.

 

                        

 

The following photo shows the body of the forward support test-fitted to the railing.

 

                        

 

A small piece of 1/8” x .025” strip was soldered to the top of the forward support body in order to form the vertical piece that the roller axis rests in.

 

                        

 

Still clamped in the jig, the vertical piece was shaped to fit the contours of the support body, using a rotary tool and files, and the notch in the vertical piece was made using a small round escapement file.

 

                        

 

                        

 

The extension for securing the roller was then soldered in place.

 

                        

 

                        

 

This completed the forward supports for the dredge rollers.

 

 

As can be seen in the above photo, the constant test fitting of the support has resulted in some marring and dirtying of the painted surface.  This will need to be cleaned up before final installation of the supports.

 

The body of the aft support was made the same way, with the addition of a front plate that was soldered to the body after bending was completed.

 

                        

 

The triangular inboard support was added to all four of the supports, using the following setup for soldering.  The heavy block on top of the ‘third hand’ is to ensure that the piece makes full contact with both the bottom and the vertical surfaces of the support.

 

                        

 

The angled piece on the aft roller support, for supporting the vertical roller, was made from a piece of brass angle, and was shaped to conform to the support body.  The forward and aft supports can be seen in the following photos.

 

                        

 

                        

 

The rollers shown in the HAER drawings, and in a photo taken at about the same time as the HAER survey, shows sleeves at both the fore and aft ends of the rollers.

 

                        

 

Although these sleeves could have been turned on the lathe, it was much simpler to make them out of tubes that would fit over the roller bodies and each other.

 

                        

 

The roller bodies (1/8” brass rod) were drilled with a center drill and then drilled to take the axis pieces (3/64” brass rod).

 

                        

 

                        

 

The rollers were test-fitted to the supports.

 

                        

 

The sleeves were then soldered to the rollers.

 

                        

 

The dredge rollers are now ready for blackening, and for the installation of the aft vertical rollers.

 

                        

 

                        

 

                        

 

I love the look of the clean brass, but in keeping with my plan to make the model look as much as possible like the real Kathryn, the brass will be (dis)colored. 

 

I feel like I should apologize for this long post and the many photos, but I wanted to show the process as complete as possible.  The next post will complete the installation of the dredge rollers.

Edited May 26, 2018 by Mahuna

[albert]

Fantastic work Frank.

[thibaultron]

Frank. They say "The Devil is in the details!". Keep up with Your level of details! Fantastic work and a great build thread!

[Jack12477]

I wish this thread had been available when I was struggling to build the roller for my Willie Bennett model. Likewise your explanation of the construction of the davits for the pusher boat. Nice work, Frank, and great explanation of the process. Your level of detail is perfect.

Edited May 26, 2018 by Jack12477

[Mahuna]

Thanks Albert, Ron, and Jack.

 

The HAER drawings are a great source of detail. In addition I have lots of photos I've taken during my two visits to Kathryn, and I also have some older photos provided by a friend.  All of this has been extremely helpful in deciding what to model on Kathryn and how to do it.     

[Omega1234]

Hi Frank

 

I’m just catching up after a few busy weeks...and..boy, am I not disappointed!

 

As usual, everything that you do is totally top notch, from the propeller to the intricacies of the winch.

 

Nice...very nice...indeed.

 

Cheers. 

 

Patrick

 

[Thistle17]

Frank your work is an inspiration and to me as well as many others I imagine. Metal work is not one of my strong points so your detailed photos are quite instructional to me. If I haven't mentioned I am especially fond of skipjacks so it is a delight to follow the progress.

Joe

 

[Mahuna]

3 hours ago, Omega1234 said:

Hi Frank

 

I’m just catching up after a few busy weeks...and..boy, am I not disappointed!

 

As usual, everything that you do is totally top notch, from the propeller to the intricacies of the winch.

 

Nice...very nice...indeed.

 

Cheers. 

 

Patrick

 

Hi Patrick - welcome back!  It's been a fairly productive short spell for me, and I'm pleased with the results.

 

2 hours ago, Thistle17 said:

Frank your work is an inspiration and to me as well as many others I imagine. Metal work is not one of my strong points so your detailed photos are quite instructional to me. If I haven't mentioned I am especially fond of skipjacks so it is a delight to follow the progress.

Joe

 

Hi Joe - thanks for the kind words.  It has taken a while but I'm fairly comfortable with metal work now.  Skipjacks are beautiful working craft and are a unique part of the American nautical heritage.  I'd love to see one of the annual skipjack races.