USS Cape (MSI-2) by Dr PR - 1:48 - Inshore Minesweeper

[TBlack]

I got an idea! If no one knew what you were looking for, you could have found anything on the bottom and claimed victory. Sort of like my Naval experience. But that’s another story!

[Dr PR]

While many of my fellow Americans are having nachos and beer while watching dumjoks chase rubber balls (which I find boring) on New Years Day I have been working on the fiddly bits on the hull while waiting for some boxwood to arrive to make the stern frame around the propeller and rudder.

 

Older wooden sailing ships rarely had deliberate openings in the hulls below the waterline, so there is nothing there to model. But steam and diesel powered vessels have a variety of hull openings, or seachests, that do give us something to model. The original MSI hull had 13 openings (Austin Cox told me he added another for new accommodations). Some were intakes for taking in sea water and the others were various overboard discharges.

 

The intakes for engine cooling water and fire pumps are the most interesting.

 

 

The openings were surrounded by 3 5/8 inch (92 mm) thick wooden "plows" that were tapered fore and aft to facilitate water flow. An odd thing about these is that they were beveled around the edges with the widest dimensions on the surface away from the hull planking, and not mating to the planking. They were "upside down" trapezoids with the narrow side against the hull plating (see Section "3-BI" above). I'm sure there was some reason for this, but it just seems odd to me.

 

Here is how I made these seachests (see photo below). The plows should be 0.078 inch (1.98 mm) thick at 1:48 scale. I don't have any stock that thick (but some a lot thicker) so they were made of 1/16 inch (1.59 mm) thick basswood with 1/32 inch 0.79 mm) thick plywood glued to the back side. That comes out to 0.94 inch (2.38 mm) thick, so I will have to sand them down a bit.

 

The plywood serves a double purpose. The smaller plow has a large hole for the seachest grating that comes close to the sides. While trying to cut out the opening the basswood piece broke. But with the plywood glued to the back the pieces came together again and I was able to finish the opening.

 

The gratings were cut from very fine HO scale (1:87) brass vent screens for the sides of a GMC F3 diesel engine that I just happened to have in my scrap box. As you can see from the blueprint the grating actually had a series of long, narrow parallel openings, but at 1:48 they would be difficult to create with photo etch.

 

The grating was spot soldered to the end of a 9/32 inch (7.14 mm) outside diameter brass tube ring, and that was soldered into a short piece of 5/16 inch (7.94 mm) OD brass tube. These assemblies were pressed into the holes in the wood.

 

 

I drilled small holes into the hull about equal to the scale inside diameter of the piping in the original ships, and then used a counter sink bit to make the openings conical, as shown in the blueprints.

 

After the plows were glued in place on the hull I painted the inside if the recess black, and then glued the grating assemblies into the holes in the plows. I used Duco Cement because I have found it adheres to both wood and metal.

 

If you look closely you will see that I did not bevel the edges of the plows undercut as shown in the blueprints. I think this would make the exposed edges of the basswood vulnerable to damage. And in most circumstances these seachests won't even be visible! Why ask for trouble?

 

 

The remaining 10 seachests were ordinary pipes with flanges attached to the outside of the hull planking.

 

There were six different sizes on the ships, but i don't have a wide enough variety of brass tubing to make them all. Using commercial "telescoping" brass tubing I could make four sizes that are close to scale to the originals.

 

For some I soldered two concentric rings around the end of the center tube to make wide flanges, and some had just one ring for narrower flanges. These were then turned in an electric drill and ground down with files to a flange thickness of about 0.020 - 0.023 inches (0.51 - 0.58 mm).

 

Some of this tubing has been in my junk box for decades and is heavily oxidized and scratched. However, this doesn't matter because only the outer face of the flange will be visible after the seachests are in place.

 

 

Here are some photos of these seachests mounted in the hull.

 

 

There is a bit of dust in the openings - I will need to clear that before the hull is painted. But before that the flanges will be filed/sanded a bit thinner to a scale thickness of 1/2 inch (12.7 mm), or 0.01 inch (0.26 mm) at 1:48. All of the seachests will be painted when I get around to that.

 

That is about all of the hull detail below the main deck except for the stern frame. I won't have the boxwood for that for a week or two. So I guess now I will have to guzzle beer and munch nachos while watching a movie.

 

And I will have to start planning the deck house and all of the minesweeping gear that crowds the after deck.

Edited Wednesday at 11:30 PM by Dr PR

[Jim Lad]

Very nice, Phil!

 

John

[KeithAug]

Nice work on all those hull penetrations Phil. It's very nice when the junk box gives up its treasures, somehow it makes all the years of hoarding worthwhile.

[Dr PR]

Oops! Wrong again! I thought there was nothing more to do on the hull until the wood for the stern frame arrived. But I forgot about the bronze stem chafing plate and those wooden lining boards on the hull to protect it from anchors, pigs and such.

 

 

The stem chafing piece is shown in green. I will make it from thin brass sheet. I have several thicknesses in stock, but I think I'll use some 0.005 inch (0.127 mm) pieces in my scrap box. It is pretty easy to work with.

 

The lining boards were a problem. They are not mentioned in the blueprints, so I guess they were added later after wear was appearing on the hull planks. Fortunately I have quite a few photos of the USS Cape MSI-2 and I can see where the linings were located. There was a lot more than I originally thought. The lining planks are shown in red in the drawing above. Note: there seem to be some differences from the linings visible in USS Cove MSI-1 photos.

 

At the bow the linings extended down to the keel - this is evident in the photos Austin Cox sent of the current Cape on blocks. The anchor could bang against the hull here as it was being lowered and raised.

 

From photos of the Cape afloat I can only see the other linings extending down to the boot topping. I am guessing the linings didn't extend much lower because the hull sides curve under at these places and the pigs (floats) wouldn't go very deep. The kites and acoustic sounder could be lowered deeper but would be hanging out over the side. The entire hull did have a thin third outer planking of red oak below the water line and this would provide some protection.

 

I counted the planks in several photos, especially the bow photos, and determined them to be about 4 inches (104 mm) wide. That would be 0.085 inches (2.16 mm) at 1:48 scale. The closest commercially available wood is 3/32 inch (0.094 inch or 2.38 mm) wide. Fortunately, I just ordered 28 feet (8.5 meters) of 3/32 x 1/32 inch boxwood strips. I will need a few feet for trim on the deck house, and the rest was just to replenish stock. Looks like I will have enough for the lining planks!

 

And while looking for drawings of the chafing piece and linings I found one showing 12" x 6" x 1 1/4" (304.8 x 152.4 x 31.75 mm) zinc bars at places on the hull. I knew about the zincs on the stern frame and rudder. But there are two zincs on the "plow" for the engine and fire water intakes! A bit more detail to add.

Edited Thursday at 11:12 PM by Dr PR

[Dr PR]

I cut the stem bands from some 0.003 inch (0.76 mm) brass sheet. The metal can be cut with scissors and is easy to shape. But first I needed to decide what the shape would be.

 

 

 

 

 

Here is the blueprint showing the outline of the stem bands. There are side pieces on either side of the stem. You can follow the vertical left side from the top outline down through the planking detail (red line) to where this edge meets the curvature of the stem.

 

From there it only shows a dashed line down to the keel foot. It shows a curved top end where it turns down to the foot.

 

Notice also the upper stem band, the narrow stem band along the forward edge of the stem, and the lower stem band at the bottom. I have already installed the narrow band along the front of the stem. I will need to add the upper and lower pieces after the side bands have been shaped.

 

One other thing to notice is the cross section "V" shapes of the stem. This will become relevant in the discussion below.

 

 

 

The first problem was the shape of the lower end. Austin Cox's photos show a squared off aft end of the side bands. He thinks these bronze pieces are original material.

 

I decided to go with what is shown in the photo of the real hull and put a squared off aft end to the side bands. The drawing (below) shows the dimensions (in inches) of the side pieces. However, when I cut out the pieces I left some extra material on the forward edges. This makes the exact positioning while gluing less precise. The extra will be removed after the side bands are glued in place.

 

 

First I cut out a paper test piece and fitted it to the hull. I expected to have to make some adjustments to fit the model hull, but the paper part fit perfectly!

 

I scratched the inner surfaces of the brass with number 80 sand paper to provide some "tooth" for the glue to adhere to. Then I shaped the pieces to fit the form of the hull (above).

 

I used Duco Cement (a solution of nitrocellulose in acetone) to attach the brass pieces to the hull.  That was a mistake! I have used this glue to attach small brass pieces to wood and it works nicely. But these larger parts had problems.

 

But first I had to hold the parts in place while the glue set - that takes several minutes. When I tried to apply the clamps shown in the photo that "V" shaped front of the stem caused the clamps to slip on the smooth brass surface and pop off the front edge. And they also squeezed the strip, causing it to slip on the wet glue and slide out of place.

 

So I was constantly picking up clamps and putting them back on, while I also pushed the brass strips back into position. As fast as I replaced one clamp another popped off. It was like the Whack-A-Mole game!

 

I eventually found a set of positions where the clamps would stay in place and could relax. I let the glue set overnight, and then removed the clamps. But when I tried shaping the leading edge to remove the extra material the brass strips pulled loose! To make matters worse, one of the brass pieces was damaged while trying to hold things together!!

 

Arrrggghhhhh!

 

To be honest, I thought there was a "small" chance of this happening. I wasn't certain that the Duco Cement was the best choice. So had thought about another option.

 

Plan B

 

When in doubt, use Epoxy! I scraped the glue from the brass pieces and the wooden hull. Then I made another brass piece, and it actually came out better than the first after forming it to fit the hull. They say practice makes perfect.

 

Then mixed up some 15 minute Epoxy. I coated the inner surface of one piece and the mating surface on the hull with thin coats of epoxy and stuck them together. The epoxy was thick enough to hold the brass piece in place while I tried to attach the clamps. The camp at the top - where the hull surfaces are parallel - went on easily. The same is true at the bottom aft end of the piece. But once again it was Whack-A-Mole with the remaining clamps.

 

But this time it was easier. The epoxy was quite messy and I got some on the outer surface of the brass piece when it squeezed out between the parts. The epoxy was much stickier than the Duco Cement, and it actually retarded the slipping of the clamps. The longer it set the stickier it got, and it was trying to glue the clamps to the brass. They still slipped slowly, and I could watch them slipping closer and closer to the leading edge of the stem. So I could catch them when they snapped off and reposition them immediately. After 10-15 minutes they were all holding in place. A couple hours later I repeated the process with the other side.

 

 

 

Persistence pays off and I now have brass stem bands on the model. The epoxy did a much better job of gluing brass to wood and the parts do not want to pull apart!

 

I did have to scrape, file and sand off quite a bit of the epoxy that had squeezed from between the pieces. Then I used files to smooth some small wrinkles and bumps in the brass. That was followed by fine grit sandpaper and #0000 steel wool.

 

I will allow it to set over night, and then I will file back the extra material on the leading edge to match the narrow brass strip on the front edge of the stem.

 

I'll add the top and bottom stem band pieces after that and it will be ready for the anchor lining strips at the bow.

 

There is a very complex shape for the bow chock that fits on top of the stem. Right now I don't know how I will make that. But if carving the the stern frame from boxwood turns out OK I may also carve the bow chock and the other chocks from boxwood.

 

If all else fails I can make a 3D CAD model and 3D print them. But I am really trying to avoid using 3D printed materials because I do not know how stable they will be in the long run.

Edited 5 hours ago by Dr PR

[Jim Lad]

Epoxy is always my fall back option when i have something difficult to glue!

 

That bow is looking good, Phil.

 

John

[Dr PR]

John,

 

Thanks.

 

I have relearned that lesson!

 

Epoxy is a bit more trouble to mix, and certainly less spontaneous than just grabbing a tube of whatever happens to be laying around. But it would have been quicker to use the epoxy in the first place!