barnstormerboats

Hi Everyone,

As Promised, I am going to show you all how we build a fighting ship From start to finish. I hope you will all find this thread interesting and educational.

This Prinz Eugen was sold Ready to fight and so we are laying up a two tone hull with dark red antifouling below the waterline. We start by taping off the mold above the waterline. Then we have to custom mix the color. We stock bright shades of primary and secondary colors, but a bright red underbelly would not be right. So we mix the gel with some red and black pigment to get the color the proper dark red. Because this is going to get a second color, the gel for the underside is mixed very hot with a 2.5% catalyst rate. That will allow us to spray the grey over it without risking running colors.

After spraying in the gel, the tape is pulled right away to get a clean line where the color change is. If we let the gel set up before pulling the tape, the gel would pull, chip and peel away leaving a ragged edge. So then the mold is re-taped at the flange on top in prep for the grey. Battleship grey is a standard color we stock so no mixing is needed.

After the grey is sprayed in, the tape is left on the flange to allow any glass or resin that ends up there during the lamination of the hull to be easily removed.

One single "skin" is applied to the mold after the gel is set up and allowed to cure before we place an extra layer in the bottom and thick fiberglass ropes are laid in on the armor belt to assure the proper shape is retained after the combat window are cut out. An extra belt of glass is added at the top of the hull sides to hold the shape until the deck is attached.

After the glass sets up in the molds for 48 hours the hull is pulled and looks great! The deck was already in stock so it is shown set in place on the hull.

More to come.....

markswihart

Hi Tim,
I got your message on the jet boat, to be honest I haven't made any more progress on it. I've been focusing all my attention and $$ to the 1/96 scale combat (I've made grate progress on the Yamato) also all the ponds are still frozen or the ice is just going out. I don't have anyone in my area that races so there's not a big push to get it finished (It will be done sometime this summer though) Some of the ponds up here also restrict the use of nitro powered boats because of noise and pollution
What or how should the plugs be made for the 1/96 scale ships? Some are quite large, how should they be sent? And will you make the main decks for them also?
Mark

barnstormerboats

Now with the hull and deck done, we need to install the stuffing tube and rudder. I dry fit the motor and rudder first then drill the stuffing tube hole from the inside of the hull to assure the hole will lie above the keel glass and not eat into it. The rudder gets centered just enough aft of the prop to allow prop changes. These are both just set in place for the layout before drilling the holes and are quickly removed to allow open access to cutting windows. I would rather not have them mounted in the when the grinding dust starts flying or the resin starts flowing.

The deck will go on after the windows are cut so that we can use the windows to work a good glass seam into the hull deck joint. Trying to join them before the combat windows or if you do not plan on fighting means a bead of bondo around the deck lip in areas you will not be able to reach or see enough to lay glass.

I will be laying out the widows in tape to be a guide for cutting. More on that later......

02WRX

My Feedback: (2)

YEAH!!! Looks awesome Tim!

Just thought of something. Is the 1/700 Tamiya Prinz Eugen kit's paint accurate? Is it too late to add the camo lines??

barnstormerboats

The main hull needed only to be two toned because of the need for the penetrable skins on the sides. We need to cut ballistic windows in the hull. The final finish will be on the skins that seal the windows.

We start with the math. This boat is 57" long so it gets 15% of impenetrable surface which means about 8" of hard surface per side. The bow gets 2" and the tail gets an inch so that leaves 5.5" of ribs per side. ribs can be a maximum of 3/8" thick and must be no less than 1" apart. SO I worked out a rib scheme to have the smallest spacing and thickest ribs in the ends with more spacing and thinner ribs in the midsection. This will beef up the armor in the ends where you will try to keep your enemy vessels aligned with the cannons.

Really focus on laying out the ribs with marker or tape until you are happy with it.

By laying out the one inch spacing in the ends the windows are too small for my large grinder to get into and I want to make sure they align perfectly with the armor belt inside the hull. So, I mark the hull with tape. Start by defining the bottom of your windows at 1" below the waterline merging to the 45º turn in the chine at the stern. Then solidly tape off the 2" bow and 1" stern sections the will remain uncut. Add a 1/8" deck level stringer line and hold the hull up to the light to see where the armor belt is so you can avoid cutting it.

Once you have your pattern of window laid out, Drill the corners of the smaller windows followed by a pattern of holes inside the perimeter of the window. Then you can cut it out by walking the drill bit from hole to hole until the center drops out. Then clean up the edges with 36 grit paper or a rotary file. Try to bevel your ribs to be thicker inside the hull to give the ribs more strength than the surface area they are limited to. Once I get to the larger broadside windows I will switch to my grinder.

More soon.

barnstormerboats

The windows are all cut now. The larger windows would allow me to make cuts with my grinder wheel. I will still drill the corners and sides to broach them more cleanly. This is the worst part of fiberglass work - MAKING DUST. I wear a mask and work in a very well ventilated booth, but still feel itchy all over. Can't wait to hop in the shower. Just wanted to post the pics of the fully cut hull so you can see the scope of the work.

The closer ribs in the ends will help define the shape of the skins and the flatter surfaces amidships can handle the spread since the armor belt runs the length of the hull giving the design a significant advantage at fending off waterline hits.

The deck is still uncut. I want to clean up all the dust in the hull before setting the motor and rudder in place. Then I will create bulkheads that will mount the Co2 tank, bilge pump, cannons, and radio gear. I am considering the options of mounting the cannon and radio gear directly to the deck and making the entire deck removable. That would allow for excellent access to the complete model but might leak around the edge if it cannot be sealed and stay sealed when the ship takes damage.

More on that tomorrow......

barnstormerboats

With all the cutting done, its time to layout the guts of this boat. My first concern is keeping the weight centered in the boat as tight as possible. This will give the boat a much better moment of inertia and thus faster turning boat. (much like an Ice Skater who spins faster with her arms tight to the body).

I lay out all the major components and check the Center of Gravity. I also weigh this whole boat will all its gear inside to check where I am at. Comes in at under 8#. That is good. It leaves plenty of room for the bulkheads, batteries and superstructure parts. The target dry weight is about 13# with a max combat loaded weight of 14# 9oz.

kotori

Nobody in California believes me when I say this is an important part of ship design. The physics textbooks agree with me, the pond-side evidence agrees with me, but nobody seems to believe me. I compared my Scharnhorst to another one at a battle. The other Scharnhorst was using all three shafts, I was using only the outer two, so he had a better prop-rudder arrangement. Because I had better weight distribution, my ship could turn in half the radius the other ship could.

johnmCA72

I believe you, but I'm not in California so I don't count. I've fought the same sort of battles, so I can relate. Nobody believes me (on a variety of topics), either.

JM

kotori

After a while I stopped talking, figuring that if people don't believe the documented experiments and fundamental physics equations, then I'd better beat it into them with cold steel They flunked my first test so I went on a ten-ship killing spree. I gave them an entire winter building season but it looks like almost everyone in my local club is going to flunk again. Oh well, this time I'm shooting for a twenty-ship killing spree

02WRX

My Feedback: (2)

I want to be there for that!!

barnstormerboats

When I was choosing what combat model ship to offer first, several factors were considered that all pointed to making the Prinz Eugen.

1st I wanted a side flipper so that the model could fight either as an axis or allied ship. The P.E. served most of the war as a German ship, and was taken by the USA as a war prize and served in the Pacific in the closing days of the war.

2nd I wanted a notable ship with historic significance. The P.E. became famous running with the Bismark on her last stand, made the channel dash with the Scharnhorst and Giestenau. It also, covered the retreat of the German army from the Baltic region. Then survived 2 atomic blasts at the Bikini Atoll.

3rd I wanted a ship that would be a good beginner choice with a variety of setup options that would allow my customers the choice of cannon arrangements that would suit them. The P.E. has 8 main guns in 4 turrets 2 forward, & 2 aft. So it can be built with triple stern guns or the fore and aft cannons as this one will be rigged. Also it had 12 torpedo launchers, which allow side mounted ball bearing launchers for the big gun guys.

Lastly, I wanted a nice looking ship with a defined armor belt that would allow a near waterline stringer that will help define its beauty as well as improve its defense. The Prinz Eugen has been called the most beautiful cruiser ever built. With graceful sweeping lines and a well-defined armor belt, It became the perfect choice for Barnstormer Boats first combat ship.

But now with the ballistic windows all cut, the hull becomes very flexible. The hull form must be set with bulkheads. The challenge is to get the bulkheads all set without interrupting the flow of water to the bilge pump. For this purpose, we will set bulkheads that do not set all the way down in the boats bottom (which is plenty strong enough to not need them). A series of bulkheads that will define the hullsides will be installed. They will also act as baffles preventing the sloshing of water fore and aft as the boat maneuvers to escape attackers after sustaining damage.

The first step is to set the center bulkhead. This will also support the Co2 tank. I have a large supply of very thick mixing stick that will serve as bulkheads. I set the first one in place very carefully keeping it below the waterline and trimming the negative angles that that set the shape of the hull below the belt. Once this is dry fit, I glass it in place and draw the ribs to it with strings. I used some scrap dowels to spread this strain out and keep the sides from showing any funky shapes where the strings apply the pressure. This sits overnight to assure the glass is very well cured before I remove the strings and start to install the remaining bulkheads.

More to come….

barnstormerboats

The main bulkhead had to be securely laminated to set the max beam and hold it fast while the rest of the bulkheads (vertical) and thwarts (horizontal) are set. Use 90second epoxy to set them in place quickly. They will be laminated in place all at once later.

Install lower baffle bulkheads at rib locations to set the negative curve of the underwater sections of the ship sides. This may cause the top edge of the deck to warp a bit so we will set a sub-deck in place after we set the bulkheads. The main focus on the lower bulkheads is to draw in the hull at the water line, as the Prinz Eugen was slimmer there than at the bilge turns.

We need to get the sub-deck ready and dry fit it before setting the upper bulkheads and cannon thwarts.

Take the deck and set it on a large flat of cardboard. I have full sheets in the shop, but you could use the box the model came in. Trace the deck edge out on the cardboard. Now cut the sub-deck inside of this trace line by 1/8� all around. This will allow the sub-deck to fit inside the hull and flush with its top edge. Dry fit this into the hull and test fit the deck. Trim as required. The deck is a bit larger than it needs to be so it will get trimmed to a clean fit when the hull is set.

Make 2 upper bulkheads with the ends matching the topsides hull angle that will fit cleanly under the sub-deck and allow it to still be flush on top of them. I install them directly over forward lower and above them motor.

Now with the sub-deck taped in place you should be able to see the beautiful curving form of the hull.

Next come the cannon mounts…….

barnstormerboats

The cannons need to be positioned under the desired turret barbette. In this case #2 turret port side and #4 turret starboard. The aft gun is a 1.5 unit cannon so it has a longer magazine. After the positions for the cannons are marked, thwarts are set on the armor belt stringer to mount them. The thwarts are set aft of the forward mount and forward of the aft mount so that the magazines can be zip tied in place making aiming adjustments possible later. I use masking tape to set the cannons in place to measure against the deck.

Also at this time I would like to set some water dams forward and aft to channel water to the bilge pump. Most bilge pumps will only be effective after 1/8 to 1/4 inch of water is in the bilge. By limiting the surface area of the lowest portion of the bilge. The pump will start bailing quicker and you are then better off with the lightweight foam in the ends and the water in the center.

Install a lower bulkhead ¼� forward of the front baffle. Set the height to the level of the lower window cutouts. Then install two wing bulkheads to the sides of the motor the same way. These will hold the expanding foam to a clean line.

Using 2 part expanding foam is very tricky. The expansion rate is very great and the foam sticks to everything it touches so you have to be very careful. Try mixing small amounts and pouring it in thin lines that will fill into the area you want. Once it starts expanding, DO NOT TOUCH IT. You are better off to let it expand fully, trim it, and mix some more to spot fill.

To trim this, I use a bare hacksaw blade and cut it down to the height of the lower widows. Walk your blade from one widow to another to get inside the ribs. Be careful not to cut any ribs in this process. The foam cuts with very little effort, so if you feel resistance, you might be cutting a rib.

I use the tail ends of the batches to build some floats in the ends. You have to be sure to not add too much foam to the boat as it must be able to sink. That said. I would prefer the boat to sink more like a dandelion seed drifting down into a meadow than a boulder from a cliff. Being a submarine builder helps me set this up with only a slight negative buoyancy with good reserve flotation high in the ends to keep the boat on its keel as she sinks. That can mean the difference between making port or making the swim of shame to recover the wreckage. We will test this before we cover the sides.

Once this is all trimmed, we are ready to glass the bulkheads, thwarts and water channels.

barnstormerboats

In preparation to glass the bulkheads, first check your cannon mountings for fit. You might need to gouge out the foam from the water channeling to allow them clearance. also make sure you have marked your cutouts for the radio and battery boxes so you can know that you are getting enough glass under them to hold without breaking while you cut these later.

Apply strips of glass across the bulkheads and thwarts before cutting the mounting areas for the radio and battery boxes. You want to be able to cut them out low so let the glass hang down past the bottom of the bulkheads to allow this without cutting the bulkhead clean through. The glass should lay out onto as much of the ribs, hull and stringer edges as possible for the strength to transfer to the hull as a whole. Do not worry about being precise with the glass. After it sets up it will get cut off cleanly. If you time it just trim it easily with a razor knife. If you try to trim it too early the glass will rip out of the structure. If you wait too long, it will get too strong to cut with a knife and you will need use a grinder or rotary file.

Also, use this mix of resin to paint the bottom and edges of the cardboard sub-deck. Lay it upside down on a strip of wax paper to allow it to release without ripping. This will stiffen it up and assure a waterproofing that will keep it intact for years to come. Do not try to install it yet, just let the resin soak in and cure. Because this was dry fit already, it should fit perfectly when it cures. You do not need to resin soak the top because we will do that after it is installed.

Once this batch of gell starts to jelly up, rub a thin coat onto the open foam of the water channels If you try to paint resin on it when it is still liquid, It will just keep soaking in. The thin coating of resin will prevent water from soaking in and making your boat heavier over time.

Once the glass sets, you can cut the mount notches for the boxes.

Also before the sub deck is installed, the rudderpost must be extended to get the rudder right in the force of the prop wash. This will get the boat around faster. The post inside had to be cut down to allow the rudder to be positioned properly (because the shaft on the rudder was not long enough. With the tube extended, a dab of epoxy will hold it fast.

once this is cured and trimmed, we will mount the cannon and rudder cable......

Sharky1528

Wow, what happened ?? it was just starting to get good.....

Sharky

barnstormerboats

A lot going on here. This model is farther along than the blog, but got delayed when we had some employee turnover that required I focus on training a new guy. This model will be fighting soon.

Blitz52

can`t wait to see more!

steve

kotori

Hey Barnstormer, any new photos? How's it coming?