Revell Gato 1/72 scale build

[salmon]

Cleaned up the white metal parts following the DVD (again a ton of tips and instruction).


A sprue was pulled over a flame and bent to give me a hook to dip the parts into ferric chloride acid. This will etch the metal and give a good hold to the primer paint.


Then you need to neutralize the acid. This is done with water and baking soda (or sodium bicarbonate). I saturated the water solution by adding baking soda until no more could dissolve and a small amount settled at the bottom. When you dip your etched piece it will bubble as the acid and basic solution react with one another.


Here is the contrast you can see. The darker parts on the right are the ones that have been etched.


Began to install the propellor shaft strut. There is an indentation were the plastic part would connect that I used to open a hole that closely matched the metal strut. Looks O.K., there is a little play for alignment with the shaft.


Marking where the stern tube exits the hull is pretty simple, just use the plastic part that came with the kit and trace around it. I marked also where the shaft stern tube ends with tape, so I can have some semblance of symmetry.


Then slowly begin to cut out the area for the shaft support struts and shaft stern tubes. I am not sure how many times I stopped to check, but this will take awhile.


Glue the shaft support with a bit of CA. Later we will fill more with CA and baking soda (sodium bicarbonate).

Insert, I made mine too parallel. Because of that David made a special pair of driveshafts to fit. Here is another crayon drawing of what I mean.

So when you build yours, keep an eye out for this. There will be steps later that I had to do additional steps to get it to work.



For now, lets move onto the bow planes.
Using a bud burr, I channeled out the area for the pins.

[salmon]

Checked out that the route that was cut for the 1/16” brass rods was deep enough.

You will notice there was also holes drilled in the edge closest to the sub for a shorter rod.

Glued them together and once dried hand drilled out the holes to clean out any glue or alignment issues due to sanding.


Temporarily installed the dive planes, checked the movement, and found that I did not make the oval big enough - grrrr. O.K. not that big of an issue just in disassembling the retract fell off. If I mounted the retract system too low it would lose mesh in the gears when the dive planes are up. Mounting the retract system higher up solved that problem.



Mounting the assembly for making the planes rise and lower, I found that mounting it higher gave me better range of motion.


I noticed one pin that goes through one of the bow plane operating shafts was slightly crooked and I had some resistance in the bore of the bow plane shaft and wanted to ream it out a little too. After disassembling the dive planes, I noticed there is a slight angle in the bow plane operating shafts ends that receive the dive plane and I installed it BACKWARDS. Once I rolled them over and facing the correct way, everything fit better and I got the 90 degree angle on the bow planes I was looking for.
Here is a drawing with exaggerated angles to demonstrate what I mean.


With that corrected, I get complete deployment of planes.


You might be able to see it here, the blue/green piece that the plane attaches to has a few degrees angle. And that angle runs parallel with the angle of the hull at that point.


Now the plane has room to move and my resistance disappeared, so the movement is smooth retracting and deploying. My range of up or down bow planes increased because the planes were not hitting the hull.

[salmon]

Also had great range on up or down motion.


In an effort not to repeat installing them wrong again, I marked them left top and right top (should be port and starboard, I know...) Also another benefit the plane hugs the side of the hull better, before the forward edge seemed to stick out a little (thats because it did - amazing what a few degrees can do).


I went ahead and worked on preparing the bow planes for priming. I CA’d the pin in and made sure enough CA was applied to coat all surfaces. Went ahead and sprinkled with baking soda then clean off the lose baking powder to see the coverage. This exposed areas that the CA did not get into and so I filled as needed. Then filed, ground, sanded the pins down to contour the dive plane.



I originally was going to put a clevis in, but when it broke, a Z bend was mention to be "better" for this install. Who am I to second guess.

I must agree that it was a better choice. Later I will share another great tool.

Time to attach the skag/propellor strut. I glued just the strut part, the very most forward area. Then cut an angle in that would offer an additional holding factor. Maybe the picture will make more sense. The rear portion of the skag hooks under the glued front. Marked where I wanted the screws to go.


One area had nothing to support the screw.


So.... break out the sprue. I melted the sprue and quickly flattened it. Then sanded and ground it down to fit. Applied a generous amount of cohesive to the sprue and surrounding areas.


When I cut the sprue off, I left a small amount above the skag. Then I drilled .063” hole and threaded a stainless steel 2-56 3/8” screw in. It WAS just that easy. I thought I was going to have to buy a tap to get a thread in, but I was told something different. Thank you David for sharing that tip! In retrospect next time I would drill a 1/16” then follow that with .063” 3/4th the way through. Leaving the last 1/4 the more tighter grip on the threads. It may not matter, just a thought for next time.

[salmon]

Put it all together and tested range of movement of the rudder and planes. It works!



I sometimes over think things and other times I do not think it through enough. Take the deck for example. Since I will be removing many of the cross braces in the superstructure, I thought glue the deck first on a flat surface, since the deck is flat from the photos and drawings I looked at. So, I broke out the wax paper and placed the deck upside down to glue. Note, the deck supplied in the kit is not flat there are “things” protruding up (well down now that I flipped it over). I over came that by angling the protrusions off the edge of the table. And applying cohesive glue to it. Held it flat and weighed it down. Then added the support pieces to strengthen the joint.


The part I did not think about so much is glue leaking (I did put wax paper down). I slopped on a lot of glue with the center and aft section. Well here is another shame picture....


But when I did the bow I was less liberal in the amount of glue (at first) then gradually added more. This worked better.


The side pieces are not glued yet, but I have very small spaces between the bow and midsection.


I am relatively sure I can fix my shame deck section, so once painted you will not see it. Let us keep that as a secret or better yet, forget about it altogether

[salmon]

Back to the aft planes/rudder/et al.
After playing with the rudder,testing fit, and preparing to paint, the brass rod came loose from the rudder and would pivot. So I needed to do few things. I marked where the brass entered and exited the rudder and skag piece. Roughed up the brass where it will be buried in the rudder and kept the areas that touch the bearings smooth. I tested out the fit and drilled a very small hole just outside where the brass rod was traveling. Then I took a 1/16” drill and drilled the hole again. What was accomplished is I cut a notch out of the rudder shaft. Once the shaft is glued in, I will put a pin in to keep it locked in place. I put the shaft in, but leaving just the distance from the bottom of the rudder to the first bearing in the skag. Placed a drop of CA at the hole of the rudder (holding the aft upside down it will be the top) and at the point where the rod enters the rudder after leaving the bearing. Quickly pushed the rod to the correct spot and wiggled the skag to make sure it did not get glued. Then I put a length of 1/16” brass rod in as my pin. Cut the rod close to the rudder, CA’d it, and put baking powder over it to harden.


Filed and sanded the pin flush.


Once it all dried I tested again to see if there is any slip or issues and there were none.


There is just enough play with the skag and rudder to get over the sprue filler. Had I made it taller, there would be another shame picture to show as I try to cut the sprue filler off.


I also cut a flat surface on the rudder shaft for the control horn’s set screw. You might be able to see it through the aft torpedo opening.


I got the shaft support, shaft tube, shaft installed. I used the D&E propellor for distance when I was adjusting it.

[salmon]

Got a moment? Lets talk about props. Here is a selection of props for the Gato. The plastic kit one measuring 32 mm, a brass prop that I got when I purchased a gentleman’s wtc and assorted pieces measuring 31.5 mm (looks like they just cast the model’s prop) by G Factor (part number 17202), a D&E white metal prop measuring just a hair short of 35mm looks like it is 34.9 mm that comes with the Gato fittings kit, and finally a Raboesch prop (A Type Ref: 147/11 and 147/12 for left and right) measuring about 35 mm maybe the same as D&E. While I was torn, I knew David did his homework, but I liked Raboesch being brass. So, I went with Raboesch.


Here is the 1:1 scale with dive planes extended.

[salmon]

Moving back to deck construction, now that I knew what cross members I would not have, I place the deck on the hull and checked fit. It did not bow down and held its shape. I still will add a reinforcement of some type - working on ideas for that.
So time to add the front vent plates. Before I could glue them, I needed to remove the forward portion of the pin receptacles. I want to be able to slide the deck forward and have several areas engage to hold the deck down. So I drilled, cut, shaped, trimmed, and tested the cutouts to the corresponding pins until with a small amount of resistance it slid in.



A closer look


Now is the time to use cohesive on the part to commit my idea.
I had to be creative here to get the fit I wanted. So using toothpicks as little leverages, I adjusted the fit of the side to the deck. Some toothpicks were placed to move the top of the vent outward.


and others were to lift the piece just enough.



Now came the test to see if it would work. My first couple of tugs the deck did not slide. GRRRRR! I took a deep breath and rather than rip it apart, I gently tried again....it came apart just the way it was supposed to! After a brief dance around the room (definitely no photos of that), I went ahead and added some side reinforcement.



Reattached the top to make sure it works the way it should and it did again. There is a click when it engages. Not sure if I need to open the sides a little more or leave it and give it time to either grow on me or push me to fix.


I am pleased with the results. There is a gap at the bow, but I can fill that and narrow the space.

[salmon]

The deck at the bow had an ever so slight lift to it. I went ahead and added the clip from the D&E fittings package. To do this I marked where it needs to go measuring from my cross members forward edge. Then transferred that distance to my deck underside. Used the clip to see what areas I needed to sand for a base. I roughed up the under side of the deck and the bottom of the clip and used thicker CA. Aligned it and in moments it was set. I was going to use both clips, but the back one would hit my plane control system.


Then came testing time. It really helped secure the bow and take away the little lift that was going on.



The Gato slopes and narrows near the bow, the WTC will lift if left as it is. So, to over come this lift (and to allow it to move a little more forward, the sides of the end cap needs to be beveled.
Mark where the end cap hits the side and before it begins to lift up.


The little bit of shaping I did, to account for the curve of the hull, made a big difference in distance or range of travel forward. There are two vertical lines the one to the left is without doing any shaping. The line on the right is from placing a bevel around the edge. The lip is about 1/8" and I trimmed it down to 1/16" or half way and tapered towards the center of the cap about 3/32" to 1/8" depending on where the hull contacted the end cap the most.


I might be able to squeeze even more forward range if I get extra aggressive on the taper. I will wait on doing that after my drive shafts are in and see how much room I need. There is something really incredible just seeing the wtc in the hull.



The inside corners of the deck had received a liberal amount of cohesive and was allowed time to dry and now it is time to reinforce the joints on the inside.Once a dat or two had passed, ran thicker CA to reinforce the joints. Also put in a tab to help the side line up with the bow.


Then, using thin CA and baking soda, filled in the gap. I plan to make sure the CA gets a good coat of primer to seal it. I have read that it can absorb water and not hold, not sure if it is true.


My clip did not do everything that I wanted it to do. The very bottom stuck out slightly.


So to fix that, I cut out a smaller clip near the bow flood holes.


Trimmed the length of the larger clip and the corner of the smaller one.

[salmon]

Erich, do you see all that I learned from you?
That is why, I think, posting your build and the steps is so important. It takes time, but someone else may see it and be willing to try something new. Thank you Erich!

Going to do some cosmetic work on the deck and hull.
Filling the seams with Nitro-Stan is just one of those things.I was a little heavy handed on application, because of that I had to do more sanding. So, lesson, less is better LOL



And fixing the deck mess I made is another (my priorities are still to get the submarine done). Here is the deck with the glue that leaked onto it and filled holes and grooves.


I began with .0145” drill bit and drilled the holes out. Not too deep, but maybe 3 or four turns drilling in and 6 turns counter clockwise to remove loose plastic bits. Then moved to .024” drill to make the hole closer to the size of the other holes on the deck. For this, I went one full turn drilling in and three or four going out. I used my engraving tool to recreate the filled in grooves and clean out the partially filled ones. Here is how it came out.


Here are the tools I used.

[salmon]

Next came the flood holes.
Credit needs to go to Scott Trosper and Crazy Ivan. Scott Trosper has worked on the pattern from several years ago (I believe he work on it with Crazy Ivan if I remember one thread I read correctly), I found his pattern on SubCommittee at Scott's members webpage and then another gentleman (Eric Moody) sent me the same pattern. When I looked through some of David's cabal reports, I saw this pattern in one of the pictures of David's build ( It looked like he used the pattern at one time) and David mentioned Scott's name in a post somewhere and that is what sent me searching for Scott's web page. Anyway that is the web of how I came to use it (oh and fueled by me trying to save a dollar).


I printed the plan to scale and marked my hull in sections and labeled the pattern the same, beginning at the bow.


Bob at rc-submarine.com has stick on patterns on his clearance list......you may want to pick them up.

They are a different pattern than the ones I used. So go with which ever one you wish. I will say this, after doing the work I did, go with the stick-ons. I am not going crazy on accuracy here, so I do not know if one pattern is more appropriate for the Gato I am building or not. I am trying to save a dollar here and there, but the time it took to cleanup the glue, I think the few dollars the pattern costs is minimal. However, if you like to go the hard road (like I seem to do) well buckle up - you are in for a ride. (note: I have yet to have anyone look at the bottom of my sub and say that is not or is the correct pattern. I am not sure how I would react if someone did LOL)


I use to do home brewing and bottle my own beer (there is a point to this digression). Then create labels for the bottles. One way of attaching the labels to the bottles is using milk. The reason for using milk is when you wash the bottles the label will separate easily and the stickiness of milk worked well as a adhesive. Do you know where I am going with this? Yep, Hey why not use it for the flood hole pattern?



I was tickled with myself, but that euphoric feeling quickly dissipated (or evaporated) by the time I got to the aft end. The bow pattern just lifted off - it was in the shape of my hull, but useless for what I wanted. It must work on glass because of the smooth surface or I have defective cow's milk.
My son had been doing his school work near by and I spotted white glue. That will work.



One section at a time, I glued and applied the pattern being careful to line up the seam on the keel with the pattern’s mid-line.


Not as euphoric, but glad it was done. Even that satisfaction did not last. These popped off as well!

Now I am ticked (well mildly aggravated). Got the CA thin and glued these on. That worked!
I drilled a small hole as a pilot hole for a larger drill. Then followed up with a drill that was smaller than the diameter of the pattern, pick one any one. At this point I used CA and touched the edge of the hole and let the capillary action draw the adhesive between the pattern and the hull. If I was to do this again, I would try tacking the pattern down the keel only, drill a hole and glue at the hole. This might localize the adhesive to a local area.
I used a jewelers saw with a wide throat to cut out the bulk of the plastic. The blade I put on was a spiral wax blade. This blade is twisted with the idea that you can cut in any direction. It is designed cutting patterns and rings off of wax stock. Since plastic is really soft, this blade worked real well. It is a rougher cut so do not get too close the the edge, if at all possible.



The holes look ugly, but that was the whole idea of drilling smaller than the pattern, cutting with the twisted blade, and leaving room for finishing. I used half-round files to clean up the holes. Then came the time to remove the paper. What a BIG mess and a pain in my ....... you get the idea. I had CA release and applied that to a test area to make sure it did not melt the plastic, it did not. So I kept adding the CA solvent and scraping, I will not repeat the same line over again, but 2 hours later, I got this much done. Still have the bow and aft to do.



Overall, not too bad. I will tackle the rest tomorrow. I also made a pattern with brass to clean up the holes and use to fill where needed.


I was told by a gentleman that the milk thing works even better with a little vinegar: http://chemistry.about.com/cs/howtos...uefrommilk.htm

Maybe next time.

[wlambing]

Tom,

The big oval holes you made weren't holes on the 1:1 scale. They were flapper valves for the fuel ballast tanks. Good thread though!!!

B^)

[Ralph --- SSBN 598]

Wlambing, this has peeked my curiosity.

You have make me do more research.

https://maritime.org/doc/fleetsub/chap4.htm#fig4-1

If I read this correctly, the flapper valves are sort of a Kingston valve.
When filled with fuel oil the valve is closed and uses a compensation water system to keep the tank full as fuel oil is used up.

These ballast tanks use to hold fuel oil are not open to sea at the bottom under way while there is s till fuel oil available.

Would you have or can you direct me to a photo of these closed valves?

[salmon]

Bill,
Thank you!
You are right, but at the time I knew not and I like the extra openings. When putting a couple of my subs in, it takes a moment for water to come into the hull. The Gato is ready to go once in.
Please share more because it helps us all!
Peace,
Tom

[salmon]

Ralph, I have a photo somewhere, but maybe Bill does or someone else. I will check and get back to you.

[salmon]

Completing the deck fastening.

Placing David's upper deck foundation part and checked fit. Before I drilled, assuming I know where the hole is to be placed, I wanted to mark the hole that the screw would come into the inside and see how it lined up.


Using a mechanical pencil, pushed out a long segment of graphite.


Then placed the pencil into the hole were the screw would go and moved the pencil around until I felt like I had a good mark (center of red circle).


The upper deck foundation piece lined up perfectly. Here you can see the hole that Revell has placed for the rear flag mast.


Using a 1/16” drill, I drilled out the hole.


Put the screw in and the upper deck foundation. It lined up perfectly. I think David might know what he is doing.


The kit comes with a slotted 2-56 machine screw, I personally like Phillips and so I replaced the screw. It is 1/32” smaller diameter head and I wanted to save the weight that David’s screw would have added plus scale wise the Phillips is 2.25” smaller (tongue placed firmly inside cheek).


I roughed up the areas with sandpaper and CA’d the upper deck foundation onto the hull.


Time to counter sink the hole. I used a hart bur about the size of the screw head counter sunk the hole.



Placed the deck on and secured it with the screw!