Small World Models 1/96th Blueback Kit Restoration

[gantu]

here some pictures.

[thor]

Hi Gantu! I sent you a PM.

[thor]

Due to the nature of the construction of the Blueback hull masters I have been forced to glue both halves together permanently to stabilize the halves. The hull is covered in hundreds of small cracks that will all need to be addressed or this hull pattern will never survive the molding process. As I have been working on cleaning up the scribing the cracks have continued to propagate.



Both halves have been machined down to establish a flat surface. Unfortunately, the patterns were not even close to flat. Both halves were cupped and twisted. I machined about .015" off each half to get them as close as possible to being flat in preparation to being re-joined to its other half.




Both hull halves were indexed and drilled to install a 1/8" alignment pin. This will allow easy re-locating each half when the adhesive is applied.














Here epoxy thickened with Cab-O-Sil is applied to the lower half.

















Both halves are now ready for gluing.




The two hull halves were placed together and LIGHTLY clamped. Great care must be taken here as the ren-shape masters are already full of cracks. Applying too much pressure will create more!

[thor]

If you look closely, you can see some of the more severe cracks and checking. These can be fixed but it is a very labor-intensive effort. To fix these cracks I will thin down some 3-hour epoxy to allow it to penetrate the surface and into the tiny open voids in the cracks. The thinned epoxy will be rubbed vigorously by hand into the cracks, then the surface will be wiped down to remove any excess epoxy. After a quick wipe, the hull will be placed into a pressure chamber and allowed to sit for 24 hrs. at 30 psig. This will assure that the epoxy will be driven deep into the cracks to fill and stabilize them from the bottom up. This may need to be repeated a few times to get these deficiencies taken care of permanently.


Here is a shot of a couple of the more severe and deep cracks.













This is the most prevalent form of cracking (checking) on the surface of the upper hull half. It covers about 70% of the upper hull. Because of this large chunks of the surface coating have popped off on me as I have attempted to clean up some of the scribing. To continue the restoration of this pattern requires complete stabilization of the surface coating before progressing further.

[thor]

Here is the latest update as of 12/21/2023

After three applications of thinned epoxy and overnight stays in the pressure chamber at 30 psig to drive the epoxy deep into the hundreds of cracks we now have a VERY solid BLUEBACK hull master. The cracks are all secured and surface filled with Nitrostan putty.










I decided to fill in the sail indent in the hull. It was more trouble than it was worth and is a pain to incorporate into the final molded product. In the background you can see the first 3D printed Sail for BLUEBACK. It is just a test shot to examine the 3D model for print quality. It still has a lot of detail to be added before completion, but it looks really good so far and is right on for dimensions.








Next job is to tackle this train wreck of a bow. The bow is missing a bit of detail from age and handling abuse. It will be all re-scribed and finished. The raised detail on this bow will be restored with paint masks and heavy build primer.



Here she sits with the sail sitting atop the hull.



There is not a lot left to the hull for restoration other than securing the aft tail cone which be presented in epoxy glass and be secured to the lower hull half. That glacier of a polyurethane resin stern will be eliminated for good. This will provide a much more robust stern and eliminate a very fragile joint that used to exist between the urethane stern cone and the glass hull.

I will document that here, then it will be off to the mold shop! I hope to have these kits available through Bob Martin at the Nautilus Drydocks in early March. So far, we are right on schedule.

[oldsubs]

This process is amazing. Most folks, I think, do not think of the detailed molding and materials knowledge that must go in to building an accurate, detailed mold master. A far cry from what I perceived as a wood, plastic and bondo process. Thanks for posting this.

[thor]

Here I am addressing that "train wreck" of a bow. I have decided to perform a "Skin Graft" by removing the lower section of the bow by Dremel and replace the damaged portions with an all-new pre-scribed skin of epoxy glass. But first a mold had to be made in order to be able to produce the replacement "skin".

The following series of photos shows the progression of steps to get to the final step of placing the "Skin Graft" in place. It fits very nicely, but I need to produce an identical skin to be modified to fit the top. At that time both "skin grafts" will be set in place to check for interferences, adjusted, then fixed permanently in place with a thickened resin-cabosil mixture applied in a very even and thin coat.

[wlambing]

I dunno, I kinda liked the red nose!!! Reminiscent of the "Brown-nose" the 637s had after they got their GRP sonar domes in the 80s. USN called the paint black, but it was brown!! Much like they think dress blues are Navy Blue, but they are black. I guess just a hazard of allowing certain officers to have an opinion, much like the uniform changes the USN has undergone in the past 50 years!

[thor]

Its been quite a while since I posted an update and there is a very good reason for it. As I was comparing the original Small World Models Blueback hull to the plans and the measurements gathered at the Museum it became readily apparent that I had a big problem on my hands. The original pattern is a very nice representation of the Blueback but it is not accurate. That was driving me nuts so I thought about the various means of correcting the hull and after a lot of thought I decided to get to work on CAD and produce an all new hull for this boat. I am into week 6 of the CAD work for this boat and it is about finished. I am laying out the scribe lines on the hull pattern which will be resin printed in full size in 8K resolution. Here are a few images from the 3D model as it stand as of today, Saturday March 16th, 2024.

[thor]

As you can see the level of detail that will be with this kit will far exceed any kit I have ever done to date. The 8K resolution in printing allows a level of detail that is not even possible with injection molding without breaking parts up into assemblies. The new hull pattern will be 3D printed at 8K resolution so all of the incredible detail can be accurately captured. Molds will be pulled off of the 3D printed hull pattern.

At this point the schedule has slipped a bit due to the complete re-tooling of this kit, but I think it is worth it. I expect the kits to be released sometime in Mid-June 2024.

The sail, scopes & shears, and appendages will all be carbon fiber reinforced resin printed 3D parts (figure that one out!). The all-new propeller will be a beautiful brass propeller with a 1/8" bore with set screw. The kit hull will be produced in epoxy glass as all of my previous kits have been produced.

We just ordered a very large format 14K resolution printer that will allow us to print tiny rivets, screw heads, and all sorts of insane detail that were not possible previously except in photo etched brass.

[sam reichart]

Hey Matt. That level of detail looks amazing. I had no idea there was anything in 14K resolution. I think it’s going to b an amazing version of this boat.

BTW, we’re relocated. Been here for just over two weeks. We’re exhausted. This shit is for young people.

[thor]

Thanks, Sam! I'll post some photos of 3D printed sail, scopes/shears & appendages later this week. The hull will begin the resin printing process this coming weekend.

I'm glad to know you completed your move safely! Moving is no fun.

[thor]

Here is a photo of the first print of the snorkel. All the the masts plug into an internal plate for mounting. The entire sail is hollow and printed in one-piece including the vented mounting plate inside the sail.

The second photo is of the very first print of the Blueback sail with some of the masts/scopes mounted. You can see the new 1/96th scale SSN-637 Sturgeon sail behind the Blueback sail. Both prints were the first test shots and still need some adjustment but they look good for a first print. The bridge of the Blueback sail has been revised since this image was taken to add more detail.

[wlambing]

Niceeeee!!!!!!

[thor]

Thanks, Bill!

I worked on the bow and upper deck scribing a bit this morning. Here is where it is as of today, March 18th, 2024. I should have all of the scribing wrapped up by the weekend so the hull can be split into a bow and stern section for 3D Resin Printing. These will then be joined to form an all-new master pattern for molding to produce the epoxy glass kit hulls from.