Ace-Garageguy

Comes in a double-sealed bag, contents of the smallest one would occupy roughly a 6"X6"x6" cube. And it doesn't take much at all to make the goo. I usually mix on a gram scale to get repeatable performance, but that's really not necessary.

https://laptrinhx.com/news/the-army-says-it-s-made-significant-improvements-to-its-troubled-new-infantry-squad-vehicle-B6J98ND/ "The second, even more scathing assessment of the ISV from the Pentagon’s DOT&E office was published in 2022 and detailed “major failures” including a loss of steering control, cracked and bent seat frames, engine cracks, and overheating that occurred during operations in cross-country and wooded terrain."

This is where I buy it. You might be able to get smaller quantities from an RC airplane supplier. https://www.aircraftspruce.com/catalog/cmpages/bubbles.php

Arranged marriages may or may not result in lasting love.

Yes, it's a fair bit of money to commit to filler you may only use a small amount of...and you have to buy microballoon too (Aircraft Spruce is my supplier). You can TRY Bob Smith 30-minute epoxy for a lot less money, and it's routinely filled with microballoon for lightweight filler on RC planes. I have NOT tested it, however, and have no idea how well it will accept scribing. https://bsi-inc.com/hobby/slow_cure.html

Well see, if you have rainbow-dyed hair, know nothing about real-world materials or fasteners or much of anything that you can't do with your phone, and come from a "diverse" background, you don't have to think about stuff like driving screws into a pressure hull that has to withstand roughly 6000 pounds per square inch. That's for old fogeys.

HUBRIS

You're missing the point entirely. I stated it above. This kind of stupidity has the potential to affect everyone who relies on anything made by somebody else.

It hardly smells at all. Really. And because it cures all the way through by polymerization, you can do thick fills. On a model, usually one fill is enough.

Everyone has opinions. I've done considerable testing. If you really want a stable, tough-enough to withstand scribing new lines without flaking off, easy-to-sand filler with no shrinkage and excellent adhesion, I recommend West 105/205 epoxy, thickened with microballoon. It's used as a lightweight filler on sport/experimental aircraft because of its superior performance. EDIT: If you're in a big hurry, forget it. It takes 12 hours to cure to the point it can be sanded and scribed. Below, I've used it over styrene inserts in the engine cover, to backdate the car to the non-supercharged configuration. Finished...and it still looks like this 11 years later. It's also tough enough to accept scribed lines, even very close together...without edge-flaking or breaking up...as shown on the Challenger roof extension below. NO other filler, in my experience, will do this.

Dedication to the truth is necessary if one wants to be a responsible citizen, but it's not a popular position.

https://www.pressherald.com/2023/06/24/bridge-over-yellowstone-river-collapses-sending-freight-train-into-waters-below/

Ultrasonic testing is SOP in the aerospace and other industries that depend on high-performance composite structures. It's well known technology, and continues to evolve rapidly due to the proliferation of composite applications. A brief overview, with some of the issues and limitations explained. https://www.sciencedirect.com/science/article/pii/S2588840420300342 https://www.compositesworld.com/articles/how-ultrasonic-testing-can-find-flaws-in-composite-materials NDT (non-destructive testing) methods for composite materials https://www.sciencedirect.com/science/article/pii/S2452321616000093 Ultrasonic NDT of composite materials, an overview https://www.sciencedirect.com/science/article/abs/pii/S2214785322074296

Ignorance, meet hubris. Y'all have a lot in common, so let's see what you can come up with together. Oops, sorry. It's pretty obvious you guys have been working together hand-in-hand since the dawn of Man.

Wow.

This unfortunate occurrence also brings into focus a disturbing push by the new-mo-better-don't-need-no-fogeys-tellin'-us-nothin engineering community to do away entirely with physical prototypes, and rely solely on computer modeling for testing...going straight from CAD/CAE to production. Can you say "stupid", boys and girls? EDIT: And now I see the internet is awash in "experts" condemning carbon fiber out of hand as being unsuitable for submersibles...the typical talking-out-their-backsides-rebleaters with probably no more real-world experience with the stuff than putting a poorly-made carbon hood on their fartcan-equipped clapped out Civic, and seeing it shatter when they drove into somebody while texting.

They say "Imitation is the most sincere form of flattery". Designed and shown here in 2013 "Designed" by some YT clown in 2020 All I can say is "what took you so long, bozo?"

Nothing in the least controversial to ignite a firestorm here. Just stating facts.

"Retired" I've been for seven years, but I continue to work almost every day in two of my "prior" professions.

EDIT: For those not following the news, debris from the instantaneous catastrophic failure last Sunday of a small submarine taking sightseers 13,000 feet under the ocean surface to visit the remains of Titanic was located on Thursday, all occupants presumed lost QUOTING FROM https://techcrunch.com/2023/06/20/a-whistleblower-raised-safety-concerns-about-oceangates-submersible-in-2018-then-he-was-fired/ "The director of marine operations at OceanGate, the company whose submersible went missing Sunday on an expedition to the Titanic in the North Atlantic, was fired after raising concerns about its first-of-a-kind carbon fiber hull and other systems before its maiden voyage, according to a filing in a 2018 lawsuit first reported by Insider and New Republic. David Lochridge was terminated in January 2018 after presenting a scathing quality control report on the vessel to OceanGate’s senior management, including founder and CEO Stockton Rush, who is on board the missing vessel. According to a court filing by Lochridge, the preamble to his report read: “Now is the time to properly address items that may pose a safety risk to personnel. Verbal communication of the key items I have addressed in my attached document have been dismissed on several occasions, so I feel now I must make this report so there is an official record in place.” The report detailed “numerous issues that posed serious safety concerns,” according to the filing. These included Lochridge’s worry that “visible flaws” in the carbon fiber supplied to OceanGate raised the risk of small flaws expanding into larger tears during “pressure cycling.” These are the huge pressure changes that the submersible would experience as it made its way and from the deep ocean floor. He noted that a previously tested scale model of the hull had “prevalent flaws.” Carbon fiber composites can be stronger and lighter than steel, making a submersible naturally buoyant. But they can also be prone to sudden failure under stress. The hull that Lochridge was writing about was made by Spencer Composites, the only company to have previously made a carbon fiber hull for a manned submersible. (That submersible was commissioned by explorer Steve Fossett for a record-breaking dive, but he died in a light aircraft crash before it could be used.) Lochridge’s recommendation was that non-destructive testing of the Titan’s hull was necessary to ensure a “solid and safe product.” The filing states that Lochridge was told that such testing was impossible, and that OceanGate would instead rely on its much touted acoustic monitoring system. The company claims this technology, developed in-house, uses acoustic sensors to listen for the tell-tale sounds of carbon fibers in the hull deteriorating to provide “early warning detection for the pilot with enough time to arrest the descent and safely return to surface.” Lochridge, however, worried in the lawsuit that the system would not reveal flaws until the vessel was descending, and then might only provide “milliseconds” of warning before a catastrophic implosion." END QUOTE (read the rest of the article at the link provided above) I've worked with composite materials in engineering and fabrication capacities for decades on and off. Anyone familiar with carbon fiber knows 2 things: 1) though it's very good in tension (where the pressure would be coming from INSIDE a pressure vessel, like compressed gas tanks), it's not so hot in compression (where the pressure would be coming from OUTSIDE a pressure vessel, like a submarine hull), and 2) although very strong up to their design limits, carbon structures are inherently brittle, and when they fail, they do so instantly, literally shattering, with almost no yield or deformation prior to catastrophic failure, unlike the behavior exhibited by most metals. Anyone familiar with composite structures is also aware that small defects in a composite laminate can propagate within the structure over repeated cycling, leading to eventual catastrophic failure at well below the design loading. Quoting another source, an engineer for a company that's designed and built numerous submersibles using carbon: https://www.designnews.com/industry/carbon-fiber-safe-submersibles-when-properly-applied "The key is diligence in designing and testing the composite structures, Hogoboom explained. “We have a very high confidence in the strength of what’s been built,” he said. “We use engineering models, but we test to failure to validate what’s been modeled. That’s a crucial step that OceanGate has skipped," according to Hogoboom. “They never brought an exact clone to failure.”" END QUOTE Looks like the OceanGate company head, quoted as saying he didn't want experienced "50 year old white guys" on staff because they're not "inspirational" might have been mistaken about that. https://www.breitbart.com/tech/2023/06/21/oceangate-ceo-didnt-hire-50-year-old-white-guys-for-titanic-sub-because-theyre-not-inspirational/ Yup, I'm pretty inspired.

Logic, eh?