Any "poop" on whether these things are safe, what they weigh, etc.? pl
Donate
Browse by category
Recent Comments
- TTG on Open Thread – 17 April 2025
- TTG on “Remembering a Father, Francis”
- TTG on “Remembering a Father, Francis”
- Stephanie on For Easter, the movie Jesus of Nazareth, released in 1977
- jim ticehurst.. on “Remembering a Father, Francis”
Browse archives
- April 2025
- March 2025
- February 2025
- January 2025
- December 2024
- November 2024
- October 2024
- September 2024
- August 2024
- July 2024
- June 2024
- May 2024
- April 2024
- March 2024
- February 2024
- January 2024
- December 2023
- November 2023
- October 2023
- September 2023
- August 2023
- July 2023
- June 2023
- May 2023
- April 2023
- March 2023
- February 2023
- January 2023
- December 2022
- November 2022
- October 2022
- September 2022
- August 2022
- July 2022
- June 2022
- May 2022
- April 2022
- March 2022
- February 2022
- January 2022
- December 2021
- November 2021
- October 2021
- September 2021
- August 2021
- July 2021
- June 2021
- May 2021
- April 2021
- March 2021
- February 2021
- January 2021
- December 2020
- November 2020
- October 2020
- September 2020
- August 2020
- July 2020
- June 2020
- May 2020
- April 2020
- March 2020
- February 2020
- January 2020
- December 2019
- November 2019
- October 2019
- September 2019
- August 2019
- July 2019
- June 2019
- May 2019
- April 2019
- March 2019
- February 2019
- January 2019
- December 2018
- November 2018
- October 2018
- September 2018
- August 2018
- July 2018
- June 2018
- May 2018
- April 2018
- March 2018
- February 2018
- January 2018
- December 2017
- November 2017
- October 2017
- September 2017
- August 2017
- July 2017
- June 2017
- May 2017
- April 2017
- March 2017
- February 2017
- January 2017
- December 2016
- November 2016
- October 2016
- September 2016
- August 2016
- July 2016
- June 2016
- May 2016
- April 2016
- March 2016
- February 2016
- January 2016
- May 2014
- April 2014
- March 2014
- February 2014
- January 2014
- December 2013
- November 2013
- October 2013
- September 2013
- August 2013
- July 2013
- June 2013
- May 2010
- April 2010
- March 2010
- February 2010
- January 2010
- December 2009
- November 2009
- October 2009
- September 2009
- August 2009
- July 2009
- June 2009
- May 2009
- April 2009
- March 2009
- February 2009
- January 2009
- December 2008
- November 2008
- October 2008
- September 2008
- August 2008
- July 2008
- June 2008
- May 2008
- April 2008
- March 2008
- February 2008
- January 2008
- December 2007
- November 2007
- October 2007
- September 2007
- August 2007
- July 2007
- June 2007
- May 2007
- April 2007
- March 2007
- February 2007
- January 2007
- December 2006
- November 2006
- October 2006
- September 2006
- August 2006
- July 2006
- June 2006
- May 2006
- April 2006
- March 2006
- February 2006
- January 2006
- December 2005
- November 2005
- October 2005
- September 2005
- August 2005
- July 2005
RSS
Meta
Fiberglass composite is very strong. In this case it is most likely it is an epoxy resin with a silane coupling agent added to bond to the glass.
Immediate technical issues I can see:
Moisture over the long term can permeate through the resin, and where there is too much water plus mechanical stress, slowly break the molecular bonds made by the coupling agent from the glass to the epoxy (or whatever resin is used). Polymers can take up a surprising amount of water, don’t be surprised to find as much 0.01 % by weight water for some resins.
Polymers degrade under UV radiation (sunlight), get oxidized, and weaken. This is true even of polymers which were cured with ultraviolet radiation. You can add UV protective additives such as carbon black to extend the service life. But it does not seem to be the case in this example.
The composite will be totally inert to propane, and the permeation rate will be negligible.
So. These are fine, but I would not store these examples permanently outside in the sunlight, or floating in water for months at time. I would obey the expiration date religiously.
Watch the videos of hexagon ragasco composite tanks – perfectly safe, light, convenient but pricey.
They are generally a multi-layer composite and blow molded liner. They’ve been around for some time and are DOT approved. Not sure of the cost difference with aluminum or steel tanks. They aren’t going to have corrosion issues, other than non-stainless fittings.
They should be OK, because fiberglass parts, granted cured differently, are widely used in aerospace–either pure fiberglass, or sometimes inter-layered with polyaramids (aka Kevlar)–and withstand surprisingly high loads. Let’s put it this way–in high thousands PSI. Any B-737, 777 or Airbus 320 or 350, or Bombardier or any other modern aircraft contain very many fiberglass parts which are subjected to the extreme conditions of flight and I never heard of them failing.
There was a recall of composite tanks back in 2013, the company in question out of Tennessee called Lite became insolvent, and had the only recall. Its competitors didn’t seem to have the same safety issues.
The 2013 article was updated in 2017
https://www.passagemaker.com/trawler-news/lite-composite-gas-tanks-recalled-company-insolvent
Here was the original recall notice by DOT back in 2013
http://static-passagemaker.s3.amazonaws.com/wp-content/uploads/2013/07/Emergency_Recall_Order_The_Lite_Cylinder_Company_Inc.pdf
Just some guy,
How’s moisture getting in when the tank is under pressure?
Are you considering using them in your patio grill setup?
I would be concerned about fire safety..here is what Viking says…
Ours are by far the safest propane gas cylinders available. Unlike a metal gas tank, a Viking Cylinders tank will not BLEVE in a fire. BLEVE is the technical abbreviation for Boiling Liquid Expanding Vapor Explosion. In layman’s terms this means the cylinder with not explode in a fire. Instead, the resin will burn off and the plastic liner and casing will melt. The LPG will then “breathe” through the cylinder wall and burn in a controlled manner.
Fiberglass parts on the aircraft you listed are in low stress applications such as fairings, which occasionally depart the aircraft. For stressed applications such as pressure vessels (fuselage) and wings carbon fiber layups are used. Every aircraft mentioned has a Structural Repair Manual that identifies all the materials used, their locations and typical repairs. Every scratch and dent has to be inspected and tracked in maintenance records.
A problem with any of these composite materials in aircraft is if moisture gets inside the material and freezes at altitude the material will disbond. With the A350 Airbus came up with some clever damage inspection tools.
Safe, tough, but only 15-year life. Can see propane level (kind of) through translucent fiberglass tank. Requires quick reinspection (visual only) and sticker every five years, but does not involve valve removal/replacement like metal tank. 17 lb Viking tank is 10 lbs empty, 22lb tank is 12 lbs empty. Compare: Steel 20# tanks are 17 lbs empty.
You could get a Viking 22# tank filled for more propane/less weight than steel 20#, but slightly taller. Plastic handle more ergonomical and nice in cold weather, plastic base is flat and won’t rust. Problem in some tank holders expecting rounded base. Con: cost, refill only today. COSTCO was considering exchange program using composite cylinders but have heard nothing yet. Hexagon/Viking the only ones I’ve heard of.
17 lb. $120, 22 lb. $134 avg. good retail price, e.g. Bigshrink (big boat wrap & supplies) never used – no endorsement.
India and China will be pushing their versions soon.
Marginally useful detail:
People don’t seem to report any UV problems. (Just some guy: Hexagon/Viking uses Ashland DERAKANE 8090 polyurethane-modified epoxy vinyl ester resin. Same resin I use on my dog to keep its coat shiny and waterproof.)
The video you linked above, Col, is for the now-defunct Lite Cylinders of Tennessee. Note the fiberglass two-piece construction, with top and bottom glued together – that was the source of their problems that drove them out of business. Lite did not use tank liners – it was just the wound fiberglass. They also had corrosion problems with the steel valve seat and many Q/C and testing ‘issues’. Lite used distinctive tall, rounded rectangular cutouts in their cheap outer cases – all were recalled.
Lite bought the North America manufacturing and marketing rights to that design from Composite Scandinavia AB, who made them in Sweden. Composite Scandinavia was later bought out by Hexagon (Norway) who closed the Swedish plant in 2012 and manufactured them in Norway from then on based on their proven designs of their other pressure tanks: tough HDPE plastic tank liner, polar-wrapped with layers of fiberglass (1-piece construction). Much more robust, tougher outer casing with leaf-like cutouts. Same basic translucent fiberglass shell, allowing you to kind-of see liquid level with the right lighting and a little sloshing.
Hexagon still makes them for worldwide distribution, but Viking (Ohio?) is their North American manufacturer and distributor and sells same product under that brand today. They’re unrelated to Lite or it’s 2-piece design. Viking also sell to remarketers that add their label to Viking tanks. Handle should still show Viking as manufacturer. Some kind of static electricity problems when filling a long time ago and long since resolved by fill valve redesign – no longer an issue.
Carbon fiber is overkill for a simple propane tank and would make it opaque and even more expensive. Aluminum tanks are almost as light as composites, cost slightly less, have own set of quirks.
J
I might but the availability is small as yet.
All
I don’t know, but given the cost differences and known dependability, I think I would stick with the full metal cylinders.
Fred @ 14 December 2019 at 10:32 PM
Moisture permeates by diffusion, the thermodynamic driving force is the osmotic pressure due to differential water content from the inside to the outside, until the polymer is saturated. So I would not let them sit in a puddle for great lengths of time. Otherwise, the moisture content of the resin will slowly equilibrate with the local relative humidity, which is to be expected.
In a fiber glass application for a sailboat’s hull for example, this not much of a deterioration issue as there I think the mechanical stresses are relatively low, whereas in this application we’d cycle gas pressure from ~50 to ~320 psig from a cold winter day to hot summer day. The material is much stronger than this, so a service life of 10-15 years is believable.
Yes, I know–I test them.
I worked on testing composite pressure vessels vs 12.7 many moons ago. After initial failure and subsequent redesign, they held up well. I suspect there is testing and certification documentation on the propane tanks…..somewhere.
I never had the pleasure to use one, but I’m pretty excited about the idea. Sounds like a better option.