Instructions for the Whisperlite Internationale 600 that I got in 1996 clearly state to use only MSR fuel bottles. The Duraseal pump came out in 2004, 8 years later. I don't know how long before 1996 they were stating that requirement. The main intent of the Duraseal pump was to correct some design deficiencies, although the redesigned pump gave the opportunity to design a seal that only worked with their fuel bottles. After all, forcing people to use their bottles solved some real (and perceived) safety and legal issues. At least that's my take on it.
Her is a thread about how to modify for use witnoter pumps, and even butane. My mod is still working well after 20 yrs. MSR Whisperlite identifcation?
The threads in the Sigg bottle were pressed in. The threads in the MSR bottle were cut, or formed, to prevent leaks around the thead insert of the Sigg. All in the intent of safety.
Many moons ago as a wee hiker I refilled a spun aluminium Sigg pint fuel bottle without leaving sufficient headspace. Temperature and/or elevation changes caused it to balloon lengthwise at both ends basically. It didn’t leak or burst. Very impressive, it’s a good piece of gear thankfully and I learned a lesson. I doubt it would be possible to hurt a Sigg bottle with a hand pump. Maybe a really super dedicated idiot. I just wonder if it was maybe MSR lawyers who counseled the change or Sigg/Optimus lawyers. It had to contribute or represent to a significant percentage of Sigg sales. “Why don’t we sell our own fuel bottles” makes sense, I guess. They do make a good fuel bottle.
All the sigg bottles I own are cut threads. They are all old though so maybe pressed threads is a newish thing
One of the reasons MSR used cut threads was the insert on the SIGG bottles could break loose and spin in the bottle neck making the pump unremovable
Sorry about going back pedanticly but... MSR brought out their own bottles and stopped recommending SIGG during the last yellow pump years. There were 2 more pumps before the Duraseal- about 20 years. I really don't think these are related facts. Fwiw, the Duraseal isn't stretched on a SIGG original fuel bottle. I still use a newer SIGG bottle with no stretch of the Duraseal. All the pre-seahorse pumps (afaik) use an o-ring seal identical in size to the SIGG bottle cap's seal and seal only the outer edge of the bottle. The Duraseal fits above but also inside the neck of the fuel bottle. The outer rim is elastic. It won't seal into anything but a necked fuel canister, but as I've said, it fits a lot more fuel canisters than people give it credit for. Looks odd on some but seals safely.
Ok I cant talk to the timeline although I did believe it at the time of writing. The MSR bottle I have came with a second hand dragonfly and was one of the first MSR bottles I ever saw which is why I believed this. Also untill I checked my bottles I believed the thread was cut into the bottle on all of them. That isnt the case. I have 5 non chinese bottles. First one I bought new in the early 80s for use with a 123r second I bought recently but identical right down to looking like they played an essential role in many rugby games. A very close look at the top shows a ridge where the top of the bottle is folded over the insert. The next bottle is optimus branded but probably sigg manufacture. It is like the other 2 in construction although the insert looks to be brass. The durasal pump goes into all of these fine although the edge distorts a lot and the square edge of the first 2 bottles makes it unreasonably hard to tighten considering the plastic parts. The 4thbottle is I believe an older blue anodised sigg bottle with a metal cap. It also has the folded over top of the bottle and insert. The plastic caps all fit this bottle fine but the cap cross threaded in every other bottle. An attempt to screw the pump in saw it cross thread every time. Last bottle is the MSR that is meant to be with this pump and everything fits like it should. Has anyone ever seen an insert fail?
The MSR bottle was introduced during the G/GK era. The instructions changed, indicating the recommendation of the use of the MSR bottle.
