Tent Modification Complete

WilliamC

Thru Hiker
No, but a real tree camo DCF Altaplex weighs 502g. My custom J.H. M.H. in real tree camo DCF weighs 445g, including the Exitex 1.5m x 3m Polycro ground sheet, and the DCF storage bag adds 10g. And if I want the very basics of flying insect protection I can throw on my Sea To Summit Nano head net, which would bring it up to 466g...36g lighter than the Altaplex.



I used to build Mclaren sports cars on the assembly line at their plant in Woking, and I saw first hand the benefits of bonded construction...Much of Mclarens cars achieve the amazingly high strength to weight ratio of their body shell and chassis, by effectively gluing the majority of their cars together, rather than bolting or riveting them together.
The Aluminium front and rear chassis rails, and all the fixed body panels, are all bonded directly onto into the immensely strong Carbon Fibre centre tub.
The reasoning is, a bolt or rivet always has a gap between it and the next one, and the next one and so on...But one part is not actually physically attached to another part in these gaps, leaving a weaker joint or fixing.
It is analogous to the hull plates on the Titanic being riveted, rather than welded...The Titanic would almost certainly have survived the collision with the iceberg and reached port safely, if it's hull plates had been welded, as it's hull would have been much stronger.
With a bonded (or welded) joint there are no gaps at all between parts so maximum joint strength between parts is achieved.
And it is the same with bonded tents.
So hardly an apples to apples comparison so irrelevant to which construction is lighter (Altaplex with inner in 0.75oz DCF and 1oz DCF floor including stuff sack = 487g; JH MH in 8oz DCF = 590g). Incidentally, Zpacks quote 465g for the, currently unavailable, camo Altaplex.
And Colin Ibbotson is an aeronautical engineer, so presumably knows a thing or two about designing for strength.
I don't think you can compare the behaviour of bonded materials such as steel or aluminium with a heterogenous composite such as DCF. Colin's claim is that since the mylar (or other PET depending on DCF type) layers can delaminate from the dyneema fibres, sewing then bonding/taping is stronger than just bonding. My suspicion is that bonding is strong enough, though sewing plus bonding will be stronger*. Those of us with a fair amount of experience with DCF will know that the delamination issue is real. And if you ever try to remove tape from DCF (or to unpeel your seams, though why would you?), you'll find that you're more likely to end up stripping the layer of PET from the dyneema.
*Note that we're talking about sewing and taping here, so you do end up with "no gaps at all between parts".
 

tarptent

Section Hiker
So hardly an apples to apples comparison so irrelevant to which construction is lighter (Altaplex with inner in 0.75oz DCF and 1oz DCF floor including stuff sack = 487g; JH MH in 8oz DCF = 590g). Incidentally, Zpacks quote 465g for the, currently unavailable, camo Altaplex.
But J.H. didn't use 8oz camo DCF...He used 6.7oz camo DCF...My M.H. 1.5P in real tree camo DCF, with the double door mod I asked for, and the 100mm snow skirt I opted for too, weighs 326g.
The DCF storage bag for it weighs 9g, and my 1.5m x 3m Exitex polycro ground sheet has a 15mm hem and several clear tape repairs, so it currently weighs 119g...That's a total of 454g.
Plus my S2S Nano head net, which weighs 11g, for basic flying insect protection, and the total is 465g...So it's still 22g lighter than the weight of Altaplex, you have quoted.
That is despite my covered floor area, excluding the vestibule area (which is uncovered), being almost 2 foot wider and at least 2 1/2 foot longer than in the Altaplex.
(My ground sheet is 5 foot by 10 foot, and when stretched out fully the whole sheet still fits entirely inside the M.H outer, leaving just the vestibule area uncovered).
 
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WilliamC

Thru Hiker
But J.H. didn't use 8oz camo DCF...He used 6.7oz camo DCF...My M.H. 1.5P in real tree camo DCF, with the double door mod I asked for, and the 100mm snow skirt I opted for too, weighs 326g.
The DCF storage bag for it weighs 9g, and my 1.5m x 3m Exitex polycro ground sheet has a 15mm hem and several clear tape repairs, so it currently weighs 119g...That's a total of 454g.
Plus my S2S Nano head net, which weighs 11g, for basic flying insect protection, and the total is 465g...So it's still 22g lighter than the weight of Altaplex, you have quoted.
That is despite my covered floor area, excluding the vestibule area (which is uncovered), being almost 2 foot wider and at least 2 1/2 foot longer than in the Altaplex.
(My ground sheet is 5 foot by 10 foot, and when stretched out fully the whole sheet still fits entirely inside the M.H outer, leaving just the vestibule area uncovered).
You said:
Yep, my J.H. Mountain House 1.5P in real tree camo DCF is almost entirely bonded together, not stitched. The only stitching is where the guy out, tie outs and their reinforcement backings are.
It makes for a stronger tent, and with such small amounts of seam sealing tape needed it end's up lighter than stitched equivalents.
For example, it's lighter than Zpacks Altplex in real tree camo DCF, but it offers about twice the internal volume.
From that I understood that you were implying that the JH MH (whick doesn't have a full inner) was lighter than the Alataplex (which does) because it was bonded not sewn. Now you seem to be saying that is not what you meant. I apologise for my poor comprehension skills.
 
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