Joe,

thanks for the reply. very informative. i do appreciate the time it took you to type it up.

sorry, don't know the deniers for 3D & Delta.

i'm a bit skeptical of the Primaloft claim. however, since i know nothing of the fiber's design, my skepticism is based upon ignorance.

>>"Wouldnt a greatly larger outer surface on the fiber create more surface for the warmth to radiate from?"

regarding that statement. it's really more of a volume to surface area ratio issue. my guess is that 3D has a lower v-2-s-area ratio than Delta. that is, in 3D a greater % of the trapped air is in direct contact with the fiber than with the larger internal vol. of air trapped in a Delta fiber.


oh...BTW...TMK??? (anyone)

thanks again, Joe.

Ill defer to your v-2-s assesment. Im still trying to figure it all out. Math is not my strong suit, and I have a feeling this is one of those "Ill never need to know this stuff" discussions.

TMK= to my knowledge.

Joe,

i was going to post a reply with a couple of examples to illustrate surface-area-to-volume ratio but did not want to seem pedantic (i know...to late for that).

i still will if you want. however, first check out this link i found a few minutes ago. see if it helps you out. if not, let me know.

this will help in understanding surface-area-to-volume ratio - it uses the classic example of cubes and then relates it to animal body sizes just like they taught "eons" ago when i was in school

Edited by pj on 11/09/2005 14:52:39 MST.

too many Re:s so I thought I would just reset the header :-)>

Paul, I get the basic idea re: surface to volume ratios... Im just not seeing how the amount of air trapped inside the Delta fiber can possibly equal the amount of air space created by an insulation that relofts quicker. Yes, for the very short term, the delta would be holding more warm air. However, in the long term, the faster lofting fiber would seem to create more air pockets by weight.

In light of the fact that Delta has a greater surface area which would expose more area to cold temps (in example, the water) and heat more effecntly radiates from hot to cold areas... It would seem that if the insulation remained in direct contact with cold enough moisture (which may not need to be THAT cold) any heat trapped inside the fibers would be drawn out into the moisture and away from the trapped air.

With the double whammy of slower reloft and increased radiant area....

This isnt to say that a new or well cared for Delta insulated item wont serve the user very well... but I, personally, would be loath to use a delta item that has sustained any hard use.

As I said, my research hasnt given me good vibes on Delta.

Edited by RavenUL on 11/09/2005 21:42:29 MST.

Joe,

ok. now i get your point. i guess i wasn't clear. i feel precisely as you do. i don't think that the trapped air is in anyway close to the volume of air b/t the fibers. i guess we were not connecting on our Posts. no disagreement on reloft issues - give it to 3D vs. Delta. my point was solely when wet. IF it were very wet, then reloft might not be occurring very much. as far as Delta being warmer than 3D when wet, i can't comment, but others have and that was their conclusion. for my part, i'll accept that.

your point on wet reloft makes sense IF reloft can occur to any appreciable amount. i guess that would depend upon how wet/SOAKED.

well,...please feel free to reply. for my part, i'm just 'bout worn out on this topic.

i've learned something from your posts, however, and appreciate the time you've taken to reply. many thanks.

Ray Jardine on March 4, 2005, posted this on his Ray's Campfire blog:

The Sales & Marketing Manager for the company that manufactures both 3D and Delta insulation sent me the following note:

"I know you are interested in running Delta but do you know it has less loft than 3D and has worse recovery after vacuum packaging than 3D? Delta has a 37% hollow void and 3D has a 20% void so the that is why Delta has less recovery. After the problems we have had I don't think Delta is a good product for you to consider. I am afraid you will be disappointed with its loft retention."

Thanks Douglas. That's exactly what Joe and I were thinking of. We've seen this info a couple of times already. I mentioned the details of the info a few weeks ago, but was unable to remember where i had read it. Was it you that actually located it a couple of weeks ago, in response to me mentioning it, or was it someone else who posted it back then in response to me mentioning it? i can't remember. well, anyways, thanks for posting it again. it's good to have that info in this Thread for others to see.

Edited by pj on 11/10/2005 18:21:27 MST.

Then there is the BPL perspective--
"Any high loft synthetic insulation - whether it's Polarguard, Primaloft, Thermolite, etc. - is prone to damage resulting from overcompression of a garment or sleeping bag. We chose Polarguard Delta for the Cocoon for its superior warmth-to-weight ratio, but just as important, it's considered to be one of the most durable insulations on the market relative to its ability to retain and recover its loft in response to compression. However, if you want to get the most out of your synthetic insulated sleeping bags and garments - take care not to overstuff it."

From my own experience, as it pertains to the Delta-filled Cocoon Pullover---in almost a year of much use (including use as a pillow for all my backpacks) this garment still retains it's full loft . It has been washed once.

Kevin, many thanks for the input. I've seen both the RayWay and the BPL take on Delta. I appreciate your first-hand experience. Delta vs. 3D is important to me because I'm planning on ordering a quilt from FanaticFringe. They make a 3D quilt and a Delta quilt - both 30degF quilts w/~2oz diff in wt (Delta being lighter). Not sure which I'll pick yet (the price diff is not an issue in this case since they're both relatively inexpensive). thanks again.

[oh...touche on the quote. :) a taste of my own medicine ;) ]

Edited by pj on 11/10/2005 18:33:13 MST.

"it's considered to be one of the most durable insulations on the market relative to its ability to retain and recover its loft in response to compression"

Who says? By what criteria?

Further, what constitutes "over compression"?

Joe--Ryan or whoever writes product copy for BPL says. You would have to ask them. I just quoted their spiel for the Cocoon Pullover.

I understand that, but the question still stands.

According to ACYE over at thru-hiker.com, Delta will no longer be manufactured. Checkout his message board for his statement.

Interesting information Tony. If its true, it would definatly confirm a few things for me.

For those who are not into counting every last ounce the MEC Northern Lite jacket probably offers the best bang for the buck. It uses the best Primaloft insulation with a good face fabric impregnated with DWR.

Best is... $110 CDN and no production shortages.

Good luck.

I guess that Ryan J. should be asked about both.
Paging Dr. Ryan...

The thru-hiker message is dodgy. Whom or What is the mystery source? You see these kinds of rumours about everything, everyday. 9 times out of
10... what do they amount to?

But, if true, what synthetic insulation options would BMW/BPL turn to for the Cocoon series products?
Including the future Arc Cocoon quilt/topbag?

" Whom or What is the mystery source?"

Probably the same mystery source Ray J got his info from... :)

"what synthetic insulation options would BMW/BPL turn to for the Cocoon series products?"

Given my choice, Id hope for exceloft. More likely, 3D would be a best bet. If your willing to take Ray J calculations to heart (http://www.ray-way.com/quilt/delta.shtml) your only talking about a very tiny weight increase. I know some people will shed a tear or two over such a minimal weight increase (Ray claims a fraction of an ounce for the total weight), but it will pay for itself in the durability of the insulation. And for the "gram weenies", they wont be looking at anything other than down.

delta gone? maybe replaced with a new insulation - 'epsilon', or 4D ???

Edited by pj on 11/11/2005 11:09:58 MST.

I hope that at some point Ryan Jordan will speak to these questions.That is, Durability and Delta's future.

If we assume Delta is kaput---
Exceloft is a proprietary product, so don't hold your breath, Joe. I doubt that 3D will be seen as a replacement, by many (especially as Delta was promoted as a superior product by it's producer--it would be a business blunder). If Delta goes, I would assume that eventually a sucessor product will be developed by Polarguard (if it hasn't already).

Finally, Joe, we "gram weenies",that you seemingly disparage, can not always turn to down for insulated clothing and bags.You know (I think) and I know that there are conditions for which down is not appropriate.

Edited by kdesign on 11/11/2005 11:21:42 MST.