View Full Version : Montbell Thermawrap Sports Vest

06-25-2015, 20:12
I am considering changing my insulation layer (for 3 season conditions) from down to synthetic. I currently have a Montbell UL Down Inner parka which has served me well but which I have restricted to an in-camp or sleep layer due to the fact that it is down and I don't want to get it wet by hiking in it. The parka weighs 9.75 ounces on my scale. While hiking, I normally wear a long sleeve micro weight smartwool layer and supplement with a wind shirt (Patagonia Houdini) when temps get down into the 40s. Below 40, or even in the 40s when hiking but not exerting myself (long downhills), a mid insulation layer would be nice. But I won't hardly ever use my down parka for that.

I came across the Montbell Thermawrap sports vest as I do some research on synthetic pieces. At an advertised weight of 6.6 ounces, I could save 3 ounces but that isn't my main motivation. I just want a more versatile piece that I can use while hiking and while in camp. But I'm not sure whether this vest will keep me as warm as the parka while in camp. Probably not given the lack of sleeves. And not sure how it would perform to supplement my sleep system when called for.

So any experience that could be shared regarding this vest or similar vests would be helpful. There is a jacket version of this product but it weighs more than my down parka and I don't really want to add weight.

06-25-2015, 20:19
I have this vest and love it. I use it for hiking only. It seems to keep me warm even when wet and dries quickly as well. I always take a separate down jacket for camp.

06-25-2015, 21:06
Thanks. Good to know that it does a good job of insulating while hiking even when wet. That's an important use case. But I really also want it to double as a camp insulation layer. Otherwise I'm adding 6.6 ounces to my pack.

06-25-2015, 22:03
I love down, and use it from time to time. However, I feel on the AT were it is mostly damp, synthetic wins out in my pack. Yes heavier, yes bulkier. But it will always be warm and dry quicker.

Just Bill
06-25-2015, 22:51
I'd stick with a Patagonia Nano-puff. You pick up two ounces...
Not sure exactly what Exoloft is, but it seems like a knock off Primaloft Gold. It is listed as a 50g s/m weight (the insulation)

Nothing wrong with Montbell at all, but I've been disappointed in everyone of their SUL things I've owned. They just cut a bit too much IMO, the down has always been a hair light. The synthetic looks to be the same thing.

The reason I worked hard to figure out how to make Primaloft Gold work in a quilt is because it is so awesome in jackets. I destroyed my nano-puff and couldn't find a reasonable way to mess it up. I sliced open the shoulder last fall carrying some metal studs and left it to see what happened. Nothing.

To give you an idea on the SUL thing...
My 25* quilt is one layer of 200g s/m (square meter) material.
My 45* quilt is one layer of 100g.
Patagonia Nanopuff is 60g s/m
Montbell is 50g sm of exoloft.

I don't know the CLO value of Exoloft but probably between Apex and PL- About 1.49 CLO in the Montbell.
The Nano-Puff is 1.84 CLO.
It doesn't seem like a lot, but those few degrees off get you after a bit... If nothing else I would bump up one weight in the montbell stuff. The shell of the jacket is the bulk of the weight, it seems silly to shave basically nothing for little gain.

Clothing is a bit tricky but to give you an idea...
The EE prodigy-(apex synthetic)
A 50* is 1.64 CLO (60gsm in Apex)
A 40* is 3.28 CLO (120 gsm in Apex)
A typical base layer is .5 CLO-.75 CLO
A little CLO goes a long way.

06-25-2015, 23:22
Can you clarify what PAT Nano Puff you are referring to JB - Pull over, vest and or Special Edition?

06-25-2015, 23:39
I'm a glutton for vests. I employ them often on hikes. I like layering with them and their greater versatility hence me getting greater usage based on how I layer. Few apparel pieces are as versatile or providing very good warmth to wt ratios as a UL synthetic vest. I'm not usually one to name TNF products but when I saw, of all things, a TNF Thermoball Vest in black in my size last of its kind on a clearance rack, priced for $55 at, of all places a Sports Authority, I bought it. It's a cooperative introduction by Primaloft and TNF. Happy with it. IMO it's warmer than a slightly used UL Montbell Thermawrap vest w/the hybrid stretch side panels.

Here's what Outdoor Gear Lab had to say bout it including some tidbits of various insulations beta including Exoloft.

06-26-2015, 00:26
I have the Thermapants and jacket. I have not tested the jacket enough to give a rating but the pants were a warmed and lighter upgrade from polar tech 200 wt pants. I use them in the late fall/winter/early spring. I have an older polarguard jacket with a hood that the new jacket replaces. Saves weight, no hood, seems about as warm but I don't have the hood anymore so I would be concerned in the winter with depending on locale. I have used synthetic vests for a good many years now, I currently have the REI cloudveil I think is the correct name. It has good length in the back, I'm longer torso and that was a major factor. Thermawraps are cut trim. The jacket is fine for me though. Anyway, I use the vest in late spring/summer/early fall, then switch to a jacket. I use a microfleece top with the vest for in camp. IMHO, there has to be a big difference in insulation quality before a vest and a jacket could be equivalent all other clothes being equal.

Just Bill
06-26-2015, 01:03
The vest compared- http://www.patagonia.com/us/product/mens-nano-puff-vest?p=84241-0
Just the current version. Listed at 8.6 oz vs the 6.6 MB.
Nothing implied against MB or even the fill they use either- with synthetic you don't measure Fill power, you measure ounces per sq yard (grams per sq meter actually) and CLO value. In this case it's a bit like MB using 600 fill and the PAT using 700 fill.

Course I got these damn numbers stuck in my brain- but it would be handy if the vendors would list CLO values just like they list Fill Power. It would make it much easier to determine what you're getting.

To use Gator's analogy- the MB is a bit like a 150wt fleece and the PAT is like a 200wt in this case.

BTW- the TNF Thermoball stuff...
Is Primaloft Gold that has been forced to "fall apart". It's roughly 650 fill down in this form and should be looked at that way if you are trying to compare (oz of fill used, not oz per sq yd like other synthetics). It also requires down like construction (mini-baffles or sewn thru-grid pattern)

Apex is continous filament insulation, the best around of it's type. (think of a full spool of fishing line spun out and clumped up)
PL is a short staple insulation, the best around of it's type. (think of the same spool of line chopped into tiny pieces)
It would take some serious effort, but more or less if you took a piece of PL Gold, you could turn it into Thermoball insulation, in fact I suppose there is some stuck to the edges of my work table right now, lol.

Apex is .82 CLO per oz/yd. It is tough, a bit stiff, and doesn't compress as well, it is rarely used in clothing. It doesn't need any quilting (support) so easy piesy for quilts. Technically it should be quilted 24" OC, but thousands of MYOG folks can't be wrong, lol.
PL Gold is .92 CLO per oz/yd. It is very soft, very compressible, has that instant on feeling down does and is used mainly in apparel. But because it is short staple it requires quilting- which is why the Patagonia Nano-Puff has that iconic "brick" pattern- PL in 60 gsm weight needs quilting every 3". 100gsm stuff needs it every 6"

I'm guessing- based upon the roughly six inch stitching on the MB stuff- that it is more like PL Silver, which is in between Apex and Gold, but closer to Apex's rating of .82 rather than the .78 of PL silver. In 50gsm weight it would fall apart at 6" OC unless it was a longer filament length insulation.

Just Bill
06-26-2015, 01:17

There you go, from my marketing collaboration with a leading synthetic insulation company. :rolleyes:
I took some and rolled it in my hand a bit and got some of the top secret stuff (palm). Left the black thread in there for scale.
On my finger tips are just the wisps that I pulled off the edge of the table from handling and cutting.