MYOG Primaloft Sport 3.0oz Insulated Pants

[And E]

I really don't know why this took me so long…. pulled an all nighter, 8 hours from start to finish all in one go… Now I just gotta make one for the wife.

Insulated pants (total weight = 186.5g/6.58oz; lighter than Montbell's UL Down Pants!):

* Impetus 1.0 in black for outer fabric (from DIY Gear Supply )
* 1.1oz ripstop 2nds DWR/uncalendered, lower thread count, super breathable liner (not wind resistant). (Also from DIY Gear Supply)
* 3oz Primaloft Sport (from Seattle Fabrics – Got this as a 2 yd remnant for 25% off)
*3/4" Velcro for the fly and 1/2" elastic band for the back and front of the waist

Lines on the Impetus shell are creases. The Insulation is quilted to the liner only

Liner (some of the quilting lines are ugly because I added more after having sewn up the leg.

Compresses down to the size of a large grapefruit. Pick your scale: my hand, 230g canister, banana, or dinosaur (sadly, no grapefruit).

When I made this, I started with the pattern I used for my rain pants and supplex pants, which had much more room in the leg than I would need for the insulated pants.
I sewed up the liner/insulation like normal, then began taking in the leg a little bit at a time until I was satisfied with the fit. I wanted it to fit close and minimize empty space while still allowing for full range of motion. The outer shell is just a touch bigger than the liner/insulation. Pants fit perfectly.

If you don't like the Hawks, I can upload a shirtless version :oP

Taking in the leg width.

[Stephen M]

Very nice, will you make me one :-)

[Anonymous]

Nice work Andy.

Just curious, why did you go with Primaloft over Apex on this? Apex would be easier and likely last longer.

[And E]

I was going to use 2.5 apex, but the Primaloft Sport was a good deal. I went into Seattle Fabrics on my way home from work to grab some webbing/grossgrain for the Arc Blast frame conversion and saw the remnant for sale. The insulation only cost me $25 for 3 3/8 yd (I needed enough to make one for me and my wife). Ordering Apex online would have cost ~$45 after shipping for 3 yards, plus the waiting.

Primaloft Sport is definitely more finicky to sew than Apex, since it doesn't have that stiff outer layer of insulation, but it wasn't too bad. 3oz vs 2.5oz would have made only half an ounce or less of a difference.

Actually, I would have preferred to use something like Thinsulate Ultra, in a 40g weight and double it up for the upper legs/waist/butt to keep it low bulk/packed size,
but Thinsulate only comes fused inbetween two layers of scrim at regular intervals (like perforations in paper or cardboard, but bigger).

[And E]

I'm gonna try to go for an overnight soon, while the weather is good and when it gets cooler in fall and see if I can just wear these plus my Stoic Hadron hooded down Anorak to sleep.

If so, I won't even need to bring my Apex quilt. Both the pants and anorak would come to 13.92 oz, less than an ounce heavier than the quilt. But, I'd have my anorak most trips anyways for just cool mornings/nights around camp (but won't need it for sleep) so I'd actually be saving ~7oz by swapping the quilt for the pants. If my feet get cold, I can just shove them in my Exped pump bag/backpack.

[Jeffrey Wong]

Alright, Andddd e, I like what you've done.

I must make one too. My DIY zip leg fleece pants weigh too much (13.3 oz) This will transform a cold night in the wilderness to a toasty sleep.

I have some Climashield, so why not, that is after another project.

Jeff

[Michael Schwartz]

Nice work! I had a similar pair by BPL but they were stolen. Is anyone making and selling this type of insulated pants?

[J-L]

What temperatures do you plan on just using the pants/down jacket combo at?

I think a small company in Spain makes the lightest synthetic pants:

https://astucas.com/en/clothing/sestrals-pants

[And E]

Probably down into the high 40's or low 50's. At this temp, I don't even cinch up my Apex quilt, just use it like a blanket.

Those pants are impressively light for ones you can readily purchase (190g = 6.7oz). The fabric they use is 1.34 g/m2, If I made some with Argon 67, it'd be half the fabric weight.

If I make another pair sometime, I'll go with 2.2 Apex from OWF Inc and either Nobul or Argon 67. Should bring the total pant weight down to 6oz or less.

[Michael Schwartz]

Thanks for the lead. They look good. I've seen that company before.

[Dustin Short]

And E, if you do go, make sure you bring booties. I did a similar trip with just my MB UL down pants/parka and was plenty warm…except for my feet. I was up all night since I forgot to bring a thick pair of socks in mid 40F weather. I also had issues with drafts between my jacket and pants, but I may have been too tired/dumb to cinch the waist cord of the jacket.

Either way they were enough to keep me up, so make sure you've got a contingency plan for it :)

[And E]

Thanks for the tip, Dustin! I usually bring thick wool socks, so my plan is to wear those and put my feet into my pack liner, and into my pack itself if I need to.

[Author]

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