Aconcagua summit clothing

I wIll be going to Aconcagua at the end of the year and have been thinking through gear, especially clothing. Am a bit confused about the best body layers to wear for summit day. Have looked around for info and found various differing views so wanted to get opinions of folks here. My initial thinking is to go with:

Upper body - lightweight merino base+heavy fleece jacket+MH Sub Zero SL jacket
Lower body - merino long johns+softshell fleece pants+down puffy pants

Do you think this will be warm enough? I could add a heavier merino sweater to the upper layers? Do I need shell pants? I have a MH Absolute Zero down suit but I assume that this would be overkill and not as flexible as a separate jacket and pants? Appreciate your thoughts!

It all depends on the weather. Aconcagua has been summitted in t-shirts and tennis shoes, and in -20 blizzards. Hard to know what you'll need until you get there.

Personally, I woudn't bother with a fleece jacket of any sort, at all. They're heavier, bulkier, and not as warm as any modern lightweight synthetic puffy. Patagonia Nanopuff, Arcteryx Atom LT Hoody, or Wild Things Hooded Insulight would all be far superior choices.

You'll be cooking in that setup. I assume you're going on a guided trip and they're not gonna let you try to summit in a blizzard (current weather technology makes it unlikely you'll be surprised by one in the middle of summit day either).

A heavier down jacket will be useful around camp and maybe(?) the first couple hours of summit day before the sun comes up.

Agreed very lightweight down or synthetic puffy would be better than fleece mid layer, and then softshell outer layer top and bottom for the wind. No need for true waterproofness up there (other than gaiters), it'll either snow or not precipitate at all.

Get the best mittens you can find, some guy in the week before we went summited with gloves and lost two knuckles on most of his fingers.

Thanks for the guidance. I have an old (2007!) MH Compressor jacket and a Marmot Driclime softshell. Based on your advice I will rely on these. Still on the lookout for mitts - WTB a pair of OR Alti mitts...

Worth a look:

alpineinstitute.com/media/5…

Have a pair of Wild Things belay Bibs in size large for $100 plus shipping. I'll cover PayPal. Grey. Primaloft insulation. 

Here are the layers I used on Denali this year, somewhat comparable:

Top:

Icebreaker base layers (had a lightweight one and a heavyweight one)

Patagonia R1 Hoody

Patagonia Nano-Air Hoody - This was the out layer when sunny and not windy

MH Ghost Whisperer Hoody - Did not get put on until summit day, would not bring if I went back

Westcomb Apoc Shell

Rab Positron Parka - Mostly wore around camp, only wore while moving during the descent on summit day

Bottom:

Stoic lightweight synthetic bottom

Icebreaker heavyweight wool bottoms

Arcteryx procline softshell pants

Marmot precip hardshell pants (Did not put on once, all precip was snow)

Feathered Friends volant down pants - Never wore them while moving, only at camp. But they were great at camp.

tagshell wrote:

Rab Positron Parka - Mostly wore around camp, only wore while moving during the descent on summit day

I am looking to upgrade my belay jacket and the Rab Positron is one of the options. How extensively have you used it? What are your thoughts? My biggest concerns are no stuff pockets for gloves inside and the sewn through sleeves. Were either of these an issue for you?

I live in CA, so a jacket like that is usually overkill, I don't see myself using it much. I only used it on Denali and a few days of ice climbing in the canadian rockies. On Denali I did not mind lack of glove pockets since extra gloves can be stored in the pack. We had one day on Denali that was -20F and very strong winds, I wore the jacket on top of my other layers and didn't feel particularly cold in the arms or anything. 

Get rid of the old synthetic puffy and buy a new one. They lose their insulating value and become pretty much worthless, especially after 10 years.

Here's a good, cheap option https://www.sierratradingpost.com/brooks-range-cirro-primaloft-hoodie-insulated-for-men~p~293mh/?filterString=mens-insulated-jackets~d~9619%2F

And if you click through Active Junky instead you get an extra 8% back