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Reviews > Clothing > Shirts > Sherpa Sonam Base Layer > Test Report by Ray Estrella

Sherpa Adventure Gear Sonam Quarter-Zip
Test Series by Raymond Estrella

INITIAL REPORT - April 30, 2010
FIELD REPORT - July 09, 2010
LONG TERM REPORT - September 12, 2010


NAME: Raymond Estrella
EMAIL: rayestrellaAThotmailDOTcom
AGE: 50
LOCATION: Orange County, California, USA
HEIGHT: 6' 3" (1.91 m)
WEIGHT: 210 lb (95.30 kg)

I have been backpacking for over 30 years, all over California, plus many western states and Minnesota. I hike year-round in all weather, and average 500+ miles (800+ km) per year. I make a point of using lightweight gear, and smaller volume packs. Doubting I can ever be truly UL, I try to be as near to it as I can yet still be comfortable. I start early and hike hard so as to enjoy the afternoons exploring/chilling. I usually take a freestanding tent and enjoy hot meals at night. If not hiking solo I am usually with brother-in-law Dave.


The Product

Manufacturer: Sherpa Adventure Gear
Web site:
Product: Sonam Quarter-Zip baselayer shirt
Size: XL
Year manufactured/received: 2010
MSRP: US $49.00
Weight listed: 8.8 oz (250 g)
Actual weight: 8.4 oz (238 g)
Color reviewed: Rara Blue/Neelo

Picture courtesy Sherpa Adventure Gear

Product Description

The Sherpa Adventure Gear Sonam Quarter-Zip (hereafter referred to as the Sonam or the shirt) is a men's long sleeved baselayer shirt made for the summer months.

The Sonam is made from 54% polyester and 46% Dry Zone nylon. This Dry Zone nylon is said by the company to be a "smart fabric developed specifically for Sherpa Adventure Gear, it controls thermal conductivity, keeping you warm in cold weather and cool in the heat of the day. It's also water resistant, fast-wicking and dries faster than you can believe." During the course of my testing I shall attempt to validate these claims.

The fabric claims to block 99% of UV rays, but the thing that interested me in the shirt was the fact that the fabric is woven with anti-bacterial silver ions to minimize odors. I have enjoyed using products that use silver to keep microbial growth from taking place in the shirt. Some have worked better than others. As I am a hiking furnace I can guarantee some sweaty times ahead for the Sonam. Hi-ho Silver…

The Sonam is very nicely made. The quality is top notch from what I see. All of the seams are serged for strength and to lay flat. The raglan style sleeves present no shoulder seams to chafe under a backpack's shoulder straps. The neck, sleeve ends and body at the bottom have been hemmed with a contrasting color polyester.

While the shirt is pretty airy due to the mesh structure of its fabric further cooling can happen by dropping the 8.75 in (22 cm)front zipper. The zipper is worked by way of a colorful pull that is reminiscent of Tibetan prayer flags. The nylon zipper runs freely, yet is stiff enough to not pull open by itself easily.

Your zipper's down

The shirt has a 2 in (5 cm) high stand-up collar. It does not like to lie down, even when unzipped. Maybe as I wash it a few times and wear it a bunch this will change. Just under the collar in the back of the shirt is a reflective Sherpa Adventure Gear logo, a Tibetan design.

On the chest of the Sonam a small pocket has been welded on. This pocket is accessed by way of a 4 in (10 cm) vertical zipper. The Sherpa name is displayed on the pocket.

The size info has been screen-printed on, something I really like to see. Inside the shirt a care tag is found telling me to:
Machine wash cold with like colors
Use no bleach
Tumble dry Low
Use a cool iron if pressing is needed
Do not dry clean

The cut is said to be athletic and it fits pretty close to my body and arms. I look forward to getting it out on the trail. As this concludes my Initial Report, please come back in a couple months to see how the Sonam is working out.


Quick & Dirty, Nitty Gritty

While I had my doubts about what looked like a mid weight base layer in warm weather hiking I have to say that the Sonam works well when it is warm and better when it is cool. I have taken it on every hiking and camping trip where it has been a welcome addition to my kit. It even repels mosquitoes! Read on for the details.

Field Data

Dinner coming right up

The first use of the Sherpa Sonam was on an 18 mi (29 km) section of the PCT near Warner Springs, California (CA). Very cold, with winds to 50 mph (81 km/h). It was 34 F (1 C) when we started.

Then we made a day hike of a 24 mi (39 km) section of the PCT south of Tehachapi, CA. Winds blowing at
50 mph (81 km/h) and gusting to 70 mph (113 km/h).blew me off the trail many times. It was 38 F (3 C) at the beginning of the hike.

Next was a trip to the Sespe Wilderness for an overnighter to visit the Willet Hot Springs. The temps ran from lows near freezing to 70 F (21 C).

Then I took it on an overnighter in Minnesota at Itasca State Park. This trip saw a lot of rain, with temps from 70 to 38 F (21 to 3 C). The picture above was taken in between storms.

I used it on an overnighter at a primitive campground called Sawmill and another called Upper Shake, both in the Angeles National Forest. Both trips saw lows to 36 F (2 C).

I took it on an overnighter to Fisherman's Camp in Cleveland National Forest. The mosquitoes were bad and the temps were to 85 F (29 C).

Next was with the kids for a camping trip to Maplewood State park where we stayed at Lida Lake.

Next was an overnighter in the upper Kern River area where the low only made it to 50 F (10 C).

Last I went back to the Kern area for three days trying to get down to the Durwood Creek/Kern River cable crossing, and to find and take pictures of waterfalls. Temps ran from a low of 48 to over 90 F (9 to 32 C). I went between 22 and 24 miles. No idea of gain. Here is a picture of it at a camp near a mine shaft near the Rincon trail.

Another Scotch coming right up...


I have really been able to get a lot of use with the Sonam shirt, and I have to say that I really like it. I was concerned going into this test because I knew that I would be in hot weather. I always do carry a long sleeved shirt even in summer, but try for the lightest weight possible. While the company's claim that it would "keep you cool in the heat of the day" is a bit of a stretch the Sonam did not make me overly warm when wearing it as long as I was not in direct sun. In that case the color works against it.

I bring a long sleeve shirt on all my trips for a few reasons. First I have nice down bags and quilts that I try to keep nice by keeping them clean. I always sleep in a shirt and a pair of liner socks to keep body oils and sweat off the bags. Sometimes I even wear long underwear too. The Sonam was great in this role, being quite comfortable under my quilts. In fact a few times the Sonam was warm enough to just sleep in by itself for the start of the evening, only pulling the quilt up after the temperatures dropped.

Another reason for a long shirt is to keep mosquitoes away. Once I get into my evening's camp site I try to get all the day's sweat, dirt and DEET off, rinsing off at the nearest creek, lake or river. I don't want to reapply bug repellant so I put on a hat, long pants and shirt that have been treated with Permethrin, a contact insecticide that is safe to apply to clothing. I soaked the Sonam in a Permethrin solution and once dried it is very effective at keeping mosquitoes off me. On a trip to the Sespe Wilderness I wore the Sonam for the 0.5 mi (0.8 km) climb from our camp up to a hot spring at dusk, right when all the flying vampires were coming to play. Here is a shot just leaving camp.

Warm soak coming right up

The Sonam works well in cool or cold weather too, but only if it is under an outer layer. The material does almost nothing to block wind, so a couple times I needed to put my rain shell over it on early starts in windy conditions.

The Sonam is holding up quite well. I wash it after every trip. Sometimes I let it hang dry, which it does very quickly. Other times I will toss it in a medium dryer with other hiking clothes and pull it out after 10 minutes where I will find it almost completely dried already.

The zipper is still tracking fine; there are no snags, holes or unraveling seams. It still looks like new. But what will two more months of use do to the Sonam? Well, come back in two months and find out when I post the Long Term Report.


Field Data

I have been out a lot since the last report. Here are some of the places I took the Sonam

It came along on a backpacking trip with my children to Itasca State park where we made camp at McKay Lake. It got down to 47 F (8 C).

I spent two days backpacking and fishing in the Dinky Lakes Wilderness. The weather was great with lows of 45 F (7 C).

Next was my big trip, a 6-day 91-mile (147 km) backpacking trip through Yosemite National Park. The low there was 33 F (1 C), but most nights were around 40 F (4 C).

I took it on a 3-day family base camp and hiking trip to the eastern Sierra. Lows of 43 F (6 C).

I went back to Yosemite for a 3 day solo trip that saw lows of 36 F (2 C).

I took it on a hike in the San Jacinto Wilderness where I camped above Miller Creek at Law's Junction. Low of only 50 F (10 C).

Last I went up the East Fork San Gabriel River I stayed in the Narrows near Iron Fork where it only made it down to 53 F (12 C).


As can be seen the Sonam has been with me on a lot of trips. As I became unemployed during the Long Term Test phase I had a lot of time to hike and have made the most of it. (And now have a LOT of writing to do. Watch for plenty of reviews right here at this Bat Channel…)

Even though it has been pretty warm on all my hikes I have worn the Sonam on every single evening and morning. This is for two reasons.

First I still use it to protect (and in a couple of case bolster) a new super-light quilt I had made for summer. With a lightweight shell and only 6 oz (170 g) of down I want to keep my sweat and body oils off, and out of it. The Sonam is its protection.

And again I used it for mosquito protection too. I Permethrin soaked it again when I did some shirts for my kids and I touched up the treatment by spraying it a couple times during the course of the past two months as I have been washing it at least once a week. It has worked great. The mosquitoes will not stay on it. And we have seen some major skeeters in Minnesota this year. They drove the kids and me inside as soon as the sun started dropping while in Itasca State Park in the picture below.

Card sharps

While I really like wool for odor control I have to say that the silver ion scheme used in the Sonam works as well as any silver shirts I have owned, and better than most. Even after using it for six days in Yosemite (granted I was not hiking in it during the heat of the day) it had no hiker funk going on. I am looking forward to using it more once the weather cools off and I can wear a long sleeve base layer all day long.

It still looks great too. The color is still vibrant, the shape still fine. Well as good as it can be since it has to conform to my shape… ;-) The zippers work (although I still have never used the chest pocket), the seams are sound, the edges are not fraying, the logo is not falling off. It is holding up very well.

I look forward to using the Sonam more this winter, and thank Sherpa Adventure Gear and for letting me test it.

This report was created with the Report Writer Version 1.5 Copyright 2010. All rights reserved.

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