Some drysuit questions

[Burner]

I'm fairly new to my drysuit and had a couple of weighting questions.
I have a CF200 suit, with the 200 thinsulate stuff made by dui that has like a windbreaker outer shell. I'm about 5'6 130

About how much weight should I be wearing?
I am currently at 8-9lbs

Sometimes I get a little cold, would putting on a cotton sweatshirt over the top of my underwear help out? How much weight would I have to add to compensate for doing this?
Is it just better to have more air in my suit?

How much warmer is argon?

 

[VTernovski]

cotton is bad. go for fleece instead. where od you dive, what temp?

 

[theskull]

Any clothing you add will add insulating air-space, and therefore will require additional weight. I recommend polar-tech tights as worn by bicyclists, worn under your undergarments. Just adding air to the suit will not help much, as it will migrate to the uppermost part of the body as buoyancy.

Argon does make a big difference, feels like warm air being pumped into the suit. But do you need it? A 14 cu ft tank costs nearly as much as a full size tank, and you still have to buy a first stage reg and lp hose, and attachment straps. Not to mention you need a source of argon fills. If I were not a trimix diver I would not have bothered with the argon myself.

You can also add a lot of warmth with a good quality 7 mm hood and 5 mm gloves!! Can't beat the Henderson 7/5 mm titanium hyperstretch hood, drysuit neck cut. Also helps a little if you soak your hood and gloves in hot water prior to donning them.

Comfortable diving,
theskull

 

[Burner]

Monterey, temp is probably 50-60 degrees depending on the day. Thermocline will get it a bit colder. The one time I tried with my cotton sweatshirt I was noticeably warmer, but I seemed to be slightly underweight. I do have a fleece shirt that I could wear over the top, would that work better?
It does seem that argon is more expensive then its worth.

 

[Bob3]

You can pick up a military surplus arctic weight polypro underwear top, about $10. It'll keep you unbeliveably warmer.
for an example, see: http://www.sportsmansguide.com/cb/cb.asp?a=69739

If you can, get the TALL top so you'll have more to tuck in, eliminates the riding up of the tail.

For something lighter in a 1-piece: http://www.tedsmilitarysurplus.com/clothacc/uwpredunion.html

Argon becomes an issue only when diving with helium; general consensus is that an extra layer of undies (preferably polypro or other hydrophobic fiber) makes the difference.

 

[scubasean]

Bob3 once bubbled...

Argon becomes an issue only when diving with helium; general consensus is that an extra layer of undies (preferably polypro or other hydrophobic fiber) makes the difference.

Except for helium being used for deeper dives, what does He have to do with Argon? If someone gets cold at depths that are less than that which would required He, why couldn't they use Argon?

I already recognize that some folks would say that anyone diving shallower should use a better undersuit...but that is personal choice, isn't it?

 

[VTernovski]

You don't need Argon for 50-60F unless you are diving Trimix. Air will be sufficient enough insulation. Does your hands get wet or damp after a dive? This might add up to the fact you are being cold, especially on repetitive dives. I suggest moving to dryglove system. Also, make sure you have a good hood, I use 6.5mm drysuit hood around here (around 50F) As far as how much weight you should wear... it all depends, and I don't think anybody can tell you what you should wear without you do a check for yourself. Try to do it with as least psi in your tank as possible. You know the drill, right? Unless you are doing the boat dive... you bring some single weights and add/remove until you achieve a good ammount of weight so that you can sink when you exhale (BC and suit fully deflated) and float at eye level when you inhale... some pople suggest doing this at 10 feet, but this gets kinda hard with adding/removing weights, so doing it on the surface is fine too.

 

[VTernovski]

scubasean once bubbled...


what does He have to do with Argon? If someone gets cold at depths that are less than that which would required He, why couldn't they use Argon?

Helium readily transmits heat away from the body; in fact it is six times more conductive than air, using a helium mix for suit inflation risks hypothermia and mental impairment due to the debilitating effects of cold on the body. In that case you use Argon for your suit inflation. Air is also a good insulator, and is sufficient enough and unless you do breath He mix such as trimix, there is no need to bother with additional gear of Argon. It simply isn't necessary in this case especially we are talking about 50-60F.

 

[ERP]

scubasean once bubbled...


Except for helium being used for deeper dives, what does He have to do with Argon? If someone gets cold at depths that are less than that which would required He, why couldn't they use Argon?

Helium has much higher heat conductivity than air, so you generally don't want to use it to inflate your suit.

 

[Burner]

Thanks for the suggestions. I'll pick up a fleece shirt for the days where it is a little cooler. I already have a think hood and gloves.
As for weighting I weighed myself off the edge of a boat and put weights onto the boat until I couldn't sink anymore. I think with 8lbs I was able to sink. I am using 9 so that I have a tad extra.