Im glad you pointed out possible excess weight : I am about 5ft10 and 90kg, I do have a S/S backplate but not sure what size it is, think it is small.
If it's a Halcyon plate, then it's probably the standard plate and if it's made out of stainless steel then it should weigh around 6-lbs, which should translate to your dive weight ballast.
But i do have a 40lb donut, maybe i should have gone 30lb, not sure how much this would help? Iwent the 40lb as i asked the diveshop if this could take 2 tanks if i happen to get a twin tank adapter down the track, think i was looking to future proof for deeper dives.
40-lbs lift is generally too much for one tank unless you want to pile on a bunch of scallops of shellfish in a game bag and use your BC to lift it up instead of a lift bag. 30-lbs lift is usually right for a single tank in cold water.
I do seem to have to really shake the exhaust hose, even with my 24lb to start to decend heads up.
Yep, air trapped in the too large wing.
1. My hood may be too large too large , i have to burp it before entry and even then air is still trapped, may have to buy the next size down.
Not enough to affect buoyancy or trim. Drill (or burn) a couple of holes at the top of the hood and the air will vent out. Take a screwdriver and a butane torch or propane torch. Heat the screwdriver up until about two inches of the tip is red hot and burn through the top of the hood.
2. I am working through equalizing issues (barotrauma in left ear on my first dive) , so at the moment i cant duck dive down the first 2 - 3 metres, have to decend head up (need more weight). Hopefully can duck dive soon and this will help lighten the weight im told, would this help?
Yes and no. Yes, you can duck dive (aka pike dive) and save some weight but not by much, a couple of pounds at most. And then you may risk being too light for end of dive safety stop. If weighted properly, you should be able to sink very, very, very slowly when you fully exhale in a vertical position. That way you can equalize for the first 10-ft or so, then you'd flip horizontal and do a horizontal descend.
3. I have mainly been diving with Alum tanks, not sure what size but they hold 200Bar. I am looking at possibly buying steel tanks as i am fishing in only 2-5m of H20 at the moment (will only be diving to around 10-15m max) and when the Alum tanks are getting low im having issues staying down. Hopefully the steel will help cut my weight down and also help with bouyancy issues when air getting lower?
Chances are the tanks you're using are colloquially known as Aluminum 80 (80-cubic feet in American parlance). As I understand it, the rest of the world use "liter" for tank displacement - actual tank displacement, that is. Typically it's about 10-liters and 207-bars equal to roughly 3000-psi. Another general rule of thumb is that a typical Al80 tank is positively buoyant when empty. That's why you have issues with staying down when your Al80 tank runs low. Not all Al80 tanks are this way, Worthington has a neutrally buoyant Al80 (-0.1lbs , so effectively it's 0-lbs in buoyancy characteristics).
As far as steel tanks may help you with not floating up when running low...yes and no. Depends on the steel tanks that you pick. Believe it or not, some steel tanks are positively buoyant. A Faber low pressure 85-cubic feet tank is actually +2.32lbs buoyant. Almost as bad as a typical Al80 tank. Don't take anybody's words for it, ask to see manufacturer's cylinder specifications & characteristics charts.
Thats handy to know that you can reach back and release the trim weights that are on your tank i presume? The shallow dives i have been doing solo at times due to convenience. Also great idea to colour them for when i do dive with someone.
Unless you have the arms and dexterity of an orangutan, I don't think that you can reach back and release the trim weights that are attached to your tank straps. I meant that you can reach back and dump the weights in your Infinity's belt mounted weight pouches.
As quoted from the Halcyon website "While at the surface Halcyon trim weights promote a heads up position, counteracting the positive tendency of bouyant cylinders. These same weights support a horizontal position while under water, reducing effort and ecouraging diving fun".
Use negatively buoyant steel tanks. End of problem.
At the moment i have to arch the back and use my flippers to stop moving face foward to the H20. Perhaps when i get a steel tank it may be better though.
Maybe it's your trim weight (or lack thereof), maybe it's the aluminum tank that acts like a balloon on your back, or maybe you have too much air in your BC on the surface. It's hard to make a diagnosis without seeing you in the water. I am fairly convinced that you have too much weight though. 30-lbs even take into account of an aluminum tank is a lot of weight for a 7mm wetsuit and single tank configuration. I doubt that you have more body fat than me, especially you're taller by 4-inches.
If in an emergency it is also helpful to be floating with face out of H20.
The beautiful thing about a BPW is that you can arch all the way back and float on your back well out of the water if you fully inflate the BC. I've done it before. It's like you're floating on a raft while facing the sky.
---------- Post added February 11th, 2014 at 09:20 AM ----------
Weightbelt doesnt seem to fit well and would prefer to go with intergrated as long as there is no compromise safety wise.
Believe you me, I know the feeling about weight belts not fitting well because of my girth. If you select your tank carefully, I see no reason that you cannot use the integrated weight pouches that are part of the Halcyon Infinity package. These weight pouches are good for 5-lbs/each side for a total of 10-lbs.
I think that you really need to double check your dive weight. Go out with your wetsuit/snorkel/mask/fins and weight yourself with a weight belt, putting in weights until you float eye level to the water with a lungful of air. Whatever gear configuration you use, the negative buoyancy should equal to this pre-determined weight of you in your wetsuit.
Also, know what material your backplate is made out of, is it steel or is it aluminum?