caseybird
Contributor
Make them black.
demands and supplies - titanium backplate
- Thread starter Homunculus
- Start date
Please register or login
Welcome to ScubaBoard, the world's largest scuba diving community. Registration is not required to read the forums, but we encourage you to join. Joining has its benefits and enables you to participate in the discussions.
Benefits of registering include
- Ability to post and comment on topics and discussions.
- A Free photo gallery to share your dive photos with the world.
- You can make this box go away
There are four types of divers I can think of that would constitute the market for a titanium backplate.
- Divers who enjoy conspicuous assumption.
- Divers who need to shave weight off their gear in order to accommodate air traveling weight limits and that do not like aluminium or polymers. As an example, a diver might be on an expedition that requires a lightweight backplate for traveling but does not have access to freshwater on location (e.g. diving off a small tropical island where freshwater is nonexistent and equipment must function without rinsing). Aluminium can corrode very quickly when exposed to a warm and humid environment. Polymers, which can be quite strong, are often not as robust as an alloy designed for harsh conditions.
- Military divers that require a robust and nonmagnetic backplate with a long service life. Aluminium will eventually corrode and need replacement. A polymer/composite backplate may not be durable enough.
- Divers who want to buy equipment that won't ever fail, regardless of how unlikely or minor a failure may be. I happen to be such a person, and as long as the price is not too extravagant, I'll save my pennies, buy it, and pass it on to my grandchildren.
A titanium alloy backplate fits the bill for all of the above.
Most people will advocate aluminium alloys over titanium alloys in diving applications. Aluminium is indeed a lighter material than titanium, but it is also softer, weaker, and prone to corrosion over long periods of marine exposure. In my view, aluminium backplates are essentially disposable, as they eventually corrode to the point where a new backplate is preferable to the aggravation. However, it takes many years of use for an aluminium backplate to suffer such effects, so most divers with aluminium backplates will only experience such problems far into the future, if ever. Yet, some people will want something that is stronger than aluminium alloy and utterly corrosion proof. Polymers and stainless steel just aren't good enough for some people. But, if a titanium backplate were more than twice the price of an equivalent stainless steel backplate, the cost/benefit ratio would be quite unfavourable to most people I think. However, if a titanium backplate were in the $200-$300 range, then there might be sufficient interest to support the product. Titanium as a material has a great many virtues, but many of those virtues are negated by its cost. If you can find some way to produce a relatively affordable titanium backplate, people will buy it. I certainly would.
As for the variety of titanium alloy to use for a backplate, I would strongly recommend using 6Al-4V (AKA grade 5) titanium alloy, the 'workhorse' of titanium alloys. 6Al-4V is widely available, it is heat treatable, it can be hot or cold formed, and has excellent strength. If a shop has experience with austenitic stainless steel alloys (300 series), then it can work with 6Al-4V titanium alloy.
Many manufacturers of titanium products use CP (commercially pure) titanium, the most common variety known as 'grade 2'. Grade 2 titanium is unalloyed, and while still a robust material, is not as strong as a titanium alloy and cannot be heat treated. I believe the primary reason for the popularity of CP titanium is its relatively low cost and wide availability. Many manufacturers will shave pennies off of material costs and still exploit the aura of invincibility that titanium has seemed to garner.
The benefits of titanium's famous strength to weight ratio are best realized with 6Al-4V or similar alloy. Using CP in my opinion would be a cop-out.
Good luck with your venture and keep us posted here on Scubaboard!
Cheers,
Sadamune
- Divers who enjoy conspicuous assumption.
- Divers who need to shave weight off their gear in order to accommodate air traveling weight limits and that do not like aluminium or polymers. As an example, a diver might be on an expedition that requires a lightweight backplate for traveling but does not have access to freshwater on location (e.g. diving off a small tropical island where freshwater is nonexistent and equipment must function without rinsing). Aluminium can corrode very quickly when exposed to a warm and humid environment. Polymers, which can be quite strong, are often not as robust as an alloy designed for harsh conditions.
- Military divers that require a robust and nonmagnetic backplate with a long service life. Aluminium will eventually corrode and need replacement. A polymer/composite backplate may not be durable enough.
- Divers who want to buy equipment that won't ever fail, regardless of how unlikely or minor a failure may be. I happen to be such a person, and as long as the price is not too extravagant, I'll save my pennies, buy it, and pass it on to my grandchildren.
A titanium alloy backplate fits the bill for all of the above.
Most people will advocate aluminium alloys over titanium alloys in diving applications. Aluminium is indeed a lighter material than titanium, but it is also softer, weaker, and prone to corrosion over long periods of marine exposure. In my view, aluminium backplates are essentially disposable, as they eventually corrode to the point where a new backplate is preferable to the aggravation. However, it takes many years of use for an aluminium backplate to suffer such effects, so most divers with aluminium backplates will only experience such problems far into the future, if ever. Yet, some people will want something that is stronger than aluminium alloy and utterly corrosion proof. Polymers and stainless steel just aren't good enough for some people. But, if a titanium backplate were more than twice the price of an equivalent stainless steel backplate, the cost/benefit ratio would be quite unfavourable to most people I think. However, if a titanium backplate were in the $200-$300 range, then there might be sufficient interest to support the product. Titanium as a material has a great many virtues, but many of those virtues are negated by its cost. If you can find some way to produce a relatively affordable titanium backplate, people will buy it. I certainly would.
As for the variety of titanium alloy to use for a backplate, I would strongly recommend using 6Al-4V (AKA grade 5) titanium alloy, the 'workhorse' of titanium alloys. 6Al-4V is widely available, it is heat treatable, it can be hot or cold formed, and has excellent strength. If a shop has experience with austenitic stainless steel alloys (300 series), then it can work with 6Al-4V titanium alloy.
Many manufacturers of titanium products use CP (commercially pure) titanium, the most common variety known as 'grade 2'. Grade 2 titanium is unalloyed, and while still a robust material, is not as strong as a titanium alloy and cannot be heat treated. I believe the primary reason for the popularity of CP titanium is its relatively low cost and wide availability. Many manufacturers will shave pennies off of material costs and still exploit the aura of invincibility that titanium has seemed to garner.
The benefits of titanium's famous strength to weight ratio are best realized with 6Al-4V or similar alloy. Using CP in my opinion would be a cop-out.
Good luck with your venture and keep us posted here on Scubaboard!
Cheers,
Sadamune
SkullDeformity
Contributor
So what if you were allergic to aluminum, and plastic killed your parents? Huh? I bet you guys didn't think of THAT!
RonFrank
Contributor
Sadamune:
I think your examples of where this plate is *needed* are a stretch. BP failure?
How would one survive on an island for a period of time long enough that saltwater would melt ALUM to the point of non-functionality where there is NO fresh water and equipment must function without rinsing? What exactly is keeping the diver alive? I would think the BP would be the last thing to melt down, first might be a reg.
So this diver has a way to fill his tanks, food, water to drink, a reason to dive, but no way to rinse gear? I really have to hear the logic behind this mission!
Single tank divers use SS/BP's in order to add appropriately positioned weight. Divers using doubles use an aluminum or Kydex BP in order to spare weight. I just don't see where using a titanium BP would be any sort of cost effective solution to either camp.
Me personally, I'll opt for aluminum when in need of cutting weight.
As far as failure rates go...unless ones aluminum BP is exposed to electrolytic degradation....It will be here long after you and I are gone.
Me personally, I'll opt for aluminum when in need of cutting weight.
As far as failure rates go...unless ones aluminum BP is exposed to electrolytic degradation....It will be here long after you and I are gone.
Where fresh water is scarce, it will be conserved for drinking and not wasted on rinsing gear. If a diver were collecting gear to be used on a series of expeditions where access to fresh water is difficult or restricted, it would be wise to acquire gear that can tolerate little to no maintenance in the field over long periods of time. A titanium backplate might appeal to someone in that position. Admittedly, such circumstances would be rare, but still conceivable. My other examples also represent uncommon scenarios, but they all are situations where a titanium might be solution.
Regarding aluminium backplates, bear in mind that I consider the minor corrosion that eventually occurs around slots and holes to be a mode of failure. The backplate would still function, but it could become a nuisance as it abrades webbing, welds to bolts, and produces slivers. There are better materials out there. Cost is the only issue.
Sadamune
Seawater is an electrolyte. The stainless nuts and bolts used to mount STAs, back pads, etc., are in direct contact with an aluminium backplate. As there are small crevices and gaps between the two metals, seawater will creep in (capillary action). Even when out of the water and having been rinsed, a tiny amount of seawater can remain in these little spaces. The two dissimilar metals, each with a different electrode potential, with the interstitial electrolyte of seawater creating a galvanic couple, produce an ion flow from anode to cathode. The next thing you know, the 'stainless' bolts have welded themselves to the aluminium. I've had to throw away several pieces of aluminium dive equipment because of galvanic corrosion that transformed the anodized aluminium into what looked like toothpaste. Galvanic corrosion is an ever present problem in the marine environment.
As for aluminium backplates, I've heard that they last for 10-20 years before they become annoyingly crusty and ugly. Practicality aside, for those who desire a backplate that can last for a thousand years, titanium is a viable option.
Sadamune
I sure didn't think of that. You raise a good point though. People who have been traumatized by plastics and who also suffer from aluminium contact dermatitis would be a potential market for titanium backplates. In fact, I'm sure they'd get all warm and fuzzy just thinking about it.
Sadamune
Zeeman
Contributor
ninja edit - point about Ti alloys already made by someone else.
Similar threads
