Backup lights material: Aluminum or Delrin ~ which is better and are both DIR?

[jonnythan]

So, in other words, the point to take home is that one isn't necessarily any better or worse than the other, and no one has probably seen either one fail to light because of the contact method.

And either one is DIR.

Now let's get on with life...

 

[lamont]

So let's reverse the question. What problems do the delrin lights solve over Al? Side note...I use delrin, just curious as to your answer.

the thing is, i don't care about the reverse question because i dive with delrin backups. if Al doesn't solve any problems over delrin, then i'm filing that one in my "solution in search of a problem" folder -- particularly if they cost more.

detroit diver has an excellent reason for why his Al lights are DIR (IMO) because he picked them up for $20 when abyss went out of business. that is solving a real problem with the delrin backups. i've got no argument there.

 

[Jason B]

the thing is, i don't care about the reverse question because i dive with delrin backups. if Al doesn't solve any problems over delrin, then i'm filing that one in my "solution in search of a problem" folder -- particularly if they cost more.

detroit diver has an excellent reason for why his Al lights are DIR (IMO) because he picked them up for $20 when abyss went out of business. that is solving a real problem with the delrin backups. i've got no argument there.

I figured you'd cop out with that standard answer, that's why I asked.

Jason

 

[Goose75]

There is no direct contact point. At the bottom, there is a spring which provides a couple of inches of contact with the housing. At the top, the battery is only in contact with the bulb asssembly which provide more than a couple of inches of contact with the housing. Why would the aluminum become corroded? Why would it become more corroded than copper? Why wouldn't I just clean off the corrosion?

The spring is likely to be steel. Steel and aluminum are dissimilar metals. Even if it is another material, they will be dissimilar. The spring material will be a good conductor and the aluminum less so. Dissimilar metals suffer from galvanic corrosion in a salt water environment. You are not flooding the battery compartment and provide preventative maintenance so you may never see it, but it is another possible failure point. They may have isolated the aluminum from the steel, but that adds another material and complexity.

I think the question you should really be asking is whether any people have had their delrin or aluminum light fail and why. Your polymer light lost the copper strip. Is that typical, a problem with a specific brand or an isolated occurrence?

Based on results, lights that have a propensity to fail during use should be discouraged, lights that fail in between dives should be a 'buy at your own risk' and all others are personal preference. I think most lights work when properly maintained, but there may be some shoddy constructed ones out there. I think you will find brand a bigger factor than the housing material.

 

[lamont]

I figured you'd cop out with that standard answer, that's why I asked.

Sorry...

Ooooohhhh... Aluminum... Shiny.... Must buy...

That better?

 

[Jason B]

No, I was looking a serious answer.
You said "as someone who currently uses delrin backup lights, what problem do the Al lights solve?"

So I asked "as someone currently using delrin, what problems do the delrin lights solve over Al?

You then gave the standard DIR cop out of "solution in search of a problem"

Maybe it's just another option....

 

[JeffG]

No, I was looking a serious answer.
You said "as someone who currently uses delrin backup lights, what problem do the Al lights solve?"

So I asked "as someone currently using delrin, what problems do the delrin lights solve over Al?

You then gave the standard DIR cop out of "solution in search of a problem"

Maybe it's just another option....

or maybe someone with delrin lights (and without Alum lights) wouldn't be able to answer that question in the first place. Hench the "cop out"

 

[jagfish]

I kinda see Jason B's point here. The original statement suggests that Delrin is the norm and the use of another substance, either more exotic/expensive material, would need to be justified as to the benefit gained...

Maybe AL lights are way more expensive than Delrin at retail (I have no idea), but given the price that the lights were bought for by this poster, I think the economic benefit speaks for itself in this case...(assuming equivalent performance)

 

[lamont]

I kinda see Jason B's point here. The original statement suggests that Delrin is the norm and the use of another substance, either more exotic/expensive material, would need to be justified as to the benefit gained...

Its not my job to do thorough consumer testing on every single bit of dive gear out there. In general, if I've got a piece of gear which i'm using which has a long track record and known issues what i want to see in alternative kind of gear some kind of problem that the alternative gear solves. Apparently this kind of sensible filter to avoid spending money on solutions in search of problem is a "cop out". *shrug*.

Note that i'm *incredibly* selfish in my perspective. I don't care to try to find the objective truth of the usefulness of a piece of gear (which is apparently where I 'cop out'). You all can argue all you want over if one is theoretically better than the other, or what weaknesses there might or might not be in the alternative piece of gear. If you can't come up with a problem that the alternative gear solves, i'm not interested. Hence, the question I asked.

If it doesn't solve a real problem, the best it can do is be equivalent, while the worst it can do is produce more problems. That bet doesn't interest me much. You guys can argue about hypothetical problems it solves, or possible issues it might have, or argue about its equivalency. Let me know when you come up with a real problem it solves.

 

[jagfish]

Lamont, I hear you....

I think the way your post was worded, it was taken, "why would anyone, use this light if it does not solve a problem", versus the intended meaning you express above..."why would Lamont use the AL light" (who is already happy with Delrin).

got it...