Trying to Find One

[BobS]

This is my first post, but I've been reading the forums for some time now trying to gain whatever information I can.

Basically, I've been thinking about getting my hands on a Synchronar for a sometime now, ever since a coworker introduced me to the watch, but its only recently that I decided to actively go about looking for one.

Unfortunately, it appears I may be a little too late to the party.

Based on what I've read on the forum, it looks like Howard Riehl discontinued production sometime last year. Is that correct, or are they still *officially* available, either new or refurbished?

I've sent a couple of e-mails to Mr. Riehl, but haven't gotten any responses, which I understand isn't altogether unusual.

Any advice would definitely be appreciated, it looks like a number of people here have gone through some difficulty acquiring your own Synchronars.

[clockace]

if you have the skills you can probably get something going if you concentrate on the mkI/II versions. the mkIII's have exposed wire bonds on the chip and they are all pretty much dead. sometimes barry, howards brother, has some mkI/II's for sale on ebay. i got all my stuff from howard before things dried up with him. i have had good success with the I/II's. they are more repairable. best wishes, peter

[bucko170]

It might be worth keeping an eye out on eBay - working ones do crop up from time to time.

[BobS]

Yeah, I guess I'll keep my eyes out on eBay. I think Howard actually still puts something up for sale once in a while; parts, bands, etc.

Thanks for the tip on the MkIIIs, I think my natural instinct would have been to assume newer=better, so that's definitely useful information.

[J Thomas]

[redcar66]

[BobS]

I've actually gone ahead and ordered one through pulsarleds.com, I was surprised how easy it was, he's got a couple of them in stock. Its a refurbished Mk I with new batteries and solar cell, can't wait.

[redcar66]

[redcar66]

hey guys looks like a nice sync has hit ebay
what do you all think?
http://shop.ebay.com/170440457971
Kevin

[dot matrix]

hey guys looks like a nice sync has hit ebay
what do you all think?

I'm really intrigued by the fact that this module has been filled with silicone gel. I can see some pluses and minuses to the idea:

On the plus side, it seems to me that having gel in the module would help to hold everything in place and prevent things from shifting around. It would probably also help cushion against any sudden impacts or shocks. A big plus in my book is aesthetics - when a module is potted and catches the light right, it can look absolutely gorgeous.

On the minus side, I'm wondering what the odds are of possibly trapping moisture inside the watch during the potting process. I would think this should be done in a dry room, and that the module should be given plenty of time to set once the gel and internals are in place. Roger once told me how long he let modules set, but I don't remember what he said. He also explained how any moisture or corrosive substances (acid, salt water, etc) would be trapped inside by the gel and slowly diffuse throughout the module, eventually causing corrosion, shorts, and other problems. I would think that if there were no gel in the module, such substances would be able to drain out. So in a sense, a gel-filled module could lull the wearer into a sense of false security, thinking the watch is more water-resistant and impermeable than it actually is - and that he would thus be more likely to inadvertently damage his watch, because in the real world, anything can get inside that lexan module.

[J Thomas]

[charger105]

Another advantage of filling with this potting gel is that it provides pressure resistance (AFAIK). SImply put, it's harder to crush when full of gel. Thinking about it, this gel would not be as compressible as air. Hence, it would help the casing to remain rigid under high pressures. My MkI manual spcifies an immersion depth of 200m.

I think they decided to market Synchronars to divers at some stage (I read somewhere that they were sold in dive shops).

Rgds,
Andrew.

[retroleds]

Another advantage of filling with this potting gel is that it provides pressure resistance (AFAIK). SImply put, it's harder to crush when full of gel. Thinking about it, this gel would not be as compressible as air. Hence, it would help the casing to remain rigid under high pressures. My MkI manual spcifies an immersion depth of 200m.

I think they decided to market Synchronars to divers at some stage (I read somewhere that they were sold in dive shops).

Rgds,
Andrew.

Hard to say about the value of an non-compressable material being placed inside a container that we(ok, anyone who has played with SYncronars that were apart) know IS compressible. I'm thinking the container flexs under pressure, the gel acts as a hydraulic fluid(non-compressible) and the components take the beating. A gas would act as a buffer. Submarines and such flex slightly under the crushing ocean pressures - mercifully air buffers the effect somewhat for the sailers inside. Ditto for airplanes but in reverse.

Common silicone would be a terrible thing to use - it is 3-5% water, in the form of acetic acid(vinger smell ), which is hard on metals. Common Silicones(like clear caulk) will corrode copper or aluminum on direct contact. Potting gels come in many types, some are water based....I could swear Howard told me he(or maybe it was Dad) was using the water-based kind for a while.

[clockace]

Well----! that would certainly explain the rust spots on the chip as well as the rusted off chip leads under the sc. i have seen this on most of the ones i have repaired to some degree or another. water and watches usually don't mix well, especially if it is inside. i had a $100,000 jacob&co for repair not long ago. the owner had gone in the water with it. it was a 5 time zone batt operated with 5 different movements in it. 3 of the 5 still work. what made it so expensive was the diamond paved dial and case. peter

[dot matrix]

Well----! that would certainly explain the rust spots on the chip as well as the rusted off chip leads under the sc. i have seen this on most of the ones i have repaired to some degree or another. water and watches usually don't mix well, especially if it is inside.

Hi peter. Most of the modules I've opened have been corroded.

I don't think it was clear in my post above, but the main problem with the gel was after the watch had been sealed and in use, not water getting in during production. Invisible micro-cracks would eventually develop in the lexan through normal use of the watch, then water would get in and slowly diffuse through the gel. This was especially a problem when the watch was used in the ocean - the temperature difference would accelerate the cracking process, and then salt water would leech in.

Late in the game, Roger experimented with a work-around: Instead of using gel, he would pot the watches with polyurethane, which did not have any of the problems that the gel did. He planned to do this with the Mark V but one of the delays with this idea was that the polyurethane filled modules all had bubbles in them and he spent a lot of time trying to figure out how to prevent that from happening.


(pic from http://www.ledwatches.net/articles/synchronar_review.html)

This was around the same time that he added the metal back. Until reading the above review, I never knew that he had actually made any polyurethane filled modules, only that he was planning to.

In addition to the bubbles (which wouldn't bother me at all), I imagine that one big drawback with the polyurethane idea is that it would be impossible to service the watch. If I ever do such a thing myself, I would leave empty space in the module for the batteries, allowing them to be replaced down the road. But anything like replacing the solar panel or adjusting the positions of the reed switches would be out of the question so I really don't recommend it - I only mention it for historical reasons.

[charger105]

I was thinking that the gel (when hardened......not the gooey stuff), would reduce the flexing of the case when under pressure. Less flexing would mean less likelihood of the case cracking or the case seams cracking.....which would be a really bad thing

I think you are right though, the gel would transfer this pressure into the watch components.

Rgds.

[bruce wegmann]

My experience with potting compounds is that they work well [and best] when de-aired...that is, placed under vacuum until all the dissolved air is pulled out of the mix. Ideally, it is also poured and allowed to cure under vacuum, as well. Then, there are absolutely no voids left to become problems. This is such an industry-standard process, that I'm surprised that Riehl apparently never thought of it.

[retroleds]

Withstanding all of this, I am also confounded that nobody(Riehl) thought of the gases that are vented by a battery as it ages and or dies. Battery chemistry reverses itself on discharge or aging. Acid cells go alkaline, alkaline go acid, gases are formed in the process. I recently sold my clear-top Synchronar to one of our members(surprised he hasn't bragged it up). It is only lightly sealed with a non-acid silicone, has a completely clean board(never potted) and solar cell which are lightly anchored also with silicone(while open for several days just in case.)
The idea of diving with a plastic watch is kind of nutty in my mind: You want something that is really sturdy(like STEEL) and something that won't attract barracudas and other aggressive underwater dwellers. Like most "diver's watches", I think most Synchronars never went any farther than the shower or pool. Besides, any true diver's watch needs at least a 9.5" band to go over one's wet-suit and they is no way you are operating those switches with wet, possibly gloved hands. I have a few workers here and two that were never potted in any fashion. I'll eventually put them together as best I can with modern products and offer them up.

Glad you finally got one Tor(liquid crystal). And thanks for giving me a chance to run this little outpost against sanity. .

[clockace]

hi ed, it has long been known that acid and alkaline cells become corrosive as they deplete. if they reverse composition as they deplete, has anyone determined what happens when the nicad and niMh deplete? it was my understanding that the niMh has nothing corrosive in it, but that may be while they are still rechargeable, nicad's of course have cadmium as a "not green" ingredient, but what happens as these cells become unusable? probably a stupid question, but someone may be more intelligent than me! peter

[J Thomas]

[dot matrix]

My experience with potting compounds is that they work well [and best] when de-aired...that is, placed under vacuum until all the dissolved air is pulled out of the mix. Ideally, it is also poured and allowed to cure under vacuum, as well. Then, there are absolutely no voids left to become problems. This is such an industry-standard process, that I'm surprised that Riehl apparently never thought of it.

According to J Thomas above, Roger Riehl did indeed pot the modules in a vacuum chamber. I have a vague memory that he may have mentioned this to me in a phone conversation as well, but at this point I'm not sure.

The bubble problem only happened with the polyurethane, not with the gel. I assume the liquid solidified while it still had bubbles forming in it, before all the gas was able to be pulled out. I base this assumption on my own experiences applying polyurethane finishes.

I suppose it was an MK4 that required a new solar cell or batteries, and so it was opened and serviced.

If the seller knows how the potting process was originally performed, (vacuum chamber) then moisture would not be an issue. Makes me wonder if he used GE90 or GE615 to pot it with.

In the description, the seller describes it as "a special two component glass clear silicone." I asked for more detail on it, and he described it as a "gel that comes from a company called nusil in US. - a special silicone developed for electronic components used in conjunction with other optical electronic parts."

(nusil.com)

He also says he potted and sealed the watch about a year ago.

[redcar66]

Well guys she just sold for US $1,234.56 (123456?)
that is a nice price I believe I would love to
to sell a few of them
Kevin