On 4/29/2025 at 10:44 PM, Susa said:

I had the same issue before 2 weeks, let it closed overnight, and next day when I opened it, there was a little water inside. Luckily it worked after drying. I did not found any problem on o-ring or elsewhere. I changed the almost new o-ring without really thinking that this was the issue :-(.

That's 3 similar HF-1 floods on this thread.

42 minutes ago, JayceeB said:

That's 3 similar HF-1 floods on this thread.

FYI - I've done about 20 successful dives with my HF-1 since the battery compartment had a flood. I cleaned it and replaced the orings for good measure and it's working great.

Dave: Did you replace the cap?

BVA

Just now, bvanant said:

Dave: Did you replace the cap?

BVA

No. The cap seems to be working just fine and no visible change.

Add us to the list of HF-1 Floods, ours flooded on the 6th dive, but Backscatter wants to place blame on us so we have to pay for the parts but the labor is free 🙄

I am the most persnickety person known to most people when it comes to gear, we inspected the seals before installing the battery cap, two of us verified no debris at all (hair, dirt, sand etc) entirely free of anything foreign both on the seals and the cap, yet if flooded on the 6th dive, brand new! I am so persnickety we even use a magnifying glass when we do it (yeah, I know, its a lot but I know stress cracks and smaller debris can cause catastrophic problems too and an extra $9 device and 5 seconds goes a long way). I talked around some folks here in South Florida, three others said the same thing happened to them, both with nearly new HF-1 strobes. Since they're not big forum people they won't post about it, but if you add them, its seven floods this year, but Backscatter wants to blame everyone else, I wonder when this becomes a bigger problem if they'll realize they have a larger issue. I have a video that even shows the difference in the thickness of the o-rings from the failed unit to the one that didn't, its very noticeable, but I won't get into how O-rings work and why, sometimes, undersized and/or oversized o-rings can still "work" but usually not long term, using an incorrect washer is more like my Australian friends call a "bush repair". The funny thing, the replacement o-rings are also thicker (same size as the one that didn't fail) from the ones that did fail, but yeah, the customer is the problem so we're done with anything Backscatter.

Sorry you had this problem. Hopefully Backscatter has upgraded the orings. I had one HF-1 flood, but it did not harm the strobe. Cleaned it up and it is still going strong.

We went and brought KS160 strobes from Reef this morning, we have zero faith in Backscatter and their customer service

Good luck. Every underwater device sealed with orings can and will fail, even if you take care. I am very meticulous and I've had a 3-4 strobe and housing leaks across 1500 camera dives. Only one (the first) can i directly attribute to my avoidable errors. I likely made other errors, but less obvious ones. Not replacing orings soon enough for example.

4 hours ago, Dave_Hicks said:

Good luck. Every underwater device sealed with orings can and will fail, even if you take care. I am very meticulous and I've had a 3-4 strobe and housing leaks across 1500 camera dives. Only one (the first) can i directly attribute to my avoidable errors. I likely made other errors, but less obvious ones. Not replacing orings soon enough for example.

This may be true, however it should not be happening after 6 dives. I think the report of differing cross section o-rings is a concern though.

I would think that 2 o-rings are there for redundancy, but it is hard to understand how it would leak unless both were small.

Bill

3 hours ago, bvanant said:

I would think that 2 o-rings are there for redundancy, but it is hard to understand how it would leak unless both were small.

Bill

I think they are saying both o-rings are small. This strobe has a third "sand" ring designed to keep particles from getting into the o-rings and they are very effective, I have one on my INON torch and it's also usually dry inside, so no water droplets on the o-ring, but I don't think it is a completely reliable seal. It may work for the first few dives but eventually water gets through to the under sized o-rings. This could explain the strobe working for a short while then flooding.

Has the issue of the different sized o-rings been presented to Backscatter, has anyone measured to the cross section with calipers? If you look at their website this photo shows an apparent difference in the size of the two o-rings installed on the strobe. It may be an optical trick, but it is worth raising with them.

1 hour ago, Chris Ross said:

I think they are saying both o-rings are small. This strobe has a third "sand" ring designed to keep particles from getting into the o-rings and they are very effective, I have one on my INON torch and it's also usually dry inside, so no water droplets on the o-ring, but I don't think it is a completely reliable seal. It may work for the first few dives but eventually water gets through to the under sized o-rings. This could explain the strobe working for a short while then flooding.

Has the issue of the different sized o-rings been presented to Backscatter, has anyone measured to the cross section with calipers? If you look at their website this photo shows an apparent difference in the size of the two o-rings installed on the strobe. It may be an optical trick, but it is worth raising with them.

I thought it was just my old eyes seeing two different sized o-rings when I looked at the picture on Backscatter’s website. In the picture the o-ring on the bottom appears to be thicker than the one on top.

5 hours ago, JS1221 said:

I thought it was just my old eyes seeing two different sized o-rings when I looked at the picture on Backscatter’s website. In the picture the o-ring on the bottom appears to be thicker than the one on top.

It seems to me that there is a problem in the production pipeline at Backscatter: I just had a look at my HF-1s that I purchased quite early, when they appeared on the market, and there is no sign that the O-rings are of different size and/or diameter, they are exactly the same (two identical grey O-rings; nothing like an additional third and smaller O-ring to protect against sand is there).

I have now approx. 100 dives with them and there was never a leak (but this, of course, does not prove anything, the N number is too small to allow a meaningful statement). On the other side there are several reports about leaking battery compartments that disturb me. Some reports of O-rings of different size/diameter, it seems to be a real thing...

Did someone ask at Backscatter from where these different size O-rings come from?

Edited August 18Aug 18 by Architeuthis

On 8/16/2025 at 9:49 PM, Chris Ross said:

This may be true, however it should not be happening after 6 dives. I think the report of differing cross section o-rings is a concern though.

This, but you can always just blame the customer and make them pay for parts with "free labor". It's horrible customer service that seems to match the product.

On 8/17/2025 at 5:13 PM, bvanant said:

I would think that 2 o-rings are there for redundancy, but it is hard to understand how it would leak unless both were small.

Bill

Both were not the same size, I'll have to trim the video and upload it, but the naked eye can see where the one that didn't fail the orings fill up the groove they're in, the one that failed showed the orings moving around when you touch them. I've done this as a "bush repair" or "Jerry rig" for systems on cars, trucks, and once an airplane we needed to limp back and it worked for the short mission and ultimately failed. My biggest mistake was not measuring the orings, but I didn't want to touch anything and be blamed for causing damage, so I left it as is.

On 8/18/2025 at 3:48 AM, Architeuthis said:

It seems to me that there is a problem in the production pipeline at Backscatter: I just had a look at my HF-1s that I purchased quite early, when they appeared on the market, and there is no sign that the O-rings are of different size and/or diameter, they are exactly the same (two identical grey O-rings; nothing like an additional third and smaller O-ring to protect against sand is there).

I have now approx. 100 dives with them and there was never a leak (but this, of course, does not prove anything, the N number is too small to allow a meaningful statement). On the other side there are several reports about leaking battery compartments that disturb me. Some reports of O-rings of different size/diameter, it seems to be a real thing...

Did someone ask at Backscatter from where these different size O-rings come from?

I doubt they'll ask, I doubt they care. It's this reason I'll choose any other strobe on the market over theirs, or even any product over anything they make.

On 4/7/2025 at 9:55 PM, Dave_Hicks said:

TLDR; The strobe lives and seems to be working normally after cleaning it up.

 

Yesterday I was doing my second dive of the day when one of my HF-1 strobes made a little tiny pop and stopped working. The green indicator light was off and turning it off and on again did nothing. I was at about 80-85 feet at the time. I turned it off, folded it away, and used the remaining strobe for the rest of the dive.

 

I had set up my camera and strobes on Friday night, and they headed out early Saturday morning for two shore dives about a 90-minute drive away. The conditions were not great, and I didn't take many photos maybe 50. I lightly rinsed the camera and strobes at the dive site and then soaked it in the sink once I got home. I had another pair of boat dives planned Sunday morning, also a 90 minute drive. Since I had not taken many photos I decided to leave the entire rig, camera and strobes alone and dive it again without opening or charging anything. I did a few test shots and packed it in the car. The first dive all worked normally and during the second dive both strobes worked until the Pop.

 

After I got home, I soaked and dried the entire rig and then went to see what was going on with the dead strobe. Had the batteries died suddenly, was the strobe broken? It didn't seem likely to me that it might had flooded. As such, I was a bit surprised to see moisture and a little black goo in the battery compartment. It made another little pop when opened, releasing pressure. There was NOT a lot of water in it. It was not fully flooded, just a bit wet. The batteries and strobes electrical contact showed some black goo and corrosion on the positive terminal at the bottom of the compartment. I dumped out the batteries as set them aside wrapped in paper towels. (they went to a can outside the house) I took the strobe and rinsed it repeatedly under the sink and scrubbed the battery compartment with a toothbrush. My handy electric blower dried it out quickly. I wrapped some sandpaper on the end of a chopstick and cleaned up the corroded Pos+ terminal at the bottom of the compartment.

 

I went to the manual and confirmed my recollection that the battery compartment is sealed from the rest of the strobe. The manual says "maybe" the strobe will survive a flood, and that unless it starts acting erratically you can keep on using it. After allowing it to continue to dry overnight, I loaded fresh batteries this morning and the strobe seems to be working correctly 100%. I'll dive it in a few days to confirm further, but the good news is that it seems to live up to the sealed compartment promise of the manual.

 

I really don't know what caused the flood. I am very meticulous in cleaning and lightly lubricating the orings and sealing surfaces with tribolube with each battery change. There was no hair or debris in the seal when I opened it. No cracks in the case or cap that I can detect. I removed the orings and cleaned the cap and groves carefully with a toothbrush and lint free laboratory wipe. The orings seem to be in good shape so I cleaned those too and put them in spares. I swapped in the spare set of orings that Backscatter provided with the HF-1 on both strobes. 

 

I didn't take any photos of the flood, but it was not very dramatic in any case. Just a touch of goo and corrosion. It just goes to show that every strobe or o-ring sealed device is never 100% foolproof and the best we can do is take care. Have a spare on hand if you can't afford to be down a strobe on a big trip. I have a couple of big trips coming up in April and May, so I'll be bringing at least 1 spare strobe and a few extra batteries!

I am just wondering how you managed to clean the contacts of your HF-1s after the flooding...

The reason I am asking is that I recently had a problem with both of my HF-1s that are now almost 2 years old: I did not flood the battery compartments, nor did I drop droplets of (salt)water on the contacts. Both flashes stopped working during my last trip to Tansania in November 25. After sending photos of the contacts to Backscatter it was decided that the problem is some kind of "stain" on the contacts, arising from corrosion. The (very kind) service department of Backscatter said that this "corrosion" can built up just from humidity or other kind of moisture, no flooding or water droplets required...

The flashes are now at Backscatter for repair (the contacts will become exchanged), but I am afraid that this phenomenon will come again. I am not aware what I did wrong. I tread the HF-1s the same way as I was treating five S&S YS-D2 and four Z330 before and these strobes never made any problems with their contacts.

=> It would be great to know an efficient procedure for contact cleaning that I could do also during a diving holiday abroad (last one was not so revealing when making photos with the single remaining MF-2 (o.k., I could practice a lot of macro snooting, to say something positive on that issue)...🙄).

Thank you, Wolfgang

Edited yesterday at 05:39 PM1 day by Architeuthis

Chopstick and sandpaper. Wrap a bit of fine grit sandpaper on the fat end of a wooden chopstick and secure it with a rubber band. Lightly sand the contacts at the bottom of the battery compartment. Maybe spray on some contact cleaner or isopropyl alcohol. Clean it up with a fine microfiber glasses cleaning cloth on a chopstick with more alcohol. Do the same on the cap contacts AND the battery contacts themselves.

Dissimilar metal oxidation is the root of many non-flood electric problems. I see it in all of my strobes and lights over time. Copper on the device and aluminum on the battery in most of them. This is why lots of electronics products use gold platted contacts. I wish i could pay an extra fee to gold plate all of my strobe products! It probably only costs pennies to do this in bulk.

7 hours ago, Architeuthis said:

The (very kind) service department of Backscatter said that this "corrosion" can built up just from humidity or other kind of moisture, no flooding or water droplets required...

Must be made with poor quality material, I'd expect this for materials left outside for extended periods, but not metal that spends its whole life inside a battery compartment sealed off from the outside. My INON Z240 strobes i had for 10 years and the contacts in the little cap thing and inside look as new. Dissimilar metal corrosion requires some moisture to condense, now if you get a trace of saltwater inside that will draw in moisture and can start corrosion.

I always pulled my o-rings every time I opened them as I could see water droplets clinging to them and dried them off and wiped out the water in the o-ring groove before replacing them, if any of that water gets inside it will cause problems. My new Retra strobes don't seem to gather droplets of water so readily so those o-rings stay on most of the time and they are serviced periodically. The best is my INON torch which has a sand seal which basically means water never gets on my o-rings.

3 hours ago, Chris Ross said:

Must be made with poor quality material, I'd expect this for materials left outside for extended periods, but not metal that spends its whole life inside a battery compartment sealed off from the outside. My INON Z240 strobes i had for 10 years and the contacts in the little cap thing and inside look as new. Dissimilar metal corrosion requires some moisture to condense, now if you get a trace of saltwater inside that will draw in moisture and can start corrosion.

I always pulled my o-rings every time I opened them as I could see water droplets clinging to them and dried them off and wiped out the water in the o-ring groove before replacing them, if any of that water gets inside it will cause problems. My new Retra strobes don't seem to gather droplets of water so readily so those o-rings stay on most of the time and they are serviced periodically. The best is my INON torch which has a sand seal which basically means water never gets on my o-rings.

You overstate the need for moisture to cause corrosion. All if takes is a little humidity which is everywhere, especially after you dip a camera in the ocean. And I would not call copper an inferior material.

For what it's worth, i have had plenty of corrosion issues with my Inon z330s requiring the whole sandpaper treatment. I borrowed a buddies Retra strobe a few weeks ago and the battery contacts were a wreck. Sanded those clean too. And don't get me started on the external charging contacts of the Sola lights! What a mess!

I once saw Alex Mustard pouring Coca Cola into the battery compartment of a flooded flash of a workshop participant and incubating for a while. It helped...😊

Can one recommend this kind of treatment, does someone have experience with it?

P.S.: Like Chris, I fear that the HF-1 contacts are made of inferior material. As I wrote already, I have never experienced a similar problem so far with several YS-D2s or Z330s over many years. Now two HF-1s died practically simultaneously within 2 days because of the same problem, after approx. 20 months of usage...

(I have tried to clean the contacts of flash and battery with alcohol soaked glass cleaning paper when I was still in Tansania, but this helped only in one case and only for one additional day, so I decided it was probably flooding and corrosion of the internal part of the flashes and stopped using them, what was probably wrong (lets see what Backscatter will report about the repair)) ...

I am wondering if the greater energy draw and resulting heat of lithium batteries results in more galvanic corrosion than AA powered devices. I have seem more of these "poor electric contact" problems on lithium ion powered lights and strobes than i was use to on AA cell devices. Maybe we really do need gold plating.

More frequent cleaning of contact surfaces seems to be required.

1 hour ago, Dave_Hicks said:

You overstate the need for moisture to cause corrosion. All if takes is a little humidity which is everywhere, especially after you dip a camera in the ocean. And I would not call copper an inferior material.

For what it's worth, i have had plenty of corrosion issues with my Inon z330s requiring the whole sandpaper treatment. I borrowed a buddies Retra strobe a few weeks ago and the battery contacts were a wreck. Sanded those clean too. And don't get me started on the external charging contacts of the Sola lights! What a mess!

Sorry, you actually do need liquid water to setup an electrochemical reaction, a thin film of salt is enough to do it as salt is hygroscopic and will pull water out of the air. But unless the humidity reaches 100% you won't get any condensation and even pure water needs a little in the way of salts to become conductive enough to facilitate dis-similar metal corrosion. I'm quite familiar with corrosion mechanisms in my line of work. It won't happen if the contacts are dry. Leaking batteries of course can cause it as they leak electrolyte. Regarding copper, it is quite resistant to sea water corrosion, but tarnishes quite readily which can reduce conduction.

Regarding Coca cola, it contains phosphoric acid which will clean away corrosion products. you just have to rinse it well or the residue will be hygroscopic and come back to haunt you at a later date.

I just looked at my Z240 again, bottom contacts seem to be brass, maybe gold plated?? but totally tarnish free after 10 years, the spring contacts in the insert cap appear to be stainless steel. Stainless is much less prone to tarnish, it's electrical conductivity is not as good as copper/brass but I expect it's good enough.and you can compensate with thicker cross sections. I never opened them up under suspect conditions like on a boat with strong winds blowing, but always made sure no water was left clinging to the o-ring before re-assembly.

9 minutes ago, Dave_Hicks said:

I am wondering if the greater energy draw and resulting heat of lithium batteries results in more galvanic corrosion than AA powered devices. I have seem more of these "poor electric contact" problems on lithium ion powered lights and strobes than i was use to on AA cell devices. Maybe we really do need gold plating.

More frequent cleaning of contact surfaces seems to be required.

I think the issue is the high currents required, they make a big deal about having properly rated batteries - unless the contacts are good the extra resistance will just reduce the current. I don't think they cause the corrosion as such but are more sensitive to the impact of it.

3 hours ago, Dave_Hicks said:

I am wondering if the greater energy draw and resulting heat of lithium batteries results in more galvanic corrosion than AA powered devices. I have seem more of these "poor electric contact" problems on lithium ion powered lights and strobes than i was use to on AA cell devices. Maybe we really do need gold plating.

More frequent cleaning of contact surfaces seems to be required.

Maybe it is the high current draw from the special Li+ batteries...

I believe it is no wonder when contacts become corroded after flooding or after exposure to (salt)water drops, but these issues did never occur with the strobes I used so far and I never experienced problems with the contacts (the other strobes I was using so far were all powered by AA cells)...

22 hours ago, Architeuthis said:

I am just wondering how you managed to clean the contacts of your HF-1s after the flooding...

The flashes are now at Backscatter for repair (the contacts will become exchanged), but I am afraid that this phenomenon will come again. I am not aware what I did wrong. I tread the HF-1s the same way as I was treating five S&S YS-D2 and four Z330 before and these strobes never made any problems with their contacts.

Thank you, Wolfgang

I am not clear here. Did Backscatter state the specific reason the strobes quit working was "stained" contacts and that there is no other malfunction involved?