CZ 20 Coming-a few QUESTIONS please

[GTzer]

Hi. MDing since 83 in the dirt with occasional trips to the beach. 28 yrs with an analog. Jan. 2012 got an xterra 705. Enjoy that on the beach. Live 70 miles from the closest saltwater. So not my primary-but I want to do more at the beach. Not a diver but I want to wade.

After deciding and looking for a few years I have a Fisher CZ 20 on the way. $, location & frequency of beach time dictated my choice. Been re- reading reviews and all I can now that I made my choice. Buyer gave me an option to return it. My criteria for final sale is-must arrive intact, be completely functional and watertight (to wade depth of 5) To be fair I want to prep it and take it to the saltwater. I will utilize the info that I have read from the two sites I belong to. So most of the info I refer to is from here or the other MD site.

A few QUESTIONS please. Any input will be welcome as I have never used a Fisher or any water MD. Ordered a manual.

Seller only used it in water 1 time- no leaks. He was the 2nd owner.

Aware from reading- potential leaks-battery door (cracks from over tightening),gaskets,silicon grease use, Face plate-PP button & LED.
Will I be able to see possible cracks-with a magnifier & bright light? If there are any-can I remedy that short of buying a replacement?

Silicon the gasket-read it many times. Manual states not to use silicon grease. Should I apply it a described in many of the threads Ive read here? (Light coat and make sure its seated properly.)

Read of sealing the PinPoint button (and LEDs) and then NOT using the PP (use detune to PP). Fine with me-BUT the manual indicated using the PP for tuning or GB. SO can you GB without using the PP?

I want to check it in the saltwater after reading about a bell tone that occurs when either the internal boards OR the coil is not aligned or out of sync. That thread stated that the unit worked fine dry but would not work properly in the saltwater.

I know that its a disco. model and has some age. Some have problems and some still work great. I believe my criteria listed above is fair. And as stated this unit wont be subjected to depths greater than 5. That leads me to my final question.

Upgrades.cant afford that now. If it passes my criteria its a done deal. SO I read many different things about the upgrade to a 21. The prices seem to change over the years. Some indicated that it was more expensive in the past-then it is now. A lot of quotes discussed in threads from 2011-2012 were around $300. That was for the face plate.
What is the current cost?
Does that include circuit boards or just the plate?
Is that PRIOR to a water leak?
If there is a leak (main compartment) what options are there?

Abbreviated answers are fine. Ill keep reading AND I will call the company to ask about the upgrade. Still I value the info I read here. I could really use some input here.
Thank you,
GTzer

 

[GTzer]

CONDENSED- updated Version
Fisher CZ 20 on the way. Seller gave me an option to return it. Seller only used it in water 1 time- no leaks. He was the 2nd owner.
My criteria for final sale is-must arrive intact, be completely functional and watertight (to wade depth of 5') I want to prep it and take it to the saltwater.
I have never used a Fisher or any water MD. SO I am only familiar with the info I have read on the net & the 2 MD sites I where I am a member.

Aware from reading- potential leak sites-battery door (cracks from over tightening),gaskets,silicon grease use, Face plate-PP button & LED.

QUESTIONS please.

I could accept & deal with a possible leak in the battery compartment. But I need for it to last through the test.
1) Will I be able to see possible cracks-with a magnifier & bright light? Is there any can I temporarily seal those so I can test the unit?

Silicon the gasket-read it many times. I will apply it a described in many of the threads Ive read here. (Light coat and make sure its seated properly.)
2) BUT why does Manual state not to use silicon grease?

Read of sealing the PinPoint button (and LEDs) and then NOT using the PP (use detune to PP).I will try it once to make sure it works then I will NOT use it again. Fine with me-BUT the manual indicated using the PP for tuning or GB.
3) SO can you Ground Balance/ Tune without using the PP with the Auto tune feature?
4) What material should I use to seal the PP & LEDs? I would like to use a temporary material to test the unit. Then a permanent material if it passes.

Upgrades-I cant afford that now and I would only do that if necessary. If it passes my criteria its a done deal. SO I read many different things about the upgrade to a 21. They cant fix a CZ 20 so you must upgrade.
5) So do you wait for total failure for this repair/upgrade or is there a way to determine that it will be necessary?

Abbreviated answers are fine. Ill keep reading AND I will call the company to ask about the upgrade. Still I value the info I read here and ANY input .
Thank you,
GTzer

 

[John(Tx)]

I use a light flim of silicone on the battery gasket and make sure it is snug but not tight before I take it on the beach. Only reason I can think of is that sand may get on the gasket thus creating a leak that is why I make sure it's snug before hitting the beach. HH

 

[GTzer]

Thanks John. Good thought. Also water suspended sand & particles are very fine and can get into the smallest places. From what I've read-the silicon keeps the gasket supple and the film helps the seal.
Wonder why the manual advises against its use.

 

[mudpuppy]

You thinking about hip or chest mounting the control box? Its a good idea to do that for ease of swing..Heres a fast simple one I made out of an unused trolling motor battery box. It also hip mounts when a guy threads a wide dive belt through the slots, which was my preferred method instead of the chest mount. You should be fine with it wading...just go easy on the battery door bolts, finger tight and a little.. the battery compartment is bulkheaded from the control boards, so even if it leaks, if you catch it in time, no problem..the PP button was a leak point when the rubber wore out or got cracked, so don't use the PP button at all if you can, some guys cover the PP button with blue RTV silicone just to be safe, but they don't use the button at all either...there was a guy on here, Scubadetector, who sent his 20's in to upgrade and had Fisher leave the pp button off altogether, since you don't really need it anyway. They are built like a tank, deep and powerful, your first duty will be to find a comfortable scoop you can carry and dig with...If you chest mount, chances are the control box will never get submerged anyway, and if it does, it wont be very deep or very long!.
Mud

 

[GTzer]

Thanks Mudpuppy.
I 'll save the mount info for after the test for possible use.
As stated-I'll use the PP 1 time to make sure it functions (dry) and never use it again. I will seal it before I try it out.
RTV on the LEDs also?
I will use the CZ 20 for wading and wet sand only. 5' max depth. I have a good water scoop.

Any other input on the 5 questions I listed. I enjoy reading your posts and value your advice.

Thanks,
GTzer

 

[tvr]

my 2 cents:

1) Will I be able to see possible cracks-with a magnifier & bright light? Is there any can I temporarily seal those so I can test the unit?

Don't know, you could try. I suspect that the only real way to tell is a leak or pressure test.

2) BUT why does Manual state not to use silicon grease?

Could be material incompatibility. Some greases contain solvents that may degrade certain gasket materials. Grease also attracts dirt. For my other water proof detectors I use a food grade silicon grease very lightly applied in a thin film coating. For the CZ20, I follow the manual and just clean and dry the gasket.

3) SO can you Ground Balance/ Tune without using the PP with the Auto tune feature?

Both pinpoint and autotune are all metal modes. Either works just as well for ground balancing.

4) What material should I use to seal the PP & LEDs? I would like to use a temporary material to test the unit. Then a permanent material if it passes.

I bought my CZ-20 with the pinpoint switch removed and the hole sealed with what looks like a piece of plastic sheet glued in from the inside of the housing. I am not sure if this was a factory mod or done by the former dealer / repairer. It has held up fine for several years. I wade in and don't dive with it. Mine still has the lights and they have held up fine.

Upgrades-I cant afford that now and I would only do that if necessary. If it passes my criteria its a done deal. SO I read many different things about the upgrade to a 21. They cant fix a CZ 20 so you must upgrade.
5) So do you wait for total failure for this repair/upgrade or is there a way to determine that it will be necessary?

That is one I would certainly call the factory about. They may give you current estimated pricing and tell you what they replace (I think they replace the entire control unit and use your coil if the coil checks good). They may advise on what to look for if there is anything that can be seen as a start of a failure. Might not be any symptoms until it goes.

Good luck with it. Mine very quickly paid for itself. Hope yours does that too.
Cheers,
tvr

 

[GTzer]

tvr- thank you for addressing all of the questions

Still would welcome any input especially on questions 1 & 4.

 

[icurabeachguy]

yeah, tvr covered it. I'd just shoot Felix an email and they'll take care of you. I sent my broken 20 back for repairs and they had to convert it to a 21...all for $325 in 2012. They even sent me a prepaid shipping label to send it in, just make sure you email them (Felix) first for the RMA #.

My father and I have used Fisher underwater units for a long time and have never used silicon grease for the seal - follow the manual. Also, don't overtighten the screws...finger tight and then a 1/4 turn with a flathead if I remember correctly (it's in the manual).

 

[dewcon4414]

Some rubber is more sticky so they dont move..... add a little grease and they might.

Dew

 

[goodmore]

Like you I just purchased a CZ-20. I knew from the pictures that I was getting an abused unit. But the price was good and I had the money. I got it the other day in the mail and noticed the headphone wire was spliced where it was broken. To make a long story short it is on the way to Fisher for repairs and the upgrade. I'll keep you posted. By the way Felix was very polite on the phone.

 

[OldBeechnut]

The best test is to take it under for several hours. And saltwater only. I had a friend that just bought a used CZ21 this past march, he found out by taking it out that it had a bad coil.....3 weeks and he has it back. But the saltwater will let you know. He paid 600.oo plus for his, the seller offered his money back once the coil was discovered to have issues but he ate the price of the coil and keep the machine....Now I get to a beach, turn him loose and he is gone....young bucks...

On the battery compartment, I give the detector a good wash the day before, dry over night, then take a med tooth brush and clean all during the break down to change the battery, I have never used anything on the gasket. The Excalibur yes, everytime...but the fisher....a real tank. I have 2, someday when I get the time, I'm going remote PP on those babies. I do the bobbing of the coil and the remote button...but hold my breath everytime. mine are old and beat up, and look like they have cracks here and there but they keep on ticking....My opinion, Get them wet for as long as possible.

 

[GTzer]

Sandman & HaroldIll explained a method of tuning that eliminates the use of the PP button for GB. As stated earlier- I will try the PP once to make sure it functions -then I will NEVER use it again. I'm going to seal the PP,LEDs and the sides of the Face plate with silicon sealant before I take it to the salt.
OBN-I will clean the battery door,seat & gasket and I'll apply that same sealant -in a very thin layer-over the battery door (while it's off) and let it dry before I re install.(in case of micro cracks )
Any suggestions on WHAT TYPE of SILICON would be appreciated.
I will drive it to the salt a test it for several hours at wade depth. I believe that would be a fair test. A long as it passes that -I'll consider final.
Thanks,
GTzer
THANKS for all of the replies.