Home » Public Forums » GMCnet » Off topic.. Any ideas to seal the water out of these things? (leaking microwave radio housing)
| Off topic.. Any ideas to seal the water out of these things? [message #243341] |
Thu, 13 March 2014 13:30  |
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RF_Burns
Messages: 2277
Registered: June 2008
Location: S. Ontario, Canada
Karma: 3
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You guys are good at fixing leaks... sooo...
http://www.gmcmhphotos.com/photos/the-murray-gets-a-home/p53625-any-ideas-how-to-seal.html
http://www.gmcmhphotos.com/photos/the-murray-gets-a-home/p53624-any-ideas-how-to-seal.html
These are Motorola PTP600 microwave radios which cost $16,000. per link and have been in service for less than 3 years.
One failed in Dec/13 so we installed a spare and paid to have it fixed. This spare failed in Feb/14 just as the first one came back from repair. We then had another one fail last weekend.
They claim its faulty installation and the water is coming in the antenna connectors, but that's up hill all the way!
I think its poor housing sealing with some of the water running down the internal antenna cables and into the back of the N Connectors. All of the housing screws were "finger tight". There is a hollow rubber 0.200" OD "O" ring around the housing. I measured the maximum crush at 0.011" which doesn't seam much to me anyway.
I'm trying to figure a way to seal it, but still allow me to get the case opened. I saw some one mention "Vacuum Grease" but I can't find out where to buy that.
Any ideas guys?
Thanks
Bruce Hislop
ON Canada
77PB, 455 Dick P. rebuilt, DynamicEFI EBL EFI & ESC.
1 ton front end
http://www.gmcmhphotos.com/photos/showphoto.php?photo=29001
My Staff says I never listen to them, or something like that
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| Re: Off topic.. Any ideas to seal the water out of these things? [message #243350 is a reply to message #243346] |
Thu, 13 March 2014 14:05  |
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Richard RV
Messages: 631
Registered: July 2012
Location: Full-timer for 12 years, ...
Karma: -17
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| rf_burns wrote on Thu, 13 March 2014 11:53 |
Funny, I was just reading their website!
Need something that won't dryout or run down into the circuit board.
I'll give them a call.
|
...and won't eat the O-ring. IIRC Hylomar was jointly developed by Boeing and Rolls Royce. Good pedigree.
Richard
'77 Birchaven TZE...777;
'76 Palm Beach under construction;
‘76 Edgemont waiting its turn
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| Re: [GMCnet] Off topic.. Any ideas to seal the water out of these things? [message #243357 is a reply to message #243341] |
Thu, 13 March 2014 15:18 |
Dave Mumert
Messages: 272
Registered: February 2004
Location: Olds, AB, Canada
Karma: 0
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Hi Bruce
Before I looked up the Hylomar stuff I was thinking you could try acoustic caulking, it is very sticky and never dries out. It
comes apart easily but you will need lots of paper towels, it is very messy.
What I want to know is why are we not using the Hylomar to install our windows.
Dave Mumert
'76 Eleganza II
Alberta, CA
> -----Original Message-----
> Subject: [GMCnet] Off topic.. Any ideas to seal the water out of these things?
>
> You guys are good at fixing leaks... sooo...
>
> These are Motorola PTP600 microwave radios which cost $16,000. per link and have been in service for less than 3 years.
>
> One failed in Dec/13 so we installed a spare and paid to have it fixed. This spare failed in Feb/14 just as the first one came
back from
> repair. We then had another one fail last weekend.
>
> They claim its faulty installation and the water is coming in the antenna connectors, but that's up hill all the way!
>
> I think its poor housing sealing with some of the water running down the internal antenna cables and into the back of the N
> Connectors. All of the housing screws were "finger tight". There is a hollow rubber 0.200" OD "O" ring around the housing. I
measured
> the maximum crush at 0.011" which doesn't seam much to me anyway.
>
> I'm trying to figure a way to seal it, but still allow me to get the case opened. I saw some one mention "Vacuum Grease" but I
can't
> find out where to buy that.
>
> Any ideas guys?
>
> Thanks
>
> --
> Bruce Hislop
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| Re: Off topic.. Any ideas to seal the water out of these things? [message #243435 is a reply to message #243349] |
Fri, 14 March 2014 08:26 |
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Matt Colie
Messages: 8547
Registered: March 2007
Location: S.E. Michigan
Karma: 7
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[quote title=rf_burns wrote on Thu, 13 March 2014 15:03]I should mention that the housing is a cast aluminum.
Also, these things sit outside at the top of a tower, usually a couple hundred feet high. Real handy to get at for servicing./quote]
Bruce,
Without seeing exactly what the problem is, I can't really be a great help. I will tell you that since I was quite young, we have used DC#7 in all our places we need to seal or exclude moisture. I have always packed outside RF connectors with the stuff. It is a bitch to get off your hands without really washing and it is terrible as toothpaste.
The actual name is Dow Corning 7. It is a silicon grease/release agent used as above and as a release for metal and plastic processes. I haven't bought any in years (the big tube is nearly a lifetime supply for any normal person), but I know it is still available because last time I was at my pattern shop supply place, they had it on the shelf.
You might get some and try filling the RF connections and the coating the Oring on the next try.
Matt
Matt & Mary Colie - Chaumière -'73 Glacier 23 - Members GMCMI, GMCGL, GMCES
Electronically Controlled Quiet Engine Cooling Fan with OE Rear Drum Brakes with Applied Control Arms
SE Michigan - Near DTW - Twixt A2 and Detroit
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| Re: [GMCnet] Off topic.. Any ideas to seal the water out of these things? [message #243443 is a reply to message #243435] |
Fri, 14 March 2014 09:03 |
GMC_LES
Messages: 569
Registered: October 2009
Location: Montreal
Karma: 0
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Senior Member |
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Matt & Bruce,
I was just going to suggest using DC4 grease. (Dow corning #4 silicone dielectric grease)
I've been using it forever for similar jobs to keep water out of sensitive joints & connections.
Regarding Hylomar, I work for Rolls Royce and have plenty of play time with the stuff. Because it uses an evaporating solvent to make it workable during application, it may not be compatible with some types of plastics, Therefore it may damage the O-ring seal used on your unit.
Hylomar also makes a damned good adhesive if the mating parts are a precision fit and they don't get hot. We use the stuff on a carbon fiber air duct where it attaches to a magnesium casing to seal out water intrusion into the joint. We need to apply a release agent to the CF duct prior to applying hylomar or the CF will delaminate during later dissassembly of the two parts. It also takes quite a bit of careful prying to separate the two parts if we forget the release agent.
DC4 is probably your easiest option as you most likely already have some on hand. If you don't, you should, [according to erf ;-) ]
Les Burt
Montreal
1975 Eleganza 26ft
A work in Progress
On Mar 14, 2014, at 9:26 AM, Matt Colie <matt7323tze@gmail.com> wrote:
[quote title=rf_burns wrote on Thu, 13 March 2014 15:03]I should mention that the housing is a cast aluminum.
Also, these things sit outside at the top of a tower, usually a couple hundred feet high. Real handy to get at for servicing./quote]
Bruce,
Without seeing exactly what the problem is, I can't really be a great help. I will tell you that since I was quite young, we have used DC#7 in all our places we need to seal or exclude moisture. I have always packed outside RF connectors with the stuff. It is a bitch to get off your hands without really washing and it is terrible as toothpaste.
The actual name is Dow Corning 7. It is a silicon grease/release agent used as above and as a release for metal and plastic processes. I haven't bought any in years (the big tube is nearly a lifetime supply for any normal person), but I know it is still available because last time I was at my pattern shop supply place, they had it on the shelf.
You might get some and try filling the RF connections and the coating the Oring on the next try.
Matt
--
Matt & Mary Colie - Members GMCMI, GMCES Going to MontgomeryThe majestic, once snow covered glacier Chaumière is in for the winter.
'73 Glacier 23 With 4 Rear Brakes that pull as they should
SE Michigan - Twixt A2 and Detroit
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Les Burt
Montreal
1975 Eleganza 26ft
A work in Progress
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| Re: Off topic.. Any ideas to seal the water out of these things? [message #243455 is a reply to message #243341] |
Fri, 14 March 2014 10:16 |
Chr$
Messages: 2690
Registered: January 2004
Location: Scottsdale, AZ
Karma: 1
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Parker O-lube or super lube from the hardware store will help, but if these things are going through wide thermal swings, you have expanding and contracting going on. It heats up in the sun, and then cools off at night.That is loosening the fasteners. You can try using lock-wire on the fasteners, that may help a bit.
There should also be two o-ring grooves on that too.
If water is being entrained through the antenna connectors, make sure there are drip loops on the cables so the water does not follow the cable to the connector.
It should also have a drain line. A drain line will also help relieve internal pressure as it heats up in the sun.
You may be better off mounting the whole can in a plastic housing.
If you have an empty/bad one and want me to take a look at it, I can see what we can do.
A heavy plastic bag can help too. We do this with our cables in our equipment when there is the chance of something else failing and leaking chemicals and water on the connector panel.
-Chr$: Perpetual SmartAss
Scottsdale, AZ
77 Ex-Kingsley 455 SOLD!
2010 Nomad 24 Ft TT 390W PV W/MPPT, EV4010 and custom cargo door.
Photosite: Chrisc GMC:"It has Begun" TT: "The Other Woman"
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| Re: Off topic.. Any ideas to seal the water out of these things? [message #243570 is a reply to message #243548] |
Sat, 15 March 2014 01:09 |
Bullitthead
Messages: 1411
Registered: November 2013
Karma: 5
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DC-4 on the o-rings, I used it on the LearJet wheels and most of the o-rings elsewhere on the plane, just run the ring through your fingers and lube it completely, and lube the groove it goes in on the case halves.
The desiccant will not turn to mush, but it will continue to draw moisture until it is waterlogged. Use it if you have a way to REALLY seal the case, and make sure it is dried out before you put it in there.
If you get an absolute case seal, then it will draw a vacuum when it cools down after the sun sets, unless the radio is keeping it warm. That vacuum can draw water right out of the cable if it goes through the case to a connection outside. Either seal the connection outside and the cable end inside with RTV or use bulkhead fittings for the cable passage through the case if you can.
If you can, get a supply of dry nitrogen and flood the case inside just before final assembly to purge the air from in there. Get the case almost closed and fill it with nitrogen using one of those tiny red tubes from an aerosol can.
Terry Kelpien
ASE Master Technician
73 Glacier 260
Smithfield, Va.
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| Re: [GMCnet] Off topic.. Any ideas to seal the water out of these things? [message #243796 is a reply to message #243341] |
Sun, 16 March 2014 16:01 |
jhbridges
Messages: 8412
Registered: May 2011
Location: Braselton ga
Karma: -74
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I've had good luck with the same sort of housing on strobes by putting a resistor across the power supply - bigger supply if necessaary - and simply letting it dissipate current and get hot. Keeps them toasty warm and dry inside. At the strobe voltages, any moisture will create havoc.
Try the grease Andrew supplies with RF connectors, it seals fairly well. If there is any warp in that aluminum case or cover, replace it. Finger tight won't weork, termp changes will make teh box 'breathe' anmd pull in moisture around the center pin of the N connector if it is not a barrier connector.
I use spread spectrum unlicensed stuff in the 2.4 and 5.8GHz bands. Lynx radios do well over paths of up to about 18 miles (longest I have) and will hop as afar as you like, Single Source Communications sells a plethora of refurbed gear at reasonable rates. They might have something which will work for you. I picked up a DS3 set from them for I think areound 1200 bux last year including a T1 mux.
--johnny
________________________________
From: Bruce Hislop <bruce@perthcomm.com>
To: gmclist@temp.gmcnet.org
Sent: Thursday, March 13, 2014 2:30 PM
Subject: [GMCnet] Off topic.. Any ideas to seal the water out of these things?
You guys are good at fixing leaks... sooo...
http://www.gmcmhphotos.com/photos/the-murray-gets-a-home/p53625-any-ideas-how-to-seal.html
http://www.gmcmhphotos.com/photos/the-murray-gets-a-home/p53624-any-ideas-how-to-seal.html
These are Motorola PTP600 microwave radios which cost $16,000. per link and have been in service for less than 3 years.
One failed in Dec/13 so we installed a spare and paid to have it fixed. This spare failed in Feb/14 just as the first one came back from repair. We then had another one fail last weekend.
They claim its faulty installation and the water is coming in the antenna connectors, but that's up hill all the way!
I think its poor housing sealing with some of the water running down the internal antenna cables and into the back of the N Connectors. All of the housing screws were "finger tight". There is a hollow rubber 0.200" OD "O" ring around the housing. I measured the maximum crush at 0.011" which doesn't seam much to me anyway.
I'm trying to figure a way to seal it, but still allow me to get the case opened. I saw some one mention "Vacuum Grease" but I can't find out where to buy that.
Any ideas guys?
Thanks
--
Bruce Hislop
ON Canada
77PB, 455 Dick P. rebuilt, DynamicEFI EBL EFI & ESC.
Hubler 1 ton front end
http://www.gmcmhphotos.com/photos/showphoto.php?photo=29001
My Staff says I never listen to them, or something like that
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Foolish Carriage, 76 26' Eleganza(?) with beaucoup mods and add - ons.
Braselton, Ga.
I forgive them all, save those who hurt the dogs. They must answer to me in hell
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| Re: Off topic.. Any ideas to seal the water out of these things? [message #243837 is a reply to message #243341] |
Sun, 16 March 2014 19:21 |
captjack
Messages: 271
Registered: February 2010
Location: Sebastopol, California
Karma: 1
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I have worked on enclosures for telephone equipment and found it's almost impossible to insure that equipment designed to be installed by a variety of folks is consistently sealed properly. For that reason most of our stuff included an appropriately located small hole in the bottom to allow water to drain out. We also included a fine mesh covering the hole to keep out the ants. Fortunately the heat generated in the equipment tended to exhaust water and water vapor so the equipment didn't fail.
I help run a small volunteer ISP and we use microwave radios and N connectors. N's are designed to be water tight, but we add a second layer of protection with self-sealing tape and a covering of electrical tape for UV protection. We have had an occasional leak though and started adding holes in the bottom of the enclosures which worked -- once again!
Jack Christensen - K6ROW,
'76 Glenbrook/Clasco - "The Silver Bullet",
Sebastopol, CA
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| Re: [GMCnet] Off topic.. Any ideas to seal the water out of these things? [message #243858 is a reply to message #243854] |
Sun, 16 March 2014 20:23 |
k2gkk
Messages: 4452
Registered: November 2009
Karma: -8
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Long ago, I came to a conclusion that water in some form will always get into places where it is unwanted! Therefore it is a better idea to provide an easy exit for it! I.E., some sort of tube at the lowest point to lead condensation or leakage out of the housing. Add some "brass wool" to the tube to keep insects out.
Good luck!
Mac, K2GKK (since 1953) in OKC
Money Pit
Sent from my iPad
> On Mar 16, 2014, at 20:10, "Bruce Hislop" <bruce@perthcomm.com> wrote:
>
>
>
> Johnny,
> These are tower top units with the power supplied through the CAT5 cable, so I don't think I can pull enough power to get any kind of heat up there.
>
> The cables were double-wrapped as is our norm.
>
> Jack,
> I'm seriously considering drilling a drain hole but I'm worried that on a damp day that turns cold there may be condensation form inside. On the other hand, there is alot of exterior electronic equipment that just depends on gravity to keep the water out.
> --
> Bruce Hislop
> ON Canada
> 77PB, 455 Dick P. rebuilt, DynamicEFI EBL EFI & ESC.
> Hubler 1 ton front end
> http://www.gmcmhphotos.com/photos/showphoto.php?photo=29001
> My Staff says I never listen to them, or something like that
> _______________________________________________
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