Transom Conducting Current but doesn't appear to be wet!

slinkeey

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Aug 20, 2008
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39
Hello,

I am a little confused. I read how people will test their transom for moisture by doing a conductive test with an ohmmeter.

Well when I measured my transom, I measures some conductivity. in the 200KOhm Range. Because of this I started to do a little digging around. I removed a screw from the top cap and probed with a brazing rod. I was not able to push the rod into the hole any farther then the screw.. Felt very solid.

Then I figured I would do a different test. I connected the ground from a 12v battery charger to one of the transom tie downs. Then I hooked the positive to a lead on my meter. Now I took the other meter lead and probed the other tie down. I got 9V so that tell me that there is a closed circuit. I probed the screw that hold the ladder and also measured 9 volts. This transom conducts a small about of current.

Well I saw a very small pinhole in the sealant by the red arrow. Basically looks like the cut in the fibreglass was a tiny bit off.

IMG00063-20110402-1211.jpg


I removed that cap, and to my surprise it was pretty dirty under there so I know that water was getting in there.

IMG00057-20110402-1139.jpg


I poked around with the welding rod into the little gap where the top cap meets the transom and it feels very sold.

Now, I touched the probe of my multimeter to this little gap and I measured 6 volts. I couldn't even see any wood from this gap.. I was only even able to get the meter probe in there like an 1/8 of an inch so I don't even think it came in contact with wood. Intact I read like 3 to 5 volts when touching the probe to on some exposed glass mat and resin.


So then I decided to probe the metal handle in the splash well. I didn't get any voltage reading there so that tells me that there is a break in conductance to that point.

Does anyone know of anything that Champion may have used in their 2000 models that conducts electricity? There has to be something.

Here is an exampe of the two points the I measured..

Champion190SX_2000_TransomTieDown.jpg



I am very confused.
 

slinkeey

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Aug 20, 2008
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39
Re: Transom Conducting Current but doesn't appear to be wet!

BTW

I don't have any stress cracks.. No movement when bouncing on the motor... No brown stains... No signs of problem.. I just want to be safe.

I know for a fact that the transom is wood cored. I beleive they used Baltec brand end grain balsa as the core.
 

Cadwelder

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Re: Transom Conducting Current but doesn't appear to be wet!

Well an interesting test to say the least. I must say I've never heard of anyone connecting a battery charger to a tie down....but with a lot of wet wood a voltage reading isn't surprising, but I wouldn't trust that as my test for a rotten transom. You need to drill some test holes to check for rot. Drill from the inside (don't go all the way thru).
 

slinkeey

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Re: Transom Conducting Current but doesn't appear to be wet!

Well an interesting test to say the least. I must say I've never heard of anyone connecting a battery charger to a tie down....but with a lot of wet wood a voltage reading isn't surprising, but I wouldn't trust that as my test for a rotten transom. You need to drill some test holes to check for rot. Drill from the inside (don't go all the way thru).

Yeah.. I did it that way because it was less second guessing.. On MOhms, the meter wouldn't stay put on a value.. It would fluctuate aroound 22-300k constantly changing.. Drop it down to KOhms and it would measure open... I cut to the chase and figured I would see if the transom would pass the current generated by the battery charger and it did..

Thanks for the advice.. Drilling into it is going to hurt..
 

Cadwelder

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Re: Transom Conducting Current but doesn't appear to be wet!

Not at all, done all the time. Put a stop on your drill bit to make sure you don't go too deep. A few holes is all you need. 3/8" drill size is fine. Dry chips...great, wet soggy, water...new transom.
 

produceguy

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Re: Transom Conducting Current but doesn't appear to be wet!

Fill the holes with 5200, if the transom is good and it won't look that bad.
You can even paint it after it cures.
I drilled mine but it was an I/O, and those transoms are 2 inches thick total, fiberglass and wood, not sure on yours.
I went in at 1 inch depth.
Hope that helps a little.
 

slinkeey

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Re: Transom Conducting Current but doesn't appear to be wet!

Then fill with Marine-Tex if all is good?

What chance do you think I have of a good transom with conductivity?

If they are nice dry chips, would I want to put some heat lamps on the transom or something to try and dry it out and lower the conductivity as that may be from moisture content??

I do know for a fact that the transom is Baltek End Grain Balsa..
 

produceguy

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Re: Transom Conducting Current but doesn't appear to be wet!

Then fill with Marine-Tex if all is good?

What chance do you think I have of a good transom with conductivity?

If they are nice dry chips, would I want to put some heat lamps on the transom or something to try and dry it out and lower the conductivity as that may be from moisture content??

I do know for a fact that the transom is Baltek End Grain Balsa..

If the chips are dry, I would just seal it up and call it good.
 

slinkeey

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Re: Transom Conducting Current but doesn't appear to be wet!

Just For Fun..

P1010024.jpg


IMG_0952.JPG


I just bought it last summer.. IT has been a great boat.. Pretty much inspected the trasom for movement, cracks, and etc.. never even thought of checking with a multimeter until I read the theory about a month ago so I thought that I would try it for fun.. Well that furn turned into feeling my stomach drop..
 

produceguy

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Re: Transom Conducting Current but doesn't appear to be wet!

Nice set up.
Hope it all checks out.
 

slinkeey

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Re: Transom Conducting Current but doesn't appear to be wet!

Is it a good idea to use a drill in by the gas tanks.. (Sparks on the brushes)

Do you think a good alternative would be to remove the screws that hold the cable clamps going down to my transducer and then poke around in there with a ice pik or something?
 

Cadwelder

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Re: Transom Conducting Current but doesn't appear to be wet!

Won't hurt, ventialate the blige well and use a battery drill, it's done all the time.
 

slinkeey

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Re: Transom Conducting Current but doesn't appear to be wet!

Well I drilled the holes..

The wood came out dry.. I poked around with a ice pick and it is not soft.

That gave me a sigh of relief.
 

Cadwelder

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Re: Transom Conducting Current but doesn't appear to be wet!

Great......seal the holes good and enjoy the water.
 

jonesg

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Re: Transom Conducting Current but doesn't appear to be wet!

So much for that test.
 

slinkeey

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Re: Transom Conducting Current but doesn't appear to be wet!

So much for that test.

Yeah the electrical resistance test appeared to be golden when I read about it.. Sure I applied my own style to it in order to pump more current..

I am going to try something with the hole for fun.. I am going to tape that ice pick so it can't contact the glass/resit and just touch wood and then take a resistance reading.

I noticed something funny about the resin/glass black there..

Everywhere on the boat has like a peachy pink fiberglass resin when you can get to it..

The transom was gray under the gelcoat.. once I got to the wood it was very light...
 

Yacht Dr.

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Re: Transom Conducting Current but doesn't appear to be wet!

That pink fiberglass is from red MEKP used in boat building. Mainly for chopper guns so the applicator Knows that MEKP is being pumped to the head of the gun and at what hue of pink determines if there is a potential problem in the pump system.

That gray might be some kind of fire retardant coating..

As far as using Ohms or Conductivity .. voltage..etc .. thats why moisture meters are not always a reliable tool in determining the amount of Moisture. It will only tell you that "something" is conductive or resistive in the readings.

Try doing that same test on boats with high copper value bottom paints..or " blister barriers " your meter will show a faulty reading.

I remember some surveyor metered the bottom of an old fiberglass Chris Craft .. Pegged his meter in a few Large areas and advised the use of a blister buster to remove the first few lams of FG. So the owner opted to do this..low and behold after the buster did its job there were 2 large areas with Copper Mesh Within the fiberglass itself ( for lighting protection from what I was told ).

There was No reason to strip and redo this bottom at all.. just because some dude with a meter cost that guy Thousands of dollars for nothing.

Visual inspection is Always the best method IMO .. meters can be a tool..but not the final say :) .

I think your looking good right now.

YD.
 

slinkeey

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Re: Transom Conducting Current but doesn't appear to be wet!

Thanks for the help and advice...

3M 5200 to seal the holes, right?

Also I have one hole that I would like to seal up on the outside. It is from a transducer.. It is a 1/4inch diamter hole.. Kind of large for a screw hole, but that can be another conversation.. :)

Would this stuff work ok for that is is it not to be trusted and order some marine tex or west epoxy from a marina.. I just go to the hardware store anytime and pick this up.

http://www.loctiteproducts.com/p/epxy_mrn_s/overview/Loctite-Epoxy-Marine.htm

epxy_mrn_s.png
 

jonesg

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Feb 22, 2008
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Re: Transom Conducting Current but doesn't appear to be wet!

Just avoid the 5 minute epoxy, the slower the better.
It might be a bit too runny though.

although...it does say marine on the package :)
 

slinkeey

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Joined
Aug 20, 2008
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39
Re: Transom Conducting Current but doesn't appear to be wet!

Bonds in 120minutes according to the website..

I just want to make sure that it doesn't let water penetrate..
 
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