Evaluating and resealing transom

[86 inches]

Swapping out jackplates this weekend and would like some advice on how to evaluate and reseal transom.

How can you tell if water has been in the transom. Where do you look for signs of damage. Having pulled the trim on the top cap how do you reseal. Any and all advice appreciated.

[Royjulius]

Start here....http://www.bbcboards.net/zerothread?id=638872

[86 inches]

Thanks.

Any other suggestions before I do this.

[Marooned]

86, my boat is the one in the link that Roy provided. On mine, I noticed that one of the lower motor mount bolts was slightly sunken into the inner fiberglass skin (inside the bilge). Also, there was a stain (again inside the bilge) where water was escaping from a crack in the glass skin near one of the knee braces. I took everything off to try to dry it out and left it under the heat lamps for 2 weeks. But when I tried to push some air through the transom from my air compressor I noticed that the force of the air caused the outer glass skin to push away from the transom core. From there I used some thin wire to probe down into the transom and realized it was soft pretty far down.

I don't remember what topic it was under but ChampionMan had a great post outlining the proper way to seal everything back up and proper torque for all the bolts.

[ChampioNman]

If you have any screws in the transom that may hold a cable clamp on remove it and wait an hour or so to see if the evil brown ooze comes out.
Also while your plate is off remove the lower bolts from the transom and check for intrusion. You'll know pretty quickly. Another thing you can try, I myself haven't tried it) but you can set a multi meter on Ohms and put one lead on one trailer tie down and the other lead on the other tie down. If you have continuity then there is water in the transom.
With your top trim piece off coat it with either 3M 4200 or Starbrite silicone. Both are for below the water line. Seal it well and silicone all screws before install.
On the mounting bolts apply the starbrite silicone around each bolt hole and let it tack up. Coat the bolts with anti-sieze grease too. Mount the plate and torque the plate to 40-50 foot pounds in an X-pattern. Run a bead of silicone around the outer and inner edge of the plate as well.
Coat the motor mounting bolts with anti-sieze also and torque to 60-80 foot pounds.

[pcmc19057]

With trim off take a 1/8 wire and push through your trim screw holes and see if its solid or soft.

Also seal top of screws ( looks like a little hersey kiss ) on trim after you tighten them.
Paul

[86 inches]

These are all great tips. Very much appreciated.

[Royjulius]

<table width="90%" cellspacing=0 cellpadding=0 align=center><tr><td>Quote, originally posted by ChampioNman &raquo;</td></tr><tr><td class="quote"> set a multi meter on Ohms and put one lead on one trailer tie down and the other lead on the other tie down. If you have continuity then there is water in the transom.
</td></tr></table>

Genius. I never would have thought of that.

[slinkeey]

Yeah that is an interesting test... You might have to go k ohms or M ohms because I am guessing that because of the distance there would still be a nice amount of resistance..

[86 inches]

Checked transom for flexing by moving motor... none. Pulled motor off and removed jackplate. Removed all screws that were holding speedo and temp gauges etc. No brown ooze. Removed all trim and everything looks solid with no signs of rot. Checked for intrusion from the lower transom bolts... none. All looks solid. Even checked for resistance using ohm meter as suggested. Meter read 0. I think its all good.

[ChampioNman]

[86 inches]

Pic of transom

[86 inches]

and another...

[BILLY]

<table width="90%" cellspacing=0 cellpadding=0 align=center><tr><td>Quote, originally posted by 86 inches &raquo;</td></tr><tr><td class="quote">Checked transom for flexing by moving motor... none. Pulled motor off and removed jackplate. Removed all screws that were holding speedo and temp gauges etc. No brown ooze. Removed all trim and everything looks solid with no signs of rot. Checked for intrusion from the lower transom bolts... none. All looks solid. Even checked for resistance using ohm meter as suggested. Meter read 0. I think its all good.</td></tr></table>

Good deal.

[86 inches]

Transom sealed and trim installed.

[DEdwards]

Great Job! Looks really good!

[pcmc19057]

I would seal around metal trim and screw heads with 4200 it might look differant but the screws won't leak.
Paul
Thats where I had my problem on my 203

[86 inches]

Everything is sealed with Starbright Marine underwater silicone. Pretty much coated the top of the transom before replacing the trim. Squirted into screw holes before running the screws. I think its pretty good. Hope I did it right.

[86 inches]

Do you mean I should cover the screws with 4200?

[BILLY]

I would think if you put it on the screw threads AND the counter sunk holes it would be fine.