Looking for Materials to Seal up Transom (Pic attached)

[ERock82]

I just recently removed my old outboard to get my transom ready for a new one. My transom trim was badly cracked and I just removed it. In the attached pic you can see what it looks like. There is an exposed edge which has some sort of sealant that is chipping away and very old.

What should I use to seal this area up? I was thinking either Marine Tex to fill this gap and sand it out smooth or 5200 or just regular silicon. Any thoughts??

Also, being that there is a curve on both sides of the transom, what do you recommend for the trim? Ideas I have are:

1.) Thick flexible white vinyl cut to size of transom trim, then screwed down and sealed with 5200. Getting the angle good might be hard though with out lots of screws.

2.) Aluminum piece that's from Home Depot that many people talk about using. It is already angled. I would just cut it on both sides before the curve. For the curve, either use nothing (just have edge sealed up real nice) or use vinyl for looks. Are these pieces corrosion resistant?

Another question:
For bolt holes when mounting new motor: Many people use 5200 but I've heard that can be a bad choice if you ever remove. Do you think regular silicon, or 4200?

Also, on my old motor there appeared to be some sort of rubber-like material under the mount holes that may have been there for vibration??? Not sure, but is that something that would be used or do most people just slap on the new motor and seal up holes?

Thanks in advance!

 

[metriccrescentwrench]

Poke around in those areas around the edges where the skins have split using an ice pick or something similar, I'll just about guarantee that you'll find you have rotten wood in there. I know that's not what you want to hear, but I've rebuilt several rotten transoms already and know the symptoms. And unfortunately most of the time rotten transoms are accompanied by rotted stringers and deck.

 

[MTboatguy]

I agree, I would do some investigation before buttoning it back up with anything, just to make sure, it is always prudent to double check at this point in time before you mount the new engine.

 

[ERock82]

Thanks for the input, but rotted or not, I'm sealing it up and going with it. It feels and sounds solid. Mount holes are clean. Boat isn't worth the time investment of a new transom. I'd junk the boat before doing that.

Anyways?.any suggestions on the questions at hand?

 

[Chinewalker]

I don't think you're going to get any recommendations, given the advice you have above. Unless you're certain the transom is solid and dry, it is simply not worth it to patch it up and continue on. A rotted transom core is potentially dangerous and can cause injury, or worse.

 

[JoshOnt]

I don't think you will find many real answers here as it is likely the transom is rotted. But since you are going to use it anyway might as well fix it. I would look at seeing of you can either use resin to seal it back up or something similar. That is about the best advice I can give you.

 

[ERock82]

Getting Transom Ready To Mount New Motor

I just recently removed my old outboard to get my transom ready for a new one. My transom trim was badly cracked and I just removed it. There is an exposed edge which has some sort of sealant that is chipping away and very old.

What should I use to seal this area up? I was thinking either Marine Tex to fill this gap and sand it out smooth or 5200 or just regular silicon. Any thoughts??

Also, being that there is a curve on both sides of the transom, what do you recommend for the trim? Ideas I have are:

1.) Thick flexible white vinyl cut to size of transom trim, then screwed down and sealed with 5200. Getting the angle good might be hard though with out lots of screws.

2.) Aluminum piece that's from Home Depot that many people talk about using. It is already angled. I would just cut it on both sides before the curve. For the curve, either use nothing (just have edge sealed up real nice) or use vinyl for looks. Are these pieces corrosion resistant?

Another question:
For bolt holes when mounting new motor: Many people use 5200 but I've heard that can be a bad choice if you ever remove. Do you think regular silicon, or 4200?

Also, on my old motor there appeared to be some sort of rubber-like material under the mount holes that may have been there for vibration??? Not sure, but is that something that would be used or do most people just slap on the new motor and seal up holes?

Thanks in advance!

 

[Woodonglass]

Aluminum, 4200, and this...http://www.iboats.com/Transom-Suppo...173196--session_id.976525705--view_id.1185373

 

[jbcurt00]

Thanks for the input, but rotted or not, I'm sealing it up and going with it. It feels and sounds solid. Mount holes are clean. Boat isn't worth the time investment of a new transom. I'd junk the boat before doing that.

Anyways….any suggestions on the questions at hand?

If you choose to disregard the advice offered, starting a new topic about the same transom will illicit similar questions of

is the transom soft?

Please don't start multiple topics across multiple forums about the same subject

I merged these topics, and strongly urge you to reconsider the offered advice.

Your boat, so yes you are free to build or rebuild it as you see fit. But the advice offered at iboats places a very high priority on safety.

Thank you

 

[ERock82]

Guys, what appears to be a crack in the transom is simply a seam where the splashwell lining meets the transom. Manufactures filled that with sealant and covered with the molded trim. I'm just trying to refill that seam and don't know what to use. The piece is screwed on. What appears dark around the edge is not wood, but molded fiberglass. It seems solid and doesn't flex.

 

[shrew]

I wouldn't get terribly worried about the responses above. ALL Fiberglass boats have a seam where the deck and hull are married. Typically this is covered by the rub rail. The rub rail doesn't inherently provide waterproofing, it servers a dual function as a cosmetic finish the hull/deck joint ..... and as a run rail. Sealant is what prevents water intrusion. Failure of the sealant around deck joints, hatches, rail stanchions and cleats is common over time and these items typically need to be rebedded.

If it needs to be periodically removed then use 3m 4200. If it rarely, if ever, needs to be removed, use 5200. If it sees UV, such as on deck (rail stanchions, cleats, etc) consider 4000, which is 4200 with a UV protectant in it.

I doubt this joint has caused transom damage. Every single fiberglass boat has one, whether they see it or not.

 

[Woodonglass]

Is this the same boat you just did a deck replacement on?