Bravo transom seal dry or 4200?
 

In the process of having my gimble ring and bell housing rebuilt by JR marine. Had some water intrusion which luckily only damaged one stud which I was able to remove. Going back on with this, is it advisable to use a conservative amount of 3M 4200 on the new mercruiser seal/gasket? Any input is appreciated!

Would like to keep this from happening again!

http://i1140.photobucket.com/albums/...ps675c7e06.jpg

After removing the old oring and a very thorough cleaning you put a skim coat of 4200 on the transom assm groove. Then you install the new oring holding it in place with masking tape. Let 4200 set up a day or so. Then remove tape and just before installing the assm, put a skim coat of 4200 on the surface of the oring. Install and be happy.

order a new seal ,,i will put a 1/4'' bead of 4200 around the inside of the seal on the alunimum part then torque the bolts/ mnuts to 50 psi.. if you cant get a torque reading then the transom is soft and will need to be replaced..

Ok I will be sure to do that. Found the bottom 3-4 inches of the transom to be somewhat soft through drilling pilot holes. Is it possible to replace the bottom half by cutting it out and glassing in new marine wood?

This:

http://i1140.photobucket.com/albums/...ps7cdb0f5f.jpg

I use weatherstrip adhesive. 4200 makes a big mess and takes to long to dry.

Per the merc manual they should be torqued to 25 ft/lbs. I do agree that if they don't torque down that the transom is toast. 50 Ft/lbs might compress the wood/glass pretty good though.

A NEW foam seal, get rid of the old one. Then a little bellow adhesive in the corners to get the foam seal to stay in place. Nothing between the foam seal and the transom.

Then you use sealer on the anode carriage bolts (bottom two) of the transom assembly.

Only the first few years had the anode bolts, and if the transom has imperfection there's a chance it won't seal without some sealant. I use bellows adhesive, on the whole transom assembly, let it tack up put the seal on then a little bit of 4200 fast cure. Put it on and tighten to 25-35 ft lbs

fixx
 

you see the missing wood,,it will only get worse the deeper you go,,i knew it was rottedon the side the stud was worn..you need a transom..poke in it with a screwdriver and see how far it goes in..

yea i know its soppose to be 35 lbs but 15 more ft lbs wont hurt..im making sure they done come loose..

BORGIE,it looks like the transom has some rot,the problem is once the rot starts it will continue to spread..if you plan on keeping the boat replace the transom,if you don.t you will be doing it soon .sorry for the bad news.

Thank you for all the input and suggestions guys. Yeah not great news, especially with all the money I have already invested into the engine and such. Was thinking about cutting out the lower half and accessing the rot. Thoughts on this? Or should I just replace the complete section? Looks like this might not be done come spring. I should have had a survey done on the boat. Oh well...

Id bite the Bullet and redo the whole transom. BUT, before you do that, take a close look at the Stringers. Nothing worse than a brand new transom, and find out the stringers are gone. Many times these boat companies did a half a$$ job sealing holes after they drilled them.

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+1

Sometimes it is assumed that the water is geting to the studs by leaking past the seal, but if you get water into the boat above the stud location, for whatever reason, water can leak from the inside, under the inner plate, and sit around the stud corroding it. Not saying that is what happened here, but I like to seal around the studs, both sides of the transom.

I knew after seeing that anode stud the transom was shot too. That is how mine looked and my transom was rotten. One nice thing about having a rotten transom is it gave me an opportunity to get the propshaft height correct. I raised it 2" and gained close to 10 mph. So the money spent on the new transom was not a total waste, it fact it improved the boat all around quite nicely.

Beau, I have to agree with the others on repairing the wood. I would determine; how far the rot goes first, before I would start cutting out the whole transom. It may only be in the area closets to the cut out. I have a customer that is faced with the same thing. You can cut the glass with a cut-off wheel and step the wood for the repair, giving the strength back with the glass lay-up. If the transom surface is level and solid, when rebuilding a transom then re installing it. I just glue the new seal into transom groove and re-install it with no extra sealer on surface. If you add a bunch of sealer to surface, you are covering up an existing problem.

The reason we use a small bead of 4200 on top of rubber seal(after seal is glued to assembly) is because we have resealed several through the years that leaked,but transom was solid.. The rubber had lost its flexability and is just laying flat,if not slightly below receiver groove in transom assembly.... You do what you do...and i'll do what I do.........6-2 and even

So i did some more drilling this morning..... Stringers all the way to the bulkhead seem to contain semi soft dark wood. None of its currently wet, although its been sitting in a shop in arizona that regularly hits 115-120. Have decided too much of the transom is compromised and now it appears stringers as well. FUN!

Don't want to bum you ,Semi soft dark wood = rot...as i'm sure you know .As much as it sux, unless you are in love with the boat ..or it is something rare and worth repairing ....You might consider licking your wounds and part it out ..Or put your drivetrain in a solid boat...Just another opinion

I have installed many transom assemblies both new and reinstalling used ones. Never used 4200 or any other caulk and never had one leak. When ever a boat comes into the shop with caulk around the seal we know it was a do it yourselfer and look for other problems.

I agree.

spoke too soon. Forward stringers are rot free. Transom was wet at the bottom so that will be replaced. Everything else is solid fresh rot free as I cut out large sections today.

I would agree that one that has been caulked after the fact, is possibly attempting to hide a problem .... If you are suggesting that anyone that uses caulk is amateur, Whatever you think ,chief. There are two ways to the other side of that tree. Glad you've had luck doing them dry.

Borgie ...What do you mean forward stringers. Do you mean the stringers get drier the farther forward of the transom you go? . Hope it all works out for you

How are the stringers forward of the bilge? Like in the cuddy, under cockpit, and bulkheads?

I agree motor. In fact I don't know how you would even keep the oring in place to install the transom assem without gluing it in place with chalk. I'd venture to say looking at borgies first pic of the flat oring and water marks on it, that if the original installer would have used a skim coat of 4200 or 5200 at install time borgie may not have a rotten transom now.

When your done repairing the transom take a wood filr and file a notch at the lower part of the hole cut out,,then apply some resin and may and glass around the whole cutout..then sand smooth and paint it with several scoats of paint,,this will ensure that water wont get into the transom again..do the same with the exhaust cut outs..

Absolutely correct. This will prevent water from collecting and sitting in those areas.

We switched to Life Seal on all our rigging a few years ago and no longer use 3M 4200/5200 unless we know without a doubt it will never need to come apart. As far as sealing a transom assembly, we replace the factory foam and use super weather strip adhesive from 3M to hold it in place. Then we have always used a sealer of some sort on the foam seal but now we use Life Seal never in an attempt to hide anything (as mentioned by others) just as a good sealing procedure that has worked for decades. Don't forget that most builders don't seal holes they drill in stringers or transom that always lead to rot..... time is money. Had the OP's boat been done this way when it was new he most likely would not have started this thread. We torque factory transoms to 25 lbs as suggested by Mercruiser, we torque our transom repairs to 35 Lbs.....because they are better than factory.

4200 will come apart ..5200 will probably assist in pulling the gellcoat off the boat if you have to take it back apart

4200/5200 are both great products they will both come apart and in most cases bring other parts with them. 4200 is still not considered removable even by 3M, it just has less polyurethane and is a bit more forgiving. Life Seal is a mix of polyurethane and silicone so it bonds and seals for use above and below the water line but is much more forgiving if it has to be removed. Years ago I quit saying "This will never have to come apart again" so I switched to Life Seal for sealing but still keep the 3M products around for the permanent repairs that I do not want to come apart.

and then
http://www.3m.com/product/informatio...e-Sealant.html

If you have to remove something with 3M 5200...this stuff works...

http://www.marineformula.com/

If you take a tube in your hand and look at them the 5200 has permanent and the the 4200 is in the middle between that and removable. Just saying and not looking to argue about it (I just work with it every day). As far as the remover troper posted good luck with that if you need it off and plan on working on it in your life time. Yes with time it will take off the the polyurethane you can see but you might as well buy some Slick50 then you can drain your oil and forget about oil changes (truth in advertising.......do you believe everything you see/read)

Who sells life seal?

It is a Boat Life product I get from Boaters Value.

Boat us and west marine ,,if you get the west marine brand i was told it is also life seal.. i still use 4200 tho,,life seal dont bond as good,,just saying..to remove 5200 and 4200 i use a port a power then move the transom just enough to get a .005 piece of piano wire behind it to cut through it and it dont hurt the gel or fiberglass..

Hi Brian, what is the difference with the life seal vs. life caulk? After reading on the site I am unable to determine.

I'm looking to replace some thru hull fittings above the waterline. Was going to use 4200, now I'm curious.

Thanks.

4200 is an Adhesive, that is why we use it .I'd rather it be a little tuff to remove than not stick very well .My experience with 4200 (not 5200) is it will come apart if necessary.....Once 5200 has dried you could pull the fasteners and still have the parts stuck.And in fact ,as you obviously know damage the boat trying to take apart. But I don't want to argue either .To each his own ..I agree with you on attempting to use any kind of remover for 4200/5200 ..The stuff you are seeing isn't holding it down .It'd Take a few years to maybe kinda wick up under the edges of a fitting .Probably works once you have pried stuff apart and are just looking at thin coating..

I was referring to the stringer section that is forward of the motor mounts. To update, my iphone got water logged and I'm without a phone( have been for the last few days). I cut out a portion of the transom and the only part that was wet, with hardly any rot( don't even think it qualifies as such), was right under that leaking stud. Everything else was solid wood. Used a small paddle to do some exploratory on the stringers, all dry solid wood. Once my cell phone is replaced or is working again, I will update with pics. My Rotozip saw made quick work of this task! Thanks for all of the replies.