'86 Sea Nymph Fishing Machine: Transom & Find leak (help!)

[wolfee]

This boat has been in the family (mostly my Dad) since he bought it new in '86. I was the last to get it, about 5 years ago and turned it into a project with my son. We tore out all the plywood and seats and reinstalled new exterior plywood, carpet and seats. The back-to-back seat that folds out into a lounge was my feable attempt to get my wife into boating, it failed :blue: Anyway, we were on the lake last weekend and after a couple hours of fishing, my son pointed out that we were taking on water. It was clearly the most water I had ever seen in the boat and immediately turned the bilge on, which pretty much kept it at bay but was not lowering the level of water. I decided not to take any chances and headed back to the dock. Before we headed home, a boat repair guy was there and mentioned he thought there was too much play in the transom and that it was probably leaking and needs replaced. I would also have to do a leak test via filling the boat up with water and looking for a leak from under the boat while it sits on the trailer. (You will see that the inside of the boat is covered with plywood/carpet)

After looking at the transom, you will see that it has been cut down even further and that one side has an open area with direct access to the edge of plywood making up the transom. I've never done leak tests or a transom replacement and wanted your expert advice. I don't know what to do about the cut section, apparently it needs to be cut that low to allow for the prop on the motor to sit low enough, so I would need to find that aluminum trim cap material somehow I guess. I will start posting pic's with more questions. Thanks for any help, much appreciated.

Ok, I have more pics but from what I can tell, this shouldn't be hard to replace? It looks like the plywood could actually slide right down between the inside and outside sheets of aluminum. From what I've read on this site, I should use (3) 1/2" pieces of plywood instead of (2) 3/4" ?? Or does it matter? Also, dumb question I guess but where do you get the drain holes? I'll check iboats first, just not sure what you would call them.

 

[wolfee]

Re: '86 Sea Nymph Fishing Machine: Transom & Find leak (help!)

Here is the boat HP and lbs limit.

 

[Pmccraney]

Re: '86 Sea Nymph Fishing Machine: Transom & Find leak (help!)

Wolfee:
Welcome to iboats. Sea Nymphs are great boats (good bones). Yeah, someone in in the family cut down that center section of the transom to accommodate a shorter prop shaft, and they added the little clamp piece for the merc... You can see where the transom cap was cut...

Leaving that wood exposed has probably caused some weakness (rot in your transom)... While a transom can get soft and flex, it is usually not the source of a bad leak (especially with a lighter clamp-on motor that is not through bolted). Do you have any holes in the transom that are below the water line (other then the drain plug - that was in right? ) Sometimes holes for transducers and such can leak.. (especially if the fasteners are imbedded in rotten wood)... [EDIT: I see a transducer wired through splashwell drain and fastened to the bottom of the boat - I would take a close look at that].... Also look for cracks in the outer transom skin that could have been caused by the stress of hanging a motor on a weak transom...

Replacing a transom is pretty easy, but will require you to remove your splashwell assembly transom cap and end pieces... You can fabricate a new transom to shape (sea nymph transoms are usually about 2 inches thick) with exterior ply bonded together, coat it in epoxy or spar, prime, paint, reinstall, and put your splashwell and transom pieces back on, then bolt on your motor. However, I would recommend fabricating a transom cap that covers all of your exposed wood.

this is my boat getting everything out to get the transom out:



A leak test is going to pretty tough (pretty much impossible) without ripping everything out of your boat (the deck, the sub-deck foam, etc...). Below is a picture of my leak test with everything out of the boat:



Since you just rebuilt your decking, I am not sure you are up for doing a complete gut and re-build... So, you may want to start by taking a very close look at all rivets and fasteners below the water and on the bottom of the hull.. Make sure no rivets are loose (or missing)... You can install/replace blind (closed-end) pop rivets without having to rip out your deck structure, etc.. (you just have to have access to the underside of the boat)...

I would start looking for an obvious source of the leak and if you can't find it, then you may have no choice to rip everything out, do a leak test, replace any bad rivets, then gluvit (epoxy) all your seams and rivets and put it all back together...

Not fun, I know, but better than sinking...

Hope that helps...

 

[Pmccraney]

Re: '86 Sea Nymph Fishing Machine: Transom & Find leak (help!)

Here are some places to investigate for a leak (your transom needs to be replaced regardless)... I can tell its rotten from the pics:

 

[wolfee]

Re: '86 Sea Nymph Fishing Machine: Transom & Find leak (help!)

The bolts are actually fine, the dark circles are from previous larger washers. The bilge is just sitting in there, no hole in the boat. I will check the seals on these. I'm adding one more pic to show the outside of the transom. I have a line to the livewell that has a plug in the livewell, a line for an aerator and the hole for the drain. All in the next pic.

I'd really like to turn this into a console setup, so I'm not completely against pulling the plywood because it's all screwed down and I think I could pull it up if I had to. (I don't want to have to recarpet)

Wouldn't I be able to level the boat on the trailer, put the plug in, and then put a hose where the bilge is and let it fill up?

Thanks again for all your help and advice, btw.

 

[Streetgang]

Re: '86 Sea Nymph Fishing Machine: Transom & Find leak (help!)

Wolf

Isnt that a FM "Fishing Machine" model, oopsy you said that in your heading....

PMC is offering some very good advise. You can also find some other SN restos and see what we all found and did but doubt if going to get much short term solutions from anyone.

You say bilge pump barely kept up so assuming a signficant amount of water is coming in. It's your boat, you can pump some water in it on the trailer if you want, guessing the foam is waterlogged anyway but a good inspection may show you the problem / problems without the leaktest.

Is the keel sound, meaning could it worn thru from grounding ? If bottom isnt painted get a small punch and tap on some discolored rivets and see if they spin.

Still thinking it must be something significant and obvious or just a multiple of seams, rivets and perhaps cracks.

Probably some heavy hitters will stop by but may be worth your time and effort to consider a restoration.

Good luck and be safe.

 

[Watermann]

Re: '86 Sea Nymph Fishing Machine: Transom & Find leak (help!)

Welcome aboard Wolfee, that is one sweet little tin SN you have there! She is very worthy of the best. I too did a partial restoration on my SN SS160 and this year it was time to go full on. I was sick of the water intrusion inside the hull and my interior was shot again. Since your boat has some emotional ties to your dad I have to assume that you plan on keeping her in the family and someday for your son to have.

Plain and simple, there is no way possible to ever repair a leaking tin boat from the outside only. PMC has stated a very eloquent argument for the full tear down just from seeing a few pics you posted. I have to agree, she need more than some band aids from the outside.

You can save and re-install all of your carpeted decking or you can go full restore mode crazy, it's all up to you. Most everyone here at the forum are very eager to help with positive and constructive suggestions. The one thing we all have in common is that we all love our boats and being on the water. When we're not out skimming the waves, we spend some time working on our boats or here helping others.

Oh yeah as the new guy we need to teach you the super secret Sea Nymph hand shake and get your SN ring sent out Fed Ex... ... JK...

 

[wolfee]

Re: '86 Sea Nymph Fishing Machine: Transom & Find leak (help!)

I ran out before dark this evening and crawled back under the motor to take a look under the boat. There is a "fresh" 12" gouge about 2 feet from the back of the boat. I coudn't get a good look to see if it goes all the way through but I could easily cut my hand on the edge. One other thing I noticed is the trim tab is broken off which would explain why it has been so hard to hold the tiller. Tomorrow I'm getting a drop light and taking a good look at the gouge and since it's so far back on the boat, I may raise the front of the boat and fill the back with water to see if it leaks. It's all bad news but at least it's news and I have something to go on. I'll keep you updated, thanks everyone.

 

[wolfee]

Re: '86 Sea Nymph Fishing Machine: Transom & Find leak (help!)

Well I'm at a loss. I raised the front of the trailer/boat as high as it would go and filled the back of the boat up with water until the water level was over the first set of motor mount bolts. I had a slow drip from the boat plug and once the water reached the motor bolts, they leaked slowly as well. Nothing else from anywhere, not a drop. So I lowered the front of the boat until it was sitting level and let the water raise about 2" above the carpet. Nothing, no leaks. All I can think is that waves were coming in over the back of the transom and going down inside the opening, which is possible because we were fishing along a steep drop next to a high traffic channel. I guess I'll do the transom and see if I take on water then.

I'll open a separate thread about switching to a console on another forum, I have no idea how to do that.

 

[Watermann]

Re: '86 Sea Nymph Fishing Machine: Transom & Find leak (help!)

wolfee, you can also just change up the name of your thread and keep this one going.

I think by the looks of your picture you may have added a bit too much water for the sake of your little SN. You can fix the leaks you found, new drain plug, pull the bolts one at a time and seal them after drying out with a heat gun. Then go out and see if she takes on water. I don't really like the fact that a boat that size has no splashwell and drain tubes for the transom. You may have to alter the way you do things on the water too and not allow the stern to take on the full on chop and waves. One good roller over the top of the transom could be a catastrophe in the making.

 

[wolfee]

Re: '86 Sea Nymph Fishing Machine: Transom & Find leak (help!)

I'm back and have removed the transom (what was left of it), see pic. It was basically a mulch transom sandwiched between two pieces of aluminum I'm getting marine grade plywood today and will try to make a template out of what was left, could be a little difficult. About the splashwell, there is one but I guess it blends in with the transom in the pic. I took out the drain holes in the splashwell and ordered new ones. Also ordered a new bilge and bilge hose plus a new thru-hull fitting for the bilge hose. Once I removed the plywood/carpet from the area covering the bilge hose, I found out the bilge hose was actually broken/severed and the water was just getting pumped right back into the boat. (most of it anyway)

I started a new thread over on the mercury forum about switching to remote/console and electric start and it sounds like it could be a very expensive project for a 25 hp. vs. buying one with everything on it. Kinda wanted to do it

 

[bonz_d]

Re: '86 Sea Nymph Fishing Machine: Transom & Find leak (help!)

wolfee you still have options.

1st option is to do as needed repairs to get'er back on the water asap with the knowledge that changes can be made at a better time.
2nd option is to make the desicion to just go for it now and do it the way you want it when finished.
3rd option is somewhere in between.

From what I see here it may not be as bad as you think to get to where you want to be. For one the Merc you have now does have a tilt tube for the steering so you could add a steering console yet still have manual pull start. Many old school boats were that way back in the day.

The console could be homebuilt, aftermarket or used. Watch graigslist boats section as these things show up from time to time. Sometimes they even include the helm, steering wheel and cable. The hard and expensive part is going to be finding a remote control box to fit that engine.

Next is that engine, boat and transom. That transom has been cut down to fit a short shaft engine which also could be the cause of your taking on water. If I were to be rebuilding that transom I'd be building it back to original height and then be on the watch for a long shaft engine. I believe those boats were designed for up to a 35hp or 40hp outboard of which most all of those are electric start. In most parts those engines are pretty readily available.

So there are just a few ideas for you to ponder!

 

[joelybob]

Re: '86 Sea Nymph Fishing Machine: Transom & Find leak (help!)

View attachment 203795I'm back and have removed the transom (what was left of it), see pic. It was basically a mulch transom sandwiched between two pieces of aluminum I'm getting marine grade plywood today and will try to make a template out of what was left, could be a little difficult. About the splashwell, there is one but I guess it blends in with the transom in the pic. I took out the drain holes in the splashwell and ordered new ones. Also ordered a new bilge and bilge hose plus a new thru-hull fitting for the bilge hose. Once I removed the plywood/carpet from the area covering the bilge hose, I found out the bilge hose was actually broken/severed and the water was just getting pumped right back into the boat. (most of it anyway)

I started a new thread over on the mercury forum about switching to remote/console and electric start and it sounds like it could be a very expensive project for a 25 hp. vs. buying one with everything on it. Kinda wanted to do it

When I redid my transom on my sea nymph it too was mulch. I used a piece of cardboard for a pattern. Had to trim it a few times. or you can use a few pieces set them down in transom area to get angels, then tape them together before you take them out.

 

[wolfee]

Re: '86 Sea Nymph Fishing Machine: Transom & Find leak (help!)

bonz_d, It has a max hp of 50 for the boat. I'm not sure what you mean about the tilt tube. Do you mean that since it is a tilt tiller, I could start it up normally (manual start) and then flip the tiller up and use a remote steering console? I thought the remote steering actually replaced the tiller, but I've never done it before. What would it connect to? I kinda agree with you about rebuilding the transom back to the way it was but then I'm looking at hiring a welder for the extra aluminum and then the boat is unusable until I find a long shaft outboard. Hmm...

 

[bonz_d]

Re: '86 Sea Nymph Fishing Machine: Transom & Find leak (help!)

The tilt tube is just that. It's a tube that goes through the transom clamp and the engine tilts around that tube. The tube then is were the cable end runs through to connect the steering to the engine with a link rod.

Many of the old late 1950's OMC tiller engines were run remotely with the old fashon rope and pulley systems and yes many of those had the tiller left on them. Just folded up.

As I was saying making this change could be something that is left until the off season when you'd have more time to do it. Rebuilding the transom isn't usually a difficult or costly job. Then also should you decide to go that way I'd save using the marine ply you have already and just use a bc exterior ply for now.

 

[Watermann]

Re: '86 Sea Nymph Fishing Machine: Transom & Find leak (help!)

That transom being mulch would allow some serious flex in the hull, be sure to carefully inspect the hull for cracks. The only way water could be coming over the top of your transom were if the boat was already laden with water inside. Otherwise your boat would just ride up over the waves, that's what boats do or they would call them anchors instead. Even with that cut out transom the water would enter the splashwell and then exit the drain tubes.

In converting your boat to remote, you have a couple options. Get all new parts or find a donor boat. Anything can be done if you want it. You can keep your little merc and convert it (remoter steering and to a long shaft). You can make the transom repairs to the original height with a welder, or do it yourself using sheet aluminum without welding, the aluminum is just skin and isn't what gives strength, it's the wood. Cut the aluminum to fit, use adhesive, like 5200 to back it, clamp it to the new wood and let it set up. You could do the same on the inside and fashion a new new cap. It's all up to you and how far you want to go on your project.

 

[wolfee]

Re: '86 Sea Nymph Fishing Machine: Transom & Find leak (help!)

I have the new transom in place and was about to cut it down for the short shaft outboard I have (in previous pics) and was wondering if a motor jack would work here if I went to remote steering/throttle and just left it as a manual start? At first I thought that since I would be lowering the motor via motor jack, the tiller would have a problem if the transom wasn't cut out for a short shaft motor but if I switched to remote control, would it work?

I'm basically at the point where the new transom is sitting in place and I'm ready to cut the transom down to allow for my short shaft merc 25hp. I know I could buy another motor and actually found a used 25hp with remote control that is a long shaft (one state away) but I know my motor works and you never know what you're buying.

 

[jigngrub]

Re: '86 Sea Nymph Fishing Machine: Transom & Find leak (help!)

Since you've replaced the decking and are in the process of replacing the transom, it would be a good idea to check your floatation foam for waterlogging saturation. Aluminum boats that have that much rot have saturated foam 9 out of 10 times. Don't just feel the top of the foam and call it good if it just feels a little damp or dry,take a core sample with a piece of pvc pipe and check the bottom of the foam.

Waterlogged foam is very heavy (hundreds of pounds) and will slow your boat down considerably, not to mention it's also a safety hazard because it has lost it's buoyancy and won't float your boat in case of an emergency and it will sink to the bottom of the lake.

Removing your floatation foam will also aid you in finding your leak while doing another leak test, the foam could be obstructing the water coming out of the boat but not coming into the boat... kind of like a backflow prevention valve.