Another Stringer Repair Question - by a Newbee

[lutzsucceed]

I'm replacing stringers and floor in a 1984 Cheetah 166 Runabout - our family's had this boat a long time but we've never tackled any major structural repairs and it's time to get er done. It's a 140 hp OMC (yeah, I know...) but it runs great and we've had no issues with getting parts and we have a local guy who works on outdrive - so we're not messing with that...

My question has to do with repairing it ON the trailer.

1. Is it imperative that I get it off the trailer? It's sitting on bunks and rollers - see PICS
2. If I do have to lift it and build a frame for it - can you point me to threads that cover the best method? Seems like HUGE JOB to lift this boat off trailer, for me...
3. THANK YOU all for this forum, I've learned so much about boat repair - thanks to you all you guys.

Dave in Nashville


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[Woodonglass]

Re: Another Stringer Repair Question - by a Newbee

Welcome to the iBoats Dry Dock!

Have you core sampled the motor mounts and transom to confirm they do not need replaced? Usually, but not always, when the deck and stringers are bad the mounts and transom have issues as well. If they do then the motor and outdrive will need come off and then taking the boat off the trailer will not be quite as big an issue. If all that is required is stringers, then leaving her on the trailer should not be an issue. Check the link in my signature for recommendations on how to fab your stringers.

 

[lutzsucceed]

Re: Another Stringer Repair Question - by a Newbee

This all started because the Engine had squashed the fiberglass portside. I cored the mount and it was rotten. It appeared to be dry rot as I cut the top off the mount and the 4x4 (or whatever it was) was pretty much dust. See PIC - EMPTY MOUNT AREA...

The transom appears to be solid - although I have yet to sample it, I've stuck it with an awl and it can't penetrate it.

My plan is as follows.

PUT ON RESPIRATOR, SAFETY GEAR...

1. CLEAN - GRIND - INSPECT Transom, Bow- CLEAN - GRIND - CLEAN - RINSE REPEAT - ETC. -
2. Remake Stringers - southern pine 1x8 clear lumber - resin coated - as explained on this site, Bed them in PL with Gap...
3. Remake Motor Mounts - cut out old Glass - need advice out how to rebuild it to support 3.0 litre engine - it's a huge void...and should it have Metal on top?
4. Get set up for Fiberglass once the Structure is reestablished...

 

[lutzsucceed]

Re: Another Stringer Repair Question - by a Newbee

I'm sorry, I forgot to mention I removed the Engine and the Outdrive...to repair the motor mounts, which lead to removing the entire sole and on and on...

I'm not very good at this posting thing yet, sorry, Kinda Nervous - out of my element...:facepalm:

thanks for your patience and experience.

 

[Woodonglass]

Re: Another Stringer Repair Question - by a Newbee

From the last pic it appears there is some discolorization around the drain tube at the bottom of the transom. I'd drill into there and see what kind of shaviings you get. Put some tape on the drill bit about 1" up so you don't go to deep. I'm betting you're gunna find dust or wet dark shavings and the transom will need to be replaced too! I'd recommend building the stringers from two layers of 3/4" plywood laminated together instead of the SYP 2x material. It's stronger and more reliable. You can use the Arauco Ply from Lowe's. Did you check out the link in my signature?

 

[Pmccraney]

Re: Another Stringer Repair Question - by a Newbee

Hey Dave:

Welcome aboard.... I'm a newb myself, but a couple of months a head of you, so I'll try to answer some of your questions.

Just a quick supplement to what WOG said... You will probably have to remove all the foam to re-do your stringers (I can't tell from the pics whether that's still foam in there or the hull, so disregard the next sentence if it's out). Its possible that you can just cut away a few inches from both sides of the stringers.... IF the foam is dry.. You can take a core sample into the foam with about 1.25 inch pvc pipe. It its wet at the bottom, it should all come out.

If you don't plan on pulling the cap as part of this process, then you can probably do it all on the trailer... You will notice your boat will flex and lose a ton of its rigidity (a lot of "play") once the stringers, foam, etc..., is out. Roller trailers can be a problem because they can create a waffling effect on the flimsy hull, and when you pour in the new foam it can conform to that waffled shape... Bunk trailers don't pose the same risks, provided that there are no "pressure points" and your bunks hug the boat fairly evenly. You will be be able to see it if the bunks portion of your trailer is creating any issues.

On the engine mounts, if you are re-using the same engine/drive line, then just take measurements of your existing mounts and rebuild accordingly.

If you are stringers and deck and mounts are shot, I am like WOG and would definitely say to drill about 5 or 6 core samples into the transom just to be sure.... If you confirm the transom is good, then I would just rip out and grind away everything at the same time (including the motor mount area). You don't want to remove the stringers, grind away, replace them and then start on the motor mounts. In fact, most people do the motor mount stringers first and then work their way forward.

Also, for what's its worth, if you do have to replace your transom and motor mounts, I'd think real hard about trading out the OMC for more modern power before you do all that work.

Good luck...

 

[lutzsucceed]

Re: Another Stringer Repair Question - by a Newbee

i did! MAN, those diagrams ARE AWESOME! It explains it ALL! THANKS FROM ALL OF US FOR THAT! I'm good with Plywood - I'm a carpenter and well, we're used to working with dimension lumber and I've seen guys use 1x material - but also read that the Ply is much stronger/flexible, which makes sense to me....

 

[lutzsucceed]

Re: Another Stringer Repair Question - by a Newbee

Pmccraney - been watching your progress while "training" here on the site. I feel like I know all you guys cause I read & watch everything I can that is relevant for my project. I have the foam out already and yeah, I notice the hull is getting a little squirrely, but I'm walking on the bunks as much as possible. AS for a repower with Merc or whatever, not in the cards for this project. No budget, so we'll just have make it work with OMC - such is life. Next boat, though, I'm getting an OUTBOARD and a Metal Boat! LOL!

My boat scares the daylights out of me - but I keep going out there each night to wade a little deeper into the abyss.

THANKS FOR THE SUPPORT - Dave

 

[lutzsucceed]

Re: Another Stringer Repair Question - by a Newbee

From the last pic it appears there is some discolorization around the drain tube at the bottom of the transom. I'd drill into there and see what kind of shaviings you get. Put some tape on the drill bit about 1" up so you don't go to deep. I'm betting you're gunna find dust or wet dark shavings and the transom will need to be replaced too! I'd recommend building the stringers from two layers of 3/4" plywood laminated together instead of the SYP 2x material. It's stronger and more reliable. You can use the Arauco Ply from Lowe's. Did you check out the link in my signature?

question: My stringers are only 3/4" wide - do you still recommend two layers of 3/4" plywood?

 

[Pmccraney]

Re: Another Stringer Repair Question - by a Newbee

Pmccraney - been watching your progress while "training" here on the site. I feel like I know all you guys cause I read & watch everything I can that is relevant for my project.
THANKS FOR THE SUPPORT - Dave

You bet! Jump on my thread and chime in - the more the merrier. Glad you been watchin'.... You are doing the right thing by reading and watching... Its amazing how much you will absorb just hanging out on here and reading. This site is blessed with a lot folks (who pre-date me) who do things right, safe, etc...

 

[Woodonglass]

Re: Another Stringer Repair Question - by a Newbee

Nope, Go back the way it was. The OMC power plants were kinda like the little girl with the Curl. When they were good they were good and when they were bad they were Horrid. If it's good then run with it especially since you have a local support system. Does the exterior of the hull need any work or is it in pretty good shape? Any serious gouges?

If you end up not having to do the transom this should be a close Guess-ti-mate on your materials shopping list.

435 Resin 10 gallons
5 qts of Cabosil
1lb of 1/4" chopped strand
1 qt microballons (to make your own fairing filler)
20 yards (1 Roll) of 1.5 oz CSM Chopped Strand Mat)
7.5 yds of 1708 Biaxial cloth
Fiberglass Roller

Everything else you'll need you can get locally.

 

[lutzsucceed]

Re: Another Stringer Repair Question - by a Newbee

Nope, Go back the way it was. The OMC power plants were kinda like the little girl with the Curl. When they were good they were good and when they were bad they were Horrid. If it's good then run with it especially since you have a local support system. Does the exterior of the hull need any work or is it in pretty good shape? Any serious gouges?

The hull is pretty good, the Keel is worn at the bow where it's been beached over the years - that's of concern to me because I can see wood coming thru in a couple of places? I was considering a "keel saver"? or gel coat or what to do? I did see one nice gouge that will need attention starboard - what can be done about these issues?

Also, I drilled into the Transom around the drain and the shavings were dry. The dark spot you mentioned was from a intermediate drive leak - we're fixing that AND installing a new impellar while they're out of the boat. I think/hope the transom will be ok ("Denial")- but I'll inspect further as I get into this.

Thank God for you all - I would have just cut out the rot and screwed a sister board on the side of the stringer and glued down a new floor like we do in houses, glue down carpet and head for the lake! YIKES!

 

[lutzsucceed]

Re: Another Stringer Repair Question - by a Newbee

Nope, Go back the way it was. The OMC power plants were kinda like the little girl with the Curl. When they were good they were good and when they were bad they were Horrid. If it's good then run with it especially since you have a local support system. Does the exterior of the hull need any work or is it in pretty good shape? Any serious gouges?

If you end up not having to do the transom this should be a close Guess-ti-mate on your materials shopping list.


435 Resin 10 gallons
5 qts of Cabosil
1lb of 1/4" chopped strand
1 qt microballons (to make your own fairing filler)
20 yards (1 Roll) of 1.5 oz CSM Chopped Strand Mat)
7.5 yds of 1708 Biaxial cloth
Fiberglass Roller

Everything else you'll need you can get locally.

Dang! Thanks for the list. We have a place called Advanced Plastics Inc here in Nashville that carries most everything on your list. You have cut through A LOT OF CLUTTER for me AND for others reading this. This is good news that I don't have to pay shipping, no?

 

[Woodonglass]

Re: Another Stringer Repair Question - by a Newbee

If you have a local supplier, You a way ahead of most of the others here on the forum. Count your blessings.

 

[Outback Jack]

Re: Another Stringer Repair Question - by a Newbee

Nope, Go back the way it was. The OMC power plants were kinda like the little girl with the Curl. When they were good they were good and when they were bad they were Horrid. If it's good then run with it especially since you have a local support system.

Exactly WOG , I know just talking to a guy locally about some of the projects being done on here. He said I would never spend the money on an upgrade unless I had too. I have connections up here in canada and he has lot's of aftermarket supplies. He said check out the internet great supplier up this way. I never got down to where he get's them. I will probably never see the guy again either.

One thing I did say to him is I play with lot's of old cars and have upgraded my trans am with lot's of aftermarket parts and in the automotive world we say most aftermarket parts are built better then oem and offer better performance. That is why I put a moser engineering ford 9 inch in my trans am. For quick gear changes . I guess I am just trying to say if I had an omc I would definately check out my options before changing anything, my back would have to be against the wall. People still run them up here and the ones that do love them.

Jack

 

[lutzsucceed]

Re: Another Stringer Repair Question - by a Newbee

Exactly WOG , I know just talking to a guy locally about some of the projects being done on here. He said I would never spend the money on an upgrade unless I had too. I have connections up here in canada and he has lot's of aftermarket supplies. He said check out the internet great supplier up this way. I never got down to where he get's them. I will probably never see the guy again either.

One thing I did say to him is I play with lot's of old cars and have upgraded my trans am with lot's of aftermarket parts and in the automotive world we say most aftermarket parts are built better then oem and offer better performance. That is why I put a moser engineering ford 9 inch in my trans am. For quick gear changes . I guess I am just trying to say if I had an omc I would definately check out my options before changing anything, my back would have to be against the wall. People still run them up here and the ones that do love them.

Jack

Jack, thanks for the support on the OMG - as usual, I'm in over my head on the boat to begin with and a repower is beyond my ability financially - so, we gonna run with what we got. I worked on the stringers last night - MAN - It takes PATIENCE. BTW, My wife's Canadian - good people. Dave - Nashville

 

[lutzsucceed]

Re: Another Stringer Repair Question - by a Newbee

AS I"m working on the boat a few things have occurred to me.

1. My stringers rotted from the top down.
2. There is no water under the foam - and the foam wasn't waterlogged. - Kinda disintegrating from age, and turning an amber gold crusty, fiberglass type foam.
3. Nothing is ever as bad as it looks - at least that's what I told my wife when she climbed up and looked in the boat!
4. Patience & TIME are the keys - 2 things I have little of - but maybe that's why God gave me a boat- to teach me Patience?

 

[lutzsucceed]

Re: Another Stringer Repair Question - by a Newbee

OK, so I got all the Stringers out - but haven't ground down the glass yet. I cannot get to the BOW Stringers for the Molded Fiberglass Seats & Floor. I've seen other guys cut these out and rebuild them - I'm looking for advice on where to cut AND will Cutting into this Compromise the Structure in any way?

Removing the CAP is not an option for me- although it would probably be the easiest?

 

[oops!]

Re: Another Stringer Repair Question - by a Newbee

My question has to do with repairing it ON the trailer.

1. Is it imperative that I get it off the trailer? It's sitting on bunks and rollers - see PICS
2. If I do have to lift it and build a frame for it - can you point me to threads that cover the best method? Seems like HUGE JOB to lift this boat off trailer, for me...
3. THANK YOU all for this forum, I've learned so much about boat repair - thanks to you all you guys.

Dave in Nashville


View attachment 128474View attachment 128473View attachment 128472View attachment 128475View attachment 128476

You have a correct set up to do it on the trailer......but you have issues here.....

Look at pic 5....
You have a point load on the speed strake....this will cause hull deformity when you re foam the boat.
that needs to be changed...before you proceed any further !!!!!!!

The bunks need to be between the speed strakes... with the weight distribution even between the keel rollers and the bunks.

to fix the situation...you will need to take the hull off the bunk and re adjust the bunk. you can just tilt the boat....you dont have to get a crane or get fancy, just jack up the side of the boat till it is off the bunk and re adjust the bunk so it is in the proper position.

you have to avoid a point load.

ill respond to the rest in separate posts,

 

[oops!]

Re: Another Stringer Repair Question - by a Newbee

The hull is pretty good, the Keel is worn at the bow where it's been beached over the years - that's of concern to me because I can see wood coming thru in a couple of places? I was considering a "keel saver"? or gel coat or what to do? I did see one nice gouge that will need attention starboard - what can be done about these issues?

Thank God for you all - I would have just cut out the rot and screwed a sister board on the side of the stringer and glued down a new floor like we do in houses, glue down carpet and head for the lake! YIKES!

This is a major hull breach.. if you can see wood from the out side of the boat.....the fiberglass has been worn away so water is now allowed to penetrate the unprotected stringer......this will need major repair.

to repair it.....the stringer must be removed and the glass ground down till you can openly see the breach.
then from the inside.....cut 3 peices of 1.5 csm....each larger than the last. cut 3 peices of 1708 the same size as each csm.

glass in the smallest csm over the ground down. vaccumed, and cleaned with acetone breach area. While still wet....lay the same sized 1708......then the next biggest csm and 1708 and repete. you can do this all at once.

the outer keel must be repaired as well......but you can do that after the stringers and sole are back in.
you will need the glassing practice before you tackle the outer hull of the boat.