My idea for temporary stringer repair

[alamantia]

I bought a 1987 Wellcraft Elite last fall. I never looked at a boat before but I read a lot to see what to look for. Two things I read about were soft floors and stringer rot. When i went to get it I looked over the boat for hours and couldn?t find anything majorly wrong with it. I think I finally came across something. Behind the back seat of my boat is a flip top engine cover to expose the engine, on either side of the engine are boxes for storage screwed to the floor. When I inspected the boat I checked the floor for soft spots and tried to inspect the engine mounts to the stringers. The floor is solid. The boxes blocked my view to the engine mounts. Last weekend I removed the storage boxes so I could get back there to install a fresh alternator and new spark plugs, wires and hoses. As I was hooking the port manifold hose up I noticed that the engine mount seemed to be pushing the glass on top of the stringer down, it looked depressed. I looked at the starboard side and it looked straight. I went back to the port side and decided to unscrew one of the two lag bolts holding the engine mount to the stringer. It came out easy, when I put it back in it just kept spinning. Son-of a *****, stringer rot. I did the same with one of the lag bolts on the starboard side and it came out tight and snugged back in like it should. Well, at least it?s just one side. So I have to yank the motor and have the stringer professionaly repaired. I don't have means to hoist the motor entorely out of the boat. My engine hoist could only get it up a few inches at most. I guess I have to bite the bullet and have a shop yank the engine. I wanted to put a 383 in it but I dont have the money and wont for another year. Damn if I could only get one season out of it before I was going to swap the motor anyway... Then when I got to work I noticed 4? wide slats of ?? steel. That engine mount is adjustable in height. The stringer runs about 36? from the back of the back seat to the transom. What if I take home a 24? long piece of this steel, drill and tap two 5/8 holes for the engine mount. A couple of thru holes for lag bolts. Suspend the engine with my hoist and run this plate in between the engine mount and along the top of the stringer adjusting the engine mount up ?? to compensate for the plate. Thread the 5/8? bolts into the tapped plate and secure the plate to other areas of the stringer assuming I find spots with good wood to sink the lag bolts?

Have you ever heard of such a repair or should I just shut up and yank the engine a season early? See the attached pdf I sketched up of my idea?

 

[oops!]

Re: My idea for temporary stringer repair

yup it will work.

however...there is risk.

first off....waiting a year will let the rot run havoc......and if it reaches the transom then the repair is a full gut.

second......you are playing with the alignment of the motor/drive......doesnt matter how careful you are with measuring....you will need to re align the drive.
dont play with this.....get an alignment tool and do it right, or it will cost you big bux.

 

[tpenfield]

Re: My idea for temporary stringer repair

The only fly in that ointment could be not finding good wood at any point along the stringer. You could drill a couple of test holes in the anticipated locations to check. Also, you should make sure that you have enough adjustment hieght on the motor mount to accomodate your plan.

If that were the case (no good wood), you could do a clean out and fill on the stringer with seacast or nidabond. You may be able to do this with the engine held up a few inches.

Keep in mind the old saying . . . where there is smoke, there is fire. That one stringer may not be alone in the progression of rot. So, you may want to be sure and factor that into the overall plans for repair.

 

[alamantia]

Re: My idea for temporary stringer repair

Thanks for the replies. I was aware if the inherent risks of buying a 25 year old boat. My intention was to get it out for one season and figure out if I still want to continue boating after this year so my goal is just getting it on the water. I have a 4 bolt main 350 with a one piece rear main seal in my garage I bought a while back for a truck project which I never used, this would make a good starting point for a boat engine. According to the casting number on the block that is in the boat, it is a one piece rear main. My plan was to enjoy the boat this summer with the current engine, and if we decide that we want to keep it, next winter I was going to research how to build a boat motor and finish out the engine for a swap next spring. Building the engine isn’t the problem, the problem is swapping it. I have an overhead hoist and a forklift at work. But would just have to see if my boss would let me use either one on a Saturday. If I perform the swap I would yank the motor and while it was out, cut away all the rot I could find and have it professionally repaired before installing the new engine. But pulling the engine now, before even using the boat, just to pull it again next season. I don’t know. I would like to reinforce the mount just for this season. I understand what you are saying. If the entire stringer is rotted my idea won’t work, but if the rest of the stringer is good. Then I am essentially extending the flange on the mounting pad, which I do not see an issue with. I heard of an engine alignment tool. I have the outdrive off now anyway, what does it look like? How much is one? Do you just stick it into the gimble bearing and check for a smooth fit?

 

[oops!]

Re: My idea for temporary stringer repair

woah.......hold it here.....

im seeing some red flags.

about the motor, not about the plate........(just make sure the plate is secured to good strong not rotted glassed-over wood.

first a truck motor....does not belong in a boat....(lol... i have the very same in mine ....and yes... i want to stroke it too)

the motor as it sits will be dangerous.
you will need to marinize the motor before you can drop it in......

(by the way.....the swap is not like a car swap....it only takes a few minits and the motor is out....less if you know what you are doing)

to marinize the motor......you will need to strip the motor to the long block.......change the cam, them add marine peripherals, every thing from the carb, alt, dist, starter, ps pump......they are all different.....every thing.
the problem is.......if you dont have another motor to donate the parts from.....you will spend more for the brackets than the motor is worth.
a simple alt bracket/power steering pump is over 500 bux !

i did it to mine......and spent a ton of cash on everything.....a ton......then i had to buy the exhst mainfolds !

one more thing......to have the mount professionally repaired......will cost any where form 1k.-5k depending on what you find when you rip the deck ! the proper repair process will take a pro a week depending on what they find.

a simple mount replacement can be done in 8 hours....but as mentioned.....rarely does the rot stop at one mount.

 

[alamantia]

Re: My idea for temporary stringer repair

I only have a block

 

[tpenfield]

Re: My idea for temporary stringer repair

What is wrong with the engine that is in there now? Is it really worth a transplant?

 

[alamantia]

Re: My idea for temporary stringer repair

What is wrong with the engine that is in there now? Is it really worth a transplant?

I figured i would run into some issues but so far it purrs. I got between 170-175psi on all cylinders. I specifically wanted a 350 because i have experience building them before and i happen to have a good uncut block. Naturally if it doesnt present any issues this summer i will leave it. But i am always working on something. Now that i found that soft spot in the stringer i would be even more inclined to have it fixed. Yet its my first boat. Its 25my years old. It seems solid (other than the stringer) and i have been all over it for the last 5 months. I need to learn on an old cheap boat before i invest in something nicer. I may run it into a dock or rip up the outdrive. Or i may fall in love with it. but to answer your question. I was kind of looking for a reason to build another 383 and i have been there and done that with my car and truck. I figured it was time to do a boat.

 

[rickryder]

Re: My idea for temporary stringer repair

This scares me...... Temp fix on a stringer??? I think once you open that can of worms you'll find more than just that one spot on the stringer that's bad.... I only had a small soft spot in my deck by the ski locker......all I can say is read thru my resto thread below and you'll see what a little rot turns into.... I'm not tryin to burst your bubble just being honest

 

[tpenfield]

Re: My idea for temporary stringer repair

I figured i would run into some issues but so far it purrs. I got between 170-175psi on all cylinders. I specifically wanted a 350 because i have experience building them before and i happen to have a good uncut block. Naturally if it doesnt present any issues this summer i will leave it. But i am always working on something. Now that i found that soft spot in the stringer i would be even more inclined to have it fixed. Yet its my first boat. Its 25my years old. It seems solid (other than the stringer) and i have been all over it for the last 5 months. I need to learn on an old cheap boat before i invest in something nicer. I may run it into a dock or rip up the outdrive. Or i may fall in love with it. but to answer your question. I was kind of looking for a reason to build another 383 and i have been there and done that with my car and truck. I figured it was time to do a boat.

Fair enough, it is good to learn without spending too much. I've had my powerboat for 7 years . . . I'm still learning things.

Regarding the engine, the major differences that will cost $$$$ from converting a truck engine are the "SAE J1171 Marine" requirements for the electrical systems. Fuel systems are also different and have requirements It all has to do with storing fuel and running an engine in a "bath tub" (i.e. a boat) the fumes are heavier than air, so they got nowhere to go. Therefore they can accumulate in your boat and reach explosive levels.

So fuel systems have to be able to avoid spillage and overflows, and electrical components cannot throw sparks. That is why having a 'donor' marine motor is a good thing when converting a truck block. You can get all the marine specific stuff from the donor motor.

 

[Scott Danforth]

Re: My idea for temporary stringer repair

if your current 350 in the boat has good compression, thats a good starting point for your build. you can also build the truck block as a marine short block for your 383. have the block bored .030 over, new crank, custom pistons, proper marine cam and brass core plugs and you have a marine 383 short block. I suggest you source vortec heads and matching vortec intake and use all the other parts from your existing engine to put back together.

however back to your engine mount block and stringers - your underestimating the rot. I can tell from experience that once you cut the mount out, you should drill test holes in the stringers, if the wood is wet or rotted, you will be tearing out stringers. if the transom is wet or rotted, you may be out for the first part of the season.

 

[alamantia]

Re: My idea for temporary stringer repair

Fair enough, it is good to learn without spending too much. I've had my powerboat for 7 years . . . I'm still learning things.

Regarding the engine, the major differences that will cost $$$$ from converting a truck engine are the "SAE J1171 Marine" requirements for the electrical systems. Fuel systems are also different and have requirements It all has to do with storing fuel and running an engine in a "bath tub" (i.e. a boat) the fumes are heavier than air, so they got nowhere to go. Therefore they can accumulate in your boat and reach explosive levels.

So fuel systems have to be able to avoid spillage and overflows, and electrical components cannot throw sparks. That is why having a 'donor' marine motor is a good thing when converting a truck block. You can get all the marine specific stuff from the donor motor.

A block is a block. I would transfer over boat assesories. The issue here is the stringer. Provided i find good wood to anchor lag bolts into i think i should be good. I have 40 inches between the back seat and ghe transom. The engine mounts are about 22 inches from the transom. That means if i cut a plate 38 inches long i have roughly 18" behind and 16" in front of the mount to find wood. Im keeping my fingers crossed. I think i will be ok. I really was just looking to see if anyone has done this before as i am new to this. Also nobody has answered my allignment tool question

 

[rickryder]

Re: My idea for temporary stringer repair

You can get one on ebay for around $50

You stick it in all greased up and read the grease tracks and adjust engine mount accordingly..... It's outlined in your out drive service manual...

 

[oops!]

Re: My idea for temporary stringer repair

an alignment tool is a long steel shaft.....with different diameteres.

looks like a bushing remover.

you insert the alignment tool thru your gimbal housing......gimbal bearing....into the coupler of the motor...

then you align the motor so the alignment is with in tollerance.

 

[alamantia]

Re: My idea for temporary stringer repair

an alignment tool is a long steel shaft.....with different diameteres.

looks like a bushing remover.

you insert the alignment tool thru your gimbal housing......gimbal bearing....into the coupler of the motor...

then you align the motor so the alignment is with in tollerance.

Thats cool, sorta like a clutch allignment tool with gear marking compound. Thanks.

Last night I begun my task and found that the manifold was just too much in my way, so I removed it and realized if I take the altenator bracket off I have a clear shot at cutting the top of the glass the length of the stringger. I think I am going to do that this weekend and scoop and chisle out all the rotted wood and install new wood. This will be hell of an undertakling for me, luckaly my brother is a carpenter for a custom kitchen place. I will have to start searching around the forum on how to perform this task and research materials. I am assuming that I will use pressure treated wood, glue it to the hull. Buy fiberglass repair kit (resin and sheets of glass) glass over the new wood. paint it, drill new pilot holes for the lag bolts and mount the engine followed bu an allignment check.

Seems like a lot of work but a good experiance for me to learn.

 

[rickryder]

Re: My idea for temporary stringer repair

No pressure treated wood.... Just regular plywood..... Your going to have a real tough time cleaning out the fiberglass stringer shell to be able to get a good bond to the new wood..... It is not recomended.... Cut the old glass away.....grind the hull down to good glass and reglass from there.... Read thru my thread below... You'll find plenty of useful info... Check the Nida Bond pour on my one motor mount...

 

[tpenfield]

Re: My idea for temporary stringer repair

Thats cool, sorta like a clutch allignment tool with gear marking compound. Thanks.

Last night I begun my task and found that the manifold was just too much in my way, so I removed it and realized if I take the altenator bracket off I have a clear shot at cutting the top of the glass the length of the stringger. I think I am going to do that this weekend and scoop and chisle out all the rotted wood and install new wood. This will be hell of an undertakling for me, luckaly my brother is a carpenter for a custom kitchen place. I will have to start searching around the forum on how to perform this task and research materials. I am assuming that I will use pressure treated wood, glue it to the hull. Buy fiberglass repair kit (resin and sheets of glass) glass over the new wood. paint it, drill new pilot holes for the lag bolts and mount the engine followed bu an allignment check.

Seems like a lot of work but a good experiance for me to learn.

I'm currently doing a similar repair process with my boat. Both engine mount stringers had become hollow due to rotting of the wood core. Here is a link to my thread, as I cut open the stringers this past weekend. http://forums.iboats.com/showthread.php?t=534913

Your engine mount stringers are probably much wider than the ones in my boat, since your engine mounts are 'lag bolts' and mine are 'thru bolts'. I do have the luxury of having the engine out of the boat. There are many threads to search for various restores and repairs - definitely a great resources here on iBoats.

Each repair is very situational, and you will get a variety of opinions on the best approach, for example - filling the stringer versus full removal and replacement. You will ultimately have to decide what is best for you and your situation.

One thing that I did before cutting things open was to drill some 'test' holes in the stringers at various places to determine the extent of the rot. In your situation, you are hoping to find solid wood further towards the ends of the stringer. A couple of test holes will prove this before you do any cutting.

You will probably have to decide somewhere along the way where to draw the line between a temporary fix and a permantent repair. That will also depend on what you find inside the stringer.

Post some pictures, when you have a chance.

 

[alamantia]

Re: My idea for temporary stringer repair

You guys are very smart and judging by the pictures in your posts very ambitious. To clairify, perhaps I dont yet kniow all the terminoligy. The part that i am refering to that is rotted is the block the engine mounts on. It looks like a big *** hunk of wood affixed to the hull somehow, incasesd in glass. They start a few inched away from the transom and continue 36 or so inches forward and stop a little before the engine. The port side seems to be colapsing. I drilled holes and found mostly rotted wet dark colered wood in this area. The floor stringers that run the length of the boat are from a thinner wood and run from the bow to the transom. I drilled 2 holes in the one on the port side next to the engine and it was hard to plunge the drill bit as white dry shavings were coming out. So if the term "stringers" is applied to both the long ones that run th elength of the boat AND those big motor mount blocks then yes, the motor mount stringer is rotted and doesnt look all that hard to replace. If it is called something else, like motor mount, my apoligies.

 

[tpenfield]

Re: My idea for temporary stringer repair

Take a look at this thread . . . I think it is a similar boat.

http://forums.iboats.com/showthread.php?t=293289

The main stringers are more towards the outside of the hull, and the inboard 'stringers' (if you can call them that) are for the purpose of mounting the engine.

It is wood encased in fiberglass and the fiberglass is holding it to the hull. What you are hoping for is that the rot is not too far advanced and a large percent of the engine mount stringer is still solid wood underneath the fiberglass. (right?)

 

[alamantia]

Re: My idea for temporary stringer repair

Yes, you are correct. That looks similar to my boat, the outside stringers seem fine. Its that large block that the engine sits un that looks depressed on the port side. Origionaly I was going to try to span a plate across the entire block to dispurse the weight until I wind up pulling the motor. As I started the job I fanagled my engine hoist to the engine to lift it up about 1" but I couldnt reach under the port exhaust manifold to perform the work of installing the plate. So I removed the manifold and riser and then I realized that I have a straight shot at the engine mount stringer. So rather than using the plate. I think I will remove the altenator bracket and the engine mount shackle and use my saws-all to cut the top piece of fiberglass off that block and dig and pick out the rot. If I get it all out I want to clean that area out as best I can, scuff it all up with a scotch brite. Cut up the pieces of wood that i need with the correct angles. Pour some resin in the hole, stack up my wood and incase it all in fiberglass. Drop the motor back down. Plunge two holes for lag bolts and torque them down and align the motor. I'ts going to be a good learning experiance I tell you that much.