1992 Marada 1800MVB.. stringer, transom, deck restore

[Marada92]

Re: 1992 Marada 1800MVB.. stringer, transom, deck restore

If it runs side to side it's not a keel stringer.. It would be a bulkhead. The keel stringer will be in the center of the hull and run from bow to stern. Some boats have them some don't.. Mine does. But yea if you can get a pic of it I'd be glad to see how it's set up. I'm considering doing an open mount and through bolting it instead of lag bolts.

 

[brn77]

Re: 1992 Marada 1800MVB.. stringer, transom, deck restore

thats wat i was looking for bulkhead my comp took a crap so borrowing one now i will try n get them up tomm for you ...srry

 

[Marada92]

Re: 1992 Marada 1800MVB.. stringer, transom, deck restore

Got all the transom out but the very bottom. Knock my fan over while I was in the process of working on it and broke it. 114 degree heat index sent me home pretty quick!

Where I'm at now...

This is a little visual example of what I'm considering in the bilge area. First is how it was built.. Two vertical 3/4" ply stringers with three 2x4's in between with the engine mounting block glassed on top. Included the outer stringer in the pic just for visual reference.

Next is how I want to rebuild it if itll be strong enough. Doing away with the 2x4's and instead placing a 3/4" plywood horizontal between the two stringers supported with 2x2 cleats on each stringer and in front on the bulkhead and possibly the transom. Would this provide the same strength as the way it was originally designed?

Figure a visual representation would help get what I'm trying to do across better.

 

[Outback Jack]

Re: 1992 Marada 1800MVB.. stringer, transom, deck restore

Hey Marada, Myself I don't think your new design is enough, there is going to be alot of tourque in this area and you want your mounts to be as solid as can be. I would think they are trying to keep the stringers from twisting in anyway.

My theory in redoing anything be it a car or a boat is at least put back what was there or at least compatible. I know there is alot of poor workmanship in what I am seeing on the forums from the manufacturers but the engineers designed their boats a certain way hoping the manufacturer will build them that way.

I myself would want something more but will let others chime in. I plan on doing an engine mod in a few years and would like to know what they have to say. It will give me some ideas as to engine mounts.

I don't believe in going with overkill on anything as all that does is add weight and we don't need that .

Cheers Jack

 

[Marada92]

Re: 1992 Marada 1800MVB.. stringer, transom, deck restore

Yea that's what I'm hoping is if kept putting it out there one of the experts on here would chime in. I've talked to some that say the majority of the torque is placed on the rear mounts others say it's placed all over... Either way the front is still holding most of the engine weight. I just don't see how the 2x4's were providing that much more strength. They were nailed into the shorter stringer and haven't found where they were mounted to the other. One corner of them rested on the hull.. And the rear was just butted up to the transom.. No glue. Everything was just covered REALLY thick in fiberglass. I have no problem putting it back in as originally done but if it doesn't need it then it's not going back in like that. We shall see what others have to say.. I'm going to tear apart one of the sides I removed in the meantime just to see how it is.

 

[Friscoboater]

Re: 1992 Marada 1800MVB.. stringer, transom, deck restore

Just make sure your weight is transferred to the hull. Like a house, you need it to be load bearing. You just might have to use lag bolts. You correct about the torque. Most is handled by the rear plate.

 

[Outback Jack]

Re: 1992 Marada 1800MVB.. stringer, transom, deck restore

Myself I have done alot of work around hot rods and I race a little too ...any v engine does have alot of twisting tourque ...I would not think they relied on the rear plate and transom to take all the tourque, the side mounts would be there to stop this from being excessive twisting tourque and do damage to the transom or plate. I would just make sure they are solid , so you have little twist as possible. All mounting points work together and have a purpose.

Statement from someone else

Mercruiser mounts are designed to: (1) balance the weight of the engine between the stringers and the transom, (2) aid in correctly aligning the motor, and (3) counteract the torque of the engine

Cheers

 

[parrisw]

Re: 1992 Marada 1800MVB.. stringer, transom, deck restore

I think your new design is fine, the way they had it before was crap. The only thing I'd change to your design is that your outside cleat that is supporting your top plate, I would carry that all the way down to the hull, since you have the engine weight on that one small cleat with not much surface area, if you carry it down to the hull the weight of the engine is supported all the way down to the hull and not just on that little cleat.

 

[Outback Jack]

Re: 1992 Marada 1800MVB.. stringer, transom, deck restore

I just don't see how the 2x4's were providing that much more strength. They were nailed into the shorter stringer and haven't found where they were mounted to the other. One corner of them rested on the hull.. And the rear was just butted up to the transom.. No glue. Everything was just covered REALLY thick in fiberglass.

Actually by that description they were doing what they were suppose to do...one main attachment point then using the other materials just to transfer and to sop that stringer from twisting. The problem here was the quality of fiberglass work and keeping out the water

The modification that parrisw pointed out , thanks ,was what I was going to say. That is how I was going to basically do mine. I will be going from a front mount 3.0 and will just add the side mounts to the side of my stringer. I didn't think the cleat was enough to be used to transfer weight or tourque to a stringer down to the hull. Then you can mount the mount to the stringer with some hardware and then be able to get a real good seal with the fiberglass .

 

[Marada92]

Re: 1992 Marada 1800MVB.. stringer, transom, deck restore

Parrisw... That's the exact idea I was thinking of next.. Could pl and glass it to the other stringer then tab it in as one. Should make it strong plus all the weight would be forced downward to the hull. Getting back to adding weight but I still think it'll weigh alot less than what came in it originally!

 

[Outback Jack]

Re: 1992 Marada 1800MVB.. stringer, transom, deck restore

Marada, I am with you on the weight thing too. I don't believe in overkill as all it does is add weight and the more weight you have takes away from how much you can carry on board, to me a safety issue too. Some people do restorations and add way to much weight.

I built fiberglass products and few boats from scratch (design and mold first). But everything we built was submitted to an engineer and we built it to his design. I have seen their designs fail too. That is why I like this forum because there is tried and tested methods here. I find them to be better then engineers decisions sometimes.

 

[Marada92]

Re: 1992 Marada 1800MVB.. stringer, transom, deck restore

Agreed outback... Now on to my next issue while I have the attention of a few of the higher ups. The keel stringer as of now is about 4 seperate pieces of either ripped 2x4 or 2x2 or something. Basically it's a slopped up mess. Looking straight down it the thing changes directions four times and ends up off center in the rear by about two inches. What would be an alternative to this? Can be no more than two inches high due to where the support for the fuel tank sits. Any higher and the deck height has to be raised which couldnt happen anyways. Ideas?

 

[parrisw]

Re: 1992 Marada 1800MVB.. stringer, transom, deck restore

Parrisw... That's the exact idea I was thinking of next.. Could pl and glass it to the other stringer then tab it in as one. Should make it strong plus all the weight would be forced downward to the hull. Getting back to adding weight but I still think it'll weigh alot less than what came in it originally!

Yes, I would just treat that extra big cleat as a stringer, I would actually glue it to the stringer then tab and glass it to the hull.

 

[brn77]

Re: 1992 Marada 1800MVB.. stringer, transom, deck restore

Here are the pics of mine the way its set up .. i hope it helps .. it is a 3.0 front and rear mounts only ??? I think it sits on a bulkhead wich is connected to the two main keal stringers and the hull ...

 

[Marada92]

Re: 1992 Marada 1800MVB.. stringer, transom, deck restore

Thanks brn... I think I've got it all figured out now.

You can't tell without knowing in this pic but the fuel tank support is out along with 3/4 of the keel stringer. Thought it would be more difficult but nope... Just cut the fiberglass of the top and pieces came right out.

And heres how what it was... Over a span of around 14' there were five individual pieces. Bonded to the hull with a big glob of absolutely nothing. Guess they just laid them on the hull and laid a piece of roving on then half wetted it out and called it good.. And ofcoarse all of this was wet.

I've put off grinding as long as possible... The fun begins Saturday! :facepalm:

 

[parrisw]

Re: 1992 Marada 1800MVB.. stringer, transom, deck restore

Sometimes I just honestly can't believe how they build boats? Like honestly WTF were they thinking? And for how much they cost new, its absolutely highway robbery!!!!!!!!!!!!

 

[brn77]

Re: 1992 Marada 1800MVB.. stringer, transom, deck restore

yeah i totally agree with you on that one , i definatley wouldnt buy a new one without knowinbg how it is built .... Good luck with the grinding i got my deck back togethter just gotta put seats in .. I will probably do transom this winter so I will be following you good luck with the grinding !!!! cant wait to start seeing the rebuild , lets go get that grinding done lol !!

 

[Outback Jack]

Re: 1992 Marada 1800MVB.. stringer, transom, deck restore

Sometimes I just honestly can't believe how they build boats? And for how much they cost new, its absolutely highway robbery!!!!!!!!!!!!

That is exactly why I am sticking with my restoration as I know what I will have when I get it done I figured newer boats would be built better, but I was informed that is not the case . It is sad but true

 

[parrisw]

Re: 1992 Marada 1800MVB.. stringer, transom, deck restore

Actually some boats now are all composite, and they are pretty nice. A friend of ours just bought a new Larson boat and it looks pretty good, its built with "VEC" technology, check this link, look at the video and article. http://larsonboats.com/overview You can actually see the core for the transom when I looked in his engine bay where the cutout is for the outdrive. That boat will never rot!!!

 

[Outback Jack]

Re: 1992 Marada 1800MVB.. stringer, transom, deck restore

very nice boats for sure...if I ever decide to upgrade that would be the technology I will be looking for, but It will probably be out of my price range. I can dream now Thanks for the info