How strong is fiberglass?

[Watercanuck]

I have a 3.8L OMC Sterndrive in a 20 foot 1984 Tempest Cuddy. The motor mount bolts on one side are lose. The motor shifts when excelerated. I can't afford to yank the motor so I was wondering if I could put fiberglass over top of the motor mount bolts on the one side and if the fiberglass would be strong enough to hold that side down?<br /><br />Any comments or suggestions?

 

[JB]

Re: How strong is fiberglass?

BAD idea, John.<br /><br />Remember that at times your life depends on your boat.

 

[Boomyal]

Re: How strong is fiberglass?

Bad idea! It's the wood under the fiberglass that holds the lag bolts. Here are, however, two SHORT TERM suggestions.<br /><br />Pull out the existing bolts, they are probably 2.5 to 3" x 7/16" unless someone has already replaced them. If they are original there is probably not much thread on them. (rusted)<br /><br />Go buy 1.5 inch longer and one size larger diameter (1/2") stainless steel bolts. Don't bother with the outboard bolts in the claw feet. You will probably have to chase the two inboard mount feet holes with a drill to slightly enlarge them. Now run your new bolts in. <br /><br />If they do not bite then you have real problems. Do not use the boat or you're liable to have an engine sitting in your rear passengers lap.<br /><br />I remind you, even if this works it is only a short term fix. You've got rot and it's not going to fix itself. Study all the projects on this forum cause you are problably going to end up an expert by the time it is all over.

 

[crazy charlie]

Re: How strong is fiberglass?

For the temp fix ,I would do as boomyal states ,but I would fill the hole with Gitrot and then put the bolt in while it is still wet.The penetrating epoxy will sure up the rot a little aND MAY HELP ANCHOR THE BOLT.If you plan to run the boat you may want to put on a torque chain.Charlie

 

[Boomyal]

Re: How strong is fiberglass?

I'll bet his bolts come out soaking wet crazy charlie. In that event, Gitrot isn't going to do any good.

 

[Watercanuck]

Re: How strong is fiberglass?

Hey guys,<br /><br />The bolts are not wet nor are they rusted. Is it possible that its not rot and it simply stripped the wood over the years?<br /><br />Thank you all for your suggestions. I am trying to weight my options.

 

[Boomyal]

Re: How strong is fiberglass?

Originally posted by John-Marshe:<br /> The bolts are not wet nor are they rusted. Is it possible that its not rot and it simply stripped the wood over the years?

The first part is a good sign. The second part is a "not likely" but, I suppose, not impossible.<br /><br />What length and diameter are your bolts?? and how big a hurry are you? I'd still be inclined to go to a longer and larger bolt at least for the two inboard bolts. I would first pull all 8 inboard bolts, probe the holes for depth and integrity. If that proved ok (hole no deeper than the length of your bolts and wood seems reasonably solid) I would go the one size larger and one inch longer bolt.<br /><br />I would also strongly recommend buying a pint of this stuff: (much better than GitRot)<br /><br /> http://www.rotdoctor.com/products/product.html+ <br /><br />...and keep pouring it down the 8 holes until it quits soaking in. Then run your new longer bolts into the holes. Keep in mind, you will have to enlarge the eight holes in your mount feet to 1/2".<br /><br />For the 4 outboard bolts, I would buy the same size but two inches longer. I would also treat those holes with CPES. If your mount stringers are otherwise sound, this should take care of you.<br /><br />Note: Gitrot will not penetrate into surrounding wood like CPES. What you are trying to do is to stabilize and strengthen the wood around the holes for as far out as possible. This will also render that wood impervious to any future rot or decay and make it withstand the any stress on the bolts pulling out.

 

[Watercanuck]

Re: How strong is fiberglass?

Hey Boomyal,<br /><br />Well I just listed the boat for sale but I am going to try this CPES. Just an idea and bear in mind, Im no boat builder... What if I used this CPES to soak into the rotted wood and get the wood's hardness back then filled the holes with a paste eproxy and put the bolts back into the holes while the paste eproxy was still wet and let it dry with the bolts in there? Would this aid in securing them?<br /><br />As for the outboard bolts, they are fine, its just one side of the inboard engine mounts.<br /><br />Thanks for the help!<br /><br />John