Motor mounts & rotted stringers

My boat is a '69 Barracuda with a 318 Chrysler.

I just pulled my engine/tranny to rebuild the tranny. The tranny barfed up all its contents last summer.

When I pulled the tranny I discovered the rear motor mounts are anchored into the stringers with 3 lag screws on each side. The screws were terribly rusty & deteriorated & I doubt they do much besides locate the motor fore-and-aft. Meaning, they probably won't resist vertical forces much once I put them back in.

At the front motor mounts there is a separate spacer piece of wood above the stringer that's about 2" tall. Two lag screws go down through that into the stringer. However, those screws only protrude below the spacer about 1/2". Meaning: they really don't screw down into the stringer; they just sit on top of it.

Now my question: does this matter? How important is it that the motor be secured down to the stringers? If it is important, how do I repair this problem? At the front, I think the lag screws are probably rusted off into the stringer.

Don't really know much about this kind of repair. Do I need to dig out the front lag screws? Do I drill out the stringers until I hit solid wood and then patch in new wood? Can I glue in dowels? What kind of glue? Then cover it all up with more fiberglass? Is there a correct way to do this? Where do I get materials? I don't think the stringers are hugely rotted. I think it's just around the motor mounts. I hope.

Thomas

I have some pics of mine where I redid mounts. Could e-mail someone here them that could post them? I took some flat stainless, bent into a "L" bolted the stainless to the sides of stringer, and then bolted engine mounts to the top of the stainless in the same place as before. (used some rubber insulated mounts from mercruiser) I drilled out all the rot I could in the stringers and filled with resin. The insulated mounts make for a lot smoother operation

Rosser, it will either be pushed forward into your back or it will start doing Eskimo rolls under your engine box. Either way is real bad - especially if your family is in the boat.

Todd, send the pics to jim@drivesys.com and I will post them. I would like to see them myself.

Jim Pics are in the mail..... I taken a 4"X6" flat piece of stainless, bent it into a L with 4" bolted to inside of stringer, the top of the "L", 2", sits on the top of stringer under engine mounts, mounts are bolted to stainless. The mounts have a lot of vertical adjustment, and the best is they are rubber insulated, OEM parts from big block mercruiser, so the vibrations are almost nil. My orginal setup however had lag bolts and the "various size" wood spacers and shims to align engine. Now every thing is bolted to stringers & mounts, (all stainless hardware) been running this deal for 4 years with no issues whatso ever.

Man I like those mounts. Where do I go to get them?

Maybe this will link to them:

http://ebasicpower.american-data.net/Merchant2/merchant.mv?Screen=CTGY&Store_Code=eBasicPower&Category_Code=MER6G

Yep

Well, sort of. Dr. Rot is essentially expensive thinned epoxy resin. Go to Home Depot, buy the two part marine epoxy resin that is sold in the paint section. Buy a pint of acetone and you are set. Another expensive product mentioned often is "Git Rot" is all essentially the same. Make it yourself and save. And you will have the resin to glass over the dowels when you are done (not thinned, of course).

Just got back from Home Depot. Not sure I got the right stuff. It's Loctite brand "Aquamarine Epoxy". It has .85 fl. oz. in a syringe-type container that has 2 parts. Container says it dries gray. Also says it sets in 10 minutes & it's for "Surfaces exposed to intermittent water immersion".

The store clerk took me right to it when I asked for "marine epoxy". I asked if they had something else like it. He gave me a vacant stare like how could I ever want anything else.

Thomas

Jim,You want to add your acetone after the resin is mixed up. You don't want a 50/50 mix as it will thin it out too much. Add a little at a time to make it water like. It will delay set up a little but not a whole lot. Use a heat gunor hair dryer to heat up your resin to make it soak into the cloth better if you don't cut it. WARNING- don't get to hot for too long or it WILL kick it off.

I thought "epoxy" was an adhesive like glue. I drilled a row of 5/8 holes in top of stinger and filled with just regular fiberglass/polyester resin. The stainless "plates" pictured above then bolted through where filled. But I had very little rot, mostly where the old lag bolts were.

Jim:

You have it correct. The other benefit to epoxy is that it does not shrink as it cures whereas polyester resin does. Epoxies have three drawbacks:

1. Can cause skin allergies after cumulative prolonged exposure...so keep it off your skin.
2. Significantly higher cost than polyester resins.
3. Harder to work with when wetting out fiberglass mat or roving. Also, does NOT disolve the binders in regular mat, so "sewn" mat should be used.

Yes I am. Probably for my '66. I am looking very hard at your pics. It looks like you have fabricated brackets that bolt to your motor and trans frames. Is that right?

The rear mounts on my '68 sit on a small piece of plywood (for a shim). It looks factory but it looks real cheezy. I'm just in the thinking stage right now.

Drilled out the holes where my motor mount lag bolts were. The consistency of the shavings could best be described as "rich, dark mud". I figured it would be bad, but there really wasn't much that was hard there.

So how bad is "bad"?

I'm not afraid to fix it, but now I'm wondering how far I need to dig into the stringer. Do I need to cut out a whole section and splice new board in? If so, how do you go about doing that to preserve structural integrity?

Thomas

I noticed the hose and I wondered where you got them. Nice.