ideas on replacing mounts and mounting shelves

[Mikelikethewind]

What I have: Universal M25 in a 1972' Stephens and Hughs 38'

( Sparkman & Stephens: Design 1903 - Hughes 38 )

My issue: I noticed the engine vibrating slightly then gradually getting worse after the last few trips out. I inspected the mounts and the front two ( pictured ) are rusted and loose allowing for the vibration. Replacing the mounts shouldn't be that hard and must be done but when I inspected the shelves the mounts bolt to and tried to turn the mounting bolts, they just spun in their holes, and what little of the wood that I can feel past the fiberglass is wet and seems rotting.

I have looked around online and haven't seen anyone with this problem, any ideas would be appreciated

[Krogensailor]

I imagine you would have to lift the engine out. Cut the tops off the bed logs to get a very clear pic of whats going on in there. Probably rotted wood. Vac/chop the wet mess out of there. Clean and dry, lots of acetone, and air. Rebuild with lumber, maybe some SS plates with welded studs to attach the mounts to. Replace the aforementioned tops. Use Expoxy only and lots of glass. Just some thoughts. Others may/will have more/better ideas. That would be the path I'd be looking at. Good luck.

[chris95040]

Agree with the above, but a cheesier, easier approach could be to pour some penetrating epoxy (smiths CPES?) in the holes, then fill holes with normal epoxy (west system?), then re drill new holes for the lag bolts. With an offset drill you could possibly get out of this without lifting the engine, particularly if it's just the fronts. Anyways it may buy you time, save your summer, and you could do a proper reconstruction later.

[GordMay]

Greetings and welcome aboard the CF, Mike.

[dick sargent]

I've had success with oversize holes by applying grease to the fastener before inserting it into the resin-filled hole. good move in limited space. another thing worth considering...I should have replaced my engine mounts rated for heavier engine....weight was1500#. Good luck. Dick

[chris95040]

Yeah thats another idea, doesn't require drilling. Insert the lag bolts while the epoxy resin is still uncured. But I believe you'd still want to cinch it up more once the epoxy cured, and there'd be no room in your hole to do it since its all full of epoxy.

[dick sargent]

forgot to mention using washers to cinch bolts securely

[JPA Cate]

Mike,

Sorry, I'm sure this isn't what you want to hear, but you need to do a proper repair on that, and you'll have to get the engine out of there to do it. Do measure everything carefully so that you know what you're going to have to build back to. Make drawings of it that are more or less to scale. [If you know how to do it to scale, do that.]

All the mushy stuff has to be taken back and then see what you have. If there is no good timber left, you'll have to grind back to a smooth surface, because you will epoxy treat the timber you will use, and you will be epoxying the engine bed back in place. Paint them. When you drill the holes for the engine mounts seal the holes with penetrating epoxy. When you bolt the engine back down, use sealant on the bolts so no water can get in.

It's a big job, and lots of the time is in letting chemicals cure. But it is something you could get your head around, perhaps, when you think how much it would cost to have a yard do it, and they might not do it properly, it may become more interesting to attempt it for yourself.

Ann

[memiller279]

I just finished replacing the vibration isolator on my boat as well and it's not an easy fix. I had to lift the back, block it up and secure it then do the same to the front. In your case you may be able to leave the back mounts in place (to keep the engine moving too much) and lift the front. After that block it off, remove the mounts and engine brackets and see if you have enough room to yard the old stringer material out and rebuild it.

[Mikelikethewind]

Thank you everyone. If you can see from the pictures there really isn't much wood available to do much with in the first place. I was taken aback by that when I got the camera around to the bottom of the mounting lip to see what was there.

If the wood is completely shot, as in epoxy filling is not an option and I have to reconstruct the entire mounting lip how easy is it to glass supports into the inner keel?

I was also considering a metal cross bar solution that would span across from one side of the inner keel to the other. I am just brain storming at this point until I can lift the engine out to remove the old mounts and really see what I am dealing with. I believe this is my only next step, ideas?

[Roy M]

What could possibly go wrong? THESE ARE, GENERALLY, THE LAST WORDS CONSIDERED BEFORE A DISASTER. Either take the time to do the job right, or take your chances and take the consequences. You are the only person that can make this decision.

These pictures document the steps I took to install new mounts for a new engine. I needed to make sure that the engine would stay put, no matter what. The only way to do that was to remove the engine, ensure the alignment was going to be right on, and that the engine bed logs were correctly aligned. oops! I forgot to show the alignment tool I fabricated to get the installation of the mounts close to final. Here it is: the measurements were taken from the engine's spec drawing. With this tool I was able to determine that the bed logs had to be lowered a bit to accommodate the new mounts (the red filler marks the chopped out sections. Having a chain hoist made raising and lowering the engine a breeze. I simply installed an access plate in the cockpit above the center of gravity of the engine. I lowered the engine into the cabin with the main halyard, onto a 2X6 timber, slid it aft into the engine compartment, then lifted it off the plank with the chain hoist. This process made it easy to place and remove the engine for trial fitting, as well as kept the space open for actual construction work.