Mainship Pilot swim platform

[sickatea]

While doing preventive maintenance on the boat, I decided it would be a good time to re-bed the bolts that are holding the 4 stanchions from the swim platform to the transom. I started to army crawl into the bilge looking to see what I would need to do to pull the bolts out. To my surprise, nothing.

I jump out of the boat with a phillips screw driver and backed out a screw. Each stanchion has three 3/4 screws fastened to transom with no sealant.

Do I re-bed the holes and use new 3/4 screws and put it back together? Or do I re-bed the holes, get 2" bolts and put washers and nuts on the inside?

Thank you

-Rich

 

[Beekeepergreg]

Swim Platform

I just pulled off my swim platform for repair. A pain holding the bolt head/washers that where probably embedded in the hull. Two spun the others held. The platform was attached by probably 5200 that I had to cut thru to get platform detached from the boat. It really attached the platform to the hull.

Before I reattach the platform I will overdrill the screw hole and fill with epoxy. Then redrill and set with sealant. Not sure if I will use 5200 between the platform and the hull. Keep going back and forth. It really holds but pain to get off. Maybe a 4200 for a compromise.
Greg

 

[Comodave]

I might wonder if they used 5200 for strength in addition to the bolts. Maybe the bolts would not be able to hold it alone. I would hope they didn’t do it that way but who knows. Sounds like the bolts are going to threaded inserts???

 

[Beekeepergreg]

The heads to the bolts had a square washer welded to the bolt on the inside. The one by the scupper can't push in due to the scupper. Must have been inserted before the deck.
No room under there.

 

[sickatea]

I wish they used threaded rods. Pardon the dirty bilge, I have only owned this boat since late August.

-Rich

 

[Comodave]

I would probably bite the bullet and go big on the repair. I would add some large S/S backing plates or some thick aluminum plates. Then if there is wood in the transom it needs to be treated so that any leaks won’t rot the wood. Marinehowto.com has a good tutorial on how to epoxy seal and fill holes so water won’t migrate. Then the all thread or some good bolts to hold it all together. It sounds like the original install was a bit shakey so now is when I would fix it properly.

 

[sickatea]

Dave,

I made cardboard templates today of the stanchion mount bolt pattern and dropped it off to have stainless steel backer plates made (8" x 4"x 3/16). I pulled all the screws out of the supports and will give it a month or so to hopefully dry out before I 5200 everything back together.

I tried to talk my wife into a larger boat because of this catastrophic failure and she wasn't having it. Then I told her how much 4 of the stainless steel plates cost and I almost convinced her.

 

[Comodave]

What is the transom cored with? You said it is wet, how wet?

 

[sickatea]

Dave,

The boat was surveyed on August 23rd 2020 just before we signed away part of our kids college funds buying this boat. The moisture readings on the transom and around through hulls never went above 35. I'm a preventative maintenance junky and what started as an easy re-bed of something that didn't appear to have an issue, has quickly shifted. According to the previous owner, she has stayed in the water for the 3 years prior to our purchase. Hopefully I found this before it got bad! I honestly don't know what the transom is cored with. This is our first Mainship! They have done some good things when building this boat, but seem to cut corners on the oddest things.

-Rich

 

[sickatea]

BTW, thank you for your input!

 

[Beekeepergreg]

Our transom is solid fiberglass below the water line. Pretty sure where my bolts is also solid fiberglass.
Greg

 

[Comodave]

That would be the best thing, having solid glass. It would make the repairs much easier. Anyway good luck and keep us informed.

 

[Beekeepergreg]

Red Bottom vs Black Bottom

I think the red looks better.
Especially while in the water.

 

[bill.kimbell]

Dave,

The boat was surveyed on August 23rd 2020 just before we signed away part of our kids college funds buying this boat. The moisture readings on the transom and around through hulls never went above 35. I'm a preventative maintenance junky and what started as an easy re-bed of something that didn't appear to have an issue, has quickly shifted. According to the previous owner, she has stayed in the water for the 3 years prior to our purchase. Hopefully I found this before it got bad! I honestly don't know what the transom is cored with. This is our first Mainship! They have done some good things when building this boat, but seem to cut corners on the oddest things.

-Rich

Use acetone to help dry the holes. If cored, once holes are dry, overdrill, fill w epoxy, redrill. Then bolts w fender washers or backing plates, bedded in 4200 or butyl tape. Do it once, should last forever...or whatever the boat maintenance equivalent of forever is.

 

[oak]

There are four struts on my 07 pilot. The middle two seem to be secured into the fore and aft stringers with screws. The out board struts are thru bolted and backed up with washers. The starboard strut seems to have a slow leak. I have not been able to access the fasteners from the stern hatch. The only way to access the fasteners is to remove the 8D battery.
I will wait to do this repair at haul out in March ( boat is in Florida). The possibility of tightening and breaking a bolt doesn’t seem to be a good option with boat in the water. I will use backing plates instead of the washers and caulk and Re bed all fasteners.