I rebedded most of my deck fittings over the winter. As Tally Ho pointed out, the backing plates on the O'Day's are lacking to say the least. If your deck is rotted by the bow you will not feel it when walking or pushing on it from above. Try to scrape out some wood from one of the bolt holes to see if its good.
My typical process for rebedding without a second person went like this
- Remove the screw/bolt
- Try using an impact driver alone
- Put some light upward force using a autobody panel remover, small crowbar, paint scraper, etc. This helps keep the nut from spinning on the other side
- If the nut still spins then attach some vice grips to it
- Remove old sealant using a knife, scraper etc. For tougher jobs and to clean up fastener threads my tool of choice was a paint/varnish wheel
- Counter sink the hole. This ensures your butyl is coming in contact with clean fiberglass and not old sealant. This also allows for more surface area for the butyl to seal with. Do increase the amount of butyl a bit to fill the larger gap. In some cases I skipped step two and only did step three because it's still making a seal. Rebedding all the fittings took way longer than expected
- Clean the sealing surface. I put some acetone in a spray bottle and wiped the area with a paper towel. Most solvents and alcohol work and evaporate very quickly which speeds things up. I've also used butyl in a pinch to remove fiberglass dust
- Put new butyl under the fastener head and around the threads that will touch your sealing surface(s)
- Tighten the nut by hand followed by a quick blast or two with the impact driver. The bolt or screw shouldn't turn much which helps keep the butyl in tact. Don't over do it with the impact driver. Even the cheaper ones can cause damage to wood and fiberglass if you overtighten it. You of course tighten these fasteners by hand if you can't get an impact driver in there
I would recommend Bolt Depot for fasteners including thicker washers. In most cases I used a flange bolt with a standard thickness fender washer.
@dlochner Advised that the rounded edge of the washer should face the fiberglass to lessend the chance of it digging in. I often used non stainless hardware on the backside for backing washers and nuts and bolts. The reason being is that A, I'm in freshwater and B, If a fastener is leaking, the rust is often a good indicator. For heavy duty applications such as my outboard mount, I used square washers made for Unistrut. They're 1/4" thick, have a galvenized or zinc coating and will without a doubt last longer than the boat. The other non stainless fastener will most likely outlast the boat or bedding material
Two other areas to check on the 25 and probably a few other O'day models
- My boat has a storage compartment for the anchor rode/line. The bottom of it is made of wood and your line will be wet when you pull it up. The wood on mine is totally shot but it doesn't appear to have any affect on other parts of the boat so it's a low priority repair. Also, if you have a anchor locker that drains above your bow eye, do an inspection of the wood behind the bow eye. If you ever need a tow in heavy seas, this is the attachment point that you want to use. I lost a winch in a storm last week (not all tow captains are created equally)
- Check your chainplates and bulkheads. These chainplates are common leak spots and can cause the bulkhead to rot. If left unrepaired the chainplates can be ripped through the deck and down goes your mast
- The cockpit drain spills water on your lower gudgeon (rudder bracket). Mine was torn in two, almost three pieces in that storm before things got ugly. When replacing it yesterday I discovered that there was no sealant of any type used. As a result the wood in that area of the transom has become waterlogged.