Replace skid plate fasteners (bolts)

[stevevoyce@yahoo.com]

When I put the boat (2008 25 Classic Ranger Tug) on the hard next month, one of the issues I must address is the bottom skid plate. Most of the fasteners have rotted and now it is only being held on by a few. I would like to drill new holes and go with 316 fasteners. This is what I need to know: What size were the original fasteners? What type? How deep can I drill? Do these fasteners go all the way through to the bilge?

 

[knotflying]

I believe that these are threaded bolts. I think there is one that even protrudes in the bilge with a bolt behind the rear bilge pump. I am not sure if they are all like that. If it were me I would remove the good existing bolts to get the size. I would then try to (using a cobolt bit) drill a pilot hole in the remaining bad bolts and then use an easy out to try and get them out. If that does not work I would then drill it out with proper size bit and re-tap. Gansett Ranger had the same problem and took care of it. Perhaps he can chime in and offer his experience.

 

[BB marine]

Here are a couple of post about the fasteners used mounting the keel shoe.


viewtopic.php?f=5&t=10992&hilit=+keel+shoe#p75449
viewtopic.php?f=19&t=8969&start=0&hilit=keel+shoe

 

[Brian B]

I did have this issue as I posted in the link previously posted. Hopefully when you remove the plate there will be enough material to grab with a vice grip. I had one bolt that was an issue. I attempted to drill it and use an easy out. The boat was low to the ground so drilling upward was difficult. I used a chisel and hammer and by working around the bolt I was able to back it out till I could get a vise grip on it. My plate was not bonded, I bonded it with the bolt that comes through the bilge.

 

[bakerboat]

I would suggest you bed your fasteners in 5200 or other underwater rated sealant when you install the new ones. The most likely cause of the bolts failing is called crevice corrosion. SS is corrosion resistant underwater when an oxide layer is formed on the surface. To do that, it needs oxygen. Seawater is able to seep in under the head of the bolt and sit there. The oxygen is eventually depleted and with no fresh seawater being flushed through, it prevents the oxide layer from forming. The bolt starts corroding and viola, the bolt head shears off. The sealant will replace the oxide layer and prevent the seawater from attacking the metal. Similar to putting Tefgel between SS and aluminum.

 

[knotflying]

I may use a less permanent sealer like life seal. 5200 would be difficult to break the seal if it is required.

 

[Kevin Lamont]

When I put the boat (2008 25 Classic Ranger Tug) on the hard next month, one of the issues I must address is the bottom skid plate. Most of the fasteners have rotted and now it is only being held on by a few. I would like to drill new holes and go with 316 fasteners. This is what I need to know: What size were the original fasteners? What type? How deep can I drill? Do these fasteners go all the way through to the bilge?

Hello,

There is one bolt that goes through the bottom and has the bonding wire attached, this will be located by the AFT bilge pump. When re-sealing be sure to use a 5200 or equivalent. It is easy to remove 5200 if needed, heat up area with heat gun and let cool, heat up little bit again and it will peel off without much effort. Hope this helps.

Thank you,
Kevin Lamont