U-Bolts Revisited

[Buzzlovelace]

Now that I am getting ready to do the u-bolts, As well as drilling new holes I have 4 old holes to fill. My first thought was marine tech. But do to the drying time and being a weekend warrior I am thinking there may be an epoxy that I can use that will penetrate some of the soft wood in the old holes to help firm it up. Any Ideas?? Especially ones that expedite the project and give me less time with my shrouds disabled.

 

[Shell]

I used products that are supposed to penetrate and fill rotted core. It penetrates very little and I think is a waste of money. At least it doesn't penetrate when used for small bolt holes. The companies use catch words like "capillary action". The product may work in a lab with perfectly dried core in a position where the product can be poured in and not drip out. This is my experience with all through deck holes such as for u bolts, chain plates and stanchions. First, I cleaned all bolt holes out with the approbiate round file. Clean it with acetone. Then where I suspected any water intrusion i but a electric heater at it a ran it for a few days. This is where i think the penetrating epoxy does not work. It is impossible to dry out the rotted core and in order for the epoxy to work it must be dry.

If any epoxy penetrates, it wont travel any further than about a half an inch. Far too little to stiffen the deck.
I then taped the bottom of the cleaned holes so the epoxy wont just run through. Pour the mixed epoxy in the holes and let dry. After dried, I re drilled the holes. Sealed all bolted hardware with Life Caulk. Remember not to tighten any running rigging deck hardware too tight. Since there is no core left all you will do it compress the fiberglass and weaken it. I possible use larger backing plates. This will diplace the pull of the mast over a larger area which will hopefully make up for a weakened deck. Stainless plates are not that expensive since they no welding or fabrication. Just holes drilled.
On items you would want to remove it the future such as the stanchions, do not use a permanent sealant.
Good luck.
Shell

 

[Buzzlovelace]

Thanks Shell. I appreciate your detailed response(s). Alot of the reason I am changing to the u-bolt is the much larger backing plate that is also a angle iron (stainless).

 

[Moody Buccaneer]

Thanks Shell. I appreciate your detailed response(s). Alot of the reason I am changing to the u-bolt is the much larger backing plate that is also a angle iron (stainless).

Here is a thought ...

Mark where the new backers will be on the inside of the boat.

Measure the thickness of the deck through one of the existing holes and set a drill stop so that you can drill a couple of holes UP from inside the boat that the new backing plates will cover.

Try about 2" either side of the existing hole for the lower shroud eye bolt. If the core is dry, cool. If not drill a couple more holes moving away from the existing hole to the limit of the backer. With luck you will find dry core before you get to the limit of what the backer will cover.

You should have a good idea of where the core is good and the limit of what you need to stabilize. Staying within the limits of what the backer will cover. drill a bunch of 1/4" holes about 1" apart. Clean the inner liner around the area and get your shop vac ... (you did remember to use the shop vac while you were drilling all those holes to control the mess you were making).

With a bit of putty, some duct tape, and some heavy plastic sheet. You need to plug the existing hole on the deck and liner. Seal the area over the holes and around the vacuum hose. Fire up the shop vac. The idea is to suck and moisture out of the core through the holes you drilled. . Let the shop vac run for hours ... over night if possible.

Now, with the existing hole in the liner still plugged and the shop vac still running, fit a funnel to the existing hole in the deck. Pour Git-Rot or the low viscosity epoxy of your choice into the funnel and let it wick into the core. The vacuum will help it penetrate. With any luck you will see some of the goo sucked out of the holes and into your shop vac (you wanted a new one anyway). When you have reached the working time limit of your epoxy of choice, plug the hole on the deck (it should be full of goo).

Shut off the shop vac. Set your cabin heater on "stun" and close the boat up to get the interior as warm as possible until the set time on your goo is reached.

Any holes that are not leaking goo can be sealed with a thickened epoxy. Use a bit of tape to keep the thickened goo in the holes.

Mask off outside the area where the backer will cover plus about 1/16 - 1/8. Mix sand the area with 80 grit. Fix the tape you messed up with the sandpaper. Locate the backer and drill your new holes. Sand the surface of the backer with 80 grit. Mix up some very thick epoxy (peanut butter) and coat the backer to within 1/4" of the edge with goo. Mount the backer and the U-Bolt and let the bolts squeeze the goo out from between the backer and the liner. Clean up the excess goo with a tongue depressor. When the epoxy has set but not at full cure, you can peel the tape off.

You should end up with the deck as stable as you can expect without cutting the core out and replacing it and you should have a layer of epoxy between the backer and the liner to even out the load as much as possible. There should be a nice fillet of epoxy around the backer.

Do one a weekend.

Have fun.

Randy

 

[Buzzlovelace]

Thank you for taking the time to explain this. If I ever get the chance I will shake your hand