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Rudder box, paint, varnish, or epoxy?


tomstock

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Since the rudder box is constantly in the water, and has holes which could allow water to enter, I am planning to simply paint it. My thinking is that varnish or epoxy would keep water in and encourage rot.

Also, for a boat left in the water for long periods, would it make any difference to go with marine quality plywood for the rudder box -vs- acx?

Seems like a painted rudder box would be wet all the time anyway so would the voids in ACX make that much of a difference?

Thanks.

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Use epoxy, three coats, then paint it. Soak inside the holes with epoxy also.

Epoxy in an unbroken coat WILL keep water out. That's why it works to use it to build epoxy/ply diesel fuel and water tanks.

as for the ACX I can't comment cause I think marine plywood is the only way to go for boats

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I do know that a rudder box minimally protected by epoxy and varnish, and not protected at drill holes etc.. made of acx etc can last up to about 8 years in a boat that lives mostly on the trailer....

But you leave her in the water for a week at Okoboji, and a couple of times for several days at a BEER cruise and 7 years and 2 months later, the box will fail at a inconvenient time somewhere on the intracoastal waterway between Navarre and Quietwater Beach, while you are motorsailing, swinging into the prop, leaving you without power or steering with the headwind and waves building and the fleet well ahead of you..

You will provide great entertainment to the rest of the fleet when you limp in after repairing the shear pin of the prop on the water, and several friends raid their tool kits, and you tear a piece of wood off the bottom of your companionway seat to make repairs on the beach in order to continue your cruise.

You will temporarily lose your autistic son in the crowd while making said repairs...and you will then think you may never be able to return home...

uh use good stuff... epoxy the heck out of it..... and don't ask me how I know :roll: :cry: :shock: :wink:

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My rudder box failed due to the line chaffing inside that wore away the epoxy at the places were it passed through the solid framing members. On the rebuild I used brass pipe epoxied into the framing to keep the line from wearing on the wood and allowing water to seep into the structure.

Jim

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Use epoxy' date=' three coats, then paint it. Soak inside the holes with epoxy also.

Epoxy in an unbroken coat WILL keep water out. That's why it works to use it to build epoxy/ply diesel fuel and water tanks.

[/quote']

Isn't the movement of the rudder in the box, and the pivot bolt, going to eventually wear through that epoxy and allow water to seep in? Also, you didn't mention using cloth... so wouldn't the epoxy check? When it checks does it allow water to seep in?

Thanks for the help guys, especially the 7 year 2 month limit on the rudder box after a few week long dunkings LOL.

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Isn't the movement of the rudder in the box, and the pivot bolt, going to eventually wear through that epoxy and allow water to seep in? Also, you didn't mention using cloth... so wouldn't the epoxy check? When it checks does it allow water to seep in?

.

The real cure for this is to always make an epoxy bushing for through holes that will be in the water. Drill oversize by as much as 1/4" all around and fill with thickened epoxy. Drill the through hole after the epoxy sets. Forget about it.

I use Jim's method of a copper or stainless tube on rudder control lines where there will be a lot of friction and wear.

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Ahhh right. I remember this from the Hull and Deck repair book. That works for the bolts, but then there is still the wear from the rudder itself against the inside of the rudder box. Is this enough to cause concern? The reason I ask is that I am building two rudder boxes... one for my weekender and one for another sailboat which has an aluminum rudder. The aluminum rudder will be a lot harder on the inside of the rudder box.

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Yes, I forgot about mentioning glass. I always glass the rudders on the boats I'm building. I have on occasion glassed the inside of the rudder housing also. Depends on the boat. That will take a LOT of wear before it goes through. In fact, in most types of usage, I doubt you will wear through it. If I don't glass the inside, my final couple of coats of epoxy will have a heavy silica mix. This would be done before the box was put together. Tough to sand, but also tough for abrasion.

The tube for the down haul/uphaul lines is an excellent idea too. And ALWAYS make a bushing from heavily thickened epoxy where the pivots go, as Tom said.

By the way- I believe Tom puts a piece of epoxy soaked line around the leading edge of rudders he builds. I take strands from a piece of roving, twist them together til they are about pencil sized and epoxy that into a groove around the leading edge. Then I glass over that. That leading edge and the lower end, can take a beating if you beach the boat regularly. The extra protection sure helps.

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Ok then, so:

1) Drill holes oversized

2) Fill holes with thickened epoxy

3) Glass inside and outside of all rudder box plys

4) Glue (epoxy) and screw the pieces together

5) More epoxy to fill any gaps, etc.

6) Drill out holes to correct size

7) Clean, Sand, and Paint

Sound good?

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We pretty well eliminated the wear factor with rudders rubbing against the rudder boxes by slipping a thin poly disc(s) over the bolts before securing it in the box. The poly disc(s) were about 6" in diameter and cut from the lids of margarine tubs. The rudder didn't come into contact with the box and the slippery characteristics of the poly lid discs didn't allow for much in the way of wear on any of the flat surfaces that would normally come into contact with each other.

Really do recommend drilling out the holes in the rudder and rudder box oversized and filling with epoxy. Like Tom stated, about 1/4" oversized and then drilling the thru hole in the epoxy. No water incursions into the surrounding material. If you are really set on going for no worries, then you can set bushing(s) into the epoxy that the thru bolt will set in. No worries mate. CPVC pipe works fine. Bolt rubs on the inside of the bushings, bushings set into epoxy and epoxy coated surfaces with glass on the rudder sides and you should outlast the issue. :wink:

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Committee meeting will be early Dec when the Gritsters will decide on date and course. They'll announce on TSBB once the schedule is set.

I don't know for sure we'll make the next one, at least not aboard Tehani. LONG long trip we've done for two years now. The miles twixt Matagorda Bay and P'cola Bay are getting boring :lol:

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