Mast step / stringer

Gregory M · November 16, 2016, 11:44:46 AM

Hi guys! Looks like not only you, dealing with the same problem! Started about three weeks ago, cutting along crack edges with Dremel pointed cone bit mounted on flex shaft (works well to open up cracks), to find out what's in there? Rotten wood, saturated with oil, diesel and god knows what else!? Looks to me, like wood was added as filler piece to fill big void, between "I" beam and keel-son. Questions:
1) Are you sure that is stainless steel? (haven't open up yet), but, upon drilling to clean hole, aluminum shavings where discovered.
2) What's your plan to fill the gap with?
(mine is to use):
1) 3/4 "maranti" plywood in layers, sealed with S-1 sealer and bonded to each other with epoxy East System (not West).
But this sound like lot of time and expense.
2) Block bow and aft sides of keel step with let's say 1/4" plywood and fill "box" with epoxy mixed with cotton fiber (heard that is structural filler) or
short stranded or chopped glass.

kh3412 · November 16, 2016, 04:36:21 PM

Greg
Hi sorry to hear about your step. You know i assume it was stainless but to be honest I did not check. Where I was chiseling the glass off the top did not groove the metal and would have thought aluminum would have. Have not come up with a plan yet was waiting to meet with Phill and see what ideas we could come up with. your second idea would be a lot of epoxy and produce a lot of heat. Under my wood in the bottom of the bilge they had globs of resin with fiber to bed the wood to the bilge. Not sure how well it worked from what is left. Thinking I have two ways to go.
1 Fill in the area using the raised glassed area I have not removed with resin/filler to have a flat surface to build up from.
2 Remove the rest of the glass and resin down to the hull and build up from there.
If you choose your second way what will the bolts holding the mast step screw into. On mine the bolts are outside the metal beam?

kh3412 · November 16, 2016, 04:48:29 PM

Open this for all to weigh in, just throwing ideas out there. Build a form bow and stern of post area fill with concrete and have studs for the step in the concrete, fiberglass over the whole thing. Concrete is great for compression, water won't hurt it, fills voids if you use a vibrator when pouring, and it won't rot.

Gregory M · November 16, 2016, 08:16:06 PM

Concrete is great for compression, absolutely, not so much for possible twisting (not to much thou), and what about when is wet and freezes, boom, we have cracks in fiberglass again.... I agree that is lots of epoxy, would estimate 2 gallons or so. East system is almost half price from West system, same 5:1 ratio, same pumps, only 5% less strength though, very insignificant and what is important, dose not blush! Also, it is laminating epoxy. Just nice stuff to work with!

. As for heat, yes it will build up, that is why has to be done in layers. An inch at the time, pretty much a sizable batch.
Not sure what route to take for bolts holding base of mast: 1) drill and tap in to fiberglass (machine bolts), possibly insert layer of 3/8 thick aluminum in last layer of bedding of "glassed" post. 2) use lag bolts (as they where), there is way to drill and "tap" lag bolts in to fiberglass. On the other hand, is ts a bit (huuuuge bit) over kill to to do it that way! Filing with epoxy, that is.. More ideas ? I do not want to look, like I'm stuck in Epoxy!

KWKloeber · November 17, 2016, 11:30:08 AM

Quote from: Gregory M on November 16, 2016, 08:16:06 PM
Concrete is great for compression, absolutely, not so much for possible twisting (not to much thou), and what about when is wet and freezes, boom, we have cracks in fiberglass again.... I agree that is lots of epoxy, would estimate 2 gallons or so. East system is almost half price from West system, same 5:1 ratio, same pumps, only 5% less strength though, very insignificant and what is important, dose not blush! Also, it is laminating epoxy. Just nice stuff to work with! . As for heat, yes it will build up, that is why has to be done in layers. An inch at the time, pretty much a sizable batch.
Not sure what route to take for bolts holding base of mast: 1) drill and tap in to fiberglass (machine bolts), possibly insert layer of 3/8 thick aluminum in last layer of bedding of "glassed" post. 2) use lag bolts (as they where), there is way to drill and "tap" lag bolts in to fiberglass. On the other hand, is ts a bit (huuuuge bit) over kill to to do it that way! Filing with epoxy, that is.. More ideas ? I do not want to look, like I'm stuck in Epoxy!

Just thibking.....

why the need to cover the concrete w/ glass or epoxy?

conc would be very easy to set bolts or studs. Using high strength conc should do fine (shear value will increase with compression value.)

In college in the whacky 70s, I wanted weights for traction (yes, a converted camper van) for the winter that lasted from May 1 to April 30. I got heavyweight, super strong (which was also SUPER dense) aggregate from a power plant construction job and cast up some 18" cubes to fit next to the wheel wells (yes, down inside the seats that made the bed bunks.) They were monster heavy and monster strong. At graduation party we had a contest trying to bust them up w/ sledge hammers (beer was involved.) No way. I slept better afterward knowing the concrete that went into that nuke plant. I don't see a problem if the block has a high enough shear value (more cement, less water, in the mix.)

If using epoxy, cast in or drill and sink in roughened-up stainless coupling nuts held into place w/ waxed up bolts -- soon after the epoxy kicks, back the bolts out, leaving a threaded receiver in the epoxy. I have no idea the depth you have there -- could use add'l coupling nuts to make the treads as longs as needed. Also a good way to set studs or threaded receivers for engine mounts (over lag bolts -- which are difficult to use in hard epoxy (no wood fibers to break and lock into the lag threads.))

Depending on volume, could you use a G-10 block ($$$$) and build up from there?

On the 34, is the stainless holding the mast -- or what?
ie, do you NEED compressive strength around or under the stainless, or is it window dressing? (I am deck stepped.)

kk

Gregory M · November 17, 2016, 06:17:25 PM

Ken, look at pictures in reply #9, this is the cavity we trying to fill, with "something", to make support for T-bar (stainless..not confirmed thou). Notice, that left and right side, under flat part of T-bar, rotten wood is not removed yet. Not sure how far it goes estimating around 5~8 inches on each side. My guess is that Catalina, made "design" of wood, to support and prevent T-bar, from rocking/stabilizing, for and aft of T-bar. [doc09714920161107160426-1.pdf] :cry4`don't know how to add link.. it's in reply #2

KWKloeber · November 17, 2016, 08:12:37 PM

Greg

Yep i see it and understand better now that I saved them and zoom in.

First things -- easy to post a link.

click on the subject line of the post that you want to link to (the subject line is a hyperlink.)
just go to to your browser address bar -- highlight and right-click > "copy" the address (or ctrl + C is the same as copy)
past into your new message (right click > paste -- or ctrl + P)

alternately -- hover over the subject line
right click > "copy link address" (or something similar if not using Chrome browser)
paste into your new message

Ahhhh I see why now.

Is that wood or mung turds I'm seeing in the bottom?

Do you think the T is fiberglassed in? Or was just embedded into the lumber?

The lumber under the T is what's supporting it -- nothing on the ends?

My bilge is narrow - maybe an inch wider each side than the cover board so I can't relate exactly to what the C34 has.

Everything's "easy" when you're not there looking at the situation, but.... I'd probably consider having my buddy (a stainless fabricator -- everyone needs a buddy (or son/in law) like that) make me a "box" to epoxy into the bilge. If I went that route, I'd make a "close" tolerance, exact not necessary, mock up for him using heavy corrugated cardboard or foam-core poster board and duct tape. Or (built-up) styrofoam insulation sheets as a template. The "box" could be an open frame -- say like a 4- sided A frame (trapezoid) with an open base and from angle or T-bar for the "legs". The legs could be angled as much or as little as you need to make the base as large as necessary to give "overturning" support. The top could be drilled and the step thru-bolted, or weld nuts underneath for the step bolts.

Hell, I see an Erector Set mock up!! Wouldn't THAT be cool!

-kk

Quote from: Gregory M on November 17, 2016, 06:17:25 PM
Ken, look at pictures in reply #9, this is the cavity we trying to fill, with "something", to make support for T-bar (stainless..not confirmed thou). Notice, that left and right side, under flat part of T-bar, rotten wood is not removed yet. Not sure how far it goes estimating around 5~8 inches on each side. My guess is that Catalina, made "design" of wood, to support and prevent T-bar, from rocking/stabilizing, for and aft of T-bar. [doc09714920161107160426-1.pdf] :cry4`don't know how to add link.. it's in reply #2

Noah · November 17, 2016, 08:42:14 PM

I believe if you back to the beginning of page one of this thread you will see the link to the Catalina fix for this problem and it shows the metal T-Bar. Why not just go with their block (or laminated sandwich) of hardwood suggested repair? Seal it up properly, glass it in, and even gelcoat over and should last another 20-30 years.

KWKloeber · November 17, 2016, 09:57:49 PM

Quote from: Noah on November 17, 2016, 08:42:14 PM
I believe if you back to the beginning of page one of this thread you will see the link to the Catalina fix for this problem and it shows the metal T-Bar. Why not just go with their block (or laminated sandwich) of hardwood suggested repair? Seal it up properly, glass it in, and even gelcoat over and should last another 20-30 years.

noah do you know...
I wonder if that's what CTY did in the first place? ie. seal it? If not, why??? not.

I don't see the point of painting gelcoat on. If you seal the entire thing in epoxy resin, what does gelcoat do? Make it pretty?
Polyester resin onto epoxy would be used only if subject to UV deterioration -- not an issue here. Anything polyester instead of epoxy resin is subject to eventual hydrophilic action (what causes hull blisters.)
If "pretty" is the reason, I'd mix some white or other color pigment into the final coating/tabbing of the block.

Another way would be to fab the block out of open cell foam and saturate it with unthickened epoxy resin.

Many ways to skin a feline!

ken

Gregory M · November 17, 2016, 10:26:15 PM

Thanks Ken! Excellent suggestion! BTW. Those pics are not from my boat. I'm just following on subject, cause I started same project and I'm assuming (hate that word) having same problem. Already, having pieces of rotten wood in my possession! and oil, and diesel...stinky mess! Going to boat Tomorrow, will see if I can open up the "thing". Getting chilly here, so not sure if can be done before winter. My goal for now is to open up and see what I'm up against. Let you know how it goes. Thank's for info about links!

Noah! I'm type of guy who want's to improve things of not necessary "good design". Saying so, I'm not fan of having wood in bilge.

, but thank you, for your input!

Noah · November 18, 2016, 01:18:32 PM

Having owned four wood boats in my lifetime, wood in the bilge doesn't worry me--if handled appropriately. Ken, Yes I believe the gelcoat was as you say just to make it "appear finished". CTY did that in the rest of the bilge and lockers instead of paint.

kh3412 · November 18, 2016, 06:12:27 PM

Ok, met with Phil today and we confirmed both our boat follow the same construction. Two blocks of wood with a "t" piece of stainless in the center. We concur filling the lower part of the bilge with an epoxy mix to provide a flat surface to build up from. The use of a solid block will not work as the keel bolts and the leg of the "T" prevent you from sliding it in. The port and starboard pieces of wood will be left to dry for the winter. Unable to get a measurement but seems more than a few inches from our cuts. So we are looking into ideas on how to fill the void between the new base and the "T" to take the compression of the mast.

KWKloeber · November 18, 2016, 10:56:21 PM

So, you're saying you can't get the T out? How far to either side does it look like it extends?

ken

kh3412 · November 20, 2016, 04:09:15 PM

Ken the "t" will not come out with the cuts I have made. Unsure how far the "t" goes back at each side but the fiberglass covering goes back about two feet on each side. You would have to cut the floor pan out to open up the glass to see how far it goes.

Breakin Away · November 22, 2016, 09:37:46 AM

I just read this thread. Sorry, I need the remedial version.

Could you please specify what you mean by "muiti tool"? Google search brings up a nice selection of Swiss Army Knives, Leatherman, etc. I suspect you mean some sort of power tool. (Dremel?)

And a comment. I used to use West System for epoxy, but never liked the severe amine blush. It creates adhesion problems when trying to build up a block from multiple layers. I'm not familiar with "East System," but a quick Google search showed some comments about blushing problems.

FWIW, here is what I used for a minor core repair on my prior boat:

http://www.epoxyusa.com/Basic_No_Blush_Marine_epoxy_p/me03.htm

You'll have to research compressive and shear strength of this brand on your own.