Mast compression repair

n6ric · Mar 13, 2011

Sebastian,
I had a similar problem on my hull just forward of the closet. The hull had a dent in it from the boat sitting on the trailer for 10 years. To remove the dent, I put the jack right on that area and ran a 4x4 up to the coach roof against a 2x6 to distribute the pressure. It took about two weeks in place before the dent pushed back out. Each day I tightened the jack a little. Hopefully, that will work for you.

With regard to the gap above your beam. If you mix up your epoxy with adhesive filler to the consistency of peanut butter, you can fill that gap and it will be stronger than the beam. If the beam is splitting a bit, you can also put several coats of penetrating epoxy on it and it will soak into the cracks and rebond the wood, giving it much of its strength back.

Fortunately, my boat only had the mast up for about 3 years total during its 35 year life and I have no warping. However, I had to replace the bulkheads because of rot and I am putting in the stainless steel plate so that I never have to worry about it. It's easier to do it now while I have everything apart.
Good luck,

Ric
s/v Blue Max
#2692

pjacobs55 · Mar 13, 2011

Sebastian,
I don't know too much about this problem, but I think the FIRST thing I'd do is drop the mast to relieve as much stress as possible from the cabin top.

Then (as already suggested) spread the load with some blocks and jack it up over a period of time, maybe even a couple of weeks, a bit at a time to let the surrounding area slowly regain it's shape.

I don't think this is something you can do in a day, after all it took years to get that way.

BTW, nothing mediocre about your pictures: they show the problem well.

Keep us posted as to how it goes!

Peter
#1331 'Sin Tacha'

vegatern · Mar 13, 2011

I was recently given a stern admonition NOT to drop the mast, but to instead gently lower it ;-)
Craig

tim_klynn · Mar 14, 2011

I also think you should give the fiberglass some time to rebound and unstep the mast.
We bought a Santana 20 had never been off it's trailer for 7 years and had some 1/2" indentations in the hull at the trailer pads. The dents came out after about a week of being in the water.

Maybe heating the hull (black plastic over the area in the sun?) might help.

I'm curious about what is in the kit. I'm going to so a proactive reinforcement on my boat and I was thinking about making a template to fit the deck underside and then plasma cutting out a flitch plate of 3/16" 316 plate to reinforce the wood beam. If you have time, could you post photos of the kit?

The thickened epoxy idea is a good one. I found mixing ground fiberglass and cabosil to the epoxy works well for filler. The ground fiberglass powder gives is strength and some thickness, but tends to sag, the cabosil doesn't have much strength, put makes it thick.-Tim

trevy_kins · Mar 14, 2011

Sebastian - I took my beam apart and replaced the entire thing with
yellow oak glued and thru-bolted to the bulkheads. I think you should
start from scratch - don't use any of the old material except the
bulkheads and the support posts. I made a nice archway to make the beam
stronger. I will try to get some pics posted in the next few weeks.
When jacking up the coach-roof you might want to use a wider contact to
spread the load - and place it directly against the interior of the
coach-roof. Remember to spread the load widely on the sole too.

Trevor Leech

Staff Lawyer

Community Legal Clinic of York Region

ph. 905-508-5018 ext 222

1-888-365-5226

fax. 905-508-7539

________________________________

From: AlbinVega@yahoogroups.com [mailto:AlbinVega@yahoogroups.com] On
Behalf Of brockhaus77
Sent: March 13, 2011 8:17 PM
To: AlbinVega@yahoogroups.com
Subject: [AlbinVega] Mast compression repair

I just started work on fixing the major sagging of the deck underneath
my mast, using Steve Birch's repair kit (which I received in October, so
I really should've started long time ago... :-(
I have a Series I Vega, and after taking apart most of the mast support
beam, I can now clearly say that it is made of several parts (counting
from aft to fore):
1) The main "beam" (1" thick wood) that is supposed to carry the load.
It spans the whole width of the cabin, but it is neither quite
underneath the mast (it's abaft of it), nor does it rest on ANY support
structure (BAD design). This beam is significantly deformed (sagging in
the middle) in my case and also shows some signs of cracking - one
previous owner unfortunately weakened it by gouging out the US
registration number.
2) The bulkheads (port and starboard). They are supposed to take the
load from the mast and transfer it to the bottom. They (used to) reach
all the way to the cabin roof, so the only way to attach something to
them is on either side of them. This is indeed how the main beam (1) is
attached: via throughbolts through the bulkheads (needless to say, once
your deck sags, these holes tend to elongate...) Of course, there is a
gap between the bulkheads for the passage from salon to forepeak...
3) which is bridged by another piece of 1/2" plywood. This is the only
piece DIRECTLY supporting the mast (on its aft edge - the mast opening
of course is left free for cables), and it is NOT supported by anything
other than MORE bolts connecting it to beam #1, as well as some small
ledges that normally rest on the door posts (which in turn are attached
to the bulkhead). Supposedly the door posts are not meant to take any
load, but of course when the deck bulges downward, this piece of plywood
will "shove" them downward as well until they hit the floor. (Maybe a
fail-safe design?)
These 3 parts together are supposed to take all the stress from mast
weight and rigging tension - they are clearly under-designed for this
purpose.
4) In my case, there was a fiberglass "channel" attached forward of the
bulkhead with an ungodly number of screws to both the cabin roof and the
bulkhead - to no apparent purpose (other than as spacer, see below); it
is much too weak for any load bearing
5) There are additional wooden spacers and thin wooden "panels", all to
hide the wiring after it comes out of the mast.
6) The foremost piece is another 1" wooden beam which LOOKS like a
support beam, but since it's only connected to the very end of the long
bolts going through all of the above pieces, really doesn't contribute
to load bearing (and therefore is mostly cosmetic).
-- You can see some of these things in the Photo Section in the album
"VegaLyra" --

I followed Steve Birch's instructions - removing all parts 4)-6) and
using a 2 ton car jack to lift up both the beam #1 and the plywood right
under the mast #3, after removing all bolts and screws (and of course
slackening all stays and shrouds). I was able to lift the mast at least
1/4" that way. But now I'm stuck: The reinforcing steel plate is shaped
like the ideal cabin roof - like a nice, round arc which is highest in
the center. However, 20 years of deck deformation don't just disappear -
the ACTUAL shape of my cabin roof right around the mast is more like a
sea gull - rising from the edges to the middle, but then turning sharply
back downwards to a lower point right underneath the mast. In fact, when
I cranked the car jack, the following happened:
- The roof lifted off the bulkhead everywhere - in places, I now have a
1/8" gap where NOTHING actually supports the deck except its
long-ingrained shape.
- The plywood support #3 did lift off the door posts leaving a 1/4" gap,
but sorta imbedded itself only deeper into the roof
- trying to jack up the roof directly (with a second jack) yielded some
scary cracking sounds, but no budging of the central depression. In
fact, cranking the jack any more would only lift the whole deck more and
more off its supports and possibly even cause damage to the deck-hull
joint, so I'm definitely not going to do it!

So, I have 2 options at this point:
1) Grind the beejesus out of that stainless steel reinforcement plate.
I've done a little of that, but it would take a long time and probably
would instead require cutting to adapt it to the "sea gull" shape. Plus,
I would have to put lots of "spacers" (wood strips and epoxy) between
the bulk head and the cabin roof to fill the present gap. As a result, I
would have weakened the reinforcement plate AND made the sea gull shape
more or less permanent.
2) OR, I hope that after a while, the deck around the mast will settle
back onto the bulkhead. This means leaving the gap for now, and making
only minor adjustments to the steel plate then install it as is (it
would cover the bulkhead nicely, but the same gap with the roof would
remain. This would definitely support the mast, but not the rest of the
deck around it (until it settles back)

WHAT SHOULD I DO? Or does anyone have an even better idea? Again, please
look under "VegaLyra" in the Photo Section for some (admittedly
mediocre) pictures of the situation.

Thanks - Sebastian (VegaLyra 1060)

tim_klynn · Mar 14, 2011

I'm you probably already know that the floor in the doorway directly below the beam is hollow, so you can't jack much up if the jack rests directly on the floor.

n6ric · Mar 18, 2011

Sebastian,
If I understand what you are doing now, you're leaving the support beam and steel plate in the rounded shape as designed and installing it so that just the center of the coach roof, at the mast, touches and leaves a gap as you move out from the center. If so, I think that is a good idea, but I thought you said that the wooden support beam was warped also. How are you planning to deal with the gap in the center above the wooden support beam? You could bolt the SS against the beam and then fill in the gap above the support beam, but only about 6' wide, with adhesive thickened epoxy. That would help support the mast and still let the deck revert back to its natural shape. Once that happens, you could fill in the rest of the gap. As I mentioned in an earlier post, it would be a good thing to sand and coat the beam in penetrating epoxy so that it soaks into the beam, binds the fibers, and adds strength back to the wood.

Both of these fixes are very easy to do and don't take any special tools. I had never worked with thickened epoxy before about 9 months ago and now I mix it and sling it like a pro. I was very nervous the first time I did it, but quickly realized the worst that could happen is that I make a mess that I have to clean up or gluing my hands together, but gloves keep that from happening.

I think a lot of good advice has been shared here and there is more than one way to approach the problem. Some may be better than others, but I believe all are better than what you started with. My advice would be to pick one and go with it. 99 percent is really common sense, so trust your instincts and go for it. That's what I've done and I've gotten a lot of great advice from here. That and books. I buy any books on boat building or repair that I can find, but two great books to have are "This Old Boat" by Don Casey and "The Gougeon Brothers on Boat Construction" by Meade Gougeon. The latter is by the people that developed West Epoxy systems and there is great information in there on how to mix and apply epoxy in just about any situation. You don't have to use West Epoxy to use the info in the book, any will work, but I will say that I'm partial to West. Good luck and keep us posted on your progress.

Ric
s/v Blue Max
#2692

tim_klynn · Mar 18, 2011

I am surprised that you can jack up the center (under the mast) and have the sides go up and retain the seagull shape as well. It seems odd that the deck (or something) is getting "longer" as the center moves up, but the roof adjacent to the center stays deformed. I would be curious as to what is deforming to allow the center to move up, as it doesn't look like it is the 2 sections adjacent to the center.

From your pictures, it looks like that even after you jacked up the roof, the center is still low, so I would have to agree that the mast is not holding down the center.

I checked the Vega Manual, and it shows wood running longitudinally and laterally under the mast. Maybe this wood is holding the seagull shape. Is/was the wood rotted? Maybe someone injected epoxy in the wood while it was in the seagull shape? Just brainstorming here..

You are probably right that heat won't do much good on this fiberglass/wood/fiberglass sandwich section. Probably wouldn't hurt either. The dents that worked themselves out on the S20 hull were just a single layer of 3/16" (?) fiberglass.

I am guessing the stainless flitch plate is about 3/16" thick and mounts to the forward surface of the beam. You might try jacking up the center under the mast so that you can put in the beam so that it is tight under the center at the top of the wood beam and flush to the bottom of the beam on the two outside ends, then screw/bolt the plate to the wood beam. Doing that would put your mast base at the correct height and set the outside bottoms of the plate at the correct height but leave the deck adjacent to the mast high.

Next, I'd slowly let off the pressure from the jacks and see what happens. I would guess that the beam/plate sandwich will load up and drop a 1/4" or so, and that the seagull shape will stay in there, with a gap between the coach roof and the top of the beam. Ideally, the beam will be in quite a bit of compression and push up the center over time an you will lose the seagull shape.

Unfortunately, I think the rig, once tightened, will hold the mast down in the center and the beam won't be able to push up and force out the seagull shape. Maybe leaving the rig loose will help, but if that shape persists through all the jacking, it will probably take a long time to work out (if ever).

That leaves you with a question: am I an optimist or not?
If you are an optimist, you will expect the seagull shape to eventually work itself out, so you wouldn't want to grind the plate too much or put in any epoxy, just yet.

If you are more of a pessimist, you will expect the seagull shape to stay there no matter what, go ahead and grind the plate to fit (to avoid putting more stress on the hull?) and fill any gaps with epoxy.

Not being an engineer, I have to guess that a 3/16" ss plate, held by the wood beam to resist twisting/deflection has got to be a lot stronger than the original 1 1/2" mahogany beam was. Some can probably figure out the strengths using a section modulus (?), but that wouldn't be me. In other words, you are probably fine not making a new beam and just screwing/bolting the plate to the old beam (w/o epoxy) and seeing how it goes with losing the seagull shape. If you lose the shape and someday don't have any other boat projects to do and are bored, you could always epoxy the plate on later.

This probably wasn't much help, but maybe it will give you some ideas....-Tim

tim_klynn · Mar 18, 2011

Just reading Rics post, and thinking that if the wood beam is in a seagull shape, you should be able to bend that back out with the jack and then bolt it to the plate. The beam really isn't that big.

tim_klynn · Mar 18, 2011

Sebastian,
Looking at you photos again, it looks like the main beam is cracked under the numbers. I would definitely epoxy this section.

Also, is the section with the numbers cut vertically above the sides of the door? On my boat, the beam is continuous from port to starboard hull sides, if yours isn't this is most likely a problem.

You are right to have labeled the forward beam as "decorative'. Can't tell how thick it is, but maybe consider laminating it over the beam with the numbers carved in it (fill the numbers with epoxy) on the aft side of this main beam?

Is it possible that someone had cut down your beam to fit the deformed coach roof and that is giving you the gaps once you jack up the center?

dougpol1 · Mar 19, 2011

I would like to look at this problem from a little different point of
view. We think of the Vega 27 as a 1970's boat. Actually the first on
was built from wood in the mid 1960's and it had a lot in common with
folk boats that were an even earlier design. Back then when racing
wooden boats, we had to keep the rigging loose or the wooden hulls would
open up and leak. We tightened the rigging at the start of a race and
often loosened it as we started a down wind leg. I wonder if the
designers of the glass boat were thinking in those terms. Banjo tight
rigging did not become the norm until the late 60;s and into the
1970's. Often more modern deck stepped rigs were supported by a metal
pole or a metal frame that a person would walk through. I don't believe
a wood beam is a suitable support for a mast unless the load is taken
off of it except when racing. If I had to keep a ton of pressure on it
all the time I would replace the wood frame with a metal one.
I don't think Vega is a suitable boat to carry this mast load
continually. She was designed for the 1960's not a 2011 racing world. I
keep my rigging somewhat loose by racer cruiser standards and have been
known to go forward and tighten a turnbuckle if trying to race another
boat to windward. Afterwards I always loosen the rigging again. I think
this is the way this boat was intended to be sailed. A wooden beam under
a heavy load will slowly bend over time, no mater how thick it is. Wood
is very plastic. When you steam bend a piece of wood all you are doing
is speeding up this bending process by using heat.
Doug

n6ric · Mar 19, 2011

Sebastian,
I was talking about 2 different kinds a epoxy. Penetrating epoxy is much thinner than regular epoxy and is what you would want to brush onto the beam over the cracks. Actually, you can coat the whole beam. It does form a waxy coating that you can wash off with soap and water, or TSP, before you do any painting or apply other epoxy. This will also seal the wood and keep moisture out. West Marine carries it in small amounts which would probably be more than enough for you needs.

If you are talking about thickened epoxy, as I mentioned I use West Systems. You need to buy the two part epoxy and mix it as directed. It needs to be thoroughly mixed before you add any fillers. West makes several different types of fillers and for this you would want to use their strongest which is called 405 Filleting Blend Adhesive Filler. You mix it to the consistency of peanut butter. You want it to stay in place until it dries. If there is an opening on both sides where you want to fill in, if the gap isn't too big you can just masking tape to cover the gap. For larger gaps, I use a piece of plywood covered in glad or saran wrap (the epoxy won't stick to the plastic wrap) and tape it over the gap on one side. I've done this a number of time now and it works great. Just give a yell if you have any other questions.

Ric
s/v Blue Max
#2692

pjacobs55 · Mar 19, 2011

Sebastian,
Not that you need any more advice ... there's been some good stuff so far ... but here goes anyway: I would want to have that beam right out and give it a thorough examination. It sounds like the wood has failed somewhere. And those numbers are carved pretty deep.

My choice would be for a new beam to go along with the new steel plate. The beam could be cut by someone (or a shop) with a bandsaw quite easily.

My beam has a slight gull shape, too.

http://www3.telus.net/sailing/beamaft.jpg

Also, I have a vertical stifener, to keep the bulkhead from buckling, on either side of the door. These do not extend to the floor.

http://www3.telus.net/sailing/beam_stifener.jpg

My beam consists of a 1" thick beam, a 3/4" plwood spacer, and another 1" thick beam. Both beams are hardwood. And it's a real head whacker!!

Peter
#1331 'Sin Tacha'

o2n7dcolin · Mar 19, 2011

Yes I would change any wood that has cracked. I have a total thickness
of 3 inches, all oak except for the bulkhead. These layers have been
bolted together with about eight 1/4" bolts after applying epoxy. This
makes a strong laminated beam. Colin... V-703, Isis.

tiempo2010 · Mar 19, 2011

If using West epoxy both 404 high density filler and 406 colloidal silica
are stronger than their 405 filleting blend.

tim_klynn · Mar 19, 2011

The exact brand of epoxy probably doesn't matter too much. The choice of fillers is probably more critical. Microballons (hollow glass of phenolic spheres) are great for adding bulk or thickening the consistency of epoxy, don't absorb water, form a lightweight "easy" to sand hardened epoxy that doesn't sag. The draw back is that it is not so strong and would be the most likely to crush.

Collodial or fumed silica will form a harder stronger finished epoxy, it will add some thickness, but tends to flow or sag.

You can add ground fiberglass or chopped fiberglass to the epoxy to make it stronger as well.

Wood flour can be added for a thickener, but it might absorb water.

I've had pretty good luck with MAS epoxies, but usually buy the additives generically.
MAS and probably the other mfgs has some youtube videos and info on their website.

I've had good luck mixing 10% alcohol to MAS's thin epoxy and injecting it into rotted wood on old house restorations to restore some structure to ornate rotted millwork.

Epoxy is very temperature dependent. Don't mix too much at once, as the bulk of the mix seems to exponentially speed up the setting reaction and the whole things sets off quickly on a warm day. You can't increase and decrease the amounts of catalyst to control the setting time as you can with fiberglass resin. You can buy epoxies that are fast or slow setting. Use a slower setting if it's hot and faster if it's cold. Good luck -Tim

tiempo2010 · Mar 19, 2011

I use West's slow hardener exclusively - 206. It gives me more time to work.

Often I mix fillers, for example colloidal silica and 404 high density
together until the consistency I want. Many say colloidal silica in the mix
makes it harder to sand, but with plastic tools or a gloved finger it is
easy to get it just where you want it so sanding extensively isn't required.
Any excess is cleaned off before it sets.