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Apr 10 09 11:34 AM

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Most first generation Bristols have deck stepped masts and the steps are constructed in the same way. Starting from the exterior cabintop and working down, the steps begins with an aluminum shoe (which can be replaced from RigRite or from Metalmast Marine, if you need to replace it) that is screwed to an exterior.  The brace is glassed and gelcoated as a part of the exterior of the boat. Under the gelcoat the brace is solid mahogany with a mild steel plate. There is no balsa coring in this area of the cabintop—simply hardwood thru the surface of the cabintop. This brace forms the top of an arch; the two legs of the arch being the two vertical frames of the head doorway. These vertical frames are 4x4 solid mahogany that extend down to a fiberglass pan that consititutes the cabin sole. Under the pan will be two wood supports that brace the underside of the pan to the top of the encapsulated keel.

The maststep structure is very sound on most of the old first generation boats—if anything the whole structure is overbult for the amount of stresses involved. There is one area of concern that should be checked:

The masthead of most of the older boats is open, allowing rain to run down the inside of the mast and accumulate at the base. The water here can work its way under the rubber seal for the electrical plug and seep down into the wood brace. To  check to see if water has leaked past the plug:

Step1: Look for dark brown streaks around the aream of the fiberglass overhead in the vicinity of the head door (the streaks are caused by the mild steel plate in the mast step brace rusting.

Step 2: Remove the #10 oval head screws from the wood trim in the vicinity of the head door and see if the threads are rusted.

To prevent additional water from seeping into the maststep, drill a drain hole at the aft end of the mast even with the top of the shoe to let any accumulated rain water escape. Alternately and a better, albeit more expensive solution is the have an enclosed masthead built for your mast.

There are certain signs of movement in the maststep support system. 

1. Spyder cracks in the gelcoat around the support brace on the cabintop. Look for a problem with the support brace.

2. Spyder cracks in the gelcoat of the floorpan around the forward or aft edge where the sole meets the forward or aft head bulkheads. Look for a problem with the supports under the floorpan that tie the support arch verticals to the keel.

3. Head door not closing or opening properly when the boat is hard on the wind and the rigging is under stress. You have a problem somewhere.

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reuben

Able Bodied Seaman

Posts: 20

#1 [url]

Jun 11 09 1:36 PM

David,

I definitely have a problem with the mast step. the aft door frame for the head is buckling slightly to starboard, The head door is not closing properly, and there are definite cracks in the gel coat around the step. I haven't begun to dig yet, but I have a feeling I am going to be doing some major structural repair. We didn't notice any of this until we got the mast stepped and the rig tensioned. there is noticeable distortion in the headliner at the head doorway.  It also apears that the cabin sole is collapsing slightly which makes me wonder if the problem might be in those wooden c posts. that go down to the top of the encapsulated keel.

any thoughts about where to start digging?

Reuben

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#2 [url]

Jun 11 09 6:19 PM


Reuben,

It sounds to me that the problems are at the keel end of the maststep not at the mast / top end. The cabin sole dropping is the giveaway. The way the structure works is that the arch of the head door terminates in the fiberglass structure of the cabin sole pan. The pan is bracked underneath with a series of wood blocks that are stached on top of the encapsluated keel. The blocks are glassed in place but very poorly situated. My guess is the blocks have rot and allowed the head door structure to be pressed down which causes the door to get cocked and the headliner to sag. Pull up the sole hatch in the forward cabin and in the saloon and look under the sole with a flashlight and you will see the blocks. To repair it properly you will probably have to cut the sole out from in from of the head, do a proper repair and then repair the sole. I have some photos of the blocks on my boat if that would help.

Now you should also check for water saturation in the maststep brace above the deck. If you read about the mastep here you will see that there is a tendancy for rain water to work its way down into that brace by getting past the wiring plug. The first check is to pull out some of the screws that hold the mahogany trim in place above the head door, and check for signs of rust and / or wetness.

Restoring a Bristol 29 in my backyard. www.bristol29.com

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reuben

Able Bodied Seaman

Posts: 20

#3 [url]

Jun 12 09 9:47 AM

David,
    Thank you for sharing all of your hard won know-how. It is such a treasure trove of hard to find,very important information.

I looked under the cabin sole, and to my astonishment, there seems to be nothing but air between the keel and the molded pan that the head door posts are resting on.

I have no idea why they would be missing altogether. there doesn't seem to be any indication that anyone has cut and repaired the sole. There is what appears to be glassed-in sockets of a thwart member that has obviously been removed, but it is forward of the head in that access cavity in the forward cabin.

Hmmm. very mysterious. I believe that my course of action is going to be cutting the sole there by the head, and building up compression members of some sort to meet the underside of the head door beams. I am going to want to provide some "push back" against the sag that has occurred--maybe with bottle jacks or something.

thanks again,
Reuben


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#4 [url]

Jun 12 09 10:00 AM



If those plywood blocks are missing (mine has a stack of them under each vertical post) then that would definitely explain the sag in the sole pan in that area. I would do exactly as you are planning, to cut out the sole in that area, and I would use ipe or teak blocks glassed in place with thickened epoxy and make it a forced fit to lift the sole pan back up to its neutral position.
 
To be a bit more elaborate but have a stronger brace for the doorway arch and step arrangement, you could consider installing two athwartship floors with linmber holes that span the width of the keel, under the two uprights, and act as steps for the uprights and a sub-floor for the sole you will reinstall (if that makes sense).

Good luck,

David

Restoring a Bristol 29 in my backyard. www.bristol29.com

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reuben

Able Bodied Seaman

Posts: 20

#5 [url]

Jun 14 09 3:49 PM

David,
    Again, I can't tell you how much I appreciate having someone to talk to about all of this that really knows their stuff, and is so intimate with the B29.

I understand you perfectly about the thwartship floors. in fact, there is definitely glassed-in areas where there used to be a thwart, but it is not directly under the head door--It is forward--curious...

 I have done something similar on our ministries' flag ship (Wellington 47--that resides int the Chesapeake). I had to glass in some thwart members for an engine bed. So if that is the necesary proceedure it isn't beyond comprehension. It just seems a little tricky doing the glass work up under the head pan.

 I do think I like the simplicity of the ipe or teak blocks, and that seems to lend itself well to building up a force fit. Maybe I could build up the columns to about 1.5 inches shy of the point of contact with the head pan, and then cut a final block into two opposing wedges that could get thickened WEST system between them and then C clamp them into each other on top of the column. This would effectifly create a jack out of the last block that could simply be left in place.  This would also allow me to crank up the step to exactly where I want it by cranking the C clamp.

I will have to cut the sole of the Bristol and study it for a while to see what is what.

Thank you again for your help
Reuben

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#6 [url]

Jun 14 09 6:13 PM

Reuben,

The wedge idea sounds good if the mast is stepped. If it isnt, the sole/floor pan will probably seek its own neutral position, and the blocks can just be a nice tight fit--everything glued in with lots of thickened epoxy of course. I was thinking to use a lever under the head door uprights if the mast was stepped, but I like your approacch better. I would think without the rigging in tension, that the blocks would not have to push the uprights and the sole up much--it is more a case of not allowing the structure to be pressed back down again when the rigging is tightened and the boat sailed hard,

Good luck and post pictures when you get a chance,

David

Restoring a Bristol 29 in my backyard. www.bristol29.com

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reuben

Able Bodied Seaman

Posts: 20

#9 [url]

Jun 15 09 9:16 AM

We have worked out a hand stepping system if you happen to be refitting your vessel on a remote island with a shoestring budget like we are----Caution it isn't easy!


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#11 [url]

Jun 15 09 12:43 PM

Great pictures, Reuben...thanks so much! Very impressive that you can step a B29 mast by hand, without even a bridge for help. Necessity certainly is the mother of boat repairs.

It is a bit hard to tell from the photos but the mast does not look original--certainly the spreaders are not and the mast has a more boxy look than the original mast. Is it the same length as the original? 

She looks like she has Beckson ports and opening ports in the saloon?

Please feel free to post as many pictures as you wish. We would all like to follow the work you are doing.

All the best,

David

Restoring a Bristol 29 in my backyard. www.bristol29.com

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reuben

Able Bodied Seaman

Posts: 20

#12 [url]

Jun 15 09 2:03 PM

Dave,

    I do believe that the mast is not original. The spreaders are hand made by me out of Brazilian ironwood. I am going to shape them and reduce a little of the weight aloft. The mast was 37'. The goose neck was a homemade contraption with a wraparound stainless attachment thing. When we pulled the gooseneck off the mast was completely corroded through underneath. Fortunately, I had your dimensions and I knew that yours was 34' 10" something. So we cut off 3' of the mast and it is now 34'.

I do like the portholes--but the plastic is fogged.

Much more to discuss about the mast,

Reuben 


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#13 [url]

Jun 16 09 6:07 AM


The nice thing about Beckson is that every single part for their windows is available to order. Also I imagine that the fogging can be buffed out with any of a number of polishing compounds made for that purpose. Once you get them clear again, or buy replacements, Clean them regularly with Pledge furniture polish and it will keep them from fogging.

Restoring a Bristol 29 in my backyard. www.bristol29.com

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#14 [url]

Jun 16 09 6:32 AM

Reuben,

Another thing about the mast--you may already know this or delt with it so please ignore if you have: on the Bristol mast the spreader sockets are thru bolted thru the mast with two 1/2" stainless bolts. There is no compression sleeve inside the mast as the wall thickness is thick enough to not need compression sleeves. Check the wall thickness of your mast and compare it to the thickness of the Bristol mast--you can find that number on the dimensions page on my website. If the thickness is close then it shouldn't be an issue.

Dave

Restoring a Bristol 29 in my backyard. www.bristol29.com

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reuben

Able Bodied Seaman

Posts: 20

#15 [url]

Jun 17 09 7:15 AM

David,

Here is what I had to start with as far as spreaders and sockets. I had to totally refab something to approximate what was there. We also had to move the spreader location up proportionally when we cut the mast. There were aluminum sleeves around the 1/2 inch bolts that I assumed were compression sleeves. I replaced them with stainless tube stock that a local mechanic friend gave me, but I am not sure how they really oppose spreader compression forces because they are the same diameter as the holes they enter the mast by.




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#16 [url]

Jun 17 09 10:54 AM

Reuben,

The compression tubes take the forces involved instead of the mast walls. I don't see any downside to having them installed. The spreaders look very beefy and should last forever. One thing that needs to be addressed regarding the mast step on deck are the cracks in the gelcoat, like this:


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Restoring a Bristol 29 in my backyard. www.bristol29.com

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reuben

Able Bodied Seaman

Posts: 20

#17 [url]

Jun 17 09 7:19 PM

David,

As to the cracks, I assume that I will take a flap disk on a grinder and feather each crack down to laminate, and then build back in with thickened WEST and 404 or something similar--then prime and paint all with one part eazypoxy?

any thoughts?

Reuben

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#18 [url]

Jun 17 09 8:12 PM


Reuben,

I would first drill some quarter inch holes into the cracks thru the top layer of glass and thru the core to see if the core is wet. I would also drill some holes into the raised mast step to see if water has worked thru the cracks. Assuming there is no core saturation then your steps will work fine. If there is saturation I would first assess how far the saturation has spread and how badly the core is damages (if at all). While you are at it, overbore the holes for the forward hatch hinges and fill with thickened epoxy. Then redrill the holes for the hinges. The hinge area becuase of the stresses involved is a very popular place for core saturation on many types of sailboats.

David

Restoring a Bristol 29 in my backyard. www.bristol29.com

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