tear down finally begins

[Ironworker]

It was actually easier than I thought to glass those gunnels from underneath. We did it with the floor out which provided some additional room. I also bought some cheap deep throat C clamps from HF to hold the coosa up while it was curing.

I also cut a 45 degree section that filled out the corner between the gunnel and side of the boat which helped.

I have been promising to add some photo graphs of my boat which I will start on the next couple of days. There might be something you can use. Its still not completely finished but its far enough along to get the basic idea.

I will say the three big changes was widening the flybridge (Thanks Bang O Rang) along with getting the step down removed, widening the outside chine to add a spray rail and opening up the gunnels.

[Snipe]

Well that is a tear down for sure. I understand the snowball affect that cost me 6 years of solid work every minute I could but so well worth it in the end. Keep the pictures coming it’s great to see so many members bringing our boats back to life again.

[S Ritzert]

Catching up on a few photos. I haven't been able to spend as much time on the boat as I would like, but slow and steady wins the race! I've been trying to get all these old repairs ground down, and searching for the HIN still. Hopefully I can start going back together soon

[Oldcreek]

Great photos.

Any deflection of the hull with the cap off and the bulkheads gone? I've considered pulling mine or, at least, removing all the bulkheads at the same time...

(I've got the hull blocked up really well.)

[S Ritzert]

Not really a lot of deflection to speak of. The hull of that thing is tremendously strong. The sides did spring out a bit, but they will go right back in place when I reinstall the cap. I have mine sitting on a trailer, and did bunk it about as perfect as I could before really cutting to much out, and to help maintain the shape of the boat. When I start the stringers, I will do one stringer at a time to minimize any deflection.


The cap on the other hand is not very strong at all. I am trying to flip it, and every attempt that I make to flip it gets to the point of being disastrous. The cap fiberglass is about 3/16" thick in fiberglass, with about 1/4" wood core that is rotten, and probably about 1/8" in glass over the core. The bow of the cap is extremely heavy. I bet center of gravity on the cap, is about 8-10" foreword the dash. I am going to have to end up building a wood support frame for the cap to get it flipped.

[Ironworker]

The cap is not very strong. The various components were put in place with gobs of resin putty then a layer of glass over the joints. I give you credit for pulling the cap. I never would have attempted to do that. I spent a lot of time installing glass upside down.

Regarding the stringers...I didn't have any rot in my stringers except in the cabin area. The engine bedding had rot where they did the diesel conversion but the original Bertram wood was good.

[S Ritzert]

The cap is not very strong. The various components were put in place with gobs of resin putty then a layer of glass over the joints. I give you credit for pulling the cap. I never would have attempted to do that. I spent a lot of time installing glass upside down.

Regarding the stringers...I didn't have any rot in my stringers except in the cabin area. The engine bedding had rot where they did the diesel conversion but the original Bertram wood was good.

I really want to shave all the rotten core, and bad glass out of the cap, and go back with glass only, nice and thick and rigid. I'd like to glass in a plate at the bow to hold the windlass, and cleats. The only way I would feel comfortable doing that, is to flip the cap. If I cannot get it flipped though, I will have to do it upside down.

[Ironworker]

I may have some photos of the coosa plate that I added in for my bow pulpit and windlass. I'll see if I can find some. I actually added a new layer of glass to the bow and gunnels ls primarily for cosmetic purposes, but it did stiffen up the bow along with the backing plate that was added. When I added the new coosa bulkheads, I fitted them to stiffen the bow deck as well.

[Ironworker]

I may have some photos of the coosa plate that I added in for my bow pulpit and windlass. I'll see if I can find some. I actually added a new layer of glass to the bow and gunnels ls primarily for cosmetic purposes, but it did stiffen up the bow along with the backing plate that was added. When I added the new coosa bulkheads, I fitted them to stiffen the bow deck as well.

[Ironworker]

BTW, you probably know this but the two halves of a 31 hull are not symmetrical. The halves of the hulls are different and the caps are different as well. Mine was off about 1.5" or so on the hull and maybe a little more on the cap.

The average person would not be able to see it but I sure can. Just be sure that if you're working on the hull and cap separate that you will be able to join it back together.

The differences in the halves of the hull requires some thinking when installing the rudders and engines.

[S Ritzert]

I have seen handcrafted boats not be symmetrical. I cannot say that I was aware of this on the 31. Is this difference because the boat was hand crafted, or is this by design?

This would probably explain why it was such a pain in the ass to bunk the trailer properly. I cut each bunk the same on the trailer, and marked out each bunk anchor the same, and bolted them all in relation to each other, and I still had to make adjustments and special cuts to make the boat fit the trailer right. I did assume it was the way the mold was supported when it was laid up, but I did not think it was a "by design" issue.


Back in the very early 90's Mastercraft did not properly support their molds on a particular model of on of their boats, and those boats looked "twisted" because of the support issue. I am aware that back before cnc mold building, and proper layup that no two boats, or two sides of the same boat were ever the same

[Ironworker]

Other guys on this board knows much more about this than I, but it's my understanding that when they built the 31 hulls they were built into two halves then joined together. If you find the center line of the keel as best you can then, draw a plumbline up the inside of the stern you will have a place to start working from. Then measure out to known distances along the sides you're going to find some discrepancies. The boat tracks from the centerline of the keel. Then you need to start measuring along keel centerline to locate a balance of the engines.


When I built mine back, I leveled the boat the best that I could, then averaged where the engine bulkheads were placed. The issue may arise when you fit the cap back. BTW, there is a thread about this somewhere on this board where we discussed it.

I saw an Youtube thread today about a tool called an Milwaukee 360 that would be a perfect laser tool for a project like this. Check it out.

[S Ritzert]

That's interesting that they built two halves, and joined them together. That explains why the center line is so distinct where I sanded the transom of the boat. I assumed that center line was a past repair or something.

I have been taking measurements and checking what is level and true as I tear down. I intended to get both outside stringers level for and aft, and port to starboard before I cut a stringer out, then do the same on the inside stringers. I think we are thinking alike on that aspect.

I actually have a similar tool, but Bosch is the manufacturer. I was going to use it to line my bulkheads back up.

What search word should I use to find the thread you are talkin about?

[Ironworker]

I don't know. I tried "Bulkheads" which is a great thread to review.

I'll search around. Perhaps someone will come along and tell us. Use the advanced search.

[Tony Meola]

I don't think the boat hull was built in two halves. I believe there is thread here on it.

It was my understanding that the mold was two halves that were clamped together then the boat was laid up. The two halves separated and the the hull removed in one piece.

But then again, I might be mistaken. I think Tommy knows for sure.

I see the boat was documented. Perhaps if you are looking for the Hull number, maybe the Coast Guard has it recorded on their documentation site. It's been a while since I have been on there, so I am not sure if they recorded the Hull Numbers.

[Craig Mac]

Tony is correct. It's a 2-part mold. The hull is laid up as one piece

If it were a one-piece mold, the hull would not be able to be popped from the mold.

[Carl]

Tony is correct. It's a 2-part mold. The hull is laid up as one piece

If it were a one-piece mold, the hull would not be able to be popped from the mold.

Tony and Craig are correct the boat was laid up in one piece. A two part mold was used as the hull would not release from a one piece mold due to the tumblehome.

The hull being laid up in two pieces and glued together has been a tall tale going around for many years. The last time I recall hearing that two part hull story, Captain Patrick stepped in and set the record straight going over the how and why.
Kinda glad I don't have to worry about the halves splitting apart anymore...lol

[Tommy]

Carl,

Text me your cell # to (919) eight-eight-zero - 0832 and I'll text you a picture showing the 2-piece mold pulled apart and the 1-piece hull so you can post.

[Ironworker]

Thats good info to know about the 2 part mold. Now can you all shed some light on the asymmetrical aspect of the boat?

[Carl]

Pictures supplied by Tommy.

Thanks for the pictures. I'm not sure where you get all this information, but glad you do and gladder you share. I'm not sure gladder is a word...

[Carl]

Picture supplied by Tommy

[Tommy]

Rick,

Regarding the port and starboard hull sides being assymetrical, the original Bertram boat was hand built out of wood the old fashion way:wood framed, planked and finished in plywood. When it performed so well in the Miami-Nassau ocean race, Dick used that actual wooden hull as a "plug" to create the mold for the manufactural process. Since the original hull was "stick built", there would be some human error in the dimensions. The assymetry was not intentional.

[S Ritzert]

Tony, when I found that documentation number, I checked the USCG records on it, and they did not have a hull number listed.



The 2 part mold makes more sense to me. I've seen multi part molds utilized when the shape of the product being made cannot be pulled out of the mold. The barrel shape of the Bertram would make it difficult to release from a conventional mold.



Tommy, Thanks for the pictures! I figured the asymmetry is just a part of hand crafting. Back then they would build a plug by hand, pop a mold off the plug, then hand lay the boat. We didn't have the CNC milling and laser measuring that we do now.

[Ironworker]

It was also my understanding there were several boatyards that were making these hulls well. Is that the case?

[S Ritzert]

I've seen decks, soles, bridges, and windshield frames being made aftermarket, along with other items. I have not seen a hulls being made aftermarket. The identifying thing for me is the old green polyester resin. I think my hull is original, I really think the deck is aftermarket, and the bridges is aftermarket.

One of the members on my thread mentioned that the deck is original, and the live well was added to the original deck. After some deck grinding, I disagree with that assessment, but I am not a Bertram 31 connoisseur either. I will take yall's word over my thoughts on these boats any day. The deck is full of voids, and poor laminate. I think someone laminated the deck half way, and finished laying it up when after the first half cured, and didn't use a laminating resin in the process. I am not impressed with the deck at all. The glass is polyester resin, but not green. If they added that live well after the fact, the only positive thing I have to say about the deck, is they did one hell of a job with the glass lines, and didn't use a bit of filler to fare those lines in.

I will post some pictures of it when I get a second

[Dug]

I'm a little late to this party, as its been a while. I have to say WOW on this project! Holy cow you are digging deep! I can't to see the final project results!

Dug

[Tommy]

Shannon,

I'm the guy that said "...the deck is original...", but based on your tear-down, I stand corrected! I had seen several renovated 31's where the crafstman had cut and glassed a baitwell into the original transom deck, and assumed yours was similar. ("ASSUME", makes an ASS out of U and ME). But clearly, your deep dive into the de-construction reveals an after-market product.

Also, your observation that the 31 has a "barrel shape" is accurate, and as Carl noted, that nautical design is called a "tumblehome".

I am not aware of Bertram 31 hulls being built anywhere but their Miami plant from 1961-1983 (and a 25th Anniversary limited run in 1986). A company in Australia operating under the name "Caribbean" was licensed to build some Bertram-designed boats, but not the 31. This is from their International Marine website:

"International Marine is one of Australia's oldest and largest FRP boat manufacturers, have been manufacturing boats in Melbourne, Australia since 1958. In our proud history of boat building, we have manufactured well in excess of 50,000 boats. Over this period we have manufactured many brands including Columbia Yachts, Pride Sports Boats, Bertram and CARIBBEAN. Currently, all our boats are branded under the name "CARIBBEAN"."

[S Ritzert]

Tommy, no ASS at all man, like I said, I'll take yalls word over my "assumption" any day. I appreciate all the information in here.

The tumblehome shape, and the way the flybridge fits the boat, and the curved windshield are the line I absolutely love on the 31's. All the boats now adays look like F-17 stealth bombers. I am not a fan

[Ironworker]

My boat is listed as manufactured by Halter Marine in Miami.

BTW, I have two 31 windshields that are free

[Ironworker]

My boat is listed as manufactured by Halter Marine in Miami.

BTW, I have two 31 windshields that are free, Actually not the cabin glass but the spray screen for the flybridge.

[S Ritzert]

My boat is listed as manufactured by Halter Marine in Miami.

BTW, I have two 31 windshields that are free

I am fiberglassing mine in. I am installing a head port and forward, where the "dash" used to be. I cut the dash out.

Are they Glass? I thought someone claimed them already.

[S Ritzert]

here's some shots of the deck where I was grinding out the rod holder, and started running into voids, and poor lamination

[Ironworker]

I added a layer of glass to the entire bow and gunnels. After, I started looking at the condition of them, it made more sense to just glass the whole area. In addition, I added a layer of 1/2" coosa underneath the gunnels to reinforce the rod holders. I bought some heavy duty swivel holders from LT Marine products, which I highly recommend.

[franzmerenda]

I am fiberglassing mine in. I am installing a head port and forward, where the "dash" used to be. I cut the dash out.

Are they Glass? I thought someone claimed them already.

Shannon, I tell you that fiberglassing the windshield frame, means making of it a strong structural component, not screwed but bonded both on deck and flybridge; this brings a huge bonus: all deck deflections and bouncing on the bow, disappear.
Not only: this allow cutting left/right part of the dash with no concern.
Moreover: due to improved stiffness, both bulkheads for dash supporting and cabinet can be removed, with significant head floor enlargement.
Last but non least: head bulkheads brought structural improvement to the whole area

[S Ritzert]

Shannon, I tell you that fiberglassing the windshield frame, means making of it a strong structural component, not screwed but bonded both on deck and flybridge; this brings a huge bonus: all deck deflections and bouncing on the bow, disappear.
Not only: this allow cutting left/right part of the dash with no concern.
Moreover: due to improved stiffness, both bulkheads for dash supporting and cabinet can be removed, with significant head floor enlargement.
Last but non least: head bulkheads brought structural improvement to the whole area

Yessir, That is pretty much exactly what I am doing.