1980 Master Marine 28' transom, stringers, deck-The itching has begun

[getusummm]

I decided to just start a new post to clean it up a bit and also to resize all my pics.

A little about the boat- It is a 1980 Master Marine "Good Go 28". These were built in New England for Giant Bluefin Tuna fishing. They are a product of Rev Moon. Remember the "Moonies"? Well these are the boats they ran. Who knows how many tuna have bloodied the deck of this boat.

The boats were orignally designed for a single outboard, with most running a 235 OMC. The newer versions offer single or twin outboards, or diesel power.

I purchased the boat on Ebay and I was supposed to be somewhat finished and only needed a little paint and it would be ready for power. I got a really good price and sold the trailer it came with, so basically the hull is free at this point if you consider the price of a new aluminum T-Top. Price was $2600. I sold the trailer for $1000. So basically the other $1600 was the price of the T-Top in my eyes.

Well the boat was in fairly good condition. For the most part the transom was dry and rot free. There were wet areas around the thru hulls and drain. Because of the engine set-in angle, I decided to just replace all the wood inorder to have whole pieces for more strength. The core is going to consist of 3 pieces of 3/4" plywood with 1.5 mat between each layer and then glassed in place using 3 or 4 layers of 1808. Sound good?

The stringers are wet in places, but i have found rot towards the transom. The rot only extends up about an inch from the hull. I am just going to replace them. I will just keep cutting towards the bow until I get to good dry solid wood. While replacing the stringers I am going to install knee braces to connect the upper transom to the stringers.


Here are my plans for the boat:

1) Remove spalshwell completely and completely replace and close in transom. The transom will end up being boxed in basically.

2) Purchase and mount an outboard bracket from Hermco or D&D Marine to mount twin Yamaha SWSII V-76 250HP outboards

3) Remove deck and replace stringers as needed, remove orginal 150 gallon fuel tank and inspect, repostion fuel tank and to allow placement of second 100 gallon fuel tank for a total for 250 gallons. Install new deck

4) Clean up unused holes in console I purchased from Four Sons Marine. It is a walk in console out of a 264 Mako center console. It will end up being cheaper than me modifying my old console considering for $500 it included the hyd steering helm, hoses, and steering wheel, and dual binacle with cables.

5) Build bow pulpit and install electric windlass

6) I may build out the existing bow into more of a point. If I decide to actually do it, I will be asking more questions when the time comes. It would be purely cosmetic and may not be done at all.


Current progress:

The splashwell has been cut out. The deck has been cut out. The top cap over the transom area has been taken off. All wood has been removed from transom and everything has been sanded and is ready for new wood, resin, and fiberglass.


The weather and humidty look good for today, so its time to start glassing.

Well on to the show. Here are the pics to date. Hope you enjoy.

Here she is in the water while i switched trailers




Safety First




Here are a couple before cutting the splashwell






After Cutting Splashwell




More in next post

 

[getusummm]

Re: 1980 Master Marine 28' transom, stringers, deck-The itching has begun




Before Cutting Deck



After Cutting Deck



Top cap off and all wood removed

 

[getusummm]

Re: 1980 Master Marine 28' transom, stringers, deck-The itching has begun

I do need a little advice on this area. This is where the engine mounted and was at a different angle than the rest of the transom. I decided to just cut it out in order to install the continous transom core. I am going to grind it down til only a 1/4" or so is left of the hull thickness on the bottom and feather it out. Then come in with 1.5oz mat and 1808 and fill til level. The transom cutout wil be ground and feathered and then filled using 1.5 mat and 1808 til level with the outer transom skin. Afterwards I will put an addition layer of mat and 1808 on the entire transom outer skin and wrap around the sides and bottom for a better tie in. Does this sound like the best way?






Thanks for any advice guys

 

[Bob_VT]

Re: 1980 Master Marine 28' transom, stringers, deck-The itching has begun

Thank You Looks good. I asked before..... where were you boating when you hit the rocks?

 

[getusummm]

Re: 1980 Master Marine 28' transom, stringers, deck-The itching has begun

I was coming into Southwest Pass near Venice, LA. Jettie had been extended at some point and not marked on my charts. Hurricanes have knocked them down to the waterline. I was not the only boat to hit them that month. A comerrcial dive boat and a crew boat also hit them.

 

[getusummm]

Re: 1980 Master Marine 28' transom, stringers, deck-The itching has begun

Yacht Dr, you mentioned riveting to the existing hull. Are you saying rivet my plywood strips to the hull, then glass both sides? Use a resin based glue mixture to apply the strips, then rivet them in place for a mechanical bond also?

 

[getusummm]

Re: 1980 Master Marine 28' transom, stringers, deck-The itching has begun

Well I didnt get as far as I wanted this weekend, but I did make some progress. I managed to get my plywood cut and fit for the transom. I cleaned them up and laminated them together. I also managed to finish grinding the inside and cleaning it up. I did grind and feather the old opening to make things easier once I get the transom in place. I will still need to grind off the old gelcoat before I lay on the 1808 on the outside skin.

I had to take numerous water breaks. I was basically down to my underwear under my tyvec suit. It is not the normal suit mind you, it is covered in a very chemical resistant coating and does not breathe at all. I had to tape up the sleeves to keep the sweat from dripping out while I was laminating the transom pieces together. Well onto the show

This will give some size to the transom project. This is whats left from a 4x8 sheet of plywood



Cardboard Pattern



3 pieces of 3/4" plywood ready to be laminated together for transom



Sorry, no pics of the laminating process. The sheets were very flat, so I screwed them together on a 6"x6" grid with screws from both of the outer sheets into the inner sheet. It took about 3lbs of 1 1/2" screws. After it cured overnight I removed all the screws and spot drilled using a 7/16 bit. I followed up with a slightly thickend mixture of milled glass and resin to fill in the screw holes.



Outer skin opening ground and feathered

 

[getusummm]

Re: 1980 Master Marine 28' transom, stringers, deck-The itching has begun

Well, between working out of town alot lately, my oldest daughter's softball games, and it just being downright miserablely hot here in Louisiana lately, I haven't gotten too far. I am however getting much closer to being done with the transom. After that, I feel the rest of the work will be a piece of cake, lol. I just dont know how OOOPS, YachtDR, and all the rest of the guys do this for a living.

So to update here are a few pics. So far I have gotten the old core out, ground and cleaned up the inside and outside of the transom, laminated the core together, installed and glassed the core using 4 layers of 1808, and started filling in the outside where the transom well and engine mounting area was. I still need 1-2 more layers of 1808 and 1 layer of 1.5oz mat to build it up flush, then on to fairing. I have already filled all of the transom holes with "peanut butter". They just need to be ground down and a layer of 1808 and a layer of .15 oz mat added. The inside of the transom is done. Next on the list is putting the 2 pieces of the cap back on and connecting them. The reason for building the cap first, is to have an idea of how the knees will need to be shaped. Then on to replacing the stringers and adding the knees to the transom to furthur support it. Then it will be on to the deck and bow pulpit.

Now that the worst of the work is done, hopefully progress will pick up when I am home to work on it, lol.

Well on to the short show:

Core glued in placed using vinyl ester resin and cabosil with a layer of 1.5oz mat between the core and outer transo skin. You can also see where i radiused the corners to get ready for glassing the inner skin.



If you look close you can see where excess glue was pushed out of a couple of holes



Inside glassed in. I used 1 layer of 1.5oz mat followed by 4 layers of 1808. Once the stringers and knees are glassed in, the entire inner transom will, will get another layer of 1.5oz mat. Then the inner transom, knees, stringers, and bilge will get gel-coated (white of course) to help seal everything.



Almost done glassing in the opening. No, I didnt cut the last layer of 1808 to fit. I was very hot and tired by this point. I cut a couple of slits to make it layout. I knew it would be a week or so before I get to work on it again, so it will have to be sanded before the next layers go on. I will take care of the excess then, lol. The outer skin is 5/8" thick, so it is taking quite a few layers to build it up. I really should have just built an insertIf I remember correctly, so far there is 1 layer of 1.5oz mat, 2 layers of 1808, 2 layers of 1.5 oz mat, and 2 more layers of 1808.

 

[jonesg]

Re: 1980 Master Marine 28' transom, stringers, deck-The itching has begun

looks good, still a bit more to fill that transom cavity eh.
I would be tempted to fill with cabosil / chopped mat putty then finish with glass.

watch this slideshow for ideas on your new transom design.
He molded his own bracket ala Hermco style.

http://s728.photobucket.com/albums/ww290/88bowtie/?albumview=slideshow

 

[getusummm]

Re: 1980 Master Marine 28' transom, stringers, deck-The itching has begun

Jonesg, thanks for the link. Lots of great ideas in that one. I have been thinking about building my own bracket for a while. I have read through a couple of threads over on classic mako and classic seacraft on home built brackets. I just cant get the nerve up to build something from scratch using fiberglass and then hanging 500hp and 1000lbs on it, lol. With the work schedule I have coming up for the next couple of months, I will most likely just order one from Hermco or D&D. There is a new guy that is also building some out of fiberglass and trying to sell them for about the same as D&D and about $1000 cheaper than Hermco. I am kinda of leary of being the guinea pig though.

I really thought about using plywood or putty to fill in the cavity, but at this point I am so close to finishing it, no sense in changing anything. A quick grinding session and one last glassing session, and it will be level, ready for fairing.

 

[jonesg]

Re: 1980 Master Marine 28' transom, stringers, deck-The itching has begun

wow $100 cheaper for a bracket wouldn't interest me unless it was used.

The thread by Strick on classicseacraft is a good one , nice workmanship.
Notice his bracket uses plenty of ply lamination. page 11 , I think.
I'd say you've already done the same work, just not in a mold.

 

[getusummm]

Re: 1980 Master Marine 28' transom, stringers, deck-The itching has begun

Jonesg, its $1000, not $100

I will kick the idea around for a while more and may at least try. I guess what concerns me most, is making sure it will be strong enough. Making sure I have thick enough transoms cores, side cores, and the inner and outer skins are thick enough, but yet dont make it too heavy.

 

[jonesg]

Re: 1980 Master Marine 28' transom, stringers, deck-The itching has begun

consider you've built a transom that your gonna bolt an engine to, its the same thing with a set back.
A 3 inch transom in the bracket will hold 3 engines, sidewall thickness is as thick as you decide to make it.

They recommend a 30 inch leg for brackets, thats why I didn't attempt it, I have a 20 inch leg. So I built a higher splashwell backwall instead.

 

[getusummm]

Re: 1980 Master Marine 28' transom, stringers, deck-The itching has begun

I have recored and closed in the transom and am moving on to the rest of the boat finally. Right now I am working on the stringers. I have removed 16' so far and will be cutting out the bow fishbox to see how much furthur I need to go to hit dry wood.

My question concerns the actual building of the new stringers. This is my plan as of now, unless someone gives me a better idea. The orginal stringers are 3/4" or 5/8" plywood encased in woven roven and tabbed to the hull. My plan is to use 3/8 or 1/2 plywood laminated together with the joints stagered every 4 feet, then bed the stringers to the hull using cabosil thickend resin. After that I plan to cover the entire stringer and extend the material at least 6" on each side of hull using 1808 biaxial and vinylester resin. Sound good? Or would I be better off using 3/4 plywood scarfed and glassed in?

If I go the 1/2" laminated route, do I need th scarf the joints? If so, how long of a scarf and what is the best way to scarf them?

Thanks for the help,
Patrick

 

[jerseysportfisher]

Re: 1980 Master Marine 28' transom, stringers, deck-The itching has begun

looking good so far, this thread caught my eye, i also have a 28 master marine i want to close off the transom , bracket it and put twins. Keep the pics coming.

 

[legoman67]

Re: 1980 Master Marine 28' transom, stringers, deck-The itching has begun

another larger boat.. Welcome to the club there was another one like yours that was finished not so long ago. here is a link to the thread

http://forums.iboats.com/showthread.php?t=271420