1973 Tsunami to Center Console Conversion
 

Ok so I picked up a 23 Tsunami/Scepter for short money and I am looking to convert her to a center console, pretty much the same way this boat was done except without the livewell. http://s728.photobucket.com/albums/w...view=slideshow


So for my first few questions: Does this fuel tank look like stainless to anyone else? Whats the chances that the "314" written on top of the tank is in fact the grade of steel used?

It looks like provisions may have been made to allow for "breathing" around the tank to prevent corrosion.

I am on a very tight budget and would rather not fork out 1k for a tank but at the same time, I don't want to die in a fiery explosion. Which of you forum members would risk keeping this tank? Thanks

The welds in the second picture, along with the fill elbow makes me want to say yes.

Actually I meant to say it's a vent elbow, my mistake.

stainless steel is a poor choice for a fuel tank- stainless is prone to failure at welds,along with it being prone to crevice corrosion...

Boats gonna be put to the test so I'm trying to think ahead a little.

Will a .25" Moeller Cross linked poly tank hold up to the abuse of daily pounding offshore?

welcome aboard. where you fishing out of? show us some pictures of the boat as she sits now. what's your plans for power. just remember to take on 1 part of the project at a time,complete that then move on to the next.

Hi Kneedeep, I'm on Cape Cod. The pics don't look like much, but I must say I am extremely impressed with the solidness of the deck, and the general condition of the gelcoat.

The only real structural issue I have found is with one of the engine bed/mounts. It seems like the mount is delaminated, i'm guessing it got water in a bolthole and freeze/thaw cycle did it in. Should be an easy fix.

Probably gonna throw a gm small block and use the I/O the PO had rebuilt.

BTW your project gave me the grapes to tackle it, thank you.

If you don't mind me picking your brain I have quite a few questions to ask about how to make things go smoothly.

The 73 Tsunami was damn near perfect. Hate to see one get carved up, but hey, it's your boat. Any chance I could get the balance of the cap, bulkhead and windshield from you? For cheap?;)

Good luck with your project. Knee Deep did a heck of a job! I'm sure he'll be a tremendous resource:cool:

Mcgillicuddy, if, i'm correct you are on the west coast? Might not be cost effective to ship 3k miles.lol If you are close by PM me and you can come check out what I have. I am trying to toss out as much as possible so it doesn't create to much of a pile as I work. Point being don't waste time getting back to me.

Cabin, bulkhead, and windshield are off. I unbolted the center section of the windshield, slid it out, and cut the cabin in half. It was too heavy for me to manhandle in one piece.

For those who may attempt this, a valuable tip is to screw a piece of 1x6 to the circular saw base, this raises the saw guide enough get the blade a little closer to the curve thus saving more usable rail. It also lets you guide the saw from a better location.

I used an old carbide blade, cut through like it was nothing, with very little dust compared to a grinder/mason blade.

try and make your cap follow the lines of the front deck where your toes meet the inliner,you want to be able to stand straight up against the bolster. you need to mark a line 3 or 4'' behind the front bulkhead across the top of the cap. maybe 8''on both sides of your center line

Yeah, You're right never mind. Carry on. :o

Thanks for the pointer Kneedeep. I get what you are saying, I definitely want to be able to lean against the rail, makes for a much safer feeling boat. Did you router the edge of the PVC board? What kind of release agent did you use? The stuff they sell up here isn't completely smooth.

I have absolutely no experience with I/O's, and I am a little overwhelmed prospect of re powering.

I was kinda thinking I could find a used GM vortec engine and buy a simple harness/pcm and drop it in, Is this doable?

Also the engine mounts seem to be hollow and kinda flexible kinda like they have been compromised. What would be the best way to go about fixing this problem?

I bought the boat without an engine so I did not get to learn by disassembling, but how is the engine actually fastened to the mount?

yes,i think i used a 1/2''roundover bit on the inside edge. used a mold release wax/paste. you could use plywood or mdf with formica for a one off mold. the pvc board i had was smooth on one side wood grain on the other. as far as the i/o goes i can't help you that was the first thing i got reed of. outboards for me. in my boat the motor mount for the i/o was about 4-5 2x6 stack on each other then glassed in. seems to me your giving up a lot of space with a i/o cover,leaning post and a cc. or are you going with a pilot house?

Kneedeep, I kinda like the idea of being able to repower for 2k or less, Pretty hard to find decent outboard for less than 5k. I definitely won't be doing the waltz on board, but it should still meet my needs. Do you think I should cut the whole mount out and start new, or should I cut the top off and pour in seacast or such? Is the motor lag bolted, or where studs/bolts placed when the mounts where set?

You don't want to use an automotive engine in an I/O for a number of reasons. First, automotive starters and alternators aren't ignition protected. Second, the cam/valve timing is different on a marine engine. You should be able to find a decent used marine engine for under $5k.

The engine mounts to the inside of the transom assembly and to the forward motor mounts. The forward mounts are height adjustable. Do yourself a favor and buy a factory service manual for the engine and drive.

Dave

j i would take a die grinder with a 3'' cut off wheel and cut 1 1/2'' down from the top all the way around it and remove the top layer. see if it's solid wood ,if so add a new top layer and re glass. if it's wet keep removing it. the mounts in my boat were lag bolted with ss lags. you may find the need to move the center console a little farther forward to offset the wt you removed from the bow and maintain your waterline and may pick up some space behind the leaning post too

Thank you both. Blue Heron, how can the timing be different? I can definitely see needing ignition protected components however. Thanks

Less overlap on the exhaust valves so it doesn't suck water back up the exhaust. I'm not much of a motor head, that's just what I've read.
Dave

Kneedeep, do you mind telling me what type of resin you used on the rails? I am sure epoxy is recommended but will polyester/vinylester get it done and stand the test of time? Its a pretty big fabrication to use all epoxy!

One more thing, will I be better off hand fairing with a long sanding board or is there a preferred power tool for this?

You can use an automotive engine, I would just suggest changing the camshaft to a marine profile. Usually a high lift, short duration with a stretched out lobe separation designed for torque. Not to go all technical, but usually an R/V cam works well. You don't want a choppy cam like in a street car because they only flow well at higher r.p.m.'s. You'll want the cam to be smooth and designed for power between idle and say 4800 r.p.m. or so. It's way cheaper to change a cam than buy a "marine" engine if you're trying to save a few bucks. Use marine electrical equipment such as starters and ignitions like blue heron said but you can use an automotive engine. I've been doing it for years. Look into freshwater cooling though. It's worth the thousand bucks or so.

How about this: 3/8 Coosa, glass on one side, fair, and call it a day? Do you think the coosa would be strong enough glassed on one side? Sorry for all the questions, just have a lot of things to consider.

Thanks CAT, sounds right.

I can get Chevy Marine V8 long blocks for a good price with water pump and all, approx 4500-5000, new from chevy

j i have never used expoxy on anything i have ever built. as far has the fairing goes yes on the long board, air file too if you have a big compressor. i would not go with 3/8 coosa with glass on one side only. 1/2'' or 3/4'' nida core or divenacell would be good for that part of the cap with layers of 1708. i wouldn't cut corners with the glass work, people stand ,sit and jump off the dock on to that part of the boat. it's a large area that is not supported by much other than the front bulkhead for along way. everything you build should be glassed on both sides composite or wood a sandwich construction is by far better. the side where the bolster goes is just 1708 glass 3-4 layers, the white is the nida core later covered with glass.

I guess there is no getting around popping the cap,:(

j once you remove the drain tubes in the back corner boxes,the rub rail & a few other screws that hold cap,inerliner& hull together the cap comes off easy. but you can do 90% of the work to the cap before you have to remove. build your one off mold,lay your glass & do all your fairing. remove the cap,flip it over and finish the glass work,flip it back over and prime & paint while it's off the boat.

Kneedeep, did you use a release agent on the PVC? I'm kinda stuck NPI on if I can get away without it. I don't see how I can effectively remove a release agent without water logging all my work. I'd like to glass up the inside of the vertical and possibly add some stiffeners. Seems like a long unsupported run. BTW I chose A/C plywood, mostly for cost and availability, as long as I use care I think it will outlast me. Here's some pics of the slow progress

j looking good so far. i used a mold release paste wax on the pvc. is the plywood a temp mold or is it your core? i was able to add a support made out of starboard under the cap where the old console was at the top of the vent box.

Well, I picked up some 3" wide packing tape and coated the pvc boards with that. Laminated up 2 woven and 3 3oz csm. The mold popped right off and NO release agent cleanup! I started doing the backside.

Here's a question: Is CSM significantly weaker than an oriented cloth? I have a pretty big roll of CSM someone gave me that I'd like to use up. I'm all out of woven :(

Kneedeep, just thinking about the support. Did you stack the starboard horizontally, like a thick shim on top of the vents? Thanks

here's a pic of the supports. on the front vent box you can put them on both sides. dam i need to start washing under the cap.

That support is easy enough. I'm looking to order some fairing compound, what would be suitable. I'm thinking i'm gonna gelcoat instead of paint. Quickfair sounds awesome but I'm not sure how gelcoat will play with it.

any updates on your project

Did you guys ever finish the projects?
 

Just wondering if you ever finished the conversion of the Sceptre to CC?