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  #1  
Old 09-16-2004, 05:10 PM
James Francis James Francis is offline
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Inboard to outboard conversion

For anyone who has attempted this type of project, what type of structural glass work is recommended at the transom? The 22 CC I have actually came in two models - an inboard and outboard version. Same Hull design - so I am not too worried about the handling/trim changes to the boat underway nor a puritanical viewpoint that a conversion will destroy the boats character - the original manufacturer thought the boat would be great as an outboard as well.

The outboard version hangs the engine right on the cut out transom but I am considering a bracket. The Transom on the inboard is obviously a full transom made of of about 3/4 of inch glass/mat and chop. - pretty beefy but probably not enough to hang a bracket and engine. I plan on adding some beef in the form of laminated plywood epoxied to the existing transom with the added reenforcement of knee braces glassed in. Any ideas would be appreciated.

Jim
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  #2  
Old 10-04-2004, 11:57 AM
Tall Timber Tall Timber is offline
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I rebuilt the transom extra heavy then through bolted to structural aluminum angles 3X5X1/4 and c channel 2X5s bolted to the inside of the boats at the engine bed and just below the joint between the top and bottom just forward of the stern. My boat was a I/O with no cutout. The bracket I drew and got waterjet cut at IRC and welded by L&M here in Oregon. A store bought one would sure save time and figuring. It is looking great, and seaworthy! 3M5200, 4200 for sealing, some bedding inside useing 100% urethane contruction adhesive (Check to see that the VOC is like 25 grams per liter, not 300-400, our ace store had it). Man a sack of stainless bolts can sure geat spendy!
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  #3  
Old 04-03-2006, 09:21 AM
topwater topwater is offline
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wondering if

Mr. Francis, have you begun/completed your project yet. If not I have been through a conversion on a 25 Grady Sailfish and could possibly input a little info for you. Rebuilt the transom, installed a twin bracket... etc
Might be of some help to you. If not, hope all went well and happy fishing times to you!
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  #4  
Old 05-09-2006, 06:34 AM
nautidog nautidog is offline
 
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To Topwater

Saw your experience with the Grady 25 transom replacement. I've a 1991 Sailfish and found 2 small cracks this winter...Must have been wet as they grew with the freeze here.

I've got the transom cut out and am grinding out the wood core... Left 3 inches of glass fore and aft to set the new transom core (Marine Ply) into with a thick bed of Cabo. I think I've got the glass work handled (Epoxy with Vacuum Infusion and about 45 oz of cloth total on the outside).. Sound right with your experience?

I seeking a bracket design (I can get the Aluminum and have the welders on standby) but I want to ensure I only do this once and do it right.... Any insight would be GREATLY appreciated as I'm doing this in a technological vacuum.. (Backyard!)

Also, do you have a source for Grady Gel Coat or epoxy paint match?


Thanks so much....
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  #5  
Old 06-12-2007, 04:19 AM
ianper ianper is offline
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Hello Mr topwater. I have a campion victoria 245 with a sterndrive. Am planning to convert it to twin outboard. Look foward to any advice?
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  #6  
Old 06-12-2007, 11:51 PM
charmc charmc is offline
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You have some good responses so far, and if you search the forum for terms like conversion inboard outboard, transom replacement, etc., you'll find that this type of conversion has been done many times. There's a lot of info available here, including photos.

Good luck!
__________________
Best,

Charlie
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  #7  
Old 06-13-2007, 09:04 AM
topwater topwater is offline
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grady transom

to nautidog and ianper. This may get lengthy, Gentlemen but here goes, for what it's worth to you.
First off, I prefer what I have over any other type of power setup and it can be done to any boat whether inboard outdrive or outboard against the transom.
My Grady was originally an outboard with the usual outboard cutout in the transom and the little pitiful transom panel to keep waves out of the boat. Found the transom to be rotten when I noticed a little movement as the engines were tilted. It was all just a little too bouncy. Took the little trim strip off the top of the transom back there and there was an opening between the transom and the top (or cap if you prefer) I stuck a tig welding rod down it and almost lost it. Incidentally, I recommend the opening be sealed with fiberglass on any boat that has the seam under the aluminum strip. It just doesnt stay sealed and that's where the woes usually begin.

A friend and I cut the transom out leaving about 3" of the original glass on the outside perimeter to retain the shape of the back and for something to bed the new transom to. I built a FULL transom, putting a bracket on the back and getting the engines out of the boat and being able to discard the flimsy little transom panel that Grady provided. Not a good design for them on that. So now thew boat can take a wave back there and I can back down on a fish hard as I want to.
I built my bracket myself after a fiberglass repairman in the area let us copy the dimensions off one that was commercially made. I used 5052 grade aluminum and migged most of it with 4043. worked ok. I tigged the outside welde where pretty counts. I welded it up and it works good. That was in 1995. I had two 200 johnsons on it and things went really well until I repowered last year with Suzuki 225's.( Yep, overpowered, but you dont have to use it just because you got it) These guys weigh a little over 500 LBS each. My bracket is 28" out. That length was for tilting clearance and was the only factor I considered when determining the amount of setback. (hint, hint)
Now the boat squats in the stern about another 2-21/2 inches deeper than it did. It's most apparent when running rough water because without a lot of tab hanging down the boat is way high in the bow. Not so good for handling rough water. So now, I am building a bracket which is a near copy of the later versions of the grady whites. At least it'll go all the way across the stern and provide a lot more lift back there. (nuther hint)
Armstrong makes a bracket which is good. Their url is: http://www.armstrongnautical.com/brackets.htm
kinda pricey but you get what you pay for. I recommend them and I am not positive but I think we used templates off one of their brackets for mine.
Some things I did that may have been overkill was I put a laminated beam inside on the front of the transom at the level where the bracket bolted on. The beam was about 4" thick and 6' wide and tied into sides of the boat for a little ways, maybe 6-8" out.

I put fiberglass blocks at the bottom of the transom where hte trim tabs screw on to eliminate water seepage into the transom wood. And I was particularly picky about drillling and bedding any hole I had to put in the transom. There were over fifty holes (yessir, I counted them!) drilled into the original transom, most of which were unsealed. That's shoddy dealer and manufacturing practices, plain out! I wrote a kinda ugly letter to Grady White about that. Just no excuse for it.
Anyway, the boat is still at it. Bracket is good, Transom is great and I'm sending the ol' gal in this fall for a complete makeover new topsides, check stringers and add some goodies I've always wanted.
I can completely rebuild for a fraction of the cost of a new boat and this boat is, in many ways, better than most nowadays. The hull is almost 3/4" thickon bottom, didnt know that.
I'd try to answer any questions you may have that I can answer. If I dont know then I'll tell you I dont. I prefer the way my boat is set up over any other I've ever been out on. Just a good functional setup.
My welding is purely vocational. I occasionally built a hard top or t-top for someone, I've built a few brackets ans I mostly have a good time working metal. I've welded for a living for much of my life and am a retired BP welding/ pressure vessel inspector. I'm 62 now. so, I may be give some sense to your welding questions if any.
Hope I helped you. Sorry it's so long but there's a lot to say and a lot more that can be said.

topwater
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  #8  
Old 06-13-2007, 11:28 AM
topwater topwater is offline
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grady transom

I dont have any suggestions for matching colors on your gel coat. I had a gentleman who has 30 or so years of experience at refinishing boats try to match mine. He came close but I could still see a difference. On the transom it's not too bad because we refinished it side to side so there was no feathering in of the colors. But it isnt the same and after gelcoat fades from sun exposure I'd thinkit would be very hard to mix out a batch to match it.
Anyway, sorry i didnt answer your question earlier.
Have a good day and keep a tight line.
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  #9  
Old 06-13-2007, 08:31 PM
mike steiger mike steiger is offline
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I am just about completed with this exact conversion on a 21 steiger block island. First off you must gain access to this area which will mean cutting back your deck and stringers.then remove any core material that is there back to the outer skin of the hull. You should then grind with a36 grit disk any remaining material until it is clean. You should then apply one layer a 1 1/2 ounce chopped strand mat (stitch mat if using epoxy) then a layer of 1708db 45 degree or 1808 db 90 degree and then another layer of chopped strand mat for bonding and leveling purposes. Core material should be at least 1 1/2 thick. You can use either marine ply or what I used which is coosa board bluewater 26. You most likely do not have transom clamps but this can be done with straight 2by4's and lengths of 3/8 threaded rod cut to size(you may havbe to run a die over the rods to clean them up but it is no biggie). Make a template of the core shape then when you are satisfied transfer that to the core material, you will most likely have to tweak it somewhat. Upon completion of the fit you are now ready to bond the core to the outer skin. (run through this with the clamping process dry) You are going to use the 2by's on the outside and inside. You will need another person to assist you in doing this. Drill holes in the 2by's so the outside and inside line up and so the threaded rod can pass through then put fender washers and nuts on both side and it will act as a clamp to bond the core to the hull's outer skin. Make sure you staple visqueen to the 2by's and wax your threaded rod to make removal easy. I bonded my core with a epoxy resin thickened with cabosil and milled fibers to a consistency of vaseline. I then applied it to both surfaces with a1/4 inch notched trowel and then clamped it with the above method. One thing I forgot to mention I made 3/4 inch fillets on the inner skin right after grinding the outer skin to make the glass tun easier(sorry about that). Let all this set up for at least 48 hours. You are now ready to build your inner skin this should be 5 layers of 1808 which will give you about 5/16 thickness overlapping into the bottom and sides of the hull. Then comes fairing, I really like Quick fair this stuuf is great and worth the price. My epoxy was purchased from aeromarine products. I have a C.D. that doccuments the whole project and would be happy to send to you for free the pictures are good and will better explain the job at hand.
I hope this vague explanation helped as I am no english major and peck and find typer. My e-mail is fendie63@hotmail.com.
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  #10  
Old 06-14-2007, 12:05 AM
boatguy64 boatguy64 is offline
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Mini craft can match most colors
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  #11  
Old 06-14-2007, 10:42 AM
ianper ianper is offline
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Thanks very much for the insight. The armstrong bracket seems to be a good idea. Initially i was considering a hyraulic jack plate like a porta item. They seem very expensive but add the advantage of adjusting the engines vertically to get the right level. However they do not have positive floatation unlike the armstrong. This is an area which concerns me. You mentioned that your boat sits 2.5 inches lower at the stern after the conversion. Would an armstrong bracket solve this problem. I'll get my fiberglass contractor to reinforce the transom so that is an issue which im not too worried about. The boat has a 5.8 volvo (ford) penta with an sx drive. This will be removed as the engine is not reliable. I prefer to have two powerful outboards to one sterndrive. The boat was made in 1997 and seems to leak a bit, about a liter an hour but only when the boat is parked. I think at the transom. So this will be rectified when the engine is removed.
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  #12  
Old 06-14-2007, 06:31 PM
topwater topwater is offline
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inboard to outboard

Mr. Ianper, I'd contact Armstrong and see if their Bracket will provide the flotation you need. Somewhere I have a simple calculation to calculate how much flotation it takes to float a given amount of weight. Maybe you or one of the other members here have a better one than I. If so feel free to plop it out on the forum. I'm always open to anything better. If you need it I'll try to find it in my junk.
Jack plates are ok on skinny water boats but once you get the optimum height for your deep water rig you wont need the the jack anymore. Spend your money on a couple of new trolling rods or something!! Remembering I have twin engines and they are four cycle which is a bit heavier so if you're going 2 cycle you might not need the additional flotation. The two I have go about 1060 pounds total plus maybe 100-150 for the bracket. That's all hanging out there about 28 inches or so off the transom. Try to talk to the folks at Armstrong. They can probably advise you. The fact that you had an inbd/outdrive may not be a factor since most of it was inboard and in front of your transom. On that I couldn't say.
A lot of people dont reinforce the transom but I keep thinking back in the back of my mind about whacking something out on the Gulf like a log or timber and breaking something out of the back end. Man, it could be a long walk home!! I was on a boat that hit a 4x4 floating out there about 3 years ago. Broke the 4x4 in half but luckily didnt damage the boat or engine. Scary deal when you think about it. But stuff like that happens to all of us in the big pond
ok. So much for my jabber. Hope I helped you out some. Keep me posted.
And to Mr. Steiger, I have never seen a Steiger boat in these parts so I looked it over on a web site. It's a fine looking boat. The only thing here that even approaches that style is the Parker 25.
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  #13  
Old 06-14-2007, 06:55 PM
topwater topwater is offline
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inboard to outboard

Mr. Nautidog, I did my bracket in my shop... in the backyard, same as you. So, go at it.
Suggestions, short and quick. use Grade 5052 aluminum plate and any extrusions (angle, flat bar, etc) use t-6061 t6. It probably wont be found at the neighborhood ace hardware store. These grades have excellent corrosion resistance and if I'm not mistaken the stress strength on 5052 is around 55,000 pounds. that's 55 thousand. I used er 4043 tig rods and 4043 mig wire for the inside welds. I only tigged where it had to look pretty.
I used 1/2 inch plate cut out with relief holes for lightening for the transom plate with 1/4" internal stiffeners in two equidistant places inside. (be sure to provide drainage between the internals you you dont have to mop out water. and 1/4" plate for the bottom piece with 1/8 sides and top. The engine plate was of 1/2" and doubled at the top where it projected above the top of the bracket with 1/4" gussets to kinda help out from springing. I put a screw in drain plug in the bottom to check it once in a while and a zinc plate on it too. No paint under the zinc. All this you may already know so please dont be offended if I tell you. I put Beckson plates over each compartment to access the internal bolting. I otherwise wouldn't have put any kind of penetration in the top. Access plates leak unless you get high dollar ones. I dont like 'em.
I used 309 S/S bolts through bracket and transom with fender washers and nylock nuts in addition to lock washers. Kinda like wearing a belt AND suspenders but I want it all to stay put and lock washers are cheap. The only thing I goofed on was that I tried to spin the nut on the first one with an impact. S/S doesnt take too kindly to fast bolt ups so I galled one. Had to cut it loose and do it again. Be generous with 3m 5200. Seal EVERYTHING but just a thin bead around the perimeter of the bracket to transom fit. If you ever have to take it off, you'll appreciate this advice.
ok. Got a question I'll help if I can. Y'all have a good un!
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  #14  
Old 06-15-2007, 04:56 AM
ianper ianper is offline
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Thanks for the info. will keep you informed.

btw, i plan to get a pair of 4 strokes.
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  #15  
Old 06-15-2007, 12:36 PM
H180DSC H180DSC is offline
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Check out this website for outboard brackets: http://www.dadmarine.com
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