Deck Removal

[aboyd]

Hey guys I have a quick questions about my 25' hardtop to centre console conversion. If I support my hull with multiple contact points is it inadvisable to remove deck from hull at joint. I have been told by a co-worker that the hull sides will most likely springout and be out of shape. Is this a common problem or is it from improper supporting of the hull. Sorry I don't have any picks of the project yet I can't seem to find patch cord for my camera. Thanks

[gonzo]

You will haver to do a complete structural redesign. The hull is a box beam. If you remove the deck it will twist and maybe break apart.

[mark775]

IMO, we're not building a piano here. Support the thing evenly and have fun. If it were to spring/sag/flop a little...put it back if you want. I'd welcome an inch or two more topside beam. It's glass, right?

[PAR]

A few 2x4's athwartship will keep the sides of the hull from flopping around. The bottom should be supported along the keel and chines well.

If you're going to walk around inside the hull, directly on the hull shell then additional support may be warranted, to keep things from distorting under your weight.

You will need to provide some additional athwartship stiffness (as Gonzo alluded to) as a center console, because removing the deck and hardtop also removes considerable athwartship strength, which must be replaced.

At this point we're shooting in the dark without pictures of your project.

Mark, if the topsides were "flared" outboard a good bit, the bottom would cup upwards, creating a lovely suction at speed and not a good suggestion for a center console, that will likely plane off at high speed.

[mark775]

I just have not seen very much movement on boats this size. I have supported well from under, just with blocks and wedges by feel and never had a problem that I know. The new construction, on the other hand, is well stiffened by a cuddy forward and some type of beefed up gunnels, no? It's just such a pain to have supporting members, inside or out, maintaining a shape. Certainly, if I felt that there was enough weight to spring a hollow in the running surface, I would brace from outside before setting the new deck/console in place, but not walk around/step over bracing unless I had to.
Hey, fellow, PAR is more qualified to have his advice heeded than I, so go with what he says. It's just that I don't have all that much respect for most of these "designed" boats anyway (if poly, they often "oil can" and a running surface is hollow anyway and needs refinement), I use my eye extensively, lay straight-edges where appropriate, and make, I feel, a better boat than what came in.

[aboyd]

Thanks everybody for responding to my questions. here are a couple shots of the boat. U can see on the deck the 4 inch or so cap that I want to cut along on the inside edge continuing all the way around the boat. There is also acouple shots of the transom and cuddy floor thats a stringer there poken out of the water. Its quite surprising to that much there because the bow is about 4" higher than the stern tells me the holes are plugged along keel.. Also the hull is quite thick on this boat the pencilis there just for a reference. This weekend I'm going to drop the outdrive and pull the motor. I don't mind doing this amount of work to it seeing how I only paid $2000 and the 351 windsor was rebuilt in 2000 bills to prove. plus the bota has minimal hours on it since rebuild.

[aboyd]

hey guys I have another question for U all. the picture shows what looks like a forty' outerlimits on its tail. how hard would this be on a transom to hull joint if it was nose up even more. I would like to build a tilt bed mechanism that would allow me to stand the boat almost vertical (which can be achieved due to the fact of being part time farmer euipment is no problem). The resson I'am asking is my hull has a massively thick and hard layer of anti-fouling paint on it due to it being docked, the boat will always be on a trailer now so I wan't rid of it. I tried to sand but that was strenous at best so I figured a good sand blast, blemishes filled smoothed and painted after wouldn't be too hard. My previous job for 6 years was an industial sandblaster painter and I blasted a few sailboats for the local boat yard. would U do this prior to replacing stringers or do it when the hull has been strengthed considerably. Thanks again ...

[mark775]

I would use a chemical stripper, scrape, random orbital sand. Just get the bottom paint off for now. After everything is rebuilt, you are going to want to lay a straight-edge along the aft edge of the running surface. Media blasting tends to find porosity most when something distracts the operator...
As far as the caprail, I would consider leaving it as best as possible and incorporating it into the new design.

[aboyd]

Hey everybody have a few more pics of the mess that I have gotten myself into. Glad I had never taken the boat out. The amount of rot and delamination of glass is startling. The engine beds are totally decomposed, but the glass is ok, only found this after sticking my drills driver bit through fiberglass. The lag bolts holding engine mounts spin freely in their holes, now thats a little scary. Especialy when my wife can't swim. HHHMMM now that I think of that a little bit more that might be a godsend lol ....:D

[aboyd]

Has any body out there used the us composites epoxy. price comparison to the west system is alot more resonable. $65 for a gallon and a half kit.

[apex1]

Has any body out there used the us composites epoxy. price comparison to the west system is alot more resonable. $65 for a gallon and a half kit.

On a repair job like yours you can use any epoxy, even the cheapest! But be sure you buy Epoxy!!! There are faux products on the US market, one is named "Fiberglass Epoxy" but in fact is just polyester. (3M I think)
Make sure you dry out the area completely before applying the glass/resin.
Do´nt blast the paint off, you are pretty fast through the glass. Use a paint remover as Mark said. Rinse thoroughly and wash with thinned denaturated alc. before applying the layup.

[aboyd]

I don't think it's the cheapest or the worst out there ,I just don't think you are paying for the name that so many companies out there do. Thanks for the heads up on the faux epoxy.

[BurnabyRocket61]

I'm using System Three Silver Tip laminating resin. I like it. 2 to 1 mix, no blush, fast or slow hardener, I use the slow, its tack free in about 6 hours at 20 centigrade. Application temperature is as low as 2 degrees which is great as you know up here in the great white north. I use those small foam paint brushes for tight areas, but for spreading over large areas I use a 6 to 10 cm square piece of card board, not the corrugated type, but the thinner stuff from a good Canadian beer box eh. You can also add thickeners for filleting and fairing, but check out there other products for that, including GelMagic it mixes to a butter like consistency and is great for gap filling. Although retail for the Silver Tip 6 liter kit is about $200, and similar for the other products by volume, although they come in smaller kits, I think they're worth it. Check it out at systemthree.com

[aboyd]

Well the boats off it's trailer and is finally gutted. I will be doing the transom real soon well as soon as i can get some real epoxy that is. I have to wait untill tommorrow Noahs in Toronto has a five gallon epoxy kit for $299.

[aboyd]

Hello all was just reading some of the previous posts here and mark brought up the point of older glass hulls like mine taking the shape of an oil can. If this happens especially to the keel area would that not be beneficial for the over all speed of the boat. I was reading somewhere where some manufacturers actually form a J near transom to controll speed. If my hull has this pronounced J on in it's under side is this something tha can be fix when new stringers are installed. Or do u fair this out on the under side with the goo.

[mark775]

No, the "oil-can" sometimes happens when production boats are made. It is shrinkage that I am referring to. This area needs to be straight. Get there without putty, as much as possible. Look at what PAR told you about bracing the hull sides, tho, I believe, the cap you have left on would hold your shape. Look at how the hull is supported. As impressed as I am with how you have gotten to the point you have, I wish you had slowed down a little and looked at things a little more carefully to begin. Is this "J" referred to possibly pulled in by the hull sides falling out? How it sits on its supports? Support this thing however you safely can, pull the hull bottom flat (gently - don't take it farther than it wants to go), then install stringers to hold that shape, then think about what to do to the bottom to get what's left true. That caprail - make it a part of the boat and not just part of a shoebox lid hanging there by a little putty and screws. I don't recall... how are you going to power this?

[PAR]

What he's referring to is called a "hook" and it's not a function of the hull design he has, though can be on other types of boats. On your boat it should avoided at all costs and if you have one, it needs to be removed.

No, you can't straighten out major distortions with the new stringers. Well, you can, but not in a driveway that's for sure. You'd need a big press and some serious skills.

The problem with an improperly supported boat is you lose control over the shape of things. Since this is likely the case now, I'm not sure what to tell you. A hook can be filled in, but as far as forcing the hull to re-shape itself, not so much. You don't have enough bulkheads to worry about oil canning, particularly now that they're removed.

[aboyd]

My hull is actually really straight and true. There is no hook that is noticable on a 6' straight piece of 2x4. The cap rail will be incorporated into the new design although it will be widened about 2-3 inches so as to I can glass in gunale supports running from the sole to underside of rail which is filled now with 1/2" ply. Plus there will be extensions off of some of the bulk heads to tie the sides more effectively to the bottom of the hull. This area i thought would also make a pretty good spot for floatation, some sort of epoxy encased foam i'm thinking. Sorry for the miss under standing Mark I wasn't really sure if you were talking about the sides or bottom of my boat. I would have liked to get some more work done on the boat but it is so stinkin hot here right now and humid plus the joyus other part of my day (work) its kind of hard to get the amount done that I would like. Mark thanks for the concerrn but every possible thing important has been measure and sketch out on graph paper so that I now where it all goes. Plus there is a little beefing up of some of the stringers and bulkheads to help with any of the support that I lost taking cabin off. Thanks once again to all and I will keep you posted on my progress. Oh one more area Iwould like your guy's expertise in is sculpers, Ya or Na, i thought once the sole of the boat is down and all back together i would take it ofr a float test and see where water line is just to make sure sole is not bellow at rest, mark the water line cut two oval slots in transom feathering back on glass a good amount and then glassing area back together. Any thoughts, or should I just let the bilge worry about any water that comes into the boat. Thanks again--- Andrew

[aboyd]

Mark I noticed I had missed a question, powerment is from a rebuilt 351 (love that blue oval, just whish it had the aftermarket like the chevs do) The motor has been spiced a little with a holley 4 barrel and a dualplane edelbrock manifold. the boat should go like a scared rabbit due to the fact that the previous owner claims 50mph not kph on the gps, speedo didn't work in the boat considering the wind resistence and weight that has been droped. And PAR I totally agree with you "Foam Sucks" every bit i pulled out was water logged. Granted if the factory had done a quality job in the first place the water most likely would not have been there, but like most things speed and quality do not mix. Another question i have is why is exterior grade ply no good to use in my transom. If it is sealed with the proper amount of epoxy where will failure come from. Has anyone ever used wrapped non water cooled exhaust manifolds in there boats. I would like to to build a pair of stainlees up swept 4into1 system tied into a pair of super trapps out the transom, high up obviously. Heat will be the #1 concern so i figured if more air is plumed into engine hatch and as i said wrap the manifolds with the heat wrap were is the problem. Thanks guy's..