Carolina all fibreglass hulls

No, no idea who made the boat in the photo, I just pulled it off the link.

I can't see where "tweaking the design" comes into play really. Whether you lay the jigs out and cut them yourself or feed some numbers into the machine, the tweaking has been done in the design phase. Either way you will end up with a lot of handwork to finish the plug or boat, which ever it is you make the mold from.

What I suggested can be done but it's not something I've done and I certainly wouldn't attempt it on a large scale unless I had certainty it was going to work. Like a LOT of experience trying that sort of thing. I think you'd be very limited on the amount of tumble home and any normal sticking of the part in the mold could probably be a disaster.

The lack of these type boats may have more to do with lack of markets than difficulty of building.

Looking around a little, there are a lot of these type boats made from composites. I would think cold molded anything commercial would be the exception, as each boat would be "custom made", every boat having to be hand built piece by piece and hand finished.

You are assuming two piece molds are too much extra work. They take a little more time to make, but as far as preparation for molding about the only difference from a one piece mold is the time it takes to roll them together and bolt them together. There might be a little gelcoat flash on the join line that has to be removed and buffed, but all in all, compared to finishing every hull like with coldmolding, it's not an argument at all.

When you finish a plug in preparation for making a mold from it, you finish the plug to perfection. When you pull a hull from that mold, that hull exterior finish is finished. You don't/shouldn't have to even buff it. At the most, you might have to wash off some pva with water.

I'm not raining on your parade at all. You can build the type boat you want to build, but I would use a two piece mold. They really aren't that much more work. In fact, prepping the mold might be easier, as you have more access to clean it and wax it.

Parts of this video are taken with a potato cam, but 036 seconds in shows half of their two piece mold clearly.

I just noticed the opening shows a guy going at a mold with a RO sander. That is not a usual thing, he is repairing the mold. I don't think I would have made that part of the video.

 

What gonzo is talking about when he refers to a dxf file is the cad file that the design was saved as. Whether it be made using rhino, AutoCAD, or fusion360 , they all design in dxf format as the most common file format.

If I get that file from the designer who will provide his hull shape and cnc cut jigs, I can then design my own super structures that would fit perfectly to the hull . I would know exactly how much space above decks that I have to work with for the enclosed pilot house that I would like to see. Just open it in fusion, and start designing with the hull in the foreground.using the software I can even set rules on the hull that won’t allow me to have my wheelhouse intercept any part of the hull , making my design process more of a success.

Gonzo - I don’t see how hand lofted stations could be drawn and cut by a human just as well as cnc cut jigs. I prefer the Cnc jigs cause there isn’t any room for error, if it doesn’t fit or line up, I did something wrong. I’ve got a steady hand with a jig saw but there’s no way I can cut the same as Cnc machines.

 

DXF is a format to interchange data but cnc machines don`t understand dxf files. And, if you have your files in native format on Inventor, Rhino, AutoCAD, whatever you like, why do you need a dxf file?.
Modern routers read also iges format and several other formats but, as they should do with dxf, need to "translate" that information into machine code. For 3D models igs format if much more sure (talking about loss of information) than dxf.
By the way, if you get the drawings from the designer, any format, even pdf files, I could help you in translating that to iges, dwg or some other formats.
Man is never more precise than the machine, now, if you give time to man, and you pay for it, he can achieve great things.

 

The process can be different depending on a proven design or a speculative design.

If you have a successful hull design you are going to copy, a straight plug is cheapest. (compared to making a boat and then a mold from that) That leaves you with a master plug, so if you somehow wreck the mold, you can make another.

A spec design is normally made into a boat and tested, tweaked or not, (or discarded as a danger to humanity) and then you can finish that into a plug for a mold.

 

Thanks Sam Sam, I’m actually not at all against a two piece mold. I was just excited to see a custom Carolina hull from a fibreglass mold on that smaller boat scale. That’s the first small mold I’ve seen. The fact that it was a one piece mold was just bonus....however....
There’s already so much work involved in making the plug and the mold, what’s a bit more to keep the full tumble home and make it a two piece mold. I’m all for two pieces.

I find it hard to believe that there is a limited market for these boats. I’m certain I can make them popular up here in the Pacific Northwest .

Fisherman here appreciate a dry hull, and one of the older mass production boat builders in this area used to have tons of tumble home in their designs and I believe that feature would be well received by fisherman once again if they saw it on a new hull. I believe it’s just gone by the wayside because it was dropped due to cost considerations. (Because of The extra time to build using two piece molds)

There’s a ridiculous aluminum boat craze up here and I feel it’s high time a real fibreglass boat re-entered the market.
Aluminum boats are garbage in my opinion. They are all too light for their size, ride like crap and only look good the first year you buy them. Did I also mention zero styling?

Everybody up here wants a 26’ pop can with a cabin. That’s got to stop.

 

Haha, you are going to educate those alloy boaters, you think ? Perhaps stylistics aren't a big selling point in your area, but I do wonder about the utility of that extravagant flare in head winds, creating unwanted bow lift, which will affect a boat all the more, as the boat sizes decrease. And with a deep vee, likely more, too.

 

Style has gone by the wayside up here(British Columbia), the first aluminum cabin cruisers in the 26’ range were designed to get a quick fleet of charter vessels together for the lodges in the queen Charlotte islands (now Haida Gwalior). They needed boats that could take a beating and also not require that much end of the day maintenance because these are guide boats with just one crew member, captain and guide in one. They will guide 120+ days straight.

The guides caught well and soon everybody wanted what Johnny fishing guide was running. Monkey see monkey do.
100 aluminum boat builders Dominate this coast. There’s only two or three glass builders.

I sell used fibreglass boats , pursuits, shamrocks, blackfins, Bertram’s,tiaras etc. I’ve never sold an aluminum boat. It’s taken 12+ years for my father and I to import these brands dozens of times and I really think these brands have gained popularity up here because of what we have brought in. Prior to 2000, the greatest sport fishing boat on this coast was a bayliner trophy in the eyes of most anglers. Just about every pursuit or shamrock I see was one we imported to bc. These are real fibreglass sport fishers of their size.

The closest thing to a Carolina custom that I’ve seen up here was a nice open ocean master 30. I agree that the added flare will create lift, but no more than a cheap aluminum boat made up here, and some of that lift from a custom Carolina could be mitigated by adding weight to the hull , no? I would add weight by having a much heavier layup schedule from the waterline down. My shamrock 290 had a hull almost 3/4” thick not far below the waterline, that’s what made her ride so nice.

You also mention the added lift that could occur as a result of the hull having a full deep vee. Isn’t that just the opposite? A flat bottom at transom will create more lift especially in a following sea. Again that’s where that shamrock I had shined. Full vee, excellent following sea capabilities. The trade off being more roll from side to side at rest or slow speeds. No?

I’ve steamed with my dad across the Atlantic, through the canal. The sea states seemed similar to ours in many ways so if a custom Carolina works on the east coast, why not the west?

I’m asking the question with an open mind, by no means am I challenging your input. I’m here to listen to the experts

 

Building plate alloy boats has become something of a cottage industry, all over, seemingly. The shaping limitations, without expensive equipment, though, are such that ride quality is still not up to the standard of the best glass hulls, even at level weights, in the past people would blame the bumpy ride of ally boats on the lightness, but today they are not much lighter, with the plate builds.
What I mentioned about a deep vee getting more aerodynamic bow lift from that over-hanging flare, is based on full vee hulls being not as stiff in pitching motion, as a boat with reduced vee aft, but obviously a lighter boat is much more prone also. Of course it also depends on what sort of cabin structure you have on the boat, sloped surfaces well forward tend to push the bow down. Similarly with smaller planing cats, high tunnels forward lead to leaping tendencies, in head sea/winds, which the inherent lack of pitch stiffness only worsens. A relatively low bow height, with a decent swept-back cabin structure well forward, can lessen it somewhat.

 

Ok so it’s been a few days and much has happened.
Thanks to all of the member input on this thread, I just purchased a 26 envi jig and all of the fast build components offered with the boat.

This journey will be three components, step one, Hull build, (got a license for one boat)
Step two, build a mold from that hull (got permission to splash)
Step three, build a solid fibreglass hull from the new mold (got per hull licensing agreements in place)

This will be my first hull build, my first real mold build and my first fibreglass hull build. Some will probably be sheepishly saying, “oh this is goona be fun to watch!” But wait, I have a plan.

My daughter and I rescued a small dingy this summer. It’s full of holes where someone melted a plastic bucket and mixed gravel to make a paste to keep her afloat. It didn’t work. It’s a beautiful hull even for just 8 feet. Tons of flare, and even some tumble home.

I plan on finishing the dingy to a class “A” finish, then practice my hand at building a two piece mold, then pulling a hull via infusion. Hopefully I can make a pile of mistakes there and also make a bunch of discovery at the same time.

Now back to the cold mold hull I’m about to build.....

QUESTIONS:
If I build using epoxy, I can’t apply tooling gel coat in the end for plug purposes because epoxy and gel coat aren’t compatible. Or are they?

If my hull is fully encapsulated in fairing compound, won’t that be enough to isolate the two incompatible products?

Would anyone build this hull using vinyl ester resin rather than epoxy ? This would save me piles in expenses and ensures compatibility with the tooling gelcoat.

Keep in mind that I’m not abandoning the cold mold hull after its used as a plug, it will have the mold flames removed and then flipped over and fully finished.

These will be the first of a thousand questions now that I’m officially in this game. Thanks

 

It does not matter what the plug is made of, in terms of compatibility with the tooling gel coat used for the mould, they will be isolated by the release agent/wax between the two. You don't need to use epoxy in either the plug, the mould, or the mouldings from it. I suggest you nut this all out thoroughly, before starting anything. If in any doubt, I'd suggest picking member ondarvr's brain (sorry to lumber him with the job !), but he is thoroughly versed in all aspects of what you are contemplating.

 

I think there’s some confusion.

I’m being told to construct this boat as a cold mold process using epoxy, and not fibreglass resin. I want to splash a mold from this boat so my natural reaction is to cover the boat with tooling gelcoat to prep it as a plug. Epoxy and gel coat do not get along. So if I use epoxy for construction, what should I finish it with to create a smooth fair surface ready to be used as a plug?

Maybe I should build with vinylester instead. I’m asking if that is frowned upon for a three layered hull made of okume. If I build with fibreglass resin, I can gel coat the hull but is that 5he wrong choice of laminating resin?

If I build using epoxy, but spray a dozen coats of fairing compound on the hull, is that not enough barrier between the epoxy and gel oat that the two incompatible products won’t disagree with one another and then I’m safe to move forward using the hull as a plug?

 

Hold on there a bit!

Epoxy gel coats are available. Using them and epoxies avoids compatibility issues

There is no such thing as fiberglass resin, so don't use such a term when delving into specifics.

All the best. You might want to know I am not a mold guy. My experience is not doing it. But I do know epoxy gel coats exist.

 

The Carolina boats seem to have a lot of forward section. Are you not sure the steep waves of the Pacific would tend to lift the bow and make visibilty difficult? It is just a question. But you might need to consider helm height carefully before building a boat you can't see out of..

Maybe find a couple for sale and sea trial them in real conditions if you are allowed.

 

I'm rambling on as we had a lightning strike with a real loud SNAP in all the outlets. Now we have no modem, cable, internet, and 3 tvs that won't even turn on. It will take awhile before this gets posted.

You don't use tooling gel on a plug, you use it on the mold. "Tooling" is in reference to the mold as a "tool". Tooling gelcoat makes a good mold surface, it doesn't mean it's good for tooling as in sanding and fairing and finishing a plug. I don't think it's properties are actually suited very well for use on boat hulls or decks.

My first plug (for a canoe with tumblehome) was wood strips on stations, a layer of mat using polyester resin, faired using Bondo and high build auto primer, a coat of auto enamel, wax and pva. The mold started from there, the first coat being polyester tooling gelcoat covering 1/2 of the plug and the temporary dam of formica affixed down the centerline. That side and dam face were then laminated with a few layers of mat. The dam was removed and the exposed lip of the new mold was indexed, (shallow dimples created with a 3/8 drill, so when the next half of the mold is laminated, protrusions form that exactly match the dimples in the first half) waxed, and then the second side of the plug got a few layers of mat. Then a few more on the first side, a few more on the second side, then some frame work supports (wheel supports too) then a few more layers each side until it was thick enough. Before it was taken off the plug, the center line lip was drilled every few feet for the bolts to clamp the two halves together. The indexes position the mold halves together correctly and the bolts basically serve only to hold them together. Even so, it's best to use bolts that aren't threaded all the way, so you can drill the holes as a snug fit for the unthreaded part of the bolt shank and then they reinforce correct alignment of the mold pieces.

That's the general idea for a two piece mold, another paragraph or two would add most of the details you might need. I posted them here a long time ago, they might still be here.

Get some isophthalic polyester unwaxed resin and try it, maybe you will get used to it. It stinks, but at least you don't become epoxy sensitized. You might not mind the smell, you might even get to like it, after awhile it brings back memories. It's cheaper. You will use mostly mat in the mold, and polyester and mat work very well together. You can use epoxy in the fiberglass boat hulls if you want, but most people don't. It's more expensive. I hear that mold prep for epoxy is extra important because of it's tendency to stick more often and more tenaciously than polyester. Sticking can really damage a mold or even destroy it. I haven't done this stuff much for 20 + years so there are sure to be better releases, resin and everything by now.

The dinghy project sounds like misdirected time, money and effort, but if you need the experience it will work. You'll end up with two dinghies and a mold that might not get used again, the mold itself utilizing enough material for at least 2 if not 3 dinghies. It will take up space, but maybe you have enough.

You will need space for the hull mold and then the same for the deck mold. You will have to have room to work and room to maneuver them around in, pull them apart etc. Then space is needed to trim and assemble the hull and deck and to finish a boat. You will have other molds too, hatches and wells and things. You will need room for all the materials, barrels of resin I would think, and room for glass and foam cutting and storage. Tool storage or workshop space for table saws, workbenches etc. It's best to have all that with a roof at least, with walls is much better, especially on the Wet Coast.

There will be a lot of heavy lifting. A forklift is handy and it might work for getting the hull and decks and cabins out of molds and moving them around. A few A frame hoists would also be useful. Vertical clearance in the shop becomes a concern.

 

We lost 2 tvs and a modem. Evidently surge protectors sometimes work, 1/3 of the time in our case.