CNC Plans not Included

Yeah I'm also an electrician - seem we have a bit in common Dennis Did you see my solar powered dive compressor setup on a variable frequency drive? It all runs off a 3kva 12v inverter. Same goes for the watermaker, that's on a VFD too. I'm all for electric also, except there's no getting around the available energy problem without a Gen set / diesel hybrid for propulsion The way to do it is like you said- I simply compared to what we normally see on existing yachts, 2 sail drive diesels and a separate gen set. No wonder the boats are heavy!

Jorge, you still need batteries either way, you still need to start engines, and still need a house bank to run everything when rhe genset is off. And your not going to run a gen set 24/7 . So you still need the house bank additional to a gen set. With a solar wind inverter setup, you might size the battery with a little more capacity, but otherwise there's not much additional weight. Using lithium, there's even less weight and you can afford lithium because you saved so much money on the genset and electric diesel hybrid system when you saved all that time installing the outboard motors!

 

I'll not try to get technical with electricians, I will just stand on the marketing angle )) ...

However, with a genset you can power your drives, not as efficiently as diesel direct to shaft but if you don't power around too much, who cares. It's also good for night time AC, especially when anchored in a protected cove and there is no wind. Albeit, with torqeedo system, the battery capacity will handle that load.

So it boils down to are you going to sail, or motor around most of the time.

My comparison to the A48 was that it has diesels and a genset and it still does well into the wind so I'm just saying I am not going to kill sailing performance by going electric but I would still have the wind gen. and lots of solar cells and hopefully never fire that genset up.

 

Groper. I saw your solar system with the compressor. I thought it was great. 2 outboards and a lightweight petrol genset with fancy installation for soundproofing and cooling for those times the batteries are low and you still need to fill tanks etc. That system would probably cost like 50k less than a fancy electric system and do everything better?

The blatant lies just about every manufacturer uses in thier marketing? Not an angle I think is worth admiring.

 

Sorry I should have been more clear, not the mfg's marketing angle, I agree with you on misinformation, I hate it.

My marketing angle - Green, blah blah blah but no misinformation

As for sailing into the wind, I think I would pick my main routes according to something like this ... check it out, pretty cool - https://earth.nullschool.net/

 

Ok enough on the propulsion, each to their own

I'm probably going to end up building again, as I doubt I can find 2hat I want on the 2nd hand market under $500k. I don't have a life savings to spend on a boat, so I'm pretty much limited to building it myself whilst I carry on working to pay for things as I go. I know this is a poor way of going about it however, I'd much rather build where there is cheap labour and just manage the construction. How much is labour in Croatia? How much will you be doing vs paid labour?

If you plan on building say 3 of these, it definitely worth building molds I think. This is where having symmetrical hull and deck would save time and money, however it's rather limiting on the internal space by not having that big flare on the inboard side of the hulls.

 

The minimum wage in Croatia, last I checked, is 415 euro per month. I would expect to pay more. I'm thinking to hire two people at most. I will be there full time, probably at least 80 hours per week. If we build more than one cat, I would think to hire 2 additional people.

The main mold would include both hulls and bridgedeck to be infused together, both sides, in one shot. The mold doesn't cost that much to build.

I'm planning on infusing bulkhead landings and anything else that doesn't complicate bagging in that same infusion as was discussed earlier.

Tops of hulls and bulkheads would be infused first on the same level work base / strongback, those are easy to move around.

I like the idea of infusing in a stack, with caul plates, maybe waxed 1/4 thick pvc, and cnc router them to shape after. These could even be painted before gluing in, just mask off the glue area. We could post cure the whole shebang while still in the mold but it might be smarter to demold first and leave that cat post curing while the next cat gets started.

Cranes are available at around $100 euro per hour for demolding and my friends family has a lot of other heavy equipment he says we can utilize, for a fee of course, but not outrageous. I will work that out first.

What I have to find out from Grainger is can a cross linked pvc be used in the non-slamming areas, say above the waterline because the foam mfg connection we have doesn't manufacturer linear foam. It's a major mfg and Gurit does distribute their pvc products. I would only use linear or corecell to a little above waterline. He has access to a saw to cut the big blocks down to sheet size.

Epoxy would be drastically reduced,, about 40% of what I paid on my build, if we purchase in 1100 kilo batches. I think he is checking into better discounts on larger qty.

There is a very decent savings in glass too and we can specify what we need - quadraxial 5 meters wide? No Problem. I don't know if big sizes makes it harder or not but providing a means for handling that large material, sems like it would make loading the mold much quicker.

So that is the plan so far. I'm putting the for sale sign out this weekend (my house) but the build wouldn't start till next summer.

Would be good if you could at least swing the shell phase as that is where most the savings are going to kick in. It looks like 40k-50k in materials depending on the foam mainly. The mold I have to pay for anyway but you would have to pay Graingers license fee, prob 3-5K Im guessing.

Will know more as soon as I can put a deposit on the plans

 

The electric argument has been done to death I agree it does not need to be addressed again here I just finished reading that thread on cruisers forum about electric propulsion. I am so glad I have a lifetime ban from that forum. I can't wait until old mate tries to hit 7 knots in his 15 ton cat with 7kw of electric propulsion in a regular conditions let alone against 25k winds and sea. My cat at half the weight needed abut 3 times the power to do that...

Surely with 3 boats, it might be worth it to do hull molds to flare the inside? But this talk seems to be about custom designs again. I thought the plan was to use a regular design from a well known designer with a few mods. Seems most designs use flare on the insides, flying fish included. I think a long narrow hull could do with the chamfer panel style flare that usually starts at the bow, for ultimate reserve buoyancy and space. Shionnings designs usually have a very pronounced version of this. I agree it will cost time and money to build it though. But with an open bridge deck, the interior space is probably needed.

Edit, just saw your above post Jorge. **** is getting real. I hope you document the build like your last one. Would you be willing to ship some materials over the AU? It should increase your buying power even more.

 

You don't even need to use epoxy Jorge, you can infuse with vinyl Ester then do just the hand laminating with epoxy. This way you can have gelocoat finishes where you want them and not put up with styrene smells whilst hand laminating. Vinyl Ester will save a bundle plus the mechanical properties are more than good enough to get the job done. You might have to use epoxies in highly stressed items such as carbon beams if you have that sort of thing in the design.

Please tell me you are going to infuse your own carbon mast and boom too ?!?!?

Foam is fine below the waterline. You might need a higher density in the slamming areas but otherwise it's all good.

 

Im down for saving money wherever possible. I think we have epoxy down to about $6 bucks a kilo though, not counting the hardener, will vinylester be much cheaper?

Funny you mention the mast, I just spent three hours looking at youtube videos to see how that is done. Looks like most prepreg into a male or female mold and then autoclave it?? Can it be infused over a core?

 

Nah, infuse it in a female mold made from sheet metal supported in Frames mounted on a strong back. Join sheets together from behind using tacky tape. Fair out the slightly imperfect joints before painting. Make it open at the sail track and make a separate piece which glues in side to form the sail track. I'll draw a pic if it doesn't make sense? You can't infuse over a mandrel, you get creases in the laminate as it compresses under the vacuum. Tried that and failed on my fore beam....

You can make dagger boards in the same fashion- Malcolm Tennant uses this method in his plans...

 

think I got it but a drawing of the glue in track piece would be nice.

 

... sort of like this? Except the track would be elliptical and glue to the inner face of the mast. I guess the track would be infused over a male mold?

 

Set up a series of frames cut from MDF. Lay in some colour bond sheet metal so it's open at the top and easy to lay in all the fiber and consumables etc.

Finally seal the bag along the top edges of the sheet metal.

Bring down the next series of frames from above and clamp together so it squashes in the sheet metal further closing the section.

Infuse the mast section.

Remove bag etc through the trailing edge gap by tying a rope to the bag and pulling it back through the gap etc.

Build the sail track U section separately with extra reinforcement, backing block etc to take the sail track bolts on the inside etc. Once it's all done, glue it in place as shown in the pic which completely closes off the mast section.

Use the same mold for the boom , straight U section. The top section can be tapered provided the section remains single curvature , just have an abrupt angular transition where the straight section meets the tapered section.

You could also use it for the fore beam too, and the tapered section can be used to make a prodder...

 

I understand the mast part, that should work. I think the the top frames and maybe the bottom too, might have to be sheathed to keep that sheet metal from wavering, no big deal, though I'm not familiar with that material.

So the sail track is bolted on, it's not a keyhole like in the pic?

 

Edit- i think it might be even easier to infuse flat, then drape the infused bag over a male mold. You could leave a little extra to
create a squared off opening where the track block would be glued..

You would have to fill the weave but no fairing.