CNC Plans not Included

Electric keeps getting better and better, soon our sails or the boats themselves will be solar panels and be even more efficient. We will be able to cruise everywhere for free till the governments start charging us for sun!! ))

 

I think it will happen and it will be great when it does.

I was in the BVI not long ago and it wouldn't be too far from accurate to say that is what its like on Tortola. Its not a laughing matter.

 

Maybe floating in the middle of the ocean is not such a bad idea ))

 

Well its not the first time ive been wrong and i learned alot throughout the building process of the last boat. Building it was an excersice in learning about which elements, materials and methods are easiest to work with.

What i learned;
1. Man hours is the biggest enemy of any boat building project. Every effort must be made to minimize man hours spent, and this includes the ship design, fabrication techniques, and materials.

2. Spend the time to build a large, full length, perfect surface infusion table.

3. The surfaces i got off the infusion table were very quick and easy to finish - i wish i used more of them and made better use of them. This could have been improved simply by making design changes to the shape and layout of things. I successfully used high build epoxy primer paint as a gelcoat in some circumstances, and epoxy gel coats are now available to suit the same purpose. A light scuff and clean would be all thats required before top coating if going the paint route provided the table is perfect.

4. Consider a combination of materials. Some allow less work in certain areas for different reasons. If building in australia for example, i would consider making some of my own foam core panels (the big exterior surfaces), buying some CNC duflex/ featherlite panels(interior), and some plywood (interior). I may even consider strip planking the hull shoes in WRC or paulownia before glassing over. Epoxy for sure below waterline regardless of core. I would consider VE above waterline for infusion panels and it would depend on the prices i could obtain. Epoxy only for hand laminating seams etc as i cant stand the smell of styrene filling the air 24/7 and maybe a real reason not to use gelcoat and VE at all. Again- costs need to be determined to base this decision around. A cat this size i figure will use around 3 tonnes of resin. Not sure what prices we could get over seas and with bulk quanities but i ended up buying epoxy directly from an australian manufacturer @ $12/kg. So theres $36k aud in resin right there. The foam was worse at an average of $150-$200 per sheet.

I learned alot more than i could possibly write here, and not doubt plenty i still dont know. But im 100% sure i could build it considerably faster second time round...

 

Excellent posting Groper. Hope you don't mind my repeating in several other subject threads.

One other question. ....have you ever had any experiences with poly-cores as opposed to foam cores??

 

...from that same forum discussion of looking for methods to cut the building cost of that Pilgrim canal boat...

 

Plastic Honeycomb Core

This is the plastic honeycomb material I want to utilize to build the superstructure(s), ie ….cabin sides and roofs

 

Yes I've thought about this, but at present I'm still leery of what the numbers could be, so I'm trying to avoid as much 'tooling investment' as possible to begin with.

Haven't priced that out recently, but I think it is still a somewhat costly endeavor.

I'm definitely thinking in those terms.

Very likely just have a steel shop weld up the CNC cut panels and deliver that to use in its frameless style cradle, primed and epoxy coated. Then you are not paying for metal workers (or bulk FG layup workers to sit around waiting for another order.

And the carpentry portion of the job might be farmed out to another 'home building supply group' that needs a little side work to fill out their schedule. I've done a little looking at operations in Thailand, and I know of some in Vietnam that could supply all the interior wood as a 'kit' to be installed. For that matter a USA company might just as well supply the CNC cut wood kit for not that much greater price,...and we'd be employing US workers. I even know personally of some home remodeling friends with a wood shop that could knock this wood kit out rather easily once all the dimensions and shapes were documented.

 

If you really want to save time, lets step it up a notch using the Groper Mast Infusion technique to infuse sides and top in one shot - then glue final join. Now that is a time saver

 

'Ladder Time' reduction

...cutting down on man-hrs

 

Brian- I believe you asked me about polycore once before. I explained that a friend of mine is building a pacific 40 catamaran entirely from polycore near where I live. It's more time consuming and less friendly to work with compared to foam core. Any joins or edges need to be decored and back filled first before bringing the join together , gluing and glassing over so there is an extra step of decoring and back filling not the mention the extra resin to fill the core along the joined chine. If you don't do this there will be air bubbles all along the Chine when you tape over the Chine
. This was a cnc cut kit of prelaminated polycore panels, and be has been on it for 5 years full time - so it is still not a quick method to build IMHO.

The next issue my friend had was out gassing due to so much Trapped air in the polycore. He always had to wait till Temps were falling to get a good glassing job done or the dreaded air bubbles would arise.
Also- did you see the thread recently where a large cat in Thailand built from polycore was completely saturated with water in the core? They pulled it out and drilled holes in it and the water just kept coming - they posted videos and all on here. You'd have to search it out I can't remember the name of the thread.
So No- I wouldn't use it except for perhaps again- certain key areas in the interior such as small bulkheads with no cutouts etc made from pre-made panels to save cost. Perhaps the front 3 watertight bulkheads for example. Certainly nothing outside like a deck which is full of leak points from all the hardware mounted all over it...

And of course because it not infusion compatible, you can't use it to make large panels yourself via KSS....

 

The saturated hull is here;
http://www.boatdesign.net/forums/materials/repair-water-core-material-fibreglass-boat-56743.html

Here is some handy info on using polypore/nidacore;
http://boatcraft.com.au/informationpages/nidaplast_working.htm

 

Is that Pacific 40 the same cat design as the Solitary Island Catamaran?

Has he had that project under way for quite a while? I believe Solitary Island stopped building their kits a number of years ago due to financial difficulties of the boat market in general.

That is if you have a hard chine in the hull design.

I believe Solitary Island had a solid glass 'shoe' below the waterline?

That's interesting

Wouldn't out-gassing (of core materials), and trapped air be 2 different things.? There can always be 'trapped air' in any fiberglass layup procedure, regardless of core material?

I would be particularly concerned if it were the chemical make-up of the core that might be producing gassing after layup.

No, I did not see that,...very interesting. I would like to find out more details about the vessel, and the builder.

Agreed, decks have many potential leak points, and regardless of what cores they are built of one has to take extra precautions at mounting deck hardware.

Balsa cores are off my list as there is just too many documented cases of water following the bond-lines and eventually rotten decks.

Lots of foam cores do not hold up well in the heat of sunlight, and tropic conditions.

I believe I had read in a number of cases that bond line failure of Nidacore type products did not occur if the job was done correct? And another thing that had impressed me about the Nidacore type product was its 'ductility'. This property helps the sandwich structure stay intact, and not delaminate so easily.

I believe i also discovered there were some examples of utilizing these core materials in an infusion process? I just can't recall right now.

Thanks for bringing this to my attention. I will have to look back and re-evalute

 

Interesting material in that document.

I saw this particular quote there that reminded me of one I must have seen before,....and that seems to indicate that this core could be utilized in an injection process

 

I worked on a luxury build down at Henderson quite a few years ago, pvc foam, kevlar, carbon and vinyl ester, all the foam was put into a hotbox and cooked before it went into the boat, purportedly to drive out gases causing delamination, not being in the industry anymore I'm not sure if this practise is widespread or not.
Sorry can't remember any time temperature regime.