worlds first honeycomb tugboat? an article.

closed thread.

i think ive made an error on this...so im closing the thread for now...:!:

 

After seeing in your video how a so small panel is deformed by the simple action of a wheel, I decided that never will use this material to build tugboats. What will happen to a panel of 1m x 1m, with the same wheel?. I hate to think.
The proof of the ax: I'm sure the steel supports better.
And, please, build the boat as you want but never carry on it a person you appreciate.

 

[thread closed....

 

I think you do not know how materials work in the structure of a ship. The material you propose is much stiffer than other materials (not talking only about steel) and, therefore, if you want to have much "deformation" and recover its shape, this material is not the ideal one. On the other hand, what can you tell me the capabilities of your material to absorb shear forces?. You can not say it's good from this point of view.
My advice as a friend, if I may, is that you study this issue more thoroughly and let advised by those who really know about strength of materials.
Cheers

 

thread closed...

 

Nothing wrong with PP core for a boat 30ft long...

A friend of mine is building a 40ft performance cruising catamaran using 100% PP core panels throughout the entire build;






The only exception to the PP cored panels is the below waterline hull - which were female molded using double cut PVC foam core so that the compound curvature could be conformed by the core and laminated via an infusion process - its not possible to do that with PP honeycomb core... The rest of the boat is built via glass laminated PP honeycomb flat panels, which can be bent or tortured or kerf cut into simple/single curvatures.

The compound curved roof of the cabin, is being laminated by hand over formas as it cant be formed from flat panels;



I suspect this will be one of the most unpleasant parts of the entire build, large scale wet layups, divided into managable sections, then removed so the underside can be laminated and faired, before reinstalling and joining... a lot of hard / heavy work in this part.

I dont see anything wrong with your idea tugboat, but your desire to build a round hull using PP core perplexes me? I dont think you could have chosen a more difficult material to form compound curves with. It will have to be cut up into strips and formed over frames or similar to get the compound. Its difficult to bond the Polypropylene itself, not many adhesives stick to it. Only the facing scrim allows bonding of the skins, so with a transverse strip planking of the core, there may be difficulties filling the voids/joins between core strips - well nothing plenty of bog wont fill i guess - but the cost of all the bog might add up considerably and im not sure how well it will hold up if the gaps are not filled as the core then becomes discontinuous - perhaps a skin buckling problem results.

The difficulty in forming compound curves is why the below waterline molding of my friends catamaran was not done with PP honeycomb.

Did you not consider a longitudinal strip planking with western red cedar or similar?

I hope you dont mind spending the next few years breathing up styrene fumes, coz this really irritates me personally - one of the main reasons i chose to build with epoxy resin rather than vinylester, its almost odorless.

Can you give some more detail as to how you will go about forming your compound curvature hull?

 

thread closed...

 

im closing this one...

 

:!::!::!::!::!::!::!:

 

I never said a word about delamination tugboat - before you deleted your postings.

And im all for doing things differently... And as i said, i dont see a problem - structurally - with using PP honeycomb core for your tug...

The main problem you will face - and im not saying its impossible - is the physical forming of the compound curvature using the PP honeycomb...

Like i said, you will most likely end up using a transverse strip planking method over formas... I hoping you would provide some more detail into how youll go about it, not whether PP honeycomb is a suitable small tug hull core material - i think its fine in that regard...