Pink or Blue Foam?

I am thinking of building a 16 foot foam ama, ala Dierking glassed foam with shear, to replace starboard ama which is salvaged Hobie 16 hull.

I researched over the WWW and EPS is the foam...but it seems some like the blue foam and some like the pink...blue Dow vs Pink Owens Corning. Confusing...

Figure to buy sheets at Big Box, epoxy, shape and glass...(I live in Winona, only degree composite engineering school) so have alternative.

Question is, blue or pink? Experiences? Appreciate the help, as always.

...which will move me into much lighter rig, much lighter than original Malibu Outrigger design I followed followed...boat is completed and does fine as it is but figure to change and see what happens.

Cannot resist fooling around. I have had out, but no pics on water...save one ashore. Just too busy adjusting rig and so on and forgot about pics.

 

Strip plank, no foam. Lighter, stronger. IMHO.

 

Mr. Upchurch, you are correct, thought of doing it, but I live in a small town and getting the wood and a place to work is a problem for me. I had thought to using strips in lieu of the glass exterior...but figured in the long haul the plan is not as durable, but might fill the bill. Still, I might do strips, over foam though...appreciate it. Wish I lived in Texas. brisket, sailing and strips...

 

Frankly I do not think there is a difference other than color and brand name. They are both the same type of foam. They are both 2 lb density. In my boats I used pink. WHy? because I bought it at Home Depot rather than Lowes.

 

Ike, I sort of wondered. One site noted the pink has bits of fiberglass in it for structural reasons. But, both closed ESP products, compatible with epoxy, it seems. Just covering all bases before I step up to plate. I may buy at Menard's. No HD or Lowe's B-Box's locally. Thanks.

 

Ah Ha...found more info on this site I must have missed... http://www.boatdesign.net/forums/boat-design/boxy-fisher-catamaran-idea-20022-7.html#post182741

 

Mr. Upchurch, got me to thinking (always a bad) cedar plank vs foam...how about a bit of each? This hull is an outrigger...16-17 feet loa, radiused a bit (rocker), as in original Malibu Outrigger plans.

Am slowly devising idea/plan to layout original shape (3-sided or chined bottom), using thin 1/8-3/16 inch ply for sides, bottom, with 3/8 shear web, lock it up somehow...,fill with polyurethane foam (2-part liquid stuff)...using cross pieces notched to sides at deck level to control width and form deck. Finish with veneer wood, under epoxy/glass exterior.

Just an idea, but his comment got me thinking of ways to avoid mess etc, and still end up with decent looking and functional light outrigger to replace current hull.

 

Mr. Upchurch...I sort of lost the handle to the thread... and messed up response.

I have given this project much thought...

Have to go with foam with shear-web loa. Seems easier and far faster, and very messy. And hot wire cutter.

Hull cross section shape is essentially trapezoidal. Flat sided, with slight loa rocker...original MO design.

So, I plan to set deck and keel in place (pattern wood) and use it to guide/run hot wire to shape glued-up foam flat sides, maybe add "false" bow or stem section forward...and then remove and replace deck and keel with glass/carbon. Maybe Kevlar base at bow - low...

Seems other methods, including strips require strong back or frame base...which I want to avoid, if possible. Goal is to keep hull to 50 lbs max, including pylons to attach ama to alum akas.

 

Menard's (close by) has OC 2" pink foam, $24 per 4x8 sheet...figure 4 sheets will suffice. Warm weather energizes.