Airex and any foam based hull materials

All this talk about Fiberglass cracks and core damage has me wondering, which type of construction requires the least maintenance?

Fiberglass gets problems due to flexing. Eventually it cracks and water gets in the laminate.

The USCG requires a 400% safty factor on hull loads , interesting that at 400% there is almost NO flex.

An almost Zero maint boat can be created with Airex , by NOT reducing the skin scantlings for the foam.

In other words if a 1/2 thick solid glass layup would be fine , splitting the laminate 1/4in outside , 3/4 Airex and 1/4 inch inside would not weigh much more than solid but WILL be about 300% TO 400% STIFFER.

A boat built by hand over a plug (no female mold) will not have bonding hassels to the foam. A bit of workmanship on thru penitrations , as there installed , and you have a boat that can be ignored for decades.

Franz Mass built many ocean racers with this technique , that are still out there sailing.
Probably because a leak , stanchon base , whatever causes no problem for the Airex core .

With no rot (ply core or balsa ) , and no water migration found in other core materials , many of the Lifeboat services prefer Airex for the unlimited service life , and ease of repair.Lifeboat service is ROUGH & Tough.!

Surface finish is time consuming , but not expensive.

FF

 

FF go back two post...................... and smile

 

Well, it is a great title for a topic that interests me a lot these days.

When would you use Airex and when would you rather use Corecell?

 

Sigurd...

........ you naturally have noticed that this thread died in 2004!


go back 4 posts....:idea:

 

Thank you F F, I've built several very successful boats utilizing that philosophy.
The biggest problems that we see in fiberglass boats today are
#1 Poor quality product ( building materials)
#2 Under trained labor and inadequate supervision
#3 A lack of stiffness

FAST FRED, I copied your above post along with the addition above to the composite boatbuilding section. I couldn't agree with you more.
http://www.boatdesign.net/forums/fi...ding-bruce-roberts-longboat-21-a-26198-2.html
Gerald

 

yes I did Apex1, but now that it was alive again, I felt like asking more questions!

 

Structurally balsa is a fine core,unfortunatly while all the lessons on how to use the stuff was learned way back in the 1960s most production builders choose choose to ignore them to save a buck so in my opinion if you are going to cut corners foam is a lot more forgiving.Baltek has done a great job of convincing people that water doesnt travel thru the balsa which is utter nonsense, i have re cored so many balsa boats i cant see a good reason to use it other than that its cheaper than foam. I have seen wet foam cores but never any degradation of the foam or delam from the skins,i have seen water migrate thru the scoring in a klegecell cored Choate 40 hull and weep out where screws penetrated the inner skin,infuriating but nothing more,if it had been balsa it would not have been worth saving.
While Airex is not a good choice for a deck it makes good hulls,klegecell divinicell etc are fine for decks,just stick with light colors.
Steve.